An air spray coating spray structure

Abstract

The present application relates to paint spraying equipment and spraying control technical field, especially a kind of gas spray type paint spraying structure, including nozzle, feed unit, pilot on-off element, pilot reversing element, energy storage unit, pressure applicator;The feed end of the nozzle is connected with the discharge end of pilot on-off element, the feed end of pilot on-off element is connected with the outlet end of feed unit, the pilot end of pilot on-off element is connected with the output end of variable air pump by pilot reversing element, the other end of pilot reversing element is connected with the import end of energy storage unit, the outlet end of energy storage unit is connected with the pressure applicator.The present application realizes the accurate extrusion and discharge of residual material after stopping spraying by the synergistic effect of energy storage unit and pressure applicator, avoids residual material dry solidification and pipe blockage, simultaneously simplifies equipment structure, does not need to additionally increase energy storage equipment, greatly reduces equipment maintenance cost and manual cleaning workload, improves equipment operation continuity.

Description

Technical Field

[0001] This invention relates to the field of paint spraying equipment and spraying control technology, and in particular to an air-jet paint spraying structure. Background Technology

[0002] Air-jet coating spraying equipment has become a standard coating process in this field due to its high spraying efficiency and good coating uniformity, making it suitable for spraying various anti-corrosion coatings. This type of equipment uses high-pressure gas to drive the coating delivery, which is then atomized through nozzles to achieve precise spraying. Its operational stability directly determines the coating quality and production efficiency.

[0003] Currently used air-jet coating spraying equipment in this field faces the persistent technical challenge of coating residue clogging the pipelines when adapting to the spraying needs of agrochemicals and new materials sectors.

[0004] Firstly, the epoxy-based, high-viscosity anti-corrosion coatings used in this field are prone to drying and hardening when they come into contact with air after the spraying operation is stopped. This can clog the flow channels and nozzles, preventing the equipment from supplying materials normally when it is started again. Manual disassembly and cleaning are required, which is not only time-consuming and labor-intensive, but also increases the equipment maintenance cost.

[0005] Secondly, although existing equipment also has a discharge step, the discharge cleaning mostly relies on simple gas purging or manual cleaning, which cannot remove the residue adhering to the inner wall of the pipeline. After a long period of accumulation, the residual paint will form a stubborn blockage, affecting the uniformity of the coating sprayed later.

[0006] Therefore, it is necessary to design an air-jet coating spray structure that can significantly reduce the probability of clogging in order to improve the quality of coating spraying. Summary of the Invention

[0007] To solve one of the aforementioned technical problems, the present invention employs the following technical solution: an air-jet coating spraying structure, comprising a nozzle, a feeding unit, a pilot opening and closing component, a pilot reversing component, an energy storage unit, and a pressure discharge device; the inlet end of the nozzle is connected to the outlet end of the pilot opening and closing component and the two are internally connected; the inlet end of the pilot opening and closing component is connected to the outlet end of the feeding unit and the two are internally connected; the pilot end of the pilot opening and closing component is connected to the output end of a variable air pump through a pilot reversing component and the two are internally connected; the other end of the pilot reversing component is connected to the inlet end of the energy storage unit and the two are internally connected; the outlet end of the energy storage unit is connected to the pressure discharge device and the two are internally connected; the energy storage unit is fixed on a mounting bracket, and the pressure discharge device is fixedly arranged relative to the energy storage unit.

[0008] As a preferred embodiment, the pilot opening and closing component includes a vertically arranged cylindrical valve cylinder, the middle left side of which is detachably fixed to the end of the feeding unit via a connector and the two are internally connected.

[0009] A valve chamber is provided inside the valve cylinder, and end caps are respectively sealed at the upper and lower ends of the valve chamber. The opening of the end cap at the upper part of the valve cylinder is connected to the pilot end of the pilot reversing component. A cylindrical valve core is coaxially and movably sealed inside the valve chamber. An injection channel is provided radially on the outer side wall of the valve core. In the idle state, the injection channel is blocked. In the working state, the injection channel is synchronously connected to the outlet end of the feeding unit and the feed end of the nozzle.

[0010] A cylindrical valve stem is coaxially fixed to the bottom center of the valve core. The lower end of the valve stem extends out of the valve cylinder and is fixed to a baffle. A tension spring is coaxially sleeved on the outside of the valve stem between the baffle and the lower end cover. The upper end of the tension spring is fixed to the bottom surface of the lower end cover, and the lower end is fixed to the top surface of the baffle.

[0011] As a preferred embodiment, the feeding unit includes a pumping hose, the outlet end of which is detachably and fixedly connected to the opening in the middle left side of the valve cylinder via a connector, and the two are internally connected. The inlet end of the pumping hose is integrally formed with a multi-port pipe, one end of which is connected to the feeding pump, and a rear sealing cap is screwed onto the rear discharge port of the other end, with the inner end of the rear sealing cap extending into the rear discharge port.

[0012] As a preferred embodiment, the pilot reversing component includes a pilot bypass and a main reversing valve. The pilot end of the pilot bypass is the outlet end. The outlet end of the pilot bypass is fixedly connected to the end cap on the upper part of the valve cylinder, and its inner end is connected to the valve cavity. The inlet end of the pilot bypass is connected to one of the outlet ends of the main reversing valve. A pilot check valve and a gas-guided reversing valve are installed in series on the pilot bypass. The gas-guided reversing valve is located near the pilot opening and closing component and is used to realize the on / off and pressure relief control of the pilot gas path.

[0013] As a preferred embodiment, before the nozzle sprays material, the air guide reversing valve connects the pilot bypass to the inside of the valve chamber and cooperates with the main reversing valve to open the passage between the variable air pump and the pilot bypass, so as to realize the high pressure gas of the variable air pump is delivered to the inside of the valve chamber, and finally control the spray channel to connect the outlet end of the feeding unit with the feed end of the nozzle.

[0014] When the nozzle needs to stop spraying, the air diversion valve cuts off the pilot bypass from the valve chamber and connects the valve chamber to the outside through the switching passage, so that the high-pressure gas in the valve chamber can be quickly discharged. Then, the pilot opening and closing part returns to its original position under the action of the tension spring, and the spray channel is blocked. At the same time, the main diversion valve cuts off the connection between the variable air pump and the pilot bypass.

[0015] As a preferred embodiment, the two outlet ends of the main reversing valve are respectively connected to the pilot bypass and the inlet end of the energy storage unit, and are used to realize the time-sharing or synchronous supply of gas from the variable gas pump to the pilot bypass and the energy storage unit. At the same time, through linkage and cooperation with the gas guide reversing valve, the coordinated control of spraying and energy storage is achieved.

[0016] The main directional valve is a two-position five-way directional valve.

[0017] As a preferred embodiment, the energy storage unit includes an accumulator, which is fixedly connected to the mounting frame via several connecting rods. The left inlet end of the accumulator is connected to the outlet end of the main reversing valve via an energy storage bypass. The outlet end of the accumulator is connected to the inlet end of the pressure discharge device. The top of the accumulator is fixedly connected to the pressure discharge device via a support rod. A pressure relief valve is also provided on the accumulator, and an energy storage check valve is installed in series on the energy storage bypass to prevent the backflow of high-pressure gas in the accumulator.

[0018] As a preferred embodiment, the pressure discharge device includes an annular extrusion airbag coaxially sleeved on the straight section of the pumping hose. The outer wall of the extrusion airbag is a rigid structure, the inner annular sidewall is an inner ring film, and a pneumatic variable volume cavity is provided inside the extrusion airbag. The inner ring film of the extrusion airbag is in close contact with the outer wall of the pumping hose.

[0019] When the pneumatic variable-volume chamber inside the airbag is inflated, the inner membrane contracts inward to squeeze the pump hose and expel the residual paint inside the hose outward.

[0020] The left outer wall of the rigid structure of the compression airbag is fixedly connected to the accumulator via a support rod. The right outer wall of the compression airbag is connected to the accumulator of the energy storage unit via a release pipe and is internally connected. A release control valve is installed on the release pipe to control the accumulator to supply air to the compression airbag. A venting connector with a venting valve is installed on the middle outer wall of the compression airbag.

[0021] As a preferred embodiment, an inlet air discharge pipe is integrally formed on the outer wall of the pumping hose near the pilot opening and closing component, and a discharge pneumatic valve is installed on the inlet air discharge pipe. The inlet air discharge pipe is connected to a variable air pump as needed through a pipeline.

[0022] As a preferred embodiment, a pressure sensor is installed at the end face of the rear sealing cap, and the pressure sensor is used to detect the current pressure inside the pipe.

