A through-type automobile lampshade UV coating line and coating control method and control system

Abstract

The present invention relates to a UV coating line for through-type automotive lampshades and its coating control method and control system. In the coating control method, a controller compares the coating thickness detected by an ultrasonic sensor with a set design coating thickness and performs surface coating uniformity analysis. Based on the comparison and analysis results, a judgment is made to control a robotic arm to perform corresponding actions, such as re-spraying or cleaning and re-spraying unqualified products. The control system includes a controller, an ultrasonic sensor, a spraying device, and a robotic arm to implement the control method. The coating line supports the control method and includes a conveyor device and the control system. The present invention can ensure that the UV coating uniformity of the through-type automotive lampshades meets design requirements.

Description

Technical Field

[0001] The present invention belongs to the field of automobile production, and in particular relates to a through-type automobile lampshade UV coating line and a coating control method and control system. Background Art

[0002] Conventional automotive headlights are split, with short, small-surface lampshades. This simplifies the UV coating process and makes it easy to control the uniformity of the UV coating on the lampshade surface. However, with the shift to electrification, many headlights now feature a through-type structure that runs from left to right. These longer lamps have larger surface areas, making it difficult to maintain UV coating uniformity using traditional spray control systems and methods due to the influence of air flow, temperature, and humidity. Summary of the Invention

[0003] The purpose of the present invention is to provide a through-type automobile lampshade UV coating line and a coating control method and control system to ensure that the uniformity of the UV coating on the surface of the through-type automobile lampshade meets the design requirements.

[0004] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a coating control method for a through-type automobile lampshade UV coating line, in which an ultrasonic sensor detects the coating thickness on the lampshade surface during the lampshade spraying process and sends a feedback signal to a controller; the controller then judges the detection result: (1) if the maximum coating thickness is greater than the set unqualified thickness, the corresponding lampshade returns to the cleaning station to remove the surface coating and re-spray; (2) if the maximum coating thickness is not greater than the set unqualified thickness, the controller performs surface coating uniformity analysis;

[0005] The surface coating uniformity Q is defined as:

[0006]

[0007] Among them, U max is the maximum thickness of the lampshade surface coating, U min is the minimum thickness of the lampshade surface coating, U ST Design coating thickness for the lampshade;

[0008] The surface coating uniformity analysis method is as follows:

[0009] (1) When Q is within the set uniformity range, if U max >U ST , then the corresponding lampshade returns to the cleaning station, removes the surface paint, and re-sprays; if U max ≤U ST, then the corresponding lampshade is sprayed again, and then the ultrasonic sensor is used to detect the spraying thickness again;

[0010] (2) When Q is greater than or equal to the maximum value of the set uniformity range, the corresponding lampshade returns to the cleaning station, removes the surface paint, and re-sprays;

[0011] (3) When Q is less than the minimum value of the set uniformity range, the coating thickness is qualified and the conveyor belt transports the lampshade to the subsequent workstation.

[0012] Preferably, the ultrasonic sensors are provided in plurality and transmit ultrasonic waves toward the lampshade from different directions, and the ultrasonic frequencies emitted by the plurality of ultrasonic sensors are not completely the same.

[0013] Further preferably, a plurality of ultrasonic sensors are distributed on the side of the lampshade conveying path along the circumferential direction, so that the ultrasonic waves emitted by the plurality of ultrasonic sensors can cover the outer surface of the lampshade.

[0014] As an option, the uniformity ranges from 20% to 50%.

[0015] The present invention also proposes a coating control system for a through-type automobile lampshade UV coating line, which is used to implement the coating control method described above. The control system includes a robot arm for grabbing the lampshade, a spraying device and a controller for spraying; an ultrasonic sensor is arranged on the side of the lampshade's transmission path, and the ultrasonic sensor is located downstream of the spraying station and is used to detect the coating thickness of the lampshade. The ultrasonic sensor and the controller are connected by signal; the robot arm is arranged on one side of the lampshade's transmission path, and the robot arm is controlled by the controller to perform corresponding actions.

