An automatic glue coating and curing system for mechanical seal assembly and method of using the same

Abstract

This invention relates to an automatic adhesive application and curing system for mechanical seal components and its application method, belonging to the field of automated manufacturing technology for mechanical seals. It includes a machine base, a workpiece positioning device, an adhesive application device, a curing device, and a control system. The adhesive application device comprises a vision-monitored quantitative adhesive application mechanism and a three-dimensional vision inspection module. The latter outputs the width, height, and positional deviation of the adhesive strip in real time at a refresh rate of no less than Hz. The control system includes a data comparison unit, a PID control unit, and a hysteresis compensation unit. The hysteresis compensation unit calculates the detection hysteresis time based on the spatial distance between the sensor installation position and the adhesive application point, as well as the adhesive application speed, and generates a compensated deviation signal. The PID control unit dynamically adjusts the adhesive dispensing amount accordingly. This invention overcomes the closed-loop instability problem caused by detection hysteresis in traditional adhesive application systems by integrating high-speed three-dimensional vision inspection with hysteresis compensation PID control, improving the adhesive application accuracy and consistency, and is compatible with various sealants and workpiece materials.

Description

Technical Field

[0001] This invention relates to the field of automated manufacturing technology for mechanical seals, and in particular to an automated adhesive application and curing system for mechanical seal components and its application method. Background Technology

[0002] Mechanical seals are key sealing components in chemical equipment, automotive engines, pumps, and rotating machinery. Their sealing performance directly affects the safe operation and service life of the equipment. In the manufacturing process of mechanical seal components, the application of sealant is one of the core processes that determines the sealing effect.

[0003] Traditional adhesive application for mechanical seal components mainly presents the following technical problems: Firstly, in manual glue application, the amount of glue cannot be precisely controlled, and the amount of glue applied each time is difficult to remain consistent, which easily leads to uneven glue application and directly affects the sealing quality. Moreover, it is inefficient, and the pass rate of manual glue application is low for sealing surfaces with irregular shapes and high edge precision requirements.

[0004] Secondly, in traditional automated adhesive application methods, the system of pneumatic pressure regulating valves combined with switching valves lacks a precise metering mechanism, making it difficult to guarantee the accuracy of adhesive application; while screw valve adhesive application systems suffer from severe equipment wear, short lifespan of sealants (on average, they need to be replaced every half month), and high maintenance costs when handling high-viscosity sealants.

[0005] Third, existing glue application systems generally lack online quality inspection and real-time closed-loop adjustment functions. Quality judgment after glue application often relies on manual visual inspection or offline equipment sampling inspection, which cannot achieve real-time feedback. When abnormalities such as glue strip width or continuity occur, they are often only discovered in subsequent processes, resulting in high rework costs and low production efficiency.

[0006] Fourth, although servo quantitative dispensing devices and 3D vision inspection devices have emerged in recent years, they are mostly independent functional modules with low detection frequencies (usually single detection after dispensing or intermittent detection below 10Hz). They cannot capture dynamic deviations caused by instantaneous fluctuations in adhesive viscosity, microscopic unevenness of the workpiece surface, or temperature changes during the dispensing process. More importantly, existing technical solutions have not solved the inherent problem of visual detection lag. Due to physical installation limitations, the scanning area of ​​3D line laser sensors inevitably lags behind the dispensing point by a certain distance (usually 15~30mm). This lag time (100~300ms) is not negligible compared to the closed-loop control cycle (below 20ms). Conventional PID control is prone to overshoot or oscillation in such pure lag systems, leading to closed-loop failure. Existing technologies do not offer a solution that deeply integrates high-frequency visual detection with lag-compensated PID control and applies it to the dispensing closed loop.

[0007] Therefore, there is an urgent need to develop a closed-loop control system that can overcome the effects of detection lag and achieve high-frequency real-time detection and dynamic correction in the coating process, so as to fundamentally solve the technical problem that deviations cannot be corrected in real time and the lag leads to system instability in open-loop or low-frequency feedback coating processes. Summary of the Invention

[0008] This invention provides an automatic adhesive application and curing system for mechanical seal components and its application method, which solves the problems mentioned in the background art. By deeply integrating three-dimensional vision online detection with a refresh rate of not less than 50Hz, a hysteresis compensation unit and PID closed-loop control, the system achieves high-frequency dynamic real-time correction of the adhesive strip size during the adhesive application process while overcoming the influence of detection hysteresis. This significantly improves the adhesive application accuracy and product consistency, and is especially suitable for the manufacturing of mechanical seal components with stringent sealing performance requirements.

[0009] The present invention provides the following solution to the above-mentioned technical problems: an automatic adhesive application and curing system for mechanical seal components and a method thereof, comprising a machine base, a workpiece positioning device, an adhesive application device, a curing device, and a control system.

[0010] The workpiece positioning device, the glue application device, and the curing device are all fixedly installed on the machine base.

[0011] The workpiece positioning device is used to clamp and position the mechanical seal workpiece to be coated with adhesive.

[0012] The adhesive application device includes a visual monitoring quantitative adhesive application mechanism and a three-dimensional vision detection module. The visual monitoring quantitative adhesive application mechanism is used to output sealant in a controlled manner during the adhesive application process. The three-dimensional vision detection module is used to perform online three-dimensional morphology detection on the adhesive strip after application, and to obtain data on the actual width, actual height, continuity, and actual positional deviation of the adhesive strip.

[0013] The curing device includes a UV curing unit and a heat curing unit. The UV curing unit is used to rapidly cure UV-curable sealants, and the heat curing unit is used to heat-cur thermosetting sealants.