[0023] As a preferred option, the main reversing valve, the air guide reversing valve, the discharge pneumatic valve, the air release valve, the pressure relief valve, the release control valve, and the pressure sensor are all electrically controlled valves and are all connected to the linkage controller that is matched with the spraying process.

[0024] Both the variable air pump and the feed pump are connected to the linkage controller signal;

[0025] The pressure sensor detects the pressure signal inside the pipe and links it with the linkage controller. The linkage controller automatically adjusts the on / off state of the main reversing valve and the air guide reversing valve and the output air pressure of the variable air pump according to the pressure inside the pipe. At the same time, it controls the opening and closing of the discharge pneumatic valve, the air release valve, the pressure relief valve and the release control valve to realize the automatic linkage of material supply, spraying, energy storage, material discharge and pressure relief.

[0026] The present invention also provides a control method based on an air-jet coating spray structure, comprising the following steps: S1. Spray preparation: the linkage controller starts the variable air pump, controls the main reversing valve to open the pilot bypass and cut off the energy storage unit passage, the air guide reversing valve to open the pilot bypass and the valve chamber, the high-pressure gas pushes the valve core to move down to open the spray flow channel, all valves are closed and the rear sealing plug is sealed.

[0027] S2. Spraying execution: The feed pump is started to deliver paint spraying, the main reversing valve synchronously opens the energy storage unit passage to store energy, the pressure sensor provides feedback on the pressure, the controller fine-tunes the air pump pressure, and the linkage coupling formula is combined to achieve coordinated control.

[0028] S3. Spraying Stop: Shut down the feed pump, cut off the pilot bypass and depressurize the air diversion valve, reset the valve core to block the flow channel, and cut off the connection between the air pump and the pilot bypass by the main diversion valve.

[0029] S4. Residual Material Discharge: Open the discharge pneumatic valve and release control valve, the main reversing valve connects the energy storage unit and the pressure discharger, the airbag squeezes the hose to discharge the material, and combined with the deformation linkage formula, the air release rate and pressure relief are adjusted according to the pressure signal.

[0030] S5. Low-pressure purging: The air pump switches to low-pressure mode, opening the passage to the inlet air discharge pipe and purging residual material from the hose.

[0031] S6. Reset Standby: Turn off the air pump, close the discharge valve and release control valve, release the residual air in the airbag to reset it, and reset all components to standby.

[0032] As a preferred option, during the S1 spraying preparation stage, the initial output air pressure of the variable air pump is adapted to the range of 0.4-0.8MPa, with 0.5-0.7MPa being preferred (to match the commonly used paint viscosity). High-pressure gas enters the valve chamber through the main reversing valve, pilot bypass, pilot check valve, and air guide reversing valve, pushing the valve core downward against the tension of the tension spring to ensure that the spray channel is synchronously connected to the feeding unit and the nozzle. The discharge pneumatic valve, vent valve, and pressure relief valve are all in the closed state. The torque of the rear sealing cap is controlled at 8-12 N.m. After sealing, the discharge port is sealed to ensure the pipeline is airtight and to avoid paint leakage.

[0033] As a preferred option, during the S2 spraying execution phase, the feed pump delivers the paint to the nozzle through the multi-port pipe, pumping hose, and pilot opening and closing component spraying channel.

[0034] High-pressure gas from the variable displacement pump enters the accumulator for energy storage via the main reversing valve, energy storage bypass, and energy storage check valve.

[0035] The preferred linkage coupling formula is:

[0036] .

[0037] In the formula: Real-time pre-charge pressure for the accumulator, in MPa; This refers to the output air supply pressure of the variable displacement air pump, in MPa. The effective pressure-bearing area of ​​the valve core is expressed in mm². The pilot gas path pressure loss coefficient is 0.90-0.98. This refers to the stiffness coefficient of the tension spring. This refers to the valve core displacement opening. This is the correction factor for the friction damping of the valve core seal, with a value ranging from 1.03 to 1.11. The duration of gas supply to the gas circuit, measured in seconds (s). This is the time constant for the gas path pressure response.

[0038] It should be noted that this solution is suitable for conventional paint spraying operations: taking the spraying of commonly used water-based anti-corrosion coatings as an example, the variable air pump output pressure is set... The effective pressure-bearing area of ​​the valve core is 0.6 MPa. The pilot gas path pressure loss coefficient is 50 mm². Take 0.95 as the stiffness coefficient of the tension spring. The valve core displacement opening is 20 N / mm. The friction damping correction coefficient for the valve core seal is 8mm. Take 1.08, gas supply duration The gas path pressure response time constant is 15s. The value is 2 seconds. Substituting this value into the formula, the real-time pre-charge pressure of the accumulator can be obtained. Approximately 0.68 MPa, this value meets the pressure requirements of conventional paint spraying, ensuring stable spray flow and sufficient energy storage.

[0039] As a preferred solution, during the S3 spraying stop phase, the air directional valve cuts off the connection between the pilot bypass and the valve chamber, opening the valve chamber to the external pressure relief passage, allowing high-pressure gas in the valve chamber to be quickly discharged; the valve core moves upward under the return force of the tension spring, misaligning and blocking the spray channel, achieving isolation and sealing between the material supply unit and the nozzle, preventing external air from entering; the main directional valve cuts off the connection between the variable air pump and the pilot bypass, maintaining the energy storage unit in an energy storage state, preparing for the discharge of residual material.

[0040] As a preferred solution, the linkage controller opens the release control valve, and the high-pressure gas in the accumulator enters the pneumatic variable volume chamber of the extrusion airbag through the release pipeline and the release control valve. The inner diaphragm of the airbag contracts to extrude the pumping hose, and the residual material is discharged through the inlet air discharge pipe and the discharge pneumatic valve.

[0041] The deformation linkage formula is as follows:

[0042] In the formula: This refers to the radial extrusion deformation of the pump hose, in mm. The actual pressure released by the accumulator is expressed in MPa. The pressure-bearing area of ​​the compressed airbag is expressed in mm². The airbag pneumatic transmission efficiency is set at 0.85-0.95. The radial elastic modulus of the pump hose; The unit is the wall thickness of the hose, in mm; The viscosity resistance coefficient of the coating; The duration of a single spray application is measured in seconds (s). This is the rated spraying reference time.

[0043] This solution is tailored to the typical scenario of cleaning up residual material after coating spraying: taking the cleaning of residual material after spraying commonly used high-viscosity epoxy coatings as an example, the actual release pressure of the accumulator is set. The pressure resistance is 0.5 MPa, and the pressure-bearing area of ​​the compressed airbag is [missing information]. The airbag air pressure transmission efficiency is 300mm². Take 0.90, radial elastic modulus of pump hose The pressure is 800MPa, and the wall thickness of the hose is [missing information]. The coating viscosity coefficient is 3mm. The value is 0.8, and the duration of a single spray is [missing information]. The rated spraying time is 20 seconds. The value is 18s. Substituting this value into the calculation yields the radial extrusion deformation of the pump hose. With a deformation of approximately 2.2 mm, this deformation ensures that high-viscosity epoxy coating residue inside the hose is squeezed out, meeting the cleanliness requirements of routine operations.

[0044] As a preferred option, during the S5 low-pressure purging stage, the variable air pump switches to a low-pressure output mode of 0.1-0.2MPa, with 0.15MPa being the preferred setting (suitable for purging water-based and oil-based paint residues). The flow path with the inlet air discharge pipe is opened, and the low-pressure gas purges the inner wall of the hose to remove trace amounts of residue, which are then discharged through the discharge pneumatic valve. The purging duration is set to 13s based on the hose length, with 1.5s for a 12m hose and 2.5s for a 23m hose. The discharge pneumatic valve is open throughout the process and closes after a 3-5s delay after purging, preferably with a 4s delay, to prevent residual gas in the pipeline from hindering subsequent material supply.

[0045] As a preferred solution, during the S6 reset standby phase, after shutting down the variable air pump, the discharge pneumatic valve and release control valve are closed, and the residual gas is discharged by opening the air bladder release valve. The air bladder returns to its original shape under its own elasticity and the reaction force of the hose, and then the release valve is closed. The linkage controller controls all components such as the main reversing valve and the air guiding reversing valve to reset, the pressure relief valve remains closed, the rear sealing cap maintains the seal, and the equipment enters the standby state.

[0046] As a preferred option, during the spraying process, the output air pressure range of the variable air pump is 0.4-0.8MPa, of which 0.4-0.6MPa is used when spraying water-based paints and 0.6-0.8MPa is used when spraying oil-based paints.

[0047] As a preferred solution, the pressure sensor monitors the pressure inside the pipe in real time, and the linkage controller synchronously adjusts the opening of the release control valve to regulate the accumulator's gas release rate. When the pressure inside the pipe is lower than 0.1MPa, the controller increases the opening of the release control valve and accelerates the accumulator's gas release rate to increase the squeezing force; when it is higher than 1.0MPa, the controller decreases the opening of the release control valve, slows down the gas release rate, and opens the pressure relief valve to assist in pressure relief, ensuring smooth material discharge without damaging the hose and avoiding material discharge failure.

[0048] As a preferred option, during the low-pressure purging stage, the purging air pressure is matched with the hose wall thickness and coating viscosity to prevent low-pressure gas from impacting and damaging the hose; the duration of delaying the closure of the discharge pneumatic valve can be finely adjusted according to the hose length to ensure that there is no large amount of residual gas in the pipeline.

[0049] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0050] 1. This invention can effectively solve the problem of frequent paint clogging in existing air-jet paint spraying equipment. Through the coordinated action of the energy storage unit and the pressure discharge device, combined with the linkage control logic, the residual material is accurately squeezed and discharged after spraying stops, avoiding the residual material from drying, solidifying and clogging the pipe. At the same time, it simplifies the equipment structure, eliminates the need for additional energy storage equipment, greatly reduces equipment maintenance costs and manual cleaning workload, and improves the continuity of equipment operation.

[0051] 2. This invention achieves precise opening and closing of the spraying channel and stable air pressure control by precisely linking the pilot opening and closing components with the pilot reversing components and combining the real-time feedback of the pipe pressure data from the pressure sensor. This avoids problems such as uneven coating thickness and paint leakage caused by air pressure fluctuations, ensuring spraying quality and meeting the anti-corrosion spraying needs of the agricultural science, chemical industry and new materials fields.

[0052] 3. This invention adopts a matching design of extrusion airbag and pumping hose. The outer side of the airbag is a rigid structure and the inner side is a flexible film, which can realize uniform extrusion of the hose, remove residual material inside the hose, and at the same time avoid damage to the hose by rigid extrusion, extend the service life of the hose, reduce the replacement cost of vulnerable parts of the equipment, balance the discharge effect and equipment protection, and improve the long-term operational stability of the equipment.

[0053] 4. This invention achieves dual functions of spraying air supply and energy storage through a single variable air pump, replacing the conventional multi-air pump design, simplifying the overall structure of the equipment, reducing the number of pipeline connections, and lowering the difficulty of equipment installation and commissioning. At the same time, through the coordinated control of the linkage controller and various valves, it realizes fully automated operation, reduces manual intervention, improves spraying and material discharge efficiency, and adapts to the needs of large-scale production. Attached Figure Description

[0054] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or components are generally identified by similar reference numerals. In the drawings, the elements or components are not necessarily drawn to scale.

[0055] Figure 1 This is a first three-dimensional structural diagram of the air-spray coating spray structure of the present invention.

[0056] Figure 2 This is a front view schematic diagram of the air-jet coating spray structure of the present invention.

[0057] Figure 3 This is a schematic diagram of the second three-dimensional structure of the air-spray coating spray structure of the present invention.

[0058] Figure 4 This is a schematic diagram of the internal structure of the air-jet coating spray structure of the present invention.

[0059] In the diagram, 1. Nozzle; 2. Mounting bracket; 3. Valve cylinder; 4. Connector; 5. Valve chamber; 6. End cap; 7. Valve core; 8. Injection channel; 9. Valve stem; 10. Baffle plate; 11. Tension spring; 12. Pumping hose; 13. Multi-port end pipe; 14. Rear sealing cap; 15. Pilot bypass; 16. Main directional valve; 17. Pilot check valve; 18. Air directional valve; 19. Energy storage bypass; 20. Accumulator; 21. Connecting rod; 22. Support rod; 23. Pressure relief valve; 24. Energy storage check valve; 25. Compressive air bladder; 26. Pneumatic variable displacement chamber; 27. Diaphragm; 28. Release pipeline; 29. ​​Release control valve; 30. Venting valve; 31. Venting connector; 32. Inlet air discharge pipe; 33. Discharge pneumatic valve; 34. Pressure sensor. Detailed Implementation

[0060] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and are therefore merely examples and should not be used to limit the scope of protection of the present invention. The specific structure of the present invention is as follows: Figures 1-4 As shown in the image.

[0061] Example 1: An air-jet coating spraying structure includes a nozzle 1, a feeding unit, a pilot opening and closing component, a pilot reversing component, an energy storage unit, and a pressure discharge device; the inlet end of the nozzle 1 is connected to the outlet end of the pilot opening and closing component and the two are internally connected; the inlet end of the pilot opening and closing component is connected to the outlet end of the feeding unit and the two are internally connected; the pilot end of the pilot opening and closing component is connected to the output end of a variable air pump through the pilot reversing component and the two are internally connected; the other end of the pilot reversing component is connected to the inlet end of the energy storage unit and the two are internally connected; the outlet end of the energy storage unit is connected to the pressure discharge device and the two are internally connected; the energy storage unit is fixed on a mounting bracket 2, and the pressure discharge device is fixedly arranged relative to the energy storage unit.

[0062] This invention uses a variable displacement air pump as the core of its pneumatic power. By distributing airflow through a pilot reversing component, it drives the pilot opening and closing component to open or close the spraying channel, achieving precise control of paint delivery and blocking. On the other hand, it stores energy for the energy storage unit. After spraying stops, the energy storage unit releases high-pressure gas to drive the pressure discharge device to clean the pipeline residue. All components form a linkage between feeding, spraying, energy storage, and discharge. Moreover, the energy storage unit and the pressure discharge device are relatively fixed to ensure stable force during operation.

[0063] This solution uses a variable displacement air pump to achieve multi-process linkage. Through the coordination of the pilot opening and closing device, the pilot reversing device, and the energy storage unit, it achieves synchronous energy storage during spraying and automatic material discharge after spraying stops, avoiding energy waste and preventing the problem of residual material solidifying and clogging the pipe.

[0064] As a preferred embodiment, the pilot opening and closing component includes a vertically arranged cylindrical valve cylinder 3, the middle left side of which is detachably fixed to the end of the feeding unit via a connector 4 and the two are internally connected.

[0065] A valve cavity 5 is provided inside the valve cylinder 3. End caps 6 are respectively sealed and installed at the upper and lower ends of the valve cavity 5. The opening of the end cap 6 at the upper part of the valve cylinder 3 is connected to the pilot end of the pilot reversing component. A cylindrical valve core 7 is coaxially and movably sealed and assembled inside the valve cavity 5. An injection channel 8 is provided radially on the outer side wall of the valve core 7. The injection channel 8 is blocked in the idle state. In the working state, the injection channel 8 is synchronously connected to the outlet end of the feeding unit and the feed end of the nozzle 1.

[0066] A cylindrical valve stem 9 is coaxially fixed to the bottom center of the valve core 7. The lower end of the valve stem 9 extends out of the valve cylinder 3 and is fixed to a baffle 10. A tension spring 11 is coaxially sleeved on the outside of the valve stem 9 between the baffle 10 and the lower end cover 6. The upper end of the tension spring 11 is fixed to the bottom surface of the lower end cover 6, and the lower end is fixed to the top surface of the baffle 10.

[0067] In the idle state, the tension spring 11 is in a naturally stretched state, pulling the valve core 7 upward, causing the spray channel 8 of the valve core 7 to be misaligned with the feeding unit and the nozzle 1, thus blocking the flow channel. In the working state, the high-pressure gas delivered by the pilot reversing component enters the valve chamber 5, acts on the upper end face of the valve core 7, overcomes the tension of the tension spring 11, and pushes the valve core 7 downward, so that the spray channel 8 is synchronously connected to the feeding unit and the nozzle 1, thus achieving stable coating delivery. After spraying stops, the gas in the valve chamber 5 is depressurized, and the tension spring 11 pulls the valve core 7 to reset, re-blocking the flow channel.

[0068] This solution adopts a two-way linkage structure with pneumatic drive and spring reset. The valve core 7 and valve cylinder 3 are coaxially and dynamically sealed, and the spray channel 8 is opened radially to ensure smooth coating delivery when the flow channel is open and tight sealing when blocked, preventing air and material leakage, and avoiding coating residue and scaling inside the valve cavity 5. In addition, the valve cylinder 3 and the feeding unit are fixedly connected by a detachable connector 4, which facilitates disassembly, maintenance, replacement of valve core 7 or cleaning of spray channel 8 in the future, reducing maintenance costs and solving the problem of inconvenient maintenance of conventional integrated structures.