[0016] Furthermore, the ultrasonic sensors are provided in plurality and send ultrasonic waves toward the lampshade from different directions, and the ultrasonic frequencies sent by the plurality of ultrasonic sensors are not completely the same.

[0017] Furthermore, a plurality of ultrasonic sensors are distributed along the circumferential direction on the side of the lampshade conveying path, so that the ultrasonic waves emitted by the plurality of ultrasonic sensors can cover the outer surface of the lampshade.

[0018] The present invention also proposes a through-type automobile lampshade UV coating line, comprising a conveying device and the control system as described above. The conveying device is also provided with a supplementary spraying station, a cleaning station and a drying station.

[0019] Furthermore, the conveying device is a conveyor belt, and a plurality of pairs of brackets are arranged on the conveyor belt along its conveying direction, and a support arm for supporting the lampshade is arranged on the top of each bracket.

[0020] Furthermore, there are multiple robotic arms, and each workstation is equipped with a robotic arm to send the lampshade to be processed out of or into the corresponding workstation.

[0021] The beneficial effects of the present invention are as follows: the present invention detects the coating thickness of the automobile lampshade by using an ultrasonic sensor, and sets a plurality of ultrasonic sensors in different directions, thereby fully covering the outer surface of the lampshade, making the detection data more reliable and accurate, and the plurality of ultrasonic sensors have different ultrasonic frequencies, respectively, which can avoid mutual interference between ultrasonic waves, further ensure the accuracy of the obtained data, and provide reliable data for the next step of thickness judgment.

[0022] In the control method provided by the present invention, a controller calculates the uniformity of the UV coating on the lampshade surface based on signals from multiple ultrasonic sensors and analyzes the uniformity. Based on the analysis results, lampshades with excessive coating thickness are sent to a cleaning station to remove the coating and then sprayed again; lampshades with insufficient coating thickness are sent to a supplementary spraying station for additional spraying; and lampshades with coating thickness that meets design requirements are sent to the next process. Through this process, the present invention can improve the lampshade spraying pass rate, save repeated testing time, and improve production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic structural diagram of the through-type automobile lampshade UV coating line of the present invention;

[0024] Figure 2 This is a schematic diagram of the composition of the control system of the present invention;

[0025] Figure 3 This is a flow chart of the control method of the present invention;

[0026] Markings in the figure: 1. Conveyor belt, 2. Bracket, 3. Lampshade, 4. Support arm, 5. Ultrasonic sensor 1, 6. Ultrasonic sensor 2, 7. Ultrasonic sensor 3, 8. Robot arm. DETAILED DESCRIPTION

[0027] The present invention will be further described in detail below with reference to the accompanying drawings and examples, but they are not intended to limit the invention in any way.

[0028] Example 1: Refer to the attached Figure 1 As shown, a through-type UV coating line for automotive lampshades includes a conveyor belt 1 and a control system. Multiple pairs of brackets 2 are spaced apart along the conveying direction of the conveyor belt 1. Each bracket 2 is provided with a vertically upward-facing support arm 4. The support arms 4 of each pair of brackets 2 jointly support a lampshade 3, with the outer surface of the lampshade 3 facing upward, and the support arms 4 do not block the outer surface of the lampshade 3. The control system includes a controller, a spraying device, an ultrasonic sensor, and a robot arm 8.

[0029] In addition to the conventional spraying station, one side of the conveyor belt 1 is also equipped with a supplementary spraying station, a cleaning station, and a drying station. The supplementary spraying station is used to spray lampshades 3 with insufficient coating thickness; the cleaning station is used to clean lampshades 3 with excessive coating thickness to remove the coating; and the drying station is used to dry the cleaned lampshades 3 for subsequent re-spraying. A UV irradiation paint curing station is also located at the end of the UV coating line, where the coating is completely cured by UV light.

[0030] Combine Figure 2 As shown, the control system comprises a spraying device comprising a plurality of nozzles and a hydraulic pump for spraying UV coating onto the surface of the lampshade 3. The hydraulic pump is used to supply UV coating at a set pressure to the nozzles. The robot arm 8 is provided on one side of the conveyor belt 1 and has both movement and rