High-performance coating thermal spraying equipment based on multi-sensor closed-loop control

Abstract

The invention relates to the technical field of thermal spraying, and discloses high-performance coating thermal spraying equipment based on multi-sensor closed-loop control, which comprises a table top, a rotating mechanism, a clamp, a horizontal moving mechanism, a vertical moving mechanism, a hot air gun, a spray gun and an electromechanical control system, the rotating mechanism is composed of a rotating platform, a rotating shaft, a large belt wheel, a small belt wheel, a belt and a motor, the horizontal moving mechanism is a cylinder for driving the hot air gun and the spray gun to move horizontally; the vertical moving mechanism is a sliding table and drives the hot air gun and the spray gun to vertically move; the electromechanical control system comprises a central controller, a temperature sensor and a position sensor and controls the motor, the air cylinder, the sliding table, the hot air gun and the spray gun to operate according to collected temperature and position signals. The automation degree and stability of the coating spraying process are improved, the spraying track control precision is improved, and the spraying efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of thermal spraying technology, and more specifically, to a high-performance coating thermal spraying device based on multi-sensor closed-loop control. Background Technology

[0002] During engine operation, the bearing shell, as a key sliding bearing component connecting the crankshaft and connecting rod, is subjected to alternating loads, high-speed friction, and high-temperature environments for extended periods. This makes it highly susceptible to wear, fatigue spalling, and galling failure, severely impacting engine reliability and service life. With the continuous development of modern engine technology, higher operating speeds and heavier loads are required, placing greater demands on the wear resistance, compliance, and embeddability of the bearing shell. While traditional copper-lead or aluminum-based bearing shells possess a certain load-bearing capacity, they still suffer from problems such as high friction coefficients and poor oil film stability under harsh conditions such as frequent start-stop cycles and boundary lubrication.

[0003] Conventional thermal spraying equipment relies heavily on manual parameter setting, lacking real-time monitoring and feedback adjustment of key variables in the spraying process. For example, when spraying the inner arc surface of a bearing bush, excessively fast spray gun movement speed can lead to an insufficiently thin coating and coverage, while excessively slow movement can cause buildup and excessive thickness. Simultaneously, a spraying angle deviating from the vertical direction significantly affects particle deposition efficiency and coating density, while fluctuations in spraying distance directly result in uneven heat dissipation and changes in powder particle size distribution, thus affecting bonding strength. Furthermore, the coating thickness needs to be precisely controlled within the range of 10±2μm to balance lubrication performance and load-bearing capacity, but traditional equipment struggles to achieve closed-loop control.

[0004] Therefore, it is necessary to design a high-performance thermal spraying equipment based on multi-sensor closed-loop control to solve the problems existing in the current technology. Summary of the Invention

[0005] In view of this, the present invention proposes a high-performance coating thermal spraying equipment based on multi-sensor closed-loop control, which aims to solve the problems of insufficient control accuracy, poor coating uniformity and unstable adhesion when spraying bearing components in the prior art.

[0006] This invention proposes a high-performance coating thermal spraying equipment based on multi-sensor closed-loop control, including a table, a rotating mechanism, a clamp, a horizontal moving mechanism, a vertical moving mechanism, a hot air gun, a spray gun, and an electromechanical control system. The platform serves as the supporting foundation for the equipment. The rotating mechanism includes a rotating platform, a rotating shaft, a large pulley, a small pulley, a belt, and a motor. The rotating platform is mounted on the platform via the rotating shaft. The motor drives the large pulley via the small pulley connected to the belt, thereby driving the rotating shaft and the rotating platform to rotate. The clamp is mounted on the rotating platform to fix the workpiece. The horizontal movement mechanism is a cylinder mounted on the platform to drive the hot air gun and spray gun to move horizontally. The vertical movement mechanism is a slide table connected to the cylinder to drive the hot air gun and spray gun to move vertically. The spray gun also includes an angle adjustment mechanism to adjust the spraying angle. The electromechanical control system includes a central controller, a temperature sensor, and a position sensor. The temperature sensor is installed at the air outlet of the hot air gun. The position sensor includes a horizontal position sensor, a vertical position sensor, and an angle sensor. The horizontal position sensor is installed at the end of the cylinder stroke. The vertical position sensor is installed on the slide rail, and the angle sensor is installed on the angle adjustment mechanism. The electromechanical control system is electrically connected to the motor, cylinder, slide, hot air gun, and spray gun, and controls the operation of the motor, cylinder, slide, hot air gun, and spray gun based on the data collected by the temperature sensor, position sensor, and angle sensor.

[0007] Furthermore, the central controller includes a temperature judgment unit, a hot air gun control unit, a spray gun control unit, and a circulation process control unit; The temperature judgment unit is used to collect the real-time temperature value of the hot air gun nozzle based on the temperature sensor, and compare the real-time temperature value with the temperature threshold to determine whether the hot air gun has completed preheating. The hot air gun control unit is used to control the cylinder and slide to move the hot air gun to the heating position when it is determined that the hot air gun has finished preheating, and to determine whether the movement to the heating position is completed based on the horizontal position sensor and the vertical position sensor; when it is determined that the movement to the heating position is completed, the heating process is performed; after the heating is completed, the slide is controlled to move the hot air gun vertically upward to a safe height. The spray gun control unit is used to control the operation of the cylinder, slide, and angle adjustment mechanism to move the spray gun to the spraying position, and dynamically adjust the spraying angle of the spray gun based on the geometric features of the workpiece surface; after determining that the spray gun position and angle adjustment are completed, spraying is performed; after spraying is completed, the slide is controlled to move the spray gun vertically upward to a safe height. The cycle process control unit is used to cycle through the operation process of hot air gun heating and spray gun spraying until the operation is completed.

[0008] Furthermore, the temperature judgment unit compares the real-time temperature value with a temperature threshold to determine whether the hot air gun has completed preheating, including: The temperature sensor is a thermocouple sensor. The temperature judgment unit receives the real-time temperature signal from the hot air gun outlet based on the thermocouple sensor, and converts the real-time temperature signal into a digital temperature value through a signal conditioning circuit; the digital temperature value is then compared with the temperature threshold. When the digital temperature value is less than or equal to the temperature threshold, it is determined that the hot air gun preheating is not complete, and the hot air gun preheating continues. When the digital temperature value is greater than the temperature threshold, it is determined that the hot air gun has completed preheating.

[0009] Furthermore, the hot air gun control unit controls the cylinder and slide to move the hot air gun towards the heating position, and determines whether the movement towards the heating position is complete based on the horizontal and vertical position sensors, including: The hot air gun control unit outputs an air path switching signal to the cylinder drive circuit through the solenoid valve control port. The cylinder drive circuit controls the intake solenoid valve to open and the outlet solenoid valve to close, driving the cylinder piston rod to move horizontally, thereby moving the hot air gun horizontally above the workpiece. Based on the horizontal position sensor, it determines whether the hot air gun has moved horizontally to the positioning position above the workpiece. When it is determined that the hot air gun has moved horizontally to the positioning position above the workpiece, a horizontal positioning signal is generated, and the hot air gun control unit performs an air path locking operation based on the horizontal positioning signal.

[0010] Furthermore, the hot air gun control unit controls the cylinder and slide to move the hot air gun towards the heating position, and when determining whether the movement towards the heating position is complete based on the horizontal and vertical position sensors, it also includes: The hot air gun control unit outputs a pulse signal to the slide driver via the stepper motor drive port; the slide driver controls the stepper motor to rotate, driving the lead screw transmission mechanism to move the slide vertically downward; this causes the hot air gun to move vertically downward into the workpiece, and the vertical position sensor determines whether the hot air gun has moved vertically to the internal heating position on the workpiece; when it is determined that the hot air gun has moved vertically to the internal heating position on the workpiece, a vertical positioning signal is generated, and the hot air gun control unit stops the motor according to the vertical positioning signal.

[0011] Furthermore, when the hot air gun control unit performs the heating process, it includes: The hot air gun control unit outputs a heating start signal through the hot air gun control port; the hot air gun control circuit connects the power supply to the heating element to maintain the heating temperature threshold, and the temperature sensor provides real-time feedback of the heating temperature value; when the heating time equals the heating duration threshold, the hot air gun control unit stops the heating process.

[0012] Furthermore, when the hot air gun control unit maintains the heating temperature threshold and the temperature sensor provides real-time feedback of the heating temperature value, it includes: The heating temperature threshold includes a first heating temperature threshold and a second heating temperature threshold, wherein the first heating temperature threshold is less than the second heating temperature threshold; the heating temperature value is compared with the first heating temperature threshold and the second heating temperature threshold respectively; When the heating temperature value is less than the first heating temperature threshold, the heating time is recalculated, and the extended heating time is calculated based on the temperature difference and the heating rate. When the heating temperature value is greater than or equal to the first heating temperature threshold and less than or equal to the second heating temperature threshold, the current heating temperature value is maintained and the heating process continues. When the heating temperature value is greater than the second heating temperature threshold, the heating temperature value is adjusted by reducing the power output of the heating element to bring the heating temperature value between the first heating temperature threshold and the second heating temperature threshold.

[0013] Furthermore, when the spray gun control unit dynamically adjusts the spray angle of the spray gun based on the geometric features of the workpiece surface, it includes: The spray gun control unit outputs an angle control signal to the angle driver through the angle adjustment mechanism drive port. The angle driver calculates the target spraying angle of the spray gun at the current position based on the three-dimensional geometric model of the workpiece and feedback from the real-time position sensor, so that the spray gun axis is consistent with the normal direction of the workpiece surface. It drives the servo motor to rotate, thereby driving the angle adjustment mechanism to dynamically adjust the spray gun angle. The angle sensor detects the actual spraying angle value in real time. When the deviation between the actual spraying angle value and the target spraying angle value is less than the angle tolerance threshold, it determines that the angle adjustment is complete and generates an angle arrival signal.

[0014] Furthermore, when the spray gun control unit performs the spraying process, it includes: The spray gun control unit outputs a spraying start signal through the spray gun control port; the spray gun control circuit connects the paint delivery pump and the atomizing gas source, and detects the spraying pressure value in real time based on the pressure sensor; when the spraying time is equal to the spraying duration threshold, the spray gun control unit stops the spraying process.

[0015] Furthermore, the cycle process control unit cyclically executes the hot air gun heating and spray gun spraying operation process until the end of the operation, including: The cycle process control unit sets an initial value for the cycle counter. After each hot air gun heating treatment and spray gun spraying treatment is completed, the cycle counter increments. The cycle count value of the cycle counter is compared with the cycle count threshold. When the cycle count value is less than the cycle count threshold, it is determined that the heating treatment and spraying treatment should be repeated. When the cycle count value is equal to the cycle count threshold, it is determined that the operation has ended.

[0016] Compared with existing technologies, the advantages of this invention are as follows: This equipment adopts multi-sensor fusion technology to achieve real-time monitoring and closed-loop control of key parameters such as hot air gun preheating temperature, heating temperature, spray gun position, spraying angle, and pressure, thereby improving the uniformity and adhesion of the coating. Especially for workpieces with complex curved surfaces, such as engine bearings, this invention creatively proposes a technical solution for dynamically adjusting the spray gun spraying angle based on the geometric features of the workpiece surface. Through an angle driver, based on the three-dimensional geometric model of the workpiece and feedback from real-time position sensors, the target spraying angle of the spray gun at the current position is accurately calculated and adjusted, ensuring that the spray gun axis is always aligned with the normal direction of the workpiece surface. This solves the problems of uneven coating thickness and adhesion differences caused by fixed-angle spraying in traditional equipment, keeping the spraying angle consistently within the optimal range of 75°~90°, thus improving the tribological properties of the inner arc surface coating of the bearing. Through the coordinated control mechanism of the hot air gun and spray gun, this equipment achieves seamless integration of heating and spraying, improving the bonding strength between the coating and the substrate. The temperature judgment unit uses a thermocouple sensor and signal conditioning circuit to convert real-time temperature signals into digital temperature values ​​for precise comparison, ensuring that subsequent operations are only performed after the hot air gun has been preheated. The hot air gun control unit employs a dual-threshold control strategy with a first heating temperature threshold and a second heating temperature threshold. When the heating temperature deviates from the ideal range, it automatically adjusts the heating time or power to ensure that the workpiece surface temperature is uniformly and stably within the optimal spraying range, avoiding coating defects caused by localized overheating or underheating. The spray gun control unit monitors the spraying pressure in real time through a pressure sensor and uses a dual-threshold pressure control mechanism. When the pressure deviates from the set range, it automatically adjusts the paint delivery pump speed or atomizing gas source pressure to ensure that the spraying pressure is stable within the ideal range, allowing the coating thickness to be precisely controlled within the range of 10±2μm, meeting the requirements of high-performance coatings. This equipment employs a bidirectional drive structure combining cylinders and a slide table, achieving high-precision horizontal and vertical positioning of the hot air gun and spray gun. Position control accuracy reaches ±0.2mm. Combined with precise control of the rotating mechanism, the spray gun's movement speed is stabilized between 50mm / s and 80mm / s, and the spraying height is precisely controlled at approximately 150mm, ensuring accurate spraying trajectory and uniform coating. The cyclic process control unit automatically manages the multi-layer spraying process through a cycle counter, ensuring the integrity and consistency of each round of heating and spraying, improving the controllability of coating thickness and surface density. Through the integrated design of the electromechanical control system, this equipment achieves fully automated operation from workpiece clamping, preheating, spraying to unloading. The entire process requires no manual intervention; operators only need to load workpieces into the fixtures in batches, and all subsequent processes are automatically completed, reducing manual operation time and human error, and increasing production capacity per unit time.The fixture can simultaneously hold multiple workpieces (e.g., 4-8 workpieces can be fed at once, the specific number can be flexibly adjusted according to the workpiece size and the layout of the rotating platform). Combined with the uniform rotation of the rotating platform, each workpiece can receive uniform spraying along a set trajectory. Through precise linkage control of the horizontal and vertical moving mechanisms, the spray gun and hot air gun can efficiently scan the work area along a preset path. The single-batch spraying cycle can be controlled within 3-5 minutes (depending on the coating thickness and material). After spraying is completed, the workpiece automatically exits, and the next batch of workpieces immediately enters, realizing a "last batch out, next batch in" assembly line operation mode, improving equipment utilization and cycle time efficiency. Attached Figure Description

[0017] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 A schematic diagram of the structure of a high-performance coating thermal spraying device based on multi-sensor closed-loop control provided in an embodiment of the present invention. Figure 1 ; Figure 2 A schematic diagram of the structure of a high-performance coating thermal spraying device based on multi-sensor closed-loop control provided in an embodiment of the present invention. Figure 2 ; Figure 3 This is a structural block diagram of the central controller for a high-performance coating thermal spraying equipment based on multi-sensor closed-loop control, provided in an embodiment of the present invention.

[0018] The components are: 1. Table; 2. Fixture; 3. Hot air gun; 4. Spray gun; 5. Rotary platform; 6. Rotary shaft; 7. Large pulley; 8. Small pulley; 9. Belt; 10. Motor; 11. Workpiece; 12. Cylinder; 13. Slide table. Detailed Implementation

[0019] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specified, embodiments and features in the embodiments of the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0020] In some embodiments of this application, see Figure 1-3As shown, a high-performance coating thermal spraying device based on multi-sensor closed-loop control is proposed, including a table 1, a rotating mechanism, a clamp 2, a horizontal moving mechanism, a vertical moving mechanism, a hot air gun 3, a spray gun 4, and an electromechanical control system. The table 1 serves as the supporting foundation for the equipment. The rotating mechanism includes a rotating platform 5, a rotating shaft 6, a large pulley 7, a small pulley 8, a belt 9, and a motor 10. The rotating platform 5 is mounted on the table 1 via the rotating shaft 6. The motor 10 drives the large pulley 7 via the small pulley 8 connected to the belt 9, thereby driving the rotating shaft 6 and the rotating platform 5 to rotate. The clamp 2 is mounted on the rotating platform 5 to fix the workpiece 11. The horizontal movement mechanism is a cylinder 12, mounted on the table 1, used to drive the hot air gun 3 and the spray gun 4 to move horizontally. The vertical movement mechanism is a slide table 13, connected to the cylinder 12, used to drive the hot air gun 3 and the spray gun 4 to move vertically. The spray gun 4 also includes an angle adjustment mechanism for adjusting the spraying angle of the spray gun 4. The electromechanical control system includes a central controller, a temperature sensor, and a position sensor. The temperature sensor is installed at the air outlet of the hot air gun 3. The position sensors include a horizontal position sensor, a vertical position sensor, and an angle sensor. The horizontal position sensor is installed at the end of the stroke of the cylinder 12; the vertical position sensor is installed on the guide rail of the slide table 13; and the angle sensor is installed on the angle adjustment mechanism. The electromechanical control system is electrically connected to the motor 10, the cylinder 12, the slide table 13, the hot air gun 3, and the spray gun 4. Based on the data collected by the temperature sensor, the position sensor, and the angle sensor, it controls the operation of the motor 10, the cylinder 12, the slide table 13, the hot air gun 3, and the spray gun 4.

[0021] Specifically, the provided high-performance thermal spraying equipment based on multi-sensor closed-loop control mainly consists of a table 1, a rotating mechanism, a clamp 2, a horizontal moving mechanism, a vertical moving mechanism, a hot air gun 3, a spray gun 4, and an electromechanical control system. The table 1 serves as the supporting foundation for the entire equipment and is made of high-strength, high-temperature resistant alloy material, possessing excellent stability and vibration resistance, effectively reducing the impact of vibration on spraying accuracy during the spraying process. The rotating mechanism, located above the table 1, includes a rotating platform 5, a rotating shaft 6, a large pulley 7, a small pulley 8, a belt 9, and a motor 10. The rotating platform 5 is mounted in the center of the table 1 via the rotating shaft 6. The motor 10 drives the large pulley 7 to rotate via the small pulley 8 and the belt 9, thereby driving the rotating shaft 6 and the rotating platform 5 to achieve uniform or variable speed rotation. This allows the workpiece 11 mounted on it to achieve omnidirectional rotational exposure during the spraying process, ensuring uniform coating thickness. The fixture 2 is mounted on the rotating platform 5 to reliably fix the workpiece 11. Its structure can be modularly designed according to workpieces 11 of different shapes and sizes. An adjustable locking mechanism is used to ensure that the workpiece 11 will not loosen or shift during rotation and heating. The horizontal movement mechanism is driven by a cylinder 12, which is fixedly installed on one side of the table 1. It can drive the hot air gun 3 and the spray gun 4 to move synchronously in the horizontal direction to achieve lateral coverage of the spraying area. The cylinder 12 is a high-precision servo-controlled cylinder with smooth start and stop characteristics, which can accurately control the spraying path and speed, thereby improving the uniformity of the surface coating. The vertical movement mechanism is a slide table 13 structure, connected to the cylinder 12. It uses a screw transmission mechanism to drive the slider to move vertically along the guide rail, which is used to adjust the vertical height of the hot air gun 3 and the spray gun 4 to adapt to the spraying requirements of workpieces 11 with different thicknesses and angles. The slide table 13 is driven by a stepper motor 10 or a servo motor 10, which can achieve micron-level position control, ensure a constant spraying distance, and thus improve process stability. The electromechanical control system is the core control unit of the equipment, consisting of a central controller, temperature sensors, and position sensors. The central controller uses an embedded industrial control chip with multi-tasking real-time processing capabilities. It coordinates the operating logic of the motor 10, cylinder 12, slide table 13, hot air gun 3, and spray gun 4 to achieve fully automated control. The temperature sensor is located at the outlet of the hot air gun 3, collecting the hot air temperature in real time and feeding it back to the central controller. This monitors the heating status and adjusts the hot air output power to ensure the workpiece 11 surface temperature is within the optimal spraying range. The position sensors include a horizontal position sensor and a vertical position sensor, respectively installed at the end of the cylinder 12's stroke and on the slide table 13's guide rail. These sensors detect the real-time spatial position of the hot air gun 3 and spray gun 4, preventing overtravel and achieving closed-loop position control. The spray gun 4 also includes an angle adjustment mechanism 14 for adjusting the spraying angle. The angle adjustment mechanism 14 includes a servo motor, a reducer, and an angle transmission mechanism, enabling precise angle adjustment of the spray gun 4 within a range of ±30°.Angle sensor 15 is mounted on angle adjustment mechanism 14 to detect the actual spraying angle of spray gun 4 in real time and feed the data back to central controller to form angle control closed loop.

[0022] During operation, the high-performance thermal spraying equipment achieves automatic rotation of the workpiece 11, heating by the hot air gun 3, spraying by the spray gun 4, and coordinated multi-axis movements through mechatronic control. The entire workflow exhibits a high degree of automation and closed-loop control. Upon startup, the central controller performs initialization checks on each actuator, confirming that the rotating mechanism, cylinder 12, slide 13, hot air gun 3, and spray gun 4 are in safe initial positions. The central controller issues a start command according to the preset spraying program, and the motor 10 drives the rotating platform 5 to rotate at a constant speed, enabling continuous rotation and exposure of the workpiece 11 fixed on the fixture 2, providing a stable motion foundation for subsequent heating and spraying. Simultaneously with the rotation of the workpiece 11, the central controller initiates the preheating program for the hot air gun 3. Temperature sensors monitor the temperature value at the outlet of the hot air gun 3 in real time and compare it with a preset temperature threshold. Once the set temperature is detected, the central controller issues a movement command, controlling cylinder 12 to move the hot air gun 3 horizontally to the predetermined heating position above workpiece 11. Simultaneously, slide 13, driven by stepper motor 10, descends vertically, bringing the hot air gun 3 closer to the surface of workpiece 11. Dual detection by horizontal and vertical position sensors ensures the hot air gun 3 moves to the precise heating point. After position confirmation, the central controller locks the motion mechanism, and the hot air gun 3 begins heating the surface of workpiece 11, achieving optimal local coating adhesion conditions. During heating, the central controller adjusts the heating power in real time based on temperature sensor feedback, maintaining the hot air temperature within the set range to prevent localized overheating or underheating of workpiece 11. After the heating phase, the central controller commands the hot air gun 3 to move upwards to a safe height and simultaneously initiates the spray gun 4's operating program. Driven by cylinder 12 and slide 13, spray gun 4 moves horizontally and vertically to the spraying position. Simultaneously, the spray gun control unit dynamically adjusts the spraying angle of spray gun 4 based on the workpiece surface geometry. The spray gun control unit outputs an angle control signal to the angle driver via the angle adjustment mechanism drive port. The angle driver calculates the target spray angle of the spray gun 4 at its current position based on the three-dimensional geometric model of the workpiece 11 or feedback from a real-time position sensor, ensuring that the axis of the spray gun 4 is aligned with the normal direction of the workpiece 11 surface. It then drives the servo motor to rotate, causing the angle adjustment mechanism 14 to dynamically adjust the angle of the spray gun 4. The angle sensor 15 detects the actual spray angle value in real time. When the deviation between the actual spray angle value and the target spray angle value is less than the angle tolerance threshold, the angle adjustment is considered complete, and an angle arrival signal is generated. For workpieces with curved inner surfaces, such as engine bearings, this system can automatically calculate and adjust the spray gun angle, ensuring that the spray angle remains within the optimal range at all positions on the workpiece surface, avoiding the uneven coating problem caused by traditional fixed-angle spraying.

[0023] After the position sensor detects the arrival signal of spray gun 4, the spray gun 4 control unit starts the spraying process. The spray gun 4 control circuit turns on the paint delivery pump and atomizing air source. Under the action of high-pressure airflow, the coating material is atomized into fine particles and sprayed at high speed onto the heated surface of workpiece 11, forming a dense and uniform coating. The pressure sensor detects the spraying pressure in real time and feeds it back to the central controller. The system dynamically adjusts the pump speed and air pressure according to the detection data to ensure that the spraying flow rate and atomization degree are stable and consistent. When the spraying time reaches the preset time threshold, spray gun 4 automatically stops spraying and moves to a safe position. The rotating platform 5 continues to rotate, so that the spraying area covers the entire surface of workpiece 11. After one spraying cycle is completed, the central controller determines whether to enter the next heating and spraying cycle according to the cycle number threshold set by the program. If the upper limit of the cycle number has not been reached, the system automatically repeats the heating and spraying operation to achieve multi-layer spraying and step heating; if the set number is reached, the equipment automatically stops rotating and heating, spray gun 4 and hot air gun 3 return to the initial position, and the system enters standby mode. Throughout the entire process, the central controller collects multi-dimensional sensor data such as temperature, position, and pressure in real time, and achieves precise control of the hot air gun 3 and spray gun 4 through closed-loop regulation, thereby ensuring that each coating layer has uniform thickness, strong adhesion, and a smooth surface.

[0024] Through the above scheme, this application achieves precise and uniform spraying of the coating on the surface of workpiece 11 by using a highly integrated electromechanical system and a multi-degree-of-freedom motion mechanism. Its core support structure is the table 1, ensuring the stability and load-bearing capacity of the entire equipment. The rotating mechanism consists of a rotating platform 5, a rotating shaft 6, a large pulley 7, a small pulley 8, a belt 9, and a motor 10. The motor 10 drives the belt 9 via the small pulley 8, which in turn drives the large pulley 7 to rotate, thereby rotating the rotating shaft 6 and the rotating platform 5, achieving continuous rotation of the workpiece 11 during the spraying process. A clamp 2 is installed on the rotating platform 5 to firmly fix various workpieces 11, ensuring their stability during spraying. The horizontal movement mechanism uses a cylinder 12, mounted on the table 1, which drives the hot air gun 3 and spray gun 4 to move smoothly in the horizontal direction. The vertical movement mechanism is a slide table 13 structure connected to the cylinder 12, enabling precise positioning and adjustment of the spraying equipment in the vertical direction, ensuring adjustable spray coverage height. The electromechanical control system includes a central controller, temperature sensors, and position sensors. The temperature sensor is installed at the outlet of the hot air gun 3 to monitor the spraying temperature in real time. The position sensors include horizontal and vertical position sensors, respectively installed at the end of the stroke of cylinder 12 and on the guide rail of slide table 13, ensuring precise and controllable movement trajectory and spraying position of the spray gun 4. Specifically, the angle sensor 15 monitors the spraying angle of the spray gun 4 in real time. The central controller dynamically adjusts the angle of the spray gun 4 according to the geometric characteristics of the workpiece 11, ensuring that the spray gun axis is aligned with the normal direction of the workpiece surface. This is a key technology for achieving uniform spraying of the polymer coating on engine bearings. The electromechanical control system is electrically connected to motor 10, cylinder 12, slide table 13, hot air gun 3, and spray gun 4. By collecting temperature and position data in real time, it achieves automatic adjustment of rotation speed, spraying trajectory, spraying height, and spraying angle, thereby improving coating uniformity, adhesion, and overall spraying efficiency. This enhances the equipment's operational accuracy and automation level while reducing manual intervention and operational risks.

[0025] This application further proposes a central controller including a temperature judgment unit, a hot air gun control unit, a spray gun control unit, and a circulation process control unit; The temperature judgment unit is used to collect the real-time temperature value of the air outlet of the hot air gun 3 based on the temperature sensor, and compare the real-time temperature value with the temperature threshold to determine whether the hot air gun 3 has completed preheating. The hot air gun 3 control unit is used to control the cylinder 12 and the slide table 13 to move the hot air gun 3 to the heating position after the hot air gun 3 has finished preheating. It also determines whether the movement to the heating position is complete based on the horizontal position sensor and the vertical position sensor. When the movement to the heating position is completed, the heating process is performed. After the heating is completed, the slide table 13 is controlled to move the hot air gun 3 vertically upward to a safe height. The spray gun 4 control unit is used to control the operation of the cylinder 12, the slide table 13 and the angle adjustment mechanism to move the spray gun 4 to the spraying position, and dynamically adjust the spraying angle of the spray gun based on the geometric features of the workpiece surface; when it is determined that the movement to the spraying position is completed, the spraying process is performed; after the spraying is completed, the slide table 13 is controlled to move the spray gun 4 vertically upward to a safe height. The cycle process control unit is used to cycle through the operation process of heating with hot air gun 3 and spraying with spray gun 4 until the operation is completed.

[0026] Specifically, the central controller integrates a temperature judgment unit, a hot air gun 3 control unit, a spray gun 4 control unit, and a cycle process control unit, enabling precise and automated control of the entire thermal spraying equipment. The temperature judgment unit collects the temperature value of the hot air gun 3 outlet in real time through a temperature sensor and compares the collected real-time temperature value with a preset temperature threshold to determine whether the hot air gun 3 has completed preheating. This unit can not only accurately determine whether the temperature meets the heating requirements but also maintain the preheating state when the temperature is below the threshold, ensuring the stability and uniformity of subsequent spraying processes. After determining that the hot air gun 3 has completed preheating, the hot air gun 3 control unit coordinates the operation of the cylinder 12 and the slide 13 to achieve smooth movement of the hot air gun 3 from its initial position to the workpiece 11 heating position. Simultaneously, it uses horizontal and vertical position sensors to determine in real time whether the hot air gun 3 has reached the target heating position. Once confirmed, the control unit initiates the heating process, ensuring that the hot air gun 3 precisely heats the surface of the workpiece 11, guaranteeing uniform temperature of the workpiece 11 before coating formation. After heating is complete, the control unit further drives the slide table 13 to move the hot air gun 3 vertically upward to a safe height, preparing for the switching of the spraying stage. The spray gun 4 control unit is the key innovation of this invention. It not only controls the cylinder 12 and the slide table 13 to move the spray gun 4 to the spraying position, but more importantly, it dynamically adjusts the spraying angle of the spray gun 4 based on the geometric features of the workpiece surface. Specifically, the spray gun 4 control unit outputs an angle control signal to the angle driver through the angle adjustment mechanism drive port; the angle driver calculates the target spraying angle of the spray gun 4 at the current position based on the three-dimensional geometric model of the workpiece 11 through real-time position sensor feedback, so that the axis of the spray gun 4 is consistent with the normal direction of the surface of the workpiece 11; it drives the servo motor to rotate, thereby driving the angle adjustment mechanism 14 to dynamically adjust the angle of the spray gun 4; the angle sensor 15 detects the actual spraying angle value in real time. When the deviation between the actual spraying angle value and the target spraying angle value is less than the angle tolerance threshold, it is determined that the angle adjustment is complete and an angle arrival signal is generated. For workpieces with complex curved surfaces, such as engine bearings, this dynamic angle adjustment mechanism based on the workpiece's geometry ensures that the optimal spraying angle can be obtained at various positions on the workpiece surface, thereby achieving a uniform distribution of coating thickness and adhesion. The cycle process control unit is responsible for managing the entire operation process. According to the preset number of cycles, it automatically executes the entire process of heating with the hot air gun 3 and spraying with the spray gun 4, ensuring that the equipment can continuously, stably, and efficiently complete multiple spraying tasks. At the same time, real-time data monitoring ensures that each heating and spraying is within the safe and precision control range.

[0027] The working process and principle are as follows: The temperature judgment unit collects the temperature data required for preheating the surface of the workpiece 11 in real time through a temperature sensor installed at the outlet of the hot air gun 3, and compares the collected real-time temperature value with a preset temperature threshold to determine whether the hot air gun 3 has completed preheating. When the temperature has not reached the threshold, the heating state is maintained until the requirements are met, ensuring that the surface temperature of the workpiece 11 is uniform and providing a stable foundation for the spraying process. After preheating, the control unit of the hot air gun 3 drives the cylinder 12 and the slide table 13 to operate synchronously, so that the hot air gun 3 moves to the heating position of the workpiece 11 in the horizontal and vertical directions, and the positioning status of the hot air gun 3 is detected in real time by the horizontal position sensor and the vertical position sensor to ensure that the hot air gun 3 is accurately positioned. After positioning, the system starts the heating process, continuously raising the temperature of the workpiece 11 through the heating element, maintaining the heating temperature within the set range, and dynamically adjusting the heating power according to the feedback of the temperature sensor to ensure the stability and safety of the heating process. After heating is completed, the hot air gun 3 is moved vertically upward by the slide table 13 to a safe height, making room for the spraying operation. The spray gun 4 control unit controls the cylinder 12 and slide 13 to move the spray gun 4 to the spraying position. Simultaneously, it dynamically adjusts the spraying angle of the spray gun 4 based on the workpiece surface geometry, ensuring the spray gun axis is aligned with the normal direction of the workpiece surface. After angle adjustment, the spray gun 4 control unit initiates the spraying process. The paint delivery pump and atomizing air source spray according to set parameters. The pressure sensor monitors and adjusts the spraying pressure in real time to ensure uniform coating thickness and a smooth surface. During spraying, the moving speed of the spray gun 4 is controlled between 50mm / s and 80mm / s, and the spraying height is controlled at approximately 150mm. Through a dynamic angle adjustment mechanism, the spraying angle is always kept within the optimal range, thereby achieving precise control of the coating thickness at 10±2μm. After spraying, the spray gun 4 moves vertically upwards to a safe height, completing one cycle of the heating and spraying process. The cycle control unit automatically repeats the heating of the hot air gun 3 and the spraying of the spray gun 4 according to the preset number of cycles until the operation ends.

[0028] Through the above scheme, the temperature judgment unit of this application collects the air outlet temperature in real time through a high-precision temperature sensor installed at the air outlet of the hot air gun 3, and compares the collected real-time temperature value with the preset temperature threshold to determine whether the hot air gun 3 has reached the preheating condition. This ensures that the surface of the workpiece 11 obtains a uniform and stable initial temperature before spraying, avoiding the decrease in coating adhesion or the generation of surface defects due to local temperature differences. The horizontal position sensor and the vertical position sensor provide real-time feedback on the precise position of the hot air gun 3, ensuring that the hot air gun 3 is accurately positioned. When the hot air gun 3 reaches the heating position, the heating process begins. The set temperature range is maintained through closed-loop temperature control, and the power of the heating element is adjusted in real time to uniformly raise the surface temperature of the workpiece 11 to the required value. At the same time, the slide table 13 controls the hot air gun 3 to move vertically upward to a safe height, preventing equipment collision and thermal damage. This heating process can precisely control the heating time, heating rate, and surface temperature gradient, thereby improving the adhesion and uniformity between the coating and the substrate. During the spraying process, the paint delivery pump and atomizing air source output stably according to preset parameters. A pressure sensor monitors the spraying pressure in real time. When the pressure deviation exceeds a set threshold, the control system automatically adjusts the pump speed or air source pressure to ensure uniform coating thickness and a smooth surface. After spraying, the slide table 13 moves the spray gun 4 vertically upwards to a safe height, providing space for the next cycle and preventing paint dripping or equipment damage. The cycle control unit manages the repeated operations of heating the hot air gun 3 and spraying with the spray gun 4. It can set the number of cycles and the spraying time for each round according to process requirements, achieving multi-round precise spraying.

[0029] This application further proposes a temperature judgment unit that compares the real-time temperature value with a temperature threshold to determine whether the hot air gun 3 has completed preheating, including: The temperature sensor is a thermocouple sensor. The temperature judgment unit receives the real-time temperature signal from the air outlet of the hot air gun 3 based on the thermocouple sensor, and converts the real-time temperature signal into a digital temperature value through the signal conditioning circuit; the digital temperature value is then compared with the temperature threshold. When the digital temperature value is less than or equal to the temperature threshold, it is determined that the preheating of the hot air gun 3 is not complete, and the preheating of the hot air gun 3 continues. When the digital temperature value is greater than the temperature threshold, the preheating of the hot air gun 3 is considered complete.

[0030] Specifically, a thermocouple sensor installed at the outlet of the hot air gun 3 continuously collects real-time temperature signals. This sensor can quickly respond to temperature changes in high-temperature environments and outputs an analog voltage signal to the temperature judgment unit. After receiving the thermocouple signal, the temperature judgment unit amplifies, filters, and linearizes the analog signal through its built-in signal conditioning circuit, converting it into a digital temperature value for accurate calculation and judgment by the central controller. The converted digital temperature value is compared with a preset temperature threshold in real time. When the digital temperature value is less than or equal to the set threshold, it is determined that the hot air gun 3 is still in the preheating stage. The central controller continues to maintain the heating element's working state and dynamically adjusts the heating power to compensate for temperature fluctuations or environmental cooling effects, thereby ensuring that the temperature of the hot air gun 3 continues to rise and is evenly distributed. When the digital temperature value is greater than the preset temperature threshold, the temperature judgment unit determines that the hot air gun 3 has completed preheating. At this time, the central controller issues a command to start the next stage of operation, such as driving the cylinder 12 and the slide 13 to move the hot air gun 3 to the heating or spraying position. During the preheating process, the temperature judgment unit samples temperature data at a millisecond frequency, records the temperature change curve in real time, and calculates the temperature rise rate and steady-state temperature deviation to ensure accurate temperature control of the hot air gun 3 throughout the preheating process, while avoiding overheating that could damage components or cause localized overheating on the surface of the workpiece 11. Through this high-precision, multi-level feedback temperature control method, the equipment can achieve rapid and stable preheating of the hot air gun 3.

[0031] Through the above scheme, this application not only shortens the preheating time and improves the thermal energy utilization efficiency through the temperature judgment mechanism, but also ensures that the surface temperature of the workpiece 11 is uniformly distributed, providing a stable temperature basis for subsequent spraying or processing, while reducing the risk of poor coating adhesion or damage to the workpiece 11 caused by insufficient temperature or overheating.

[0032] This application further proposes that the control unit of the hot air gun 3 controls the cylinder 12 and the slide 13 to move the hot air gun 3 towards the heating position, and determines whether the movement towards the heating position is complete based on the horizontal position sensor and the vertical position sensor, including: The hot air gun 3 control unit outputs an air path switching signal to the cylinder 12 drive circuit through the solenoid valve control port; the cylinder 12 drive circuit controls the intake solenoid valve to open and the outlet solenoid valve to close, driving the piston rod of the cylinder 12 to move horizontally, causing the hot air gun 3 to move horizontally above the workpiece 11, and determines whether the hot air gun 3 has moved horizontally to the positioning position above the workpiece 11 based on the horizontal position sensor; when it is determined that the hot air gun 3 has moved horizontally to the positioning position above the workpiece 11, a horizontal positioning signal is generated, and the hot air gun 3 control unit performs an air path locking operation based on the horizontal positioning signal.

[0033] Specifically, the hot air gun 3 control unit, based on instructions from the central controller, sends an air path switching signal to the cylinder 12 drive circuit via the solenoid valve control port. Upon receiving the signal, the cylinder 12 drive circuit controls the inlet solenoid valve to open and the outlet solenoid valve to close, causing the piston rod of cylinder 12 to move smoothly horizontally, simultaneously moving the hot air gun 3 upwards along the X-axis towards the workpiece 11. During this movement, a horizontal position sensor continuously collects the real-time horizontal position of the hot air gun 3 and continuously compares the collected data with the preset positioning coordinates above the workpiece 11. When the hot air gun 3 reaches the predetermined horizontal position, the horizontal position sensor feeds back a horizontal alignment signal to the hot air gun 3 control unit, which immediately executes an air path locking operation, stopping the movement of cylinder 12 and ensuring that the hot air gun 3 remains stably suspended horizontally. This closed-loop position control achieves high-precision positioning of the hot air gun 3 during horizontal movement, avoiding deviations caused by the inertia or vibration of cylinder 12.

[0034] Through the above-described scheme, this application achieves high precision and stability in the horizontal movement of the hot air gun 3 by using cylinder 12 drive and closed-loop feedback from a high-precision horizontal position sensor. This improves the uniformity and efficiency of heating the workpiece 11, and avoids defects caused by localized overheating or unheated areas of the workpiece 11. Air path locking ensures that the hot air gun 3 remains stably suspended in a horizontal position, providing reliable support for vertical movement and spraying, improving the consistency and safety of the overall spraying process, and reducing human intervention.

[0035] This application further proposes that when the control unit of the hot air gun 3 controls the cylinder 12 and the slide 13 to move the hot air gun 3 to the heating position, and determines whether the movement to the heating position is complete based on the horizontal position sensor and the vertical position sensor, it also includes: The hot air gun 3 control unit outputs a pulse signal to the slide table 13 driver through the stepper motor 10 drive port; the slide table 13 driver controls the stepper motor 10 to rotate, driving the lead screw transmission mechanism to move the slide table 13 vertically downward; driving the hot air gun 3 vertically downward to the inside of the workpiece 11, and judging whether the hot air gun 3 has moved vertically to the internal heating position on the workpiece 11 based on the vertical position sensor; when it is determined that the hot air gun 3 has moved vertically to the internal heating position on the workpiece 11, a vertical positioning signal is generated, and the hot air gun 3 control unit stops the motor 10 according to the vertical positioning signal.