[0014] The control system is electrically connected to the workpiece positioning device, the adhesive application device, and the curing device, respectively.

[0015] The three-dimensional vision inspection module includes a 3D line laser sensor and an image processing unit. The image processing unit continuously outputs the actual width, actual height, and actual position deviation data of the adhesive strip to the control system at a refresh rate of not less than 50Hz.

[0016] The control system includes a data comparison unit, a PID control unit, and a hysteresis compensation unit.

[0017] The data comparison unit is used to compare the actual width and actual height of the adhesive strip acquired in real time by the three-dimensional vision detection module with preset width thresholds and height thresholds, respectively, and generate a deviation signal.

[0018] The hysteresis compensation unit calculates the detection hysteresis time based on the spatial distance between the installation position of the 3D line laser sensor and the adhesive application point, and the current adhesive application speed, and generates the compensated deviation signal e_compensated(t) according to the following formula: e_compensated(t) = W_target - [W_actual(t) + K_comp(u(t) - u(t-(t)))] Where W_target is the target value of the adhesive strip width, W_actual(t) is the actual width detected at the current time, u(t) is the control output at the current time, u(t-(t)) is the control output before the lag time (t), and K_comp is the compensation gain coefficient.

[0019] The PID control unit is electrically connected to the hysteresis compensation unit and the visual monitoring quantitative adhesive applicator. It is used to receive the compensated deviation signal and calculate the correction amount in real time according to the PID control algorithm, and dynamically adjust the adhesive output of the visual monitoring quantitative adhesive applicator so that the actual adhesive strip size approaches the preset target value in real time.

[0020] The PID adjustment unit has an adjustment frequency no lower than the refresh rate of the image processing unit, and performs at least one adjustment action in each detection cycle to achieve real-time closed-loop control of the adhesive application process. By combining high-frequency three-dimensional vision detection of no less than 50Hz with PID closed-loop control with hysteresis compensation, the technical problem of closed-loop instability caused by detection hysteresis in traditional solutions is overcome, and real-time dynamic correction of adhesive strip size is achieved during the adhesive application process, which significantly improves the adhesive application accuracy and consistency.

[0021] Furthermore, the continuity data output by the 3D vision detection module is used as follows: when the number of adhesive strip breaks within a unit length exceeds a preset threshold, the control system determines that the adhesive application is interrupted, immediately stops the adhesive application, and issues an alarm signal; the actual position deviation data is used to compare with the preset adhesive application trajectory. When the deviation exceeds the allowable threshold, the control system issues a trajectory correction command to the workpiece positioning device to adjust the adhesive application path in real time, or records the defect location for subsequent rework. This achieves immediate alarm for adhesive application interruption and online correction of trajectory deviation, avoiding the generation of batch defects, while providing accurate defect location for subsequent rework and reducing rework costs.

[0022] Furthermore, the workpiece positioning device includes a rotating platform, a clamping mechanism, a clamping force sensor, and a clamping force PID control module. The rotating platform is rotatably mounted on the machine base. The clamping mechanism is located on the rotating platform and is used to clamp the mechanical seal workpiece. The clamping force sensor is located on the clamping mechanism and is used to detect the clamping force in real time. The clamping force PID control module is electrically connected to the clamping force sensor and is used to receive the clamping force feedback signal. Based on the preset clamping force target value, the module dynamically adjusts the drive output of the clamping mechanism through a PID algorithm to adapt to mechanical seal workpieces of different materials and sizes. This achieves adaptive clamping of workpieces of different materials (such as metal, rubber, polytetrafluoroethylene, etc.), avoiding workpiece deformation due to excessive clamping force or positioning failure due to insufficient clamping force, thus improving the system's compatibility and positioning reliability.

[0023] Furthermore, the visual monitoring-type quantitative adhesive application mechanism includes: a servo motor, a precision metering cylinder, an adhesive application valve, and an adhesive storage container. The precision metering cylinder is driven by the servo motor for quantitative feeding. The adhesive application valve is connected to the outlet of the precision metering cylinder and is used to control the start and stop of adhesive spraying. The adhesive storage container is connected to the inlet of the precision metering cylinder and is used to store sealant. The rotational speed of the servo motor is controlled by a PID control unit, and the adhesive application rate is dynamically adjusted by changing the feed speed of the precision metering cylinder. By using a servo motor-driven precision metering cylinder to replace the traditional pneumatic pressure regulating valve or screw valve, high-precision and high-response speed adjustment of the adhesive application rate is achieved, while significantly extending the service life of the sealant and reducing maintenance costs.

[0024] Furthermore, the 3D line laser sensor acquires the three-dimensional point cloud data of the adhesive strip based on the laser triangulation principle. The image processing unit filters, extracts features, and performs geometric calculations on the point cloud data, outputting the width, height, continuity, and positional deviation of the adhesive strip. It can acquire the three-dimensional morphological parameters of the adhesive strip non-contactly and with high precision, providing accurate and reliable feedback signals for closed-loop control. Moreover, the measurement speed is high, meeting the requirements of refresh rates above 50Hz.

[0025] Furthermore, the UV curing unit includes a UV LED lamp assembly, a light shield, and a cooling device. The UV LED lamp assembly is mounted on the machine and is used to emit UV light to irradiate the adhesive application area. The light shield is placed outside the UV LED lamp assembly to prevent UV light leakage. The cooling device is connected to the UV LED lamp assembly and is used to cool the LED lamp assembly, thereby achieving rapid curing of the UV-curable sealant (completed within seconds). At the same time, the light shield and cooling device ensure operational safety and equipment stability.

[0026] Furthermore, the heating and curing unit includes a heating chamber, a heating element, a temperature sensor, and a circulating fan. The heating chamber is fixedly installed on the machine base; the heating element is located inside the heating chamber; the temperature sensor is located inside the heating chamber for real-time detection of the heating temperature; and the circulating fan is located inside the heating chamber to ensure uniform temperature distribution within the chamber. This allows for uniform and controllable heating and curing of the thermosetting sealant, with good temperature uniformity (temperature difference within 3°C) and compatibility with various thermosetting adhesive materials.

[0027] The present invention also provides an automated adhesive application and curing method for mechanical seal components using the above-described system, comprising the following steps: S1: Positioning and clamping step: The mechanical seal workpiece is placed on the workpiece positioning device, and the clamping mechanism clamps and fixes the workpiece. The clamping force sensor monitors the clamping force in real time and feeds it back to the clamping force PID control module to dynamically maintain the clamping force within the preset range. S2: Parameter setting step, the control system sets the glue application path, glue application speed, and target values ​​for the width and height of the glue strip and the allowable deviation threshold according to the pre-stored sealant type and workpiece shape data; S3: Glue application and synchronous detection steps. The visual monitoring quantitative glue application mechanism is started to apply sealant along the preset path. During the glue application process, the 3D line laser sensor of the three-dimensional vision detection module scans the glue strip that has been applied. The image processing unit outputs the actual width, actual height and actual position deviation data of the glue strip in real time at a refresh rate of not less than 50Hz. S4: Deviation comparison and hysteresis compensation step, the hysteresis compensation unit of the control system generates the compensated deviation signal according to the detection hysteresis time and the glue application speed according to the following formula: e_compensated(t) = W_target - [W_actual(t) + K_comp(u(t) - u(t-(t)))], where the meaning of each symbol is the same as above; S5: PID adjustment step, wherein the PID adjustment unit receives the compensated deviation signal, calculates the correction amount in real time through the PID control algorithm, and dynamically adjusts the glue dispensing amount of the visual monitoring quantitative glue applicator, so that the actual glue strip size approaches the preset target value in real time; wherein, the update frequency of PID adjustment is not lower than the output frequency of the image processing unit, and at least one adjustment action is performed in each detection cycle to form closed-loop feedback control; when any parameter of glue strip width, height or position deviation exceeds the corresponding allowable threshold, the control system issues an alarm signal and records the defect location; S6: Curing step. After the adhesive is applied, select the appropriate curing method according to the type of sealant: if it is a UV-curing sealant, send the workpiece into the UV curing unit for irradiation curing; if it is a thermosetting sealant, send the workpiece into the heat curing unit for heat curing. S7: Removal Step. After curing, remove the workpiece from the workpiece positioning device to complete the adhesive application and curing process.

[0028] By organically combining system hardware and control methods, a fully automated closed-loop process flow has been formed, which includes clamping setting, glue application detection, lag compensation, PID adjustment, curing, and part removal. This process achieves high-precision and high-consistency glue application and is compatible with various types of sealants.

[0029] Furthermore, the PID control unit employs a positional PID algorithm or an incremental PID algorithm. The PID parameters are preset based on the rheological properties of the sealant or optimized online through self-tuning. The self-tuning method includes initial parameter tuning based on the Ziegler-Nichols critical proportionality method and online correction based on the deviation integral performance index. Through PID parameter self-tuning, it can automatically adapt to changes in the rheological properties of different sealants (such as viscosity changes with temperature or shear time), always maintaining the optimal control response, further improving the robustness and adaptability of the system.

[0030] The beneficial effects of this invention are as follows: This invention provides an automatic adhesive application and curing system for mechanical seal components and its method of use, which has the following advantages: 1. Significantly improved closed-loop control accuracy: Through high-frequency detection (50Hz), hysteresis compensation, PID calculation, and dynamic adjustment, high-speed closed-loop feedback can instantly correct the size deviation of the rubber strip caused by various disturbances.

[0031] 2. Fundamentally solves the detection lag problem: The lag compensation unit aligns the current detection data with the historical control quantity through spatiotemporal mapping, eliminating the influence of the inherent lag (100~300ms) caused by the physical installation position of the sensor on the closed-loop stability, making high-frequency feedback truly usable, and avoiding the oscillation of conventional PID in a pure lag system.

[0032] 3. Adaptive clamping and wide compatibility: The clamping force PID control module can automatically optimize the clamping force for workpieces of different materials to avoid deformation or positioning failure; the UV / heat curing dual unit is integrated into the same system and is compatible with a variety of sealant materials.

[0033] 4. High equipment lifespan and reliability: Servo-driven precision metering cylinders replace easily damaged screw valves or pressure regulating valves, extending the seal replacement cycle from half a month for traditional screw valves to more than 10 months, significantly reducing maintenance costs.

[0034] 5. Online quality inspection and intelligent alarm: The 3D vision inspection module provides data such as adhesive strip continuity and positional deviation, enabling immediate alarm for adhesive application interruption and online correction of trajectory deviation, and recording the defect location for subsequent rework, thus avoiding batch defects.

[0035] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it according to the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Specific embodiments of the present invention are given in detail below with reference to the accompanying drawings. Attached Figure Description

[0036] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings: Figure 1 This is a schematic diagram of an automatic adhesive application and curing system for mechanical seal components and its usage method provided in an embodiment of the present invention; Figure 2 A front view of an automatic adhesive application and curing system for a mechanical seal assembly and its usage method provided in an embodiment of the present invention; Figure 3 A system architecture diagram of an automatic adhesive application and curing system for mechanical seal components and its usage method provided in an embodiment of the present invention; Figure 4 This is a flowchart illustrating an automatic adhesive application and curing system for mechanical seal components and its usage method, as provided in an embodiment of the present invention.

[0037] The attached diagram lists the components represented by each number as follows: 1. Machine base; 2. Workpiece positioning device; 201. Rotary platform; 202. Clamping mechanism; 203. Clamping force sensor; 3. Glue application device; 301. Visual monitoring type quantitative glue application mechanism; 3011. Servo motor; 3012. Precision metering cylinder; 3013. Glue application valve; 3014. Glue storage container; 302. 3D vision inspection module; 3021. 3D line laser sensor; 3022. Image processing unit; 4. Curing device; 401. Ultraviolet curing unit; 4011. Ultraviolet LED lamp group; 4012. Light shield; 4013. Cooling device; 402. Heating curing unit; 4021. Heating chamber; 4022. Heating element; 4023. Temperature sensor; 4024. Circulating fan; 5. Control system. Detailed Implementation

[0038] The following is in conjunction with the appendix Figure 1-4The principles and features of the present invention are described below. The examples given are for illustrative purposes only and are not intended to limit the scope of the invention. The invention is described more specifically in the following paragraphs by way of example with reference to the accompanying drawings. The advantages and features of the invention will become clearer from the following description. It should be noted that the drawings are in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the invention.

[0039] It should be noted that when a component is said to be fixed to another component, it can be directly on the other component or it may have a component in between. When a component is said to be connected to another component, it can be directly connected to the other component or it may have a component in between. When a component is said to be set to another component, it can be directly set to the other component or it may have a component in between. The terms vertical, horizontal, left, right, and similar expressions used in this document are for illustrative purposes only.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The terminology used herein includes, and / or encompasses, any and all combinations of one or more of the associated listed items.

[0041] Example 1, please refer to Figures 1 to 3 Embodiment 1 of the present invention provides an automatic glue application and curing system for mechanical seal components. The system includes a machine base 1, a workpiece positioning device 2, a glue application device 3, a curing device 4, and a control system 5.

[0042] Machine 1 serves as the support platform for the entire system. It is constructed with high-rigidity steel structure and undergoes aging treatment to ensure the overall stability of the system during high-speed glue application. The workpiece positioning device 2, glue application device 3, and curing device 4 are all fixedly installed on the worktable of machine 1 using precision bolts.

[0043] The workpiece positioning device 2 is used to clamp and position the mechanical seal workpiece to be coated with adhesive. In this embodiment, the device specifically includes a rotating platform 201, a clamping mechanism 202, a clamping force sensor 203, and a clamping force PID control module 204. The rotating platform 201 is rotatably mounted on the machine base 1 and is driven by a high-precision servo motor, which can drive the workpiece to rotate precisely along a preset adhesive coating trajectory. The clamping mechanism 202 is located on the rotating platform 201 and is preferably a three-jaw or four-jaw self-centering pneumatic chuck for radially clamping the mechanical seal workpiece. The clamping force sensor 203 is a strain gauge pressure sensor embedded in the root of the jaws of the clamping mechanism 202 for real-time detection of the clamping force applied to the workpiece. The clamping force PID control module 204... The module is an independent proportional-integral-derivative controller or its functions are integrated into a programmable logic controller (PLC). Its input is electrically connected to the clamping force sensor 203, and its output is electrically connected to the pneumatic proportional valve or servo motor driving the clamping mechanism 202. The module receives the clamping force feedback signal and dynamically adjusts the drive output of the clamping mechanism 202 according to the preset clamping force target value (e.g., 200N for copper sealing rings and 80N for polytetrafluoroethylene rings) through a PID algorithm. This adaptive clamping method can effectively avoid deformation of soft workpieces such as rubber or polytetrafluoroethylene due to excessive clamping force, or displacement of metal workpieces during high-speed adhesive application due to insufficient clamping force, thus making it compatible with mechanical seal workpieces of different materials and sizes.

[0044] The adhesive application device 3 includes a vision-monitored quantitative adhesive application mechanism 301 and a three-dimensional vision inspection module 302. The vision-monitored quantitative adhesive application mechanism 301 is used to controllably output sealant during the adhesive application process. Specifically, it includes a servo motor 3011, a precision metering cylinder 3012, an adhesive application valve 3013, and an adhesive storage container 3014. The precision metering cylinder 3012 is a high-precision plunger-type metering cylinder, whose piston rod is connected to the servo motor 3011 via a high-rigidity coupling, and is driven by the servo motor for precise linear feed. The adhesive application valve 3013 is a needle valve or a spray valve, and its inlet is connected to the precision metering cylinder 3014. The outlet of the precision metering cylinder 3012 is connected to a high-pressure resistant hose for precise control of the start and stop of glue spraying. The glue storage container 3014 is a pressure tank with degassing function. Its outlet is connected to the inlet of the precision metering cylinder 3012 for storing and supplying sealant. During operation, the speed and angle of the servo motor 3011 are controlled by the PID control unit. By changing the feed speed of the precision metering cylinder 3012, stepless and high-precision dynamic adjustment of the glue output is achieved. Compared with traditional screw valves, this structure significantly reduces the wear of seals and extends the maintenance cycle from half a month to more than 10 months.

[0045] The 3D vision inspection module 302 is used to perform online 3D morphology inspection on adhesive strips that have not yet cured after application. It includes a 3D line laser sensor 3021 and an image processing unit 3022. The 3D line laser sensor 3021 projects a line laser onto the surface of the adhesive strip based on the principle of laser triangulation, and acquires the laser contour line modulated by the height of the adhesive strip through a high-speed CMOS camera, thereby obtaining the 3D point cloud data of the cross-section of the adhesive strip. The image processing unit 3022 is an embedded processor with a built-in high-performance FPGA or DSP. It sequentially performs median filtering to remove noise, spline curve fitting to extract the boundary and peak of the adhesive strip, and geometric dimension calculation on the point cloud data. Finally, it outputs the actual width, actual height, continuity (number of breakpoints per unit length), and actual position deviation (offset of the center line of the adhesive strip from the preset trajectory) of the adhesive strip. The key point is that the image processing unit 3022 can continuously output the above data to the control system 5 at a refresh rate of not less than 50Hz (i.e., 50 times per second), providing real-time feedback for high-frequency closed-loop control.

[0046] The curing device 4 includes a UV curing unit 401 and a heat curing unit 402, which are arranged side-by-side or separately on the machine base 1. The UV curing unit 401 is used to rapidly cure UV-curable sealants (such as acrylic UV adhesives). Specifically, it includes a UV LED lamp group 4011, a light shield 4012, and a cooling device 4013. The UV LED lamp group 4011 emits UV light with a wavelength of 365nm or 395nm to irradiate the coated area. The light shield 4012 is made of black acrylic or stainless steel and is placed over the UV LED lamp group 4011 to prevent UV light leakage from harming the operator. The cooling device 4013 is an air-cooled or water-cooled heat sink, and its heat-conducting surface is tightly attached to the heat dissipation substrate of the UV LED lamp group 4011 to force cooling of the LED lamp group. However, to ensure that it is within the working temperature range, the heating and curing unit 402 is used to heat and cure thermosetting sealants (such as epoxy resin and silicone rubber). It includes a heating chamber 4021, a heating element 4022, a temperature sensor 4023, and a circulating fan 4024. The heating chamber 4021 is a double-layer stainless steel structure filled with insulation cotton and is fixedly installed on the machine base 1. The heating element 4022 is an electric heating tube or a ceramic heating plate, which is located at the bottom or side wall of the heating chamber 4021. The temperature sensor 4023 is a K-type thermocouple or a PT100 platinum resistance thermometer, which is located inside the heating chamber 4021 and is used to detect the heating temperature in real time. The circulating fan 4024 is located at the top inside the heating chamber 4021 and is used to forcibly stir the internal air to make the temperature inside the chamber uniformly distributed and the temperature difference controlled within 3°C.

[0047] The control system 5 is the central hub of the entire system. It is electrically connected to the workpiece positioning device 2, the glue application device 3, and the curing device 4. In this embodiment, the core of the control system 5 is a PLC controller, which integrates a data comparison unit, a PID adjustment unit, and a hysteresis compensation unit internally or externally.

[0048] The data comparison unit is used to compare the actual width and actual height of the adhesive strip acquired in real time by the 3D vision inspection module 302 with the preset width threshold (such as target value 2.0mm, upper limit 2.1mm, lower limit 1.9mm) and height threshold (such as target value 1.5mm, upper limit 1.6mm, lower limit 1.4mm) read from the process simulation optimization module, and generate width deviation signal and height deviation signal in real time.

[0049] Since the physical installation position of the 3D line laser sensor 3021 inevitably lags behind the glue application point of the glue application valve 3013 (in this embodiment, the spatial straight-line distance is 25mm, corresponding to a glue application speed of 50mm / s, and the detection lag time is 500ms), this pure lag element, if left untreated, will cause severe oscillations in conventional PID control. Therefore, this invention specifically designs a lag compensation unit. This unit dynamically calculates the detection lag time (t) = distance / current speed based on the spatial distance between the installation position of the 3D line laser sensor 3021 and the glue application point and the current glue application speed, and generates the compensated deviation signal e_compensated(t) based on the Smith predictor principle. The specific formula is as follows: e_compensated(t) = W_target - [W_actual(t) + K_comp(u(t) - u(t-(t)))] Where W_target is the target width of the adhesive strip, W_actual(t) is the actual width detected at the current time t, u(t) is the control output at the current time (e.g., servo motor speed), u(t-(t)) is the control output before the lag time, and K_comp is the compensation gain coefficient, which is usually in the range of 0.5-1.2. Through experimental calibration, the core idea of ​​this formula is to use historical control quantities to infer how much of the currently detected deviation is caused by past control actions, and then subtract it from the current deviation to obtain a forward deviation that theoretically eliminates the lag effect.

[0050] The PID control unit is electrically connected to the hysteresis compensation unit and the servo motor 3011 driver of the vision monitoring quantitative dispensing mechanism 301. This unit receives the compensated deviation signal e_compensated(t) output by the hysteresis compensation unit and calculates the correction amount in real time according to the positional or incremental PID control algorithm. It dynamically adjusts the speed of the servo motor 3011, thereby changing the feed speed of the precision metering cylinder 3012, so that the amount of glue dispensed changes in real time. Finally, the actual glue strip width and height approach the preset target value in real time. In order to achieve seamless closed loop, the adjustment update frequency of the PID control unit is also set to no less than 50Hz (e.g., 100Hz) to ensure that at least one adjustment action is performed in each three-dimensional vision detection cycle. This effectively suppresses disturbances such as glue dispensing speed fluctuations and instantaneous changes in glue viscosity, and realizes real-time closed-loop control of the glue dispensing process.

[0051] Example 2, please refer to Figure 4 This embodiment provides an automated adhesive application and curing method for mechanical seal components using the system described in Embodiment 1 above. The method includes the following steps performed sequentially: S1: Positioning and clamping step. The operator or automatic loading and unloading robot places the mechanical seal workpiece to be processed on the rotating platform 201 of the workpiece positioning device 2. The control system 5 issues a command, and the clamping mechanism 202 clamps and fixes the workpiece. During this process, the clamping force sensor 203 monitors the clamping force in real time at millisecond intervals and feeds back the force signal to the clamping force PID control module 204. This module compares the actual force value with the preset target clamping force (automatically retrieved from the workpiece material database stored in the system). After PID calculation, it dynamically adjusts the drive air pressure or servo motor torque to stabilize the clamping force within the preset allowable error range (e.g., 5%). After clamping is completed, the rotating platform 201 rotates the workpiece one revolution. The workpiece installation alignment accuracy is confirmed by an encoder or laser rangefinder to ensure the correct reference of the adhesive application trajectory.

[0052] S2: Parameter setting steps. The operation interface of the control system 5 receives the sealant model (e.g., UV-3103) and workpiece drawing number (e.g., MS-100) input by the operator. The system automatically calls the corresponding glue application process parameter package from the internal process database or through the process simulation optimization module. The parameter package includes at least: glue application path (circular, involute, or contour trajectory), glue application speed of the rotating platform 201 (e.g., adjustable from 30-80mm / s), target width value and allowable deviation threshold of the glue strip (e.g., width 2mm 0.1mm), target height value and allowable deviation threshold (e.g., height 1.2mm 0.08mm), and continuity judgment threshold (e.g., a maximum of 1 breakpoint is allowed within every 10mm length).

[0053] S3: Glue application and synchronous detection steps. The system starts the glue application operation. The servo motor 3011 of the visual monitoring quantitative glue application mechanism 301 starts, driving the precision metering cylinder 3012 to supply glue according to the basic glue dispensing amount. The glue application valve 3013 opens. At the same time, the rotating platform 201 drives the workpiece to move along the preset trajectory to apply sealant. In a very short time after the glue application starts (after the lag distance / speed), the three-dimensional vision detection module 302 starts working. The 3D line laser sensor 3021 scans the glue strip that has been applied but has not yet cured in real time. The image processing unit 3022 processes the original point cloud data at a refresh rate of 50Hz and outputs the actual width W_actual, actual height H_actual, and actual position deviation P_error data of the glue strip in real time through a high-speed fieldbus (such as EtherCAT).

[0054] S4: Deviation Comparison and Lag Compensation Step. The data comparison unit of the control system 5 receives the real-time data from step S3 and calculates the original width deviation e(t) = W_target - W_actual(t). Simultaneously, the lag compensation unit dynamically calculates the lag time according to (t) = L / v(t) based on the fixed spatial distance L between the sensor 3021 and the glue application valve 3013 (25mm in this embodiment) and the current real-time glue application speed v(t). Then, the unit retrieves the control quantity output u(t-(t)) from the historical data buffer before time (t) and calculates the compensated deviation signal according to the following formula: e_compensated(t) = W_target - [W_actual(t) + K_comp(u(t) - u(t-(t)))] K_comp was calibrated to 0.85 through previous step response experiments. For the height deviation of the adhesive strip, the same compensation logic was used, but each independent compensation gain coefficient was used.

[0055] S5: PID adjustment and online quality judgment steps. The PID adjustment unit reads the compensated deviation signal e_compensated(t) at a frequency of 100Hz (i.e., once every 10ms). The positional PID algorithm running in the unit (formula: u(t)=Kpe(t)+Kie(t)dt+Kd*de(t) / dt, where Kp, Ki, and Kd are preset parameters) calculates the correction amount in real time based on the current deviation and adds this correction amount to the basic control amount, outputting it to the driver of the servo motor 3011, thereby dynamically adjusting the feed speed of the precision metering cylinder 3012 and changing the dispensing amount. This step forms an ultra-high-speed closed loop of high-speed detection-compensation-calculation-execution, enabling the adhesive strip width to follow the target value in real time.

[0056] Meanwhile, the control system 5 monitors quality data in three dimensions in real time: when any parameter of the actual width, actual height or positional deviation of the adhesive strip exceeds the allowable threshold set in step S2, the system immediately issues an audible and visual alarm and highlights the three-dimensional coordinates of the defect location on the human-machine interface. At the same time, the coordinates are recorded in the local database to guide subsequent manual rework. In particular, for continuous data, when the system detects that the number of adhesive strip breaks within a unit length (e.g., 5mm) exceeds the preset threshold (e.g., 2), it is judged as a serious adhesive application interruption event. The system will immediately stop the operation of the rotating platform 201 and the adhesive application device 3 to prevent the generation of large-area waste.

[0057] S6: Curing Step. After all the adhesive application is completed, the control system 5 automatically selects the curing path according to the sealant type set in step S2. If the adhesive is UV-curable, the workpiece is directly transferred from the rotating platform 201 to the working position of the UV curing unit 401. The control system 5 lights up the UV LED lamp group 4011 and sets the irradiation time (e.g., 10-30 seconds). At the same time, the cooling device 4013 is turned on, and the light shield 4012 is automatically closed to prevent UV leakage. If the adhesive is thermosetting, the workpiece is sent into the heating chamber 4021 of the heating curing unit 402. The control system 5 controls the power of the heating element 4022 according to the preset curing curve (e.g., 80℃ constant temperature for 30 minutes). The temperature sensor 4023 provides real-time temperature feedback, and the circulating fan 4024 keeps running to maintain a uniform temperature inside the chamber.

[0058] S7: Removal Step. After the curing time is reached, the curing device automatically closes or opens, the control system 5 indicates that curing is complete, the clamping mechanism 202 automatically releases, and the operator or unloading robot safely removes the mechanical seal workpiece that has been coated and cured from the workpiece positioning device 2, thus ending the entire process.

[0059] Example 3: Based on Examples 1 and 2, this example optimizes the self-tuning function of PID parameters.