[0069] As a preferred embodiment, the feeding unit includes a pumping hose 12. The outlet end of the pumping hose 12 is detachably and fixedly connected to the opening in the middle left side of the valve cylinder 3 via a connector 4, and the two are internally connected. The inlet end of the pumping hose 12 is integrally formed with a multi-port pipe 13. One end of the multi-port pipe 13 is connected to the feeding pump, and a rear sealing cap 14 is screwed onto the rear discharge port at the other end. The inner end of the rear sealing cap 14 extends into the rear discharge port.

[0070] The feed pump delivers paint to the pumping hose 12 through the multi-port pipe 13. The paint enters the pilot opening and closing device through the pumping hose 12 and is finally sprayed out from the nozzle 1. After the rear sealing cap 14 is screwed on to seal the discharge port, it ensures that the paint can only be delivered to the nozzle 1 and avoids leakage. Removing the rear sealing cap 14 can clean the end of the pipeline and help to discharge the residual material in the pipe.

[0071] As a preferred embodiment, the pilot reversing component includes a pilot bypass 15 and a main reversing valve 16. The pilot end of the pilot bypass 15 is the outlet end. The outlet end of the pilot bypass 15 is fixedly connected to the end cap 6 on the upper part of the valve cylinder 3 and its inner end is connected to the valve cavity 5. The inlet end of the pilot bypass 15 is connected to one of the outlet ends of the main reversing valve 16. A pilot check valve 17 and a gas-guided reversing valve 18 are installed in series on the pilot bypass 15. The gas-guided reversing valve 18 is located near the pilot opening and closing component and is used to realize the on / off and pressure relief control of the pilot gas path.

[0072] The main directional valve 16 receives a signal from the linkage controller and controls whether the gas from the variable air pump enters the pilot bypass 15; the pilot check valve 17 is used to prevent the high-pressure gas in the valve chamber 5 from flowing back to the main directional valve 16, thus avoiding gas pressure disturbance; the pilot gas directional valve 18 controls the opening and closing of the pilot bypass 15 and the valve chamber 5, and at the same time realizes the rapid depressurization of the valve chamber 5, thereby accurately controlling the opening and resetting of the pilot opening and closing element.

[0073] In this design, the pilot bypass 15 and the main directional valve 16 are designed separately, and the pilot check valve 17 and the air directional valve 18 are connected in series to achieve triple control of air circuit opening and closing, pressure relief, and backflow prevention, replacing the conventional single directional valve control mode and greatly improving the accuracy and stability of air circuit control. Secondly, the air directional valve 18 is set close to the pilot opening and closing element, which greatly shortens the pressure relief path, allowing the gas in the valve chamber 5 to be discharged quickly, ensuring that the valve core 7 is quickly reset, and avoiding continuous paint leakage or air entering the pipeline after spraying stops. In addition, the setting of the pilot check valve 17 can prevent gas backflow caused by pressure fluctuations in the valve chamber 5 during spraying, avoid increasing the load on the variable air pump, and at the same time ensure that the energy storage process of the energy storage unit on the other side is not affected by air circuit fluctuations.

[0074] As a preferred embodiment, before the nozzle sprays material, the air diversion valve 18 connects the pilot bypass 15 with the inside of the valve chamber 5 and cooperates with the main diversion valve 16 to open the passage between the variable air pump and the pilot bypass 15, so as to realize the high pressure gas of the variable air pump is delivered into the valve chamber 5, and finally control the spray channel 8 to connect the outlet end of the feeding unit with the feed end of the nozzle 1.

[0075] When the nozzle needs to stop spraying, the air diversion valve 18 cuts off the pilot bypass 15 from the valve chamber 5 and connects the valve chamber 5 to the outside through the switching passage, so that the high-pressure gas in the valve chamber 5 can be quickly discharged. Then, the pilot opening and closing part returns to its original position under the action of the tension spring 11, and the spray channel 8 is blocked. At the same time, the main diversion valve 16 cuts off the connection between the variable air pump and the pilot bypass 15.

[0076] Before spraying, the air guide valve 18 and the main reversing valve 16 work together to connect the variable air pump and the air passage of the valve chamber 5. The high-pressure gas drives the valve core 7 to move down and open the spraying channel. When spraying stops, the two work synchronously to cut off the air intake passage and connect the valve chamber 5 to the outside pressure relief passage. The tension spring 11 pulls the valve core 7 to reset and block the flow channel, forming a precise timing control from spraying to stopping spraying.

[0077] As a preferred embodiment, the two outlet ends of the main reversing valve 16 are respectively connected to the pilot bypass 15 and the inlet end of the energy storage unit, and are used to realize the time-sharing or synchronous supply of gas from the variable gas pump to the pilot bypass 15 and the energy storage unit. At the same time, through linkage with the gas guide reversing valve 18, the coordinated control of spraying and energy storage is completed.

[0078] The main directional valve 16 is a two-position five-way directional valve.

[0079] The two-position five-way directional valve, switched via valve core 7, enables time-sharing or synchronous gas distribution. During spraying, it simultaneously supplies gas to the pilot bypass 15 and the energy storage unit, ensuring stable opening of the pilot opening and closing components while simultaneously storing energy in the energy storage unit. When spraying stops, the gas supply to the pilot bypass 15 is cut off, maintaining the energy storage state of the energy storage unit to prepare for subsequent discharge of residual material. Simultaneously, it works in conjunction with the gas guide directional valve 18 to achieve coordinated control of spraying and energy storage. This solution uses a two-position five-way directional valve instead of a conventional two-position three-way directional valve, allowing a single valve to control two gas paths, reducing the number of valves and equipment installation space. It enables time-sharing or synchronous gas supply, with synchronous energy storage during spraying, avoiding the need for a separate energy storage gas path, saving operating energy consumption, and ensuring that the energy storage unit completes energy storage during spraying, improving operational efficiency. Furthermore, its linkage with the gas guide directional valve 18 ensures precise connection between gas distribution and flow control, preventing problems such as insufficient energy storage leading to material discharge or gas path disorder causing equipment failure.

[0080] As a preferred embodiment, the energy storage unit includes an accumulator 20, which is fixedly connected to the mounting frame 2 via several connecting rods 21. The left inlet end of the accumulator 20 is connected to the outlet end of the main reversing valve 16 via an energy storage bypass 19, and the outlet end of the accumulator 20 is connected to the inlet end of the pressure discharge device. The top of the accumulator 20 is fixedly connected to the pressure discharge device via a support rod 22. A pressure relief valve 23 is also provided on the accumulator 20, and an energy storage check valve 24 is installed in series on the energy storage bypass 19 to prevent the high-pressure gas in the accumulator 20 from flowing back.

[0081] During spraying, the main reversing valve 16 opens the energy storage bypass 19, and the gas from the variable air pump enters the accumulator 20 for storage through the energy storage check valve 24. The energy storage check valve 24 prevents gas backflow. When the pressure inside the accumulator 20 exceeds the set value, the pressure relief valve 23 automatically releases pressure to ensure the safe operation of the accumulator 20. After spraying stops, the accumulator 20 releases high-pressure gas to drive the pressure discharge device. The accumulator 20 and the pressure discharge device are fixed by the support rod 22 to ensure stable force during operation.

[0082] The accumulator 20 is linked with the main reversing valve 16, and stores energy synchronously during spraying. There is no need to start the energy storage device separately, which simplifies the control logic. At the same time, the stored high-pressure gas can quickly drive the pressure discharge device, avoiding the problem of insufficient discharge power.

[0083] As a preferred embodiment, the pressure discharge device includes an annular compression airbag 25 coaxially sleeved on the straight section of the pumping hose 12. The outer wall of the compression airbag 25 is a rigid structure, the inner annular sidewall is an inner ring film 27, and a pneumatic variable volume cavity 26 is provided inside the compression airbag 25. The inner ring film 27 of the compression airbag 25 is in close contact with the outer wall of the pumping hose 12.

[0084] When the pneumatic variable volume chamber 26 inside the compression airbag 25 is inflated, the inner membrane 27 contracts inward to compress the pump hose 12 and is used to expel the residual paint inside the hose outward.