[0036] Specifically, the hot air gun 3 control unit sends precise pulse signals to the slide table 13 driver via the stepper motor 10 drive port. Upon receiving the signal, the slide table 13 driver controls the stepper motor 10 to rotate at a predetermined step distance, driving the lead screw transmission mechanism to move vertically downwards along the Z-axis. This allows the slide table 13 as a whole and the hot air gun 3 mounted on it to move precisely towards the surface and interior of the workpiece 11. During this movement, a vertical position sensor continuously collects the current position of the hot air gun 3 and compares it with the preset internal heating position coordinates on the workpiece 11. When the sensor detects that the hot air gun 3 has reached the target height, it generates a vertical positioning signal and feeds it back to the hot air gun 3 control unit. Upon receiving the signal, the control unit immediately stops the stepper motor 10 to ensure the hot air gun 3 is precisely positioned vertically, preventing overtravel or deviation, and ensuring uniform heating inside the workpiece 11.

[0037] Through the above scheme, this application achieves high-precision controllable movement of the hot air gun 3 in the vertical direction by driving the slide table 13 and the lead screw transmission mechanism through the stepper motor 10, ensuring that the internal heating position of the workpiece 11 is accurate and uniform, avoiding uneven heating or local overheating caused by offset or vibration, and improving the coating adhesion quality and process stability of the surface and internal coating of the workpiece 11.

[0038] This application further proposes that when the hot air gun 3 control unit performs heating treatment, it includes: The hot air gun 3 control unit outputs a heating start signal through the hot air gun 3 control port; the hot air gun 3 control circuit connects the power supply to the heating element to maintain the heating temperature threshold, and the temperature sensor provides real-time feedback on the heating temperature value; when the heating time equals the heating duration threshold, the hot air gun 3 control unit stops the heating process.

[0039] Specifically, the hot air gun 3 control unit sends a heating start signal to the hot air gun 3 control circuit via the control port, triggering the heating element to operate. The heating element begins to deliver heat to the hot air gun 3 outlet, rapidly raising the airflow temperature to the preset temperature threshold. A temperature sensor monitors the hot air outlet temperature in real time, feeding the temperature data back to the hot air gun 3 control unit at a millisecond sampling frequency. The control unit performs closed-loop adjustment based on the sensor data and the preset temperature threshold, adjusting the heating element power or on / off state to ensure the hot air gun 3 outlet temperature remains stable within the target range, while preventing temperature overshoot or undershoot. When the heating time reaches the heating duration threshold, the control unit automatically cuts off the heating signal, stopping the heating process and completing the entire heating cycle, ensuring uniform heating of the workpiece 11's surface and interior.

[0040] Through the above scheme, this application achieves high-precision stability of the outlet temperature of the hot air gun 3 by real-time closed-loop monitoring and precise heating time control, ensuring uniform surface temperature of the workpiece 11, avoiding local overheating or underheating, and improving coating adhesion and uniformity.

[0041] This application further proposes that when the hot air gun 3 control unit maintains the heating temperature threshold and the temperature sensor provides real-time feedback of the heating temperature value, it includes: The heating temperature threshold includes a first heating temperature threshold and a second heating temperature threshold, where the first heating temperature threshold is less than the second heating temperature threshold; the heating temperature value is then compared numerically with the first heating temperature threshold and the second heating temperature threshold, respectively; When the heating temperature is less than the first heating temperature threshold, the heating time is recalculated, and the extended heating time is calculated based on the temperature difference and the heating rate. When the heating temperature value is greater than or equal to the first heating temperature threshold and less than or equal to the second heating temperature threshold, maintain the current heating temperature value and continue heating. When the heating temperature value is greater than the second heating temperature threshold, the heating temperature value is adjusted by reducing the power output of the heating element to bring the heating temperature value between the first heating temperature threshold and the second heating temperature threshold.

[0042] Specifically, during the maintenance of the heating temperature threshold, the hot air gun 3 control unit sets a first heating temperature threshold and a second heating temperature threshold, wherein the first heating temperature threshold is lower than the second heating temperature threshold. A temperature sensor collects the outlet temperature of the hot air gun 3 at a high frequency in real time and feeds the data back to the control unit. The control unit compares the real-time temperature value with the two thresholds: when the temperature is lower than the first threshold, it indicates insufficient heating; the control unit recalculates the required extended heating time based on the temperature difference and heating rate, and automatically extends the heating process; when the temperature is between the two thresholds, it indicates that the heating temperature has reached the ideal range; the control unit maintains the current heating power and continues heating until the preset heating time is completed; when the temperature exceeds the second threshold, it indicates excessive heating; the control unit adjusts the temperature between the first and second thresholds by reducing the power output of the heating element, thereby preventing localized overheating and damage to the workpiece 11 surface, and maintaining overall temperature uniformity.

[0043] Through the above scheme, this application achieves stable control of the outlet temperature of the hot air gun 3 by adjusting the dual threshold precision, avoiding insufficient heating due to excessively low temperature or damage to the workpiece 11 due to excessively high temperature, ensuring uniform temperature on the surface and inside of the workpiece 11, and improving the adhesion and uniformity of the coating.

[0044] This application further proposes that when the spray gun control unit dynamically adjusts the spraying angle of the spray gun 4 based on the geometric features of the workpiece surface, it includes: The spray gun control unit outputs an angle control signal to the angle driver through the angle adjustment mechanism drive port. The angle driver calculates the target spraying angle of the spray gun 4 at the current position based on the three-dimensional geometric model of the workpiece and feedback from the real-time position sensor, so that the axis of the spray gun 4 is consistent with the normal direction of the workpiece surface. The servo motor is driven to rotate, which drives the angle adjustment mechanism to dynamically adjust the angle of the spray gun 4. The angle sensor detects the actual spraying angle value in real time. When the deviation between the actual spraying angle value and the target spraying angle value is less than the angle tolerance threshold, the angle adjustment is determined to be completed, and an angle arrival signal is generated.

[0045] Specifically, the spray gun control unit outputs an angle control signal to the angle driver via the angle adjustment mechanism drive port. The angle driver, based on the workpiece's three-dimensional geometric model and feedback from a real-time position sensor, calculates the target spraying angle of the spray gun at its current position, ensuring the spray gun axis aligns with the normal direction of the workpiece surface. It then drives a servo motor to rotate, causing the angle adjustment mechanism to dynamically adjust the spray gun angle. The angle sensor continuously monitors the actual spraying angle value; when the deviation between the actual and target spraying angle values ​​is less than the angle tolerance threshold, the angle adjustment is considered complete, and an angle arrival signal is generated. In practice, the angle driver first acquires the workpiece's three-dimensional geometric model data (which can be pre-imported or obtained through scanning), and combines this with the spray gun's current position information from the real-time position sensor to calculate the normal direction of the workpiece surface at that position, thus determining the target spraying angle. The servo motor precisely drives the angle adjustment mechanism based on the calculation results, achieving dynamic adjustment of the spray gun angle. The angle sensor continuously monitors the actual angle value and compares it with the target angle value; when the deviation is less than the set tolerance threshold (e.g., ±2°), the angle adjustment is considered complete. This closed-loop control mechanism ensures the accuracy and reliability of the angle adjustment.

[0046] By employing the above-described solution, this application addresses a significant challenge faced by traditional thermal spraying equipment when processing complex curved workpieces (such as engine bearings). Traditional equipment typically uses a fixed spraying angle (e.g., 80°), which cannot adapt to variations in the workpiece surface curvature. This results in significant differences in spraying effects at different locations on the curved inner surface of the bearing: when the angle between the spray gun axis and the workpiece surface normal is too large, the coating particle deposition efficiency decreases, and adhesion declines; when the angle is too small, coating accumulation and uneven thickness easily occur. This invention, by calculating and adjusting the spray gun angle in real time, ensures that the spray gun axis remains aligned with the workpiece surface normal throughout the entire spraying process, thereby guaranteeing uniform coating distribution and optimal adhesion on complex curved surfaces.