[0060] Given the differences in rheological properties (such as viscosity and thixotropy) between different batches or brands of sealant, the PID control unit incorporates a parameter self-tuning function to maintain optimal control performance.

[0061] Initial parameter tuning: After changing to a new type of sealant, the system can execute a self-tuning program. This program automatically uses the Ziegler-Nichols critical proportional gain method: temporarily masking the integral and derivative actions (Ki=0, Kd=0), retaining only the proportional element, and gradually increasing it from a small Kp value until the closed-loop control system exhibits constant amplitude oscillation. The critical gain K_u and critical oscillation period T_u at this point are recorded. Then, based on the Ziegler-Nichols empirical formula, the basic PID parameters suitable for the current system are automatically calculated: Kp=0.6K_u, Ki=2K_p / T_u, Kd=K_p*T_u / 8.

[0062] Online parameter optimization: During continuous production, the control system 5 continuously monitors the integral performance index (ITAE, i.e., time multiplied by absolute error integral) of the deviation signal. If the index shows an upward trend for 10 consecutive workpieces, it indicates that the current PID parameters are no longer optimal due to factors such as changes in adhesive temperature or equipment wear. At this time, the system triggers an online fine-tuning program, using gradient descent or genetic algorithm to optimize Kp, Ki, and Kd with small steps, aiming to minimize ITAE and dynamically correct the PID parameters. At the same time, the compensation gain coefficient K_comp in the hysteresis compensation unit can also be automatically calibrated through a similar online learning strategy, so that the entire adhesive coating closed-loop system can work in the optimal state in a long-term and robust manner without frequent manual intervention.

[0063] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Content not described in detail in this specification is prior art known to those skilled in the art.

[0064] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Those skilled in the art can readily implement the present invention based on the accompanying drawings and the above description. However, any modifications, alterations, or variations made by those skilled in the art without departing from the scope of the present invention, utilizing the disclosed technical content, are equivalent embodiments of the present invention. Furthermore, any modifications, alterations, or variations made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the present invention.

Claims

1. An automatic glue coating and curing system for mechanical seal assembly, comprising a machine table (1), a workpiece positioning device (2), a glue coating device (3), and a curing device (4), characterized in that: The workpiece positioning device (2), the glue application device (3) and the curing device (4) are all fixedly installed on the machine base (1); The workpiece positioning device (2) is used to clamp and position the mechanical seal workpiece to be coated with adhesive; The adhesive applicator (3) includes a visual monitoring quantitative adhesive applicator (301) and a three-dimensional visual inspection module (302). The visual monitoring quantitative adhesive applicator (301) is used to output sealant in a controlled manner during the adhesive applicator process. The three-dimensional visual inspection module (302) is used to perform online three-dimensional morphology inspection on the adhesive strip after adhesive applicator application and obtain the actual width, actual height, continuity and actual position deviation data of the adhesive strip. The curing device (4) includes an ultraviolet curing unit (401) and a heat curing unit (402). The ultraviolet curing unit (401) is used to rapidly cure the UV-curable sealant, and the heat curing unit (402) is used to heat-cure the thermosetting sealant. The control system (5) is electrically connected to the workpiece positioning device (2), the glue application device (3) and the curing device (4) respectively; The three-dimensional vision detection module (302) includes a 3D line laser sensor (3021) and an image processing unit (3022). The image processing unit (3022) continuously outputs the actual width, actual height and actual position deviation data of the adhesive strip to the control system (5) at a refresh rate of not less than 50Hz. The control system (5) includes a data comparison unit, a PID control unit, and a hysteresis compensation unit; The data comparison unit is used to compare the actual width and actual height of the adhesive strip acquired in real time by the three-dimensional vision detection module (302) with the preset width threshold and height threshold respectively, and generate a deviation signal; The hysteresis compensation unit calculates the detection hysteresis time based on the installation position of the 3D line laser sensor (3021) and the spatial distance between the adhesive application point and the current adhesive application speed, and generates the compensated deviation signal e_compensated(t) according to the following formula: e_compensated(t) = W_target - [W_actual(t) + K_comp (u(t) - u(t-(t)))] Where W_target is the target value of the adhesive strip width, W_actual(t) is the actual width detected at the current time, u(t) is the control output at the current time, u(t-(t)) is the control output before the lag time (t), and K_comp is the compensation gain coefficient; The PID control unit is electrically connected to the hysteresis compensation unit and the visual monitoring quantitative glue applicator (301). It is used to receive the compensated deviation signal and calculate the correction amount in real time according to the PID control algorithm, and dynamically adjust the glue output of the visual monitoring quantitative glue applicator (301) so that the actual glue strip size approaches the preset target value in real time. The PID adjustment unit has an adjustment frequency that is not lower than the refresh rate of the image processing unit (3022), and performs at least one adjustment action in each detection cycle to achieve real-time closed-loop control of the adhesive application process.

2. The automatic glue application and curing system for mechanical seal assembly as claimed in claim 1 wherein, The continuity data output by the three-dimensional vision detection module (302) is used for: when the number of adhesive strip breaks within a unit length exceeds a preset threshold, the control system (5) determines that the adhesive application is interrupted, immediately stops the adhesive application, and issues an alarm signal; the actual position deviation data is used to compare with the preset adhesive application trajectory. When the deviation exceeds the allowable threshold, the control system (5) issues a trajectory correction command to the workpiece positioning device (2) to adjust the adhesive application path in real time, or records the defect location for subsequent rework.