[0085] The outer left wall of the rigid structure of the compression airbag 25 is fixedly connected to the accumulator 20 via a support rod 22. The outer right wall of the compression airbag 25 is connected to the accumulator 20 of the energy storage unit via a release pipe 28 and is internally connected. A release control valve 29 is installed on the release pipe 28. The release control valve 29 is used to control the accumulator 20 to supply air to the compression airbag 25. A venting connector 31 with a venting valve 30 is installed on the outer middle wall of the compression airbag 25.

[0086] When the remaining material is discharged, the release control valve 29 is opened, and the high-pressure gas from the accumulator 20 enters the pneumatic variable volume chamber 26 of the extrusion airbag 25. Because the outer wall is a rigid structure, the inner membrane 27 can only contract inward, uniformly extruding the pumping hose 12 and squeezing out the residual material inside the hose. After the discharge is completed, the vent valve 30 is opened to release the residual gas in the airbag, and the airbag resets under its own elasticity.

[0087] The compression airbag 25 in this solution adopts a structure with a rigid outer wall and a flexible inner membrane 27, replacing the conventional rigid compression block. This avoids damage to the pump hose 12 caused by rigid compression, while ensuring that the compression force is evenly applied around the hose, avoiding local material residue. The release control valve 29 can precisely control the air supply from the accumulator 20 to the airbag, and can adjust the air supply rate according to the pressure inside the pipe, solving the problems of excessive compression force damaging the hose and insufficient material discharge caused by insufficient compression force in conventional systems without control valves.

[0088] As a preferred embodiment, an inlet air discharge pipe 32 is integrally formed on the outer wall of the pumping hose 12 near the pilot opening and closing component, and a discharge pneumatic valve 33 is installed on the inlet air discharge pipe 32. The inlet air discharge pipe 32 is connected to the variable air pump as needed through a pipeline.

[0089] When the residual material is discharged, the discharge pneumatic valve 33 is opened, and the residual material squeezed by the compression airbag 25 is discharged through the inlet air discharge pipe 32; when the low pressure is purged, the low pressure gas of the variable air pump enters the pumping hose 12 after being connected to the inlet air discharge pipe 32 through the manual pipeline, purging the residual material on the inner wall, and then being discharged through the discharge pneumatic valve 33.

[0090] As a preferred embodiment, a pressure sensor 34 is installed at the end face of the rear sealing cap 14, and the pressure sensor 34 is used to detect the current pressure inside the pipe.

[0091] Pressure sensor 34 is installed on the end face of the rear sealing cap 14, directly contacting the coating inside the pipeline. It detects the pressure inside the pipeline in real time and feeds the pressure signal back to the linkage controller, providing data support for the controller to regulate various valves and variable air pumps.

[0092] As a preferred solution, the main reversing valve 16, the air guiding reversing valve 18, the discharging pneumatic valve 33, the air release valve 30, the pressure relief valve 23, the release control valve 29, and the pressure sensor 34 are all electrically controlled valves and are all signal-connected to the linkage controller supporting the spraying process; the linkage controller adopts the existing Siemens S7-200 SMART type PLC controller, and this type of controller is widely used in the industrial spraying process control scenario; the variable air pump and the feeding pump are both signal-connected to the linkage controller; the in-pipe pressure signal detected by the pressure sensor 34 is linked with the linkage controller, and the linkage controller automatically adjusts the on-off states of the main reversing valve 16 and the air guiding reversing valve 18 and the output air pressure of the variable air pump according to the in-pipe pressure, and simultaneously controls the opening and closing of the discharging pneumatic valve 33, the air release valve 30, the pressure relief valve 23, and the release control valve 29 in a linkage manner, so as to achieve the automatic linkage of feeding, spraying, energy storage, discharging, and pressure relief.

[0093] In addition, according to actual requirements, the linkage controller can also adopt general controllers commonly used in spraying equipment, such as Mitsubishi FX3U series PLC controllers and Omron CP1E series PLC controllers.

[0094] After the linkage controller is powered on, it first executes the system initialization self-check, collects the valve position feedback signals of the main reversing valve 16, the air guiding reversing valve 18, the discharging pneumatic valve 33, the release control valve 29, the air release valve 30, and the pressure relief valve 23 through the built-in digital input module, and collects the in-pipe pressure signal of the pressure sensor 34 and the air pressure feedback signal of the variable air pump through the analog input module. After confirming that all components are in the initial closed state and there is no fault alarm, it enters the standby mode.

[0095] When receiving the spraying start instruction, the controller enters the spraying preparation stage. First, it sends a start signal to the variable air pump through the digital output module. After the variable air pump starts, the controller synchronously sends a control signal to the main reversing valve 16 to control the main reversing valve 16 to switch to the working position where the pilot bypass 15 is导通 and the energy storage unit passage is截断. At the same time, it sends a signal to the air guiding reversing valve 18 to control the air guiding reversing valve 18 to导通 the passage between the pilot bypass 15 and the valve cavity 5. During the process that the high-pressure gas enters the valve cavity 5 and pushes the valve core 7 to move, the controller continuously collects the in-pipe pressure change signal of the pressure sensor 34 to judge whether the spraying flow channel is normally opened. After confirming that the flow channel is导通, it enters the spraying execution stage.

[0096] During the spraying execution phase, the controller sends a start signal to the feed pump, which delivers paint at a set speed. Simultaneously, the controller controls the main reversing valve 16 to switch to the position where the pilot bypass 15 and the energy storage unit passage are synchronously connected. Part of the high-pressure gas output from the variable air pump enters the accumulator 20 to complete energy storage. During this process, the controller collects real-time pressure data from the pressure sensor 34 at a frequency of 100ms / time, and performs logical calculations in conjunction with the pre-built linkage coupling formula logic to adjust the output air pressure of the variable air pump in real time. At the same time, the controller collects the pressure signal of the accumulator 20 in real time. When the pressure reaches the set upper limit, a control signal is sent to the pressure relief valve 23 to open and release pressure, maintaining stable energy storage pressure and ensuring uniform spraying flow and sufficient energy storage.

[0097] Upon receiving the spraying stop command, the controller enters the spraying stop phase. First, it sends a shutdown signal to the feed pump. After a 0.5s delay to ensure that the paint in the pipeline has been completely delivered, it sends a control signal to the gas directional valve 18. The gas directional valve 18 cuts off the passage between the pilot bypass 15 and the valve chamber 5, while simultaneously opening the pressure relief passage between the valve chamber 5 and the outside. The high-pressure gas in the valve chamber 5 is quickly discharged. The controller determines that the valve core 7 has been fully reset and the flow channel has been blocked by the pressure signal change. Then, it sends a control signal to the main directional valve 16 to cut off the passage between the variable gas pump and the pilot bypass 15, maintaining the energy storage state of the energy storage unit and preparing for the discharge of residual material.

[0098] Subsequently, the controller enters the residual material discharge stage. First, it sends an opening signal to the discharge pneumatic valve 33. After confirming that the valve is fully open, it sends an opening signal to the release control valve 29. The high-pressure gas in the accumulator 20 enters the pneumatic variable-volume chamber 26 of the compression airbag 25, and the compression hose discharges the residual material. During this process, the controller collects the pipe pressure data from the pressure sensor 34 in real time, and completes the calculation by combining the built-in deformation linkage formula. The controller adjusts the opening of the release control valve 29 in real time through PID regulation logic to control the gas release rate of the accumulator 20. When the pipe pressure is lower than the set threshold of 0.1MPa, the opening of the release control valve 29 is increased to increase the compression force. When the pipe pressure is higher than the set threshold of 1.0MPa, the opening of the release control valve 29 is decreased, and the pressure relief valve 23 is opened at the same time to assist in pressure relief and avoid damage to the pipeline due to overpressure.

[0099] After the residual material is discharged, the controller enters the low-pressure purging stage, sends a control signal to switch the variable air pump to low-pressure output mode, and at the same time opens the passage between the variable air pump and the inlet air discharge pipe 32. Low-pressure gas enters the hose to purge the trace amount of residual material on the inner wall. After the controller completes the purging according to the preset purging time matched with the hose length, it delays for 3-5 seconds and then sends a shut-off signal to the discharge pneumatic valve 33 to ensure that the residual material and residual gas in the pipeline are completely discharged.

[0100] Finally, the controller enters the reset standby stage, sends a shutdown signal to the variable air pump, and simultaneously sends a shutdown signal to the release control valve 29. After confirming that the valve is closed, it sends an opening signal to the air release valve 30 of the squeezing airbag 25 to release the residual gas in the airbag. After the airbag is completely reset, the air release valve 30 is closed. The controller controls all actuators to return to their initial state, shuts down all unnecessary outputs, and re-enters standby mode to wait for the next spraying command.