[0047] This application further proposes that when the spray gun control unit performs spraying treatment, it includes: The spray gun control unit outputs a spraying start signal through the spray gun 4 control port; the spray gun 4 control circuit connects the paint delivery pump and the atomizing gas source, and detects the spraying pressure value in real time based on the pressure sensor; when the spraying time is equal to the spraying duration threshold, the spray gun control unit stops the spraying process.

[0048] Specifically, the spray gun control unit first sends a spraying start signal through the control port, triggering the spray gun 4 control circuit to connect the paint delivery pump and the atomizing air source, ensuring that the paint is evenly delivered to the nozzle of the spray gun 4. Simultaneously, the atomizing air source is activated to create a high-pressure airflow, fully atomizing the paint particles and ensuring uniform coverage of the sprayed surface. A pressure sensor collects the pressure value of the spraying system in real time and feeds it back to the control unit. The spray gun 4 control unit adjusts the paint pump speed or the atomizing air source pressure according to pressure changes to maintain stable spraying pressure, ensuring uniform spray thickness and reliable adhesion. When the spraying time reaches the preset spraying duration threshold, the control unit automatically shuts off the spraying signal, stopping the paint delivery and air supply, completing the current spraying cycle.

[0049] Through the above scheme, this application uses a real-time pressure feedback and automatic adjustment mechanism to precisely maintain the spraying pressure, thus avoiding problems such as uneven spraying thickness or insufficient coating adhesion.

[0050] This application further proposes a cyclic process control unit that cyclically executes the operation process of heating with hot air gun 3 and spraying with spray gun 4 until the end of the operation, including: The cycle process control unit sets the initial value of the cycle counter. After each hot air gun 3 heating treatment and spray gun 4 spraying treatment is completed, the cycle counter increments. The cycle count value of the cycle counter is compared with the cycle count threshold. When the cycle count value is less than the cycle count threshold, it is determined that the heating treatment and spraying treatment should be repeated. When the cycle count value is equal to the cycle count threshold, it is determined that the operation has ended.

[0051] Specifically, the cycle control unit is responsible for the overall process cycle management. After the system starts, the cycle counter is initialized to zero to record the number of heating and spraying cycles completed. Each time the hot air gun 3 completes a preheating cycle and reaches the set temperature threshold, and the spray gun 4 completes a spraying cycle and maintains the preset spraying pressure value, the cycle counter automatically increments by 1. The control unit then compares the current cycle count with the preset cycle count threshold. If the current cycle count is less than the threshold, it is determined that the overall process flow has not been completed, and the system automatically restarts the hot air gun 3 for preheating and the spray gun 4 for spraying to continue the next cycle. When the cycle count reaches the threshold, the control unit determines that the processing flow has ended and performs safety reset and stop operations on each piece of equipment.

[0052] Through the above scheme, this application can accurately control the number of coating layers and the overall spraying process sequence by using the automatic counting and judgment mechanism of the cyclic process control unit, ensuring the integrity and consistency of each round of heating and spraying, improving the uniformity of coating thickness and surface density, and realizing a repeatable automated coating preparation process.

[0053] In the above scheme, the temperature threshold is used to determine whether the hot air gun has completed preheating. Its setting is based on the activation temperature of the spraying material and the suitable heating range of the workpiece substrate. For example, for polymer coatings such as polyimide, the hot air outlet temperature needs to reach a range where the material is sufficiently softened but not decomposed (e.g., 550°C~650°C) to ensure good adhesion to the workpiece surface during subsequent spraying. The first heating temperature threshold and the second heating temperature threshold (dual-threshold temperature control) are set to a reasonable temperature range (e.g., first threshold 500°C, second threshold 550°C) to dynamically maintain temperature stability during the heating process. This range is slightly lower than the preheating temperature threshold, leaving an adjustment margin to avoid frequent starting and stopping of the heating element and to prevent overheating damage to the workpiece or coating. The angle tolerance threshold (angle adjustment completion determination) represents the maximum allowable deviation (e.g., ±2°) between the actual spraying angle and the target angle, set according to the spray gun atomization cone angle and coating uniformity requirements. Too large a tolerance will affect the spraying quality, while too small a tolerance may cause servo system oscillation. The optimal tolerance range is usually determined through trial spraying tests. The first and second spraying pressure thresholds (pressure closed-loop control) are set within a working pressure range (e.g., 0.5MPa~0.6MPa) based on the coating type, viscosity, and atomization requirements. This range ensures sufficient powder atomization and high deposition efficiency; exceeding this range can easily lead to splashing or accumulation, requiring optimization through atomization experiments. The heating time threshold, spraying time threshold, and cycle number threshold are all set based on process experimental data. The heating time ensures sufficient surface heating of the workpiece; the spraying time controls the thickness of a single coating layer; and the cycle number determines the total coating thickness. These three factors work together to achieve a final coating thickness within the range of 10±2μm. In summary, all thresholds are not fixed but are set for specific workpieces (e.g., engine bearings) and coating materials to match the process, and can be flexibly adjusted through a human-machine interface, reflecting the system's adaptability and intelligence.

[0054] In summary, this equipment employs multi-sensor fusion technology to achieve real-time monitoring and closed-loop control of key parameters such as hot air gun preheating temperature, heating temperature, spray gun position, spraying angle, and pressure, thereby improving coating uniformity and adhesion. Particularly for workpieces with complex curved surfaces, such as engine bearings, this invention creatively proposes a technical solution for dynamically adjusting the spray gun's spraying angle based on the workpiece's surface geometry. Through an angle driver, based on the workpiece's three-dimensional geometric model and real-time position sensor feedback, the target spraying angle of the spray gun at the current position is precisely calculated and adjusted, ensuring that the spray gun axis is always aligned with the workpiece surface normal. This solves the problems of uneven coating thickness and adhesion differences caused by fixed-angle spraying in traditional equipment, keeping the spraying angle consistently within the optimal range of 75°~90°, thus improving the tribological properties of the inner arc surface coating of the bearing. This equipment, through a collaborative control mechanism between the hot air gun and the spray gun, achieves seamless integration of heating and spraying, improving the bonding strength between the coating and the substrate. The temperature judgment unit uses a thermocouple sensor and signal conditioning circuit to convert real-time temperature signals into digital temperature values ​​for precise comparison, ensuring that subsequent operations are only performed after the hot air gun has been preheated. The hot air gun control unit employs a dual-threshold control strategy with a first heating temperature threshold and a second heating temperature threshold. When the heating temperature deviates from the ideal range, it automatically adjusts the heating time or power to ensure that the workpiece surface temperature is uniformly and stably within the optimal spraying range, avoiding coating defects caused by localized overheating or underheating. The spray gun control unit monitors the spraying pressure in real time through a pressure sensor and uses a dual-threshold pressure control mechanism. When the pressure deviates from the set range, it automatically adjusts the paint delivery pump speed or atomizing gas source pressure to ensure that the spraying pressure is stable within the ideal range, allowing the coating thickness to be precisely controlled within the range of 10±2μm, meeting the requirements of high-performance coatings. This equipment employs a bidirectional drive structure combining cylinders and a sliding table, achieving high-precision horizontal and vertical positioning of the hot air gun and spray gun. Position control accuracy reaches ±0.2mm. Combined with precise control of the rotating mechanism, the spray gun's movement speed is stabilized between 50mm / s and 80mm / s, and the spraying height is precisely controlled at approximately 150mm, ensuring accurate spraying trajectory and uniform coating. The cyclic process control unit automatically manages the multi-layer spraying process through a cycle counter, ensuring the integrity and consistency of each round of heating and spraying, improving the controllability of coating thickness and surface density. The entire equipment boasts a high degree of automation, reducing manual intervention, improving production efficiency and product consistency, and lowering the labor intensity and safety risks for operators.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A high-performance thermal spraying equipment for coating based on multi-sensor closed-loop control, characterized in that, Includes a table, a rotating mechanism, a clamp, a horizontal moving mechanism, a vertical moving mechanism, a hot air gun, a spray gun, and an electromechanical control system; The platform serves as the supporting foundation for the equipment. The rotating mechanism includes a rotating platform, a rotating shaft, a large pulley, a small pulley, a belt, and a motor. The rotating platform is mounted on the platform via the rotating shaft. The motor drives the large pulley via the small pulley connected to the belt, thereby driving the rotating shaft and the rotating platform to rotate. The clamp is mounted on the rotating platform to fix the workpiece. The horizontal movement mechanism is a cylinder mounted on the platform to drive the hot air gun and spray gun to move horizontally. The vertical movement mechanism is a slide table connected to the cylinder to drive the hot air gun and spray gun to move vertically. The spray gun also includes an angle adjustment mechanism to adjust the spraying angle. The electromechanical control system includes a central controller, a temperature sensor, and a position sensor. The temperature sensor is installed at the air outlet of the hot air gun. The position sensor includes a horizontal position sensor, a vertical position sensor, and an angle sensor. The horizontal position sensor is installed at the end of the cylinder stroke. The vertical position sensor is installed on the slide rail, and the angle sensor is installed on the angle adjustment mechanism. The electromechanical control system is electrically connected to the motor, cylinder, slide, hot air gun, and spray gun, and controls the operation of the motor, cylinder, slide, hot air gun, and spray gun based on the data collected by the temperature sensor, position sensor, and angle sensor.

2. The high-performance coating thermal spraying equipment based on multi-sensor closed-loop control according to claim 1, characterized in that, The central controller includes a temperature judgment unit, a hot air gun control unit, a spray gun control unit, and a circulation process control unit; The temperature judgment unit is used to collect the real-time temperature value of the hot air gun nozzle based on the temperature sensor, and compare the real-time temperature value with the temperature threshold to determine whether the hot air gun has completed preheating. The hot air gun control unit is used to control the cylinder and slide to move the hot air gun to the heating position when it is determined that the hot air gun has finished preheating, and to determine whether the movement to the heating position is completed based on the horizontal position sensor and the vertical position sensor; when it is determined that the movement to the heating position is completed, the heating process is performed. After heating is complete, control the slide to move the hot air gun vertically upward to a safe height; The spray gun control unit is used to control the operation of the cylinder, slide, and angle adjustment mechanism to move the spray gun to the spraying position, and dynamically adjust the spraying angle of the spray gun based on the geometric features of the workpiece surface; after determining that the spray gun position and angle adjustment are completed, the spraying process is performed. After the spraying is completed, control the slide to move the spray gun vertically upward to a safe height; The cycle process control unit is used to cycle through the operation process of hot air gun heating and spray gun spraying until the operation is completed.

3. The high-performance coating thermal spraying equipment based on multi-sensor closed-loop control according to claim 2, characterized in that, The temperature judgment unit compares the real-time temperature value with a temperature threshold to determine whether the hot air gun has completed preheating, including: The temperature sensor is a thermocouple sensor. The temperature judgment unit receives the real-time temperature signal from the hot air gun outlet based on the thermocouple sensor, and converts the real-time temperature signal into a digital temperature value through a signal conditioning circuit; the digital temperature value is then compared with the temperature threshold. When the digital temperature value is less than or equal to the temperature threshold, it is determined that the hot air gun preheating is not complete, and the hot air gun preheating continues. When the digital temperature value is greater than the temperature threshold, it is determined that the hot air gun has completed preheating.

4. The high-performance coating thermal spraying equipment based on multi-sensor closed-loop control according to claim 3, characterized in that, The hot air gun control unit controls the cylinder and slide to move the hot air gun towards the heating position, and determines whether the movement towards the heating position is complete based on the horizontal and vertical position sensors, including: The hot air gun control unit outputs an air path switching signal to the cylinder drive circuit through the solenoid valve control port. The cylinder drive circuit controls the intake solenoid valve to open and the outlet solenoid valve to close, driving the cylinder piston rod to move horizontally, thereby moving the hot air gun horizontally above the workpiece. Based on the horizontal position sensor, it determines whether the hot air gun has moved horizontally to the positioning position above the workpiece. When it is determined that the hot air gun has moved horizontally to the positioning position above the workpiece, a horizontal positioning signal is generated, and the hot air gun control unit performs an air path locking operation based on the horizontal positioning signal.

5. A high-performance coating thermal spraying device based on multi-sensor closed-loop control according to claim 4, characterized in that, The hot air gun control unit controls the cylinder and slide to move the hot air gun towards the heating position, and, based on the horizontal and vertical position sensors, determines whether the movement towards the heating position is complete, also includes: The hot air gun control unit outputs a pulse signal to the slide driver via the stepper motor drive port; the slide driver controls the stepper motor to rotate, driving the lead screw transmission mechanism to move the slide vertically downward; this causes the hot air gun to move vertically downward into the workpiece, and the vertical position sensor determines whether the hot air gun has moved vertically to the internal heating position on the workpiece; when it is determined that the hot air gun has moved vertically to the internal heating position on the workpiece, a vertical positioning signal is generated, and the hot air gun control unit stops the motor according to the vertical positioning signal.

6. A high-performance coating thermal spraying device based on multi-sensor closed-loop control according to claim 5, characterized in that, When the hot air gun control unit performs the heating process, it includes: The hot air gun control unit outputs a heating start signal through the hot air gun control port; the hot air gun control circuit connects the power supply to the heating element to maintain the heating temperature threshold, and the temperature sensor provides real-time feedback of the heating temperature value; when the heating time equals the heating duration threshold, the hot air gun control unit stops the heating process.

7. A high-performance coating thermal spraying device based on multi-sensor closed-loop control according to claim 6, characterized in that, When the hot air gun control unit maintains the heating temperature threshold and the temperature sensor provides real-time feedback of the heating temperature value, it includes: The heating temperature threshold includes a first heating temperature threshold and a second heating temperature threshold, wherein the first heating temperature threshold is less than the second heating temperature threshold; the heating temperature value is compared with the first heating temperature threshold and the second heating temperature threshold respectively; When the heating temperature value is less than the first heating temperature threshold, the heating time is recalculated, and the extended heating time is calculated based on the temperature difference and the heating rate. When the heating temperature value is greater than or equal to the first heating temperature threshold and less than or equal to the second heating temperature threshold, the current heating temperature value is maintained and the heating process continues. When the heating temperature value is greater than the second heating temperature threshold, the heating temperature value is adjusted by reducing the power output of the heating element to bring the heating temperature value between the first heating temperature threshold and the second heating temperature threshold.

8. A high-performance coating thermal spraying device based on multi-sensor closed-loop control according to claim 7, characterized in that, When the spray gun control unit dynamically adjusts the spray angle of the spray gun based on the geometric features of the workpiece surface, it includes: The spray gun control unit outputs an angle control signal to the angle driver through the angle adjustment mechanism drive port. The angle driver calculates the target spraying angle of the spray gun at the current position based on the three-dimensional geometric model of the workpiece and feedback from the real-time position sensor, so that the spray gun axis is consistent with the normal direction of the workpiece surface. It drives the servo motor to rotate, thereby driving the angle adjustment mechanism to dynamically adjust the spray gun angle. The angle sensor detects the actual spraying angle value in real time. When the deviation between the actual spraying angle value and the target spraying angle value is less than the angle tolerance threshold, it determines that the angle adjustment is complete and generates an angle arrival signal.

9. A high-performance coating thermal spraying device based on multi-sensor closed-loop control according to claim 8, characterized in that, When the spray gun control unit performs the spraying process, it includes: The spray gun control unit outputs a spraying start signal through the spray gun control port; the spray gun control circuit connects the paint delivery pump and the atomizing gas source, and detects the spraying pressure value in real time based on the pressure sensor; when the spraying time is equal to the spraying duration threshold, the spray gun control unit stops the spraying process.

10. A high-performance coating thermal spraying device based on multi-sensor closed-loop control according to claim 9, characterized in that, The cycle control unit cyclically executes the hot air gun heating and spray gun spraying operation process until the end of the operation, including: The cycle process control unit sets an initial value for the cycle counter. After each hot air gun heating treatment and spray gun spraying treatment is completed, the cycle counter increments. The cycle count value of the cycle counter is compared with the cycle count threshold. When the cycle count value is less than the cycle count threshold, it is determined that the heating treatment and spraying treatment should be repeated. When the cycle count value is equal to the cycle count threshold, it is determined that the operation has ended.

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