3. The automatic adhesive application and curing system for mechanical seal components according to claim 1, characterized in that, The workpiece positioning device (2) includes a rotating platform (201), a clamping mechanism (202), a clamping force sensor (203), and a clamping force PID control module; The rotating platform (201) is rotatably mounted on the machine base (1); The clamping mechanism (202) is mounted on the rotating platform (201) and is used to clamp the mechanical seal workpiece; The clamping force sensor (203) is mounted on the clamping mechanism (202) and is used to detect the magnitude of the clamping force in real time; The clamping force PID control module is electrically connected to the clamping force sensor (203) to receive the clamping force feedback signal and dynamically adjust the drive output of the clamping mechanism (202) according to the preset clamping force target value through the PID algorithm to adapt to mechanical seal workpieces of different materials and sizes.

4. The automatic adhesive application and curing system for mechanical seal components according to claim 1, characterized in that, The visual monitoring type quantitative glue application mechanism (301) includes: a servo motor (3011), a precision metering cylinder (3012), a glue application valve (3013), and a glue storage container (3014). The precision metering cylinder (3012) is connected to the servo motor (3011) and is driven by the servo motor to perform quantitative feeding; The glue-applying valve (3013) is connected to the glue outlet of the precision metering cylinder (3012) and is used to control the start and stop of glue spraying. The glue storage container (3014) is connected to the glue inlet of the precision metering cylinder (3012) and is used to store sealant; The rotational speed of the servo motor (3011) is controlled by the PID control unit, and the amount of glue dispensed is dynamically adjusted by changing the feed speed of the precision metering cylinder (3012).

5. The automatic adhesive application and curing system for mechanical seal components according to claim 1, characterized in that, The 3D line laser sensor (3021) acquires three-dimensional point cloud data of the adhesive strip based on the principle of laser triangulation. The image processing unit (3022) performs filtering, feature extraction and geometric calculation on the point cloud data and outputs the width, height, continuity and position deviation of the adhesive strip.

6. The automatic adhesive application and curing system for mechanical seal components according to claim 1, characterized in that, The ultraviolet curing unit (401) includes an ultraviolet LED lamp group (4011), a light shield (4012), and a cooling device (4013). The ultraviolet LED lamp group (4011) is installed on the machine (1) and is used to emit ultraviolet light to irradiate the adhesive coating area; The light shield (4012) is placed over the outside of the ultraviolet LED lamp assembly (4011) to prevent ultraviolet light from leaking out; The cooling device (4013) is connected to the ultraviolet LED lamp group (4011) and is used to cool the LED lamp group.

7. The automatic adhesive application and curing system for mechanical seal components according to claim 1, characterized in that, The heating and curing unit (402) includes a heating chamber (4021), a heating element (4022), a temperature sensor (4023), and a circulating fan (4024). The heating box (4021) is fixedly installed on the machine base (1); The heating element (4022) is located inside the heating chamber (4021); The temperature sensor (4023) is located inside the heating chamber (4021) and is used to detect the heating temperature in real time; The circulating fan (4024) is located inside the heating chamber (4021) to ensure a uniform temperature distribution within the chamber.

8. An automated adhesive application and curing method for a mechanical seal assembly using the system according to any one of claims 1 to 7, characterized in that, Includes the following steps: S1: Positioning and clamping step, the mechanical seal workpiece is placed on the workpiece positioning device (2), and the workpiece is clamped and fixed by the clamping mechanism (202). The clamping force sensor (203) monitors the clamping force in real time and feeds it back to the clamping force PID control module to dynamically maintain the clamping force within the preset range. S2: Parameter setting step, the control system (5) sets the glue application path, glue application speed, and the target values ​​for the width, height and allowable deviation threshold of the glue strip according to the pre-stored sealant type and workpiece shape data; S3: Glue application and synchronous detection steps: The visual monitoring quantitative glue application mechanism (301) is started to apply sealant along the preset path; During the glue application process, the 3D line laser sensor (3021) of the three-dimensional visual detection module (302) scans the applied glue strip, and the image processing unit (3022) outputs the actual width, actual height and actual position deviation data of the glue strip in real time at a refresh rate of not less than 50Hz. S4: Deviation comparison and hysteresis compensation step, the hysteresis compensation unit of the control system (5) generates the compensated deviation signal according to the detection hysteresis time and the glue application speed according to the following formula: e_compensated(t) = W_target - [W_actual(t) + K_comp (u(t) - u(t-(t)))], where the meaning of each symbol is the same as in claim 1; S5: PID adjustment step, the PID adjustment unit receives the compensated deviation signal, calculates the correction amount in real time through the PID control algorithm, and dynamically adjusts the glue output of the visual monitoring quantitative glue applicator (301) so that the actual glue strip size approaches the preset target value in real time; wherein, the update frequency of PID adjustment is not lower than the output frequency of the image processing unit, and at least one adjustment action is performed in each detection cycle to form a closed-loop feedback control; when any parameter of glue strip width, height or position deviation exceeds the corresponding allowable threshold, the control system (5) issues an alarm signal and records the defect location; S6: Curing step. After the adhesive is applied, select the appropriate curing method according to the type of sealant: if it is a UV-curable sealant, send the workpiece into the UV curing unit (401) for irradiation curing; if it is a thermosetting sealant, send the workpiece into the heat curing unit (402) for heat curing. S7: Removal step. After curing, remove the workpiece from the workpiece positioning device (2) to complete the gluing and curing operation.

9. The automatic adhesive application and curing method for a mechanical seal assembly according to claim 8, characterized in that, In steps S4 and S5, the PID control unit adopts a positional PID algorithm or an incremental PID algorithm. The PID parameters are preset according to the rheological properties of the sealant or optimized online through self-tuning. The self-tuning method includes initial parameter tuning based on the Ziegler-Nichols critical proportionality method and online correction based on the deviation integral performance index.

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