[0101] Example 2: Compared with Example 1, this example also includes the following technical features:

[0102] The present invention also provides a control method based on an air-jet coating spray structure, comprising the following steps: S1. Spray preparation: The linkage controller starts the variable air pump, controls the main reversing valve 16 to open the pilot bypass 15 and cut off the energy storage unit passage, the air guide reversing valve 18 to open the pilot bypass 15 and the valve chamber 5, the high-pressure gas pushes the valve core 7 to move down to open the spray channel, all valves are closed and the rear sealing cap 14 is sealed.

[0103] S2. Spraying execution: The feed pump is started to deliver paint spraying, the main reversing valve 16 synchronously opens the energy storage unit passage to store energy, the pressure sensor 34 provides feedback on the pressure, the controller fine-tunes the air pump pressure, and the coordinated control is achieved by combining the linkage coupling formula.

[0104] S3. Spraying Stop: Shut down the feed pump, the air diversion valve 18 cuts off the pilot bypass 15 and releases pressure, the valve core 7 resets and blocks the flow channel, and the main diversion valve 16 cuts off the connection between the air pump and the pilot bypass 15.

[0105] S4. Residual material discharge: Open the discharge pneumatic valve 33 and release control valve 29, the main reversing valve 16 connects the energy storage unit and the pressure discharger, the airbag squeezes the hose to discharge the material, and combined with the deformation linkage formula, the air release rate and pressure relief are adjusted according to the pressure signal.

[0106] S5. Low-pressure purging: The air pump switches to low-pressure mode, opening the passage to the inlet air discharge pipe 32 to purge residual material from the hose.

[0107] S6. Reset Standby: Turn off the air pump, close the discharge valve and release control valve 29, release the residual air in the airbag to reset it, and reset all components to standby.

[0108] During the spraying preparation stage, the controller synchronously adjusts the position switching of the main reversing valve 16 and the air guiding reversing valve 18 to precisely open the spraying channel, while locking relevant valves and sealing pipelines to eliminate the risk of air and material leakage. During the spraying execution stage, while stably delivering the paint to complete the spraying operation, the accumulator 20 simultaneously stores energy. Through the built-in linkage coupling logic, the supply air pressure, valve core 7 opening degree and energy storage pressure are quantitatively matched. The pressure signal in the pipe is collected at a frequency of 100ms / time and the air pump output is finely adjusted in real time to ensure uniform and stable spraying flow and avoid quality defects such as uneven coating thickness and sagging.

[0109] During the spraying stop phase, the valve chamber 5 is quickly depressurized and the flow channel is sealed, isolating the material supply pipeline from the outside air and preventing the paint from solidifying and clogging the pipe at the source. During the residual material discharge phase, the opening degree and depressurization rhythm of the release control valve 29 are dynamically adjusted through deformation linkage logic to precisely match the hose compression deformation and internal pressure, remove residual paint from the pipeline, and avoid excessive compression force that could damage the hose.

[0110] During the low-pressure purging stage, the system switches to a low-pressure air supply mode to remove trace amounts of residue adhering to the inner wall of the hose, further enhancing the anti-clogging effect. Finally, all components are reset, and the equipment enters a low-power standby state, awaiting the next operating command. The entire process is precisely timed, balancing coating quality, residue removal effectiveness, and equipment lifespan.

[0111] As a preferred option, during the S1 spraying preparation stage, the initial output air pressure of the variable air pump is adapted to the range of 0.4-0.8MPa, with 0.5-0.7MPa being preferred (to match the viscosity of commonly used paints). High-pressure gas enters the valve chamber 5 through the main reversing valve 16, pilot bypass 15, pilot check valve 17, and air guide reversing valve 18, pushing the valve core 7 to move downward against the tension of the tension spring 11, ensuring that the spray channel 8 is synchronously connected to the feeding unit and the nozzle 1. The discharge pneumatic valve 33, vent valve 30, and pressure relief valve 23 are all in the closed state. The rear sealing cap 14 is screwed on to seal the discharge port, ensuring the pipeline is airtight and preventing paint leakage.

[0112] During the spraying preparation stage, the linkage controller first sets the initial output air pressure of the variable air pump based on the viscosity characteristics of commonly used industrial coatings. It prioritizes the 0.5-0.7MPa range, suitable for most water-based and oil-based coatings. This avoids excessive pressure causing the valve core 7 to move excessively downwards and damage the sealing structure of the valve chamber 5, while also preventing insufficient pressure from overcoming the spring tension and failing to fully open the spraying channel. Subsequently, the controller controls the main reversing valve 16 and the guide air reversing valve 18 to synchronously switch positions according to a preset timing sequence. High-pressure gas passes sequentially along the pilot bypass 15 through the pilot check valve 17 and the guide air check valve 18. The air reversing valve 18 enters the valve chamber 5. The pilot check valve 17 prevents pressure fluctuations caused by gas backflow throughout the process, ensuring that the valve core 7 moves smoothly downwards until the spray channel 8 is precisely aligned with the feeding unit and the nozzle 1, completing the full-bore opening of the spraying channel. At the same time, the controller locks the discharge pneumatic valve 33, the vent valve 30, and the pressure relief valve 23 in the normally closed state. After screwing them on, the sealing cap 14 is closed, which not only ensures the sealing reliability of the rear discharge pipe port and avoids leakage during paint transportation, but also prevents excessive screwing torque from damaging the pipe thread, ensuring the pipeline airtightness and equipment safety during the spraying preparation stage.

[0113] As a preferred option, during the S2 spraying execution stage, the feed pump delivers the paint to the nozzle 1 through the multi-port pipe 13, the pumping hose 12, and the pilot opening and closing component spraying channel 8.

[0114] High-pressure gas from the variable displacement pump enters the accumulator 20 for energy storage via the main reversing valve 16, the energy storage bypass 19, and the energy storage check valve 24.

[0115] The preferred linkage coupling formula is:

[0116] .

[0117] In the formula: The real-time pre-charge pressure of accumulator 20 is expressed in MPa. The variable pressure is the output air supply pressure of the air pump, in MPa; the value ranges from 0.4 to 0.8 MPa, which follows the normal working pressure range of industrial pneumatic equipment. At the same time, it is fully compatible with the standard air supply pressure of 0.5-0.7 MPa of the common compressed air pipeline network in domestic factories, without the need for additional high-pressure air source equipment.

[0118] The effective pressure-bearing cross-sectional area of ​​the valve core 7 corresponds to the effective pressure-bearing area of ​​approximately 50 mm². The valve core 7 of a conventional industrial spraying valve has a diameter of 8-10 mm. The industry-standard valve core 7 can be directly purchased. The standard value is 10-30 N / mm. This stiffness range can ensure that the valve core 7 can quickly reset and block the flow channel under the spring tension when the spray stops, and will not require too high air source pressure to open the valve core 7 due to excessive stiffness. It is suitable for the working air pressure range of 0.4-0.8 MPa.

[0119] The pilot gas path pressure loss coefficient is 0.90-0.98. This refers to the valve core 7 displacement opening. The friction damping correction coefficient for the valve core 7 sealing element is 1.03-1.11. The duration of gas supply to the gas circuit, measured in seconds (s). This is the time constant for the gas path pressure response.

[0120] The controlled object on the left side of the formula is the real-time pre-charge pressure of the accumulator 20. The right side of the formula integrates four categories of variables: air source input parameters, core parameters of spraying conditions, inherent parameters of equipment structure, and dynamic response correction parameters, forming a closed-loop control logic. This logic can be directly written into the control program of the linkage controller (Siemens S7-200SMART PLC) to achieve real-time calculation and automatic regulation.

[0121] Unlike conventional spraying equipment where the spraying and energy storage systems are independently adjustable and have no synergistic relationship, this formula deeply couples the valve core 7 displacement opening, the variable air pump output pressure, and the accumulator 20 pre-charge pressure, which directly determine the spraying flow rate. This achieves a synergistic logic where the higher the spraying flow rate and the higher the air source pressure, the higher the accumulator 20 pre-charge pressure will increase simultaneously. This ensures stable flow rate during the spraying process and reserves sufficient power to match the working conditions for subsequent residual material discharge.

[0122] The main body of the formula is divided into two parts: basic operational terms and dynamic correction terms. The basic operational terms strictly follow Hooke's Law and the basic principles of aerodynamic pressure transmission. The output air source pressure of the variable air pump is multiplied by the effective pressure-bearing area of ​​the valve core 7 to obtain the theoretical axial thrust of the high-pressure gas acting on the valve core 7; the pressure loss coefficient along the pilot air path is used to correct the theoretical thrust to obtain the actual effective driving force on the valve core 7; the stiffness coefficient of the tension spring 11 is the core impedance parameter for the reset of the valve core 7, which, together with the effective driving force, determines the displacement opening of the valve core 7.

[0123] At the end of the formula This is a dynamic correction term based on a first-order inertial element, a classic model used in industrial pneumatic system design to characterize the pressure response of the air path. Conventional static pressure calculation formulas only fit steady-state conditions and cannot cover the dynamic pressure changes during spraying start-up and continuous spraying processes. However, in this correction term… For the duration of continuous gas supply, The time constant of the gas path pressure response. The correction coefficient for the friction damping of the valve core 7 seal fully considers the delayed characteristics of air circuit charging and the influence of seal friction damping on pressure transmission: in the initial stage of spraying, With a relatively small value and a correction term approaching 0, the pre-charge pressure of accumulator 20 will not spike instantly, preventing overload of the variable displacement pump during startup; as spraying continues, As the pressure gradually increases, the correction term approaches 1, and the pressure of the accumulator 20 stabilizes at the rated value that matches the operating conditions. This conforms to the actual pressure response law of industrial pneumatic systems, effectively avoiding pressure overshoot and oscillation problems in the control process and ensuring the stability of the spraying process.

[0124] This solution is suitable for conventional paint spraying operations: taking the spraying of commonly used water-based anti-corrosion coatings as an example, it sets the output air supply pressure of the variable air pump. The effective pressure-bearing area of ​​valve core 7 is 0.6 MPa. The pilot gas path pressure loss coefficient is 50 mm². Take 0.95, stiffness coefficient of tension spring 11 The valve core displacement is 20 N / mm. The friction damping correction coefficient for valve core 7 seal is 8mm. Take 1.08, gas supply duration The gas path pressure response time constant is 15s. The value is 2 seconds. Substituting this into the formula, the real-time pre-charge pressure of the accumulator 20 can be obtained. Approximately 0.68 MPa, this value meets the pressure requirements of conventional paint spraying, ensuring stable spray flow and sufficient energy storage.

[0125] As a preferred solution, during the S3 spraying stop phase, the air diversion valve 18 cuts off the connection between the pilot bypass 15 and the valve chamber 5, opening the valve chamber 5 to the external pressure relief passage, allowing the high-pressure gas in the valve chamber 5 to be quickly discharged; the valve core 7 moves upward under the reset pulling force of the tension spring 11, and the spray channel 8 is misaligned and blocked, achieving isolation and sealing between the material supply unit and the nozzle 1 to prevent external air from entering; the main diversion valve 16 cuts off the connection between the variable air pump and the pilot bypass 15, maintaining the energy storage state of the energy storage unit, preparing for the discharge of residual material.

[0126] As a preferred solution, the linkage controller opens the release control valve 29, and the high-pressure gas in the accumulator 20 enters the pneumatic variable volume chamber 26 of the extrusion airbag 25 through the release pipeline 28 and the release control valve 29. The inner ring membrane 27 of the airbag contracts to extrude the pumping hose 12, and the residual material is discharged through the inlet air discharge pipe 32 and the discharge pneumatic valve 33.

[0127] The deformation linkage formula is as follows:

[0128] In the formula: The radial extrusion deformation of pump hose 12 is expressed in mm. The actual pressure released by accumulator 20 is expressed in MPa. The pressure-bearing area of ​​the compressed airbag 25 is shown in mm². The airbag pneumatic transmission efficiency is set at 0.85-0.95. The radial elastic modulus of the pump hose 12; The unit is the wall thickness of the hose, in mm; The viscosity resistance coefficient of the coating; The duration of a single spray application is measured in seconds (s). This is the rated spraying reference time.

[0129] The core requirement of residual material discharge is to generate sufficient and uniform extrusion pressure through the controllable deformation of the extrusion airbag 25 to discharge the residual material in the pumping hose 12, while avoiding excessive extrusion pressure that could damage the hose and insufficient extrusion pressure that could leave residual material.

[0130] Based on this, the left side of the formula (Radial extrusion deformation of the hose) is the core controlled object, which directly determines the extrusion force and discharge effect; the right side integrates five major categories of key variables, including pressure parameters, structural parameters, efficiency parameters, coating characteristic parameters and operating condition parameters, forming a complete quantitative control logic.

[0131] The main structure of the formula is divided into two parts, the first part This is a fundamental calculation item for hose deformation, following the basic laws of elastic deformation and the principle of aerodynamic pressure transmission in mechanics of materials: (Actual release pressure of accumulator 20) and Multiplying the pressure-bearing area of ​​the airbag by the airbag gives the theoretical compressive force exerted by the airbag on the hose. (Airbag pneumatic transmission efficiency) is used to correct for pressure loss caused by gas leakage and airbag deformation, so as to obtain the actual effective extrusion force; The (coating viscosity resistance coefficient) is adjusted according to the coating viscosity to correct the extrusion pressure requirement. The higher the viscosity, the larger the correction coefficient, to ensure that high-viscosity coatings can be effectively extruded. (Radial elastic modulus of hose) and (Hose wall thickness) is an inherent characteristic parameter of the hose, determining its resistance to deformation. The larger the product of the two, the greater the compressive force required for the hose, and the smaller the deformation. Part Two It is a dynamic correction item for working conditions, which is tailored to the differentiated needs of actual spraying operations.

[0132] (Duration of a single spray) and The ratio of (rated spraying reference time) is used to characterize the intensity of a single spraying operation—the longer the spraying duration, the more residual paint in the hose, the higher the degree of drying, the greater the required extrusion force, and the corresponding hose deformation also needs to increase accordingly. This correction breaks through the limitations of conventional static extrusion control, dynamically adjusting the deformation according to different spraying durations. This avoids the problems of excessive extrusion damaging the hose during short-duration spraying and insufficient extrusion leading to incomplete material discharge during long-duration spraying, making the formula adaptable to various operating conditions such as intermittent and continuous spraying, and improving the versatility and accuracy of material discharge control.

[0133] in, The value of (actual release pressure of accumulator 20) is matched with the air supply pressure during the spraying stage, and is usually 0.4-0.8MPa, which ensures sufficient extrusion pressure without exceeding the pressure limit of the hose. (Airbag pressure-bearing area) corresponds to the design specification of a standard annular extrusion airbag 25. The pressure-bearing area of ​​commonly used airbags in industrial spraying is 200-400mm², and general-purpose products can be purchased directly. The (airbag pneumatic transmission efficiency) is set at 0.85-0.95. Based on the measured data of conventional transmission efficiency of industrial pneumatic airbags, and conforming to the sealing performance and deformation characteristics of commonly used airbag materials such as rubber and polyurethane, it can effectively compensate for pressure loss. (Radial elastic modulus of hose) and (Hose wall thickness) are all standard parameters for industrial spraying pump hoses 12. The elastic modulus of commonly used hoses is 600-1000MPa, the wall thickness is 2-4mm, and they are suitable for extrusion pressure of 0.4-0.8MPa to avoid excessive deformation or damage to the hose. The value of (viscosity resistance coefficient of coating) is set according to the viscosity of commonly used water-based and oil-based coatings, and is usually 0.7-0.9. The value is higher for high viscosity coatings and lower for low viscosity coatings. It can be quickly calibrated through simple actual measurement. (Duration of a single spraying session) is collected and recorded in real time by the linkage controller. The rated spraying reference time is set to 18-20 seconds, which is consistent with the typical single operation time of industrial spraying, and can be dynamically corrected without manual intervention.

[0134] Taking the cleaning of residual material after spraying commonly used high-viscosity epoxy coatings as an example, the actual release pressure of the accumulator 20 is set. The pressure is 0.5 MPa, and the compressive strength of the airbag is 25 mm. The airbag air pressure transmission efficiency is 300mm². Take 0.90, radial elastic modulus of pump hose 12 The pressure is 800MPa, and the wall thickness of the hose is [missing information]. The coating viscosity coefficient is 3mm. The value is 0.8, and the duration of a single spray is [missing information]. The rated spraying time is 20 seconds. The value is 18s. Substituting this into the calculation, we can obtain the radial extrusion deformation of the pump hose 12. With a deformation of approximately 2.2 mm, this deformation ensures that high-viscosity epoxy coating residue inside the hose is squeezed out, meeting the cleanliness requirements of routine operations.

[0135] As a preferred option, during the S5 low-pressure purging stage, the variable air pump switches to a low-pressure output mode of 0.1-0.2MPa, with 0.15MPa being the preferred setting (suitable for purging water-based and oil-based paint residues). The flow path is opened to the inlet air discharge pipe 32, and the low-pressure gas purges the inner wall of the hose to remove trace amounts of residue, which are then discharged through the discharge pneumatic valve 33. The purging duration is set to 13s based on the hose length, with 1.5s for a 12m hose and 2.5s for a 23m hose. The discharge pneumatic valve 33 is open throughout the purging process and closes after a 3-5s delay, preferably with a 4s delay, to prevent residual gas in the pipeline from hindering subsequent material supply.

[0136] As a preferred solution, during the S6 reset standby phase, after shutting down the variable air pump, the discharge pneumatic valve 33 and the release control valve 29 are closed, the compression airbag 25 and the vent valve 30 are opened to release residual gas. The airbag returns to its original shape under its own elasticity and the reaction force of the hose, and then the vent valve 30 is closed. The linkage controller controls all components such as the main reversing valve 16 and the air guiding reversing valve 18 to reset, the pressure relief valve 23 remains closed, the rear sealing cap 14 maintains the seal, and the equipment enters the standby state.

[0137] As a preferred option, during the spraying process, the output air pressure range of the variable air pump is 0.4-0.8MPa, of which 0.4-0.6MPa is used when spraying water-based paints and 0.6-0.8MPa is used when spraying oil-based paints.

[0138] As a preferred solution, the pressure sensor 34 monitors the pressure inside the pipe in real time, and the linkage controller synchronously adjusts the opening of the release control valve 29 to regulate the venting rate of the accumulator 20. When the pressure inside the pipe is lower than 0.1MPa, the controller increases the opening of the release control valve 29 and accelerates the venting rate of the accumulator 20 to increase the squeezing force; when it is higher than 1.0MPa, the controller decreases the opening of the release control valve 29, slows down the venting rate, and opens the pressure relief valve 23 to assist in pressure relief, ensuring smooth material discharge without damaging the hose and avoiding material discharge failure.

[0139] As a preferred option, during the low-pressure purging stage, the purging air pressure is matched with the hose wall thickness and coating viscosity to prevent low-pressure gas from impacting and damaging the hose; the duration of delaying the closure of the discharge pneumatic valve 33 can be finely adjusted according to the hose length to ensure that there is no large amount of residual gas in the pipeline.

[0140] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention. For those skilled in the art, any alternative improvements or transformations made to the implementation of the present invention fall within the protection scope of the present invention.

[0141] Any aspects of this invention not described in detail are well-known to those skilled in the art.

Claims

1. An air-assisted coating spray configuration, characterized by: The device includes a nozzle, a feeding unit, a pilot opener / closer, a pilot reversing device, an energy storage unit, and a pressure discharger. The inlet end of the nozzle is connected to the outlet end of the pilot opener / closer, and the two are internally connected. The inlet end of the pilot opener / closer is connected to the outlet end of the feeding unit, and the two are internally connected. The pilot end of the pilot opener / closer is connected to the output end of the variable air pump through the pilot reversing device, and the two are internally connected. The other end of the pilot reversing device is connected to the inlet end of the energy storage unit, and the two are internally connected. The outlet end of the energy storage unit is connected to the pressure discharger, and the two are internally connected. The energy storage unit is fixed on a mounting bracket, and the pressure discharger is fixedly arranged relative to the energy storage unit.

2. An air-assisted coating spray configuration according to claim 1, wherein: The pilot opening and closing component includes a vertically arranged cylindrical valve cylinder. The middle left side of the valve cylinder is detachably fixed to the end of the feeding unit through a connector, and the two are internally connected. A valve chamber is provided inside the valve cylinder, and end caps are respectively sealed at the upper and lower ends of the valve chamber. The opening of the end cap at the upper part of the valve cylinder is connected to the pilot end of the pilot reversing component. A cylindrical valve core is coaxially and movably sealed inside the valve chamber. An injection channel is provided radially on the outer side wall of the valve core. In the idle state, the injection channel is blocked. In the working state, the injection channel is synchronously connected to the outlet end of the feeding unit and the feed end of the nozzle. A cylindrical valve stem is coaxially fixed to the bottom center of the valve core. The lower end of the valve stem extends out of the valve cylinder and is fixed to a baffle. A tension spring is coaxially sleeved on the outside of the valve stem between the baffle and the lower end cover. The upper end of the tension spring is fixed to the bottom surface of the lower end cover, and the lower end is fixed to the top surface of the baffle.

3. An air-assisted coating spray arrangement according to claim 2, wherein: The feeding unit includes a pumping hose. The outlet end of the pumping hose is detachably fixed to the opening in the middle left side of the valve cylinder through a connector, and the two are internally connected. The inlet end of the pumping hose is integrally formed with a multi-port pipe. One end of the multi-port pipe is connected to the feeding pump, and a rear sealing cap is screwed onto the rear discharge port at the other end. The inner end of the rear sealing cap extends into the rear discharge port.

4. An air-assisted coating spray arrangement according to claim 3, wherein: The pilot switching component includes a pilot bypass and a main switching valve. The pilot end of the pilot bypass is the outlet end. The outlet end of the pilot bypass is fixedly connected to the end cap on the upper part of the valve cylinder and its inner end is connected to the valve cavity. The inlet end of the pilot bypass is connected to one of the outlet ends of the main switching valve. A pilot check valve and a gas-guided switching valve are installed in series on the pilot bypass. The gas-guided switching valve is located near the pilot opening and closing component and is used to realize the on / off and pressure relief control of the pilot gas path.

5. The air-jet coating spraying structure according to claim 4, characterized in that: Before the nozzle sprays material, the air guide reversing valve connects the pilot bypass to the inside of the valve chamber and works with the main reversing valve to open the passage between the variable air pump and the pilot bypass, so as to deliver the high-pressure gas of the variable air pump into the valve chamber, and finally control the spray channel to connect the outlet end of the feeding unit with the feed end of the nozzle. When the nozzle needs to stop spraying, the air diversion valve cuts off the pilot bypass from the valve chamber and connects the valve chamber to the outside through the switching passage, so that the high-pressure gas in the valve chamber can be quickly discharged. Then, the pilot opening and closing part returns to its original position under the action of the tension spring, and the spray channel is blocked. At the same time, the main diversion valve cuts off the connection between the variable air pump and the pilot bypass.

6. The air-jet coating spraying structure according to claim 5, characterized in that: The two outlets of the main reversing valve are connected to the pilot bypass and the inlet of the energy storage unit, respectively, and are used to realize the time-sharing or synchronous supply of gas from the variable gas pump to the pilot bypass and the energy storage unit. At the same time, through linkage with the gas guide reversing valve, the coordinated control of spraying and energy storage is achieved.

7. The air-jet coating spraying structure according to claim 6, characterized in that: The energy storage unit includes an accumulator, which is fixedly connected to the mounting frame via several connecting rods. The left inlet end of the accumulator is connected to the outlet end of the main reversing valve via an energy storage bypass. The outlet end of the accumulator is connected to the inlet end of the pressure discharge device. The top of the accumulator is fixedly connected to the pressure discharge device via a support rod. A pressure relief valve is also provided on the accumulator. An energy storage check valve is installed in series on the energy storage bypass to prevent the backflow of high-pressure gas in the accumulator.

8. The air-jet coating spraying structure according to claim 7, characterized in that: The pressure discharge device includes an annular extrusion airbag coaxially sleeved on the straight section of the pumping hose. The outer wall of the extrusion airbag is a rigid structure, the inner annular sidewall is an inner ring film, and a pneumatic variable volume cavity is provided inside the extrusion airbag. The inner ring film of the extrusion airbag is in close contact with the outer wall of the pumping hose. When the pneumatic variable-volume chamber inside the airbag is inflated, the inner membrane contracts inward to squeeze the pump hose and expel the residual paint inside the hose outward. The left outer wall of the rigid structure of the compression airbag is fixedly connected to the accumulator via a support rod. The right outer wall of the compression airbag is connected to the accumulator of the energy storage unit via a release pipe and is internally connected. A release control valve is installed on the release pipe to control the accumulator to supply air to the compression airbag. A venting connector with a venting valve is installed on the middle outer wall of the compression airbag.

9. The air-jet coating spraying structure according to claim 8, characterized in that: An inlet air discharge pipe is integrally formed on the outer wall of the pumping hose near the pilot opening and closing component. A discharge pneumatic valve is installed on the inlet air discharge pipe. The inlet air discharge pipe is connected to a variable air pump as needed through a pipeline.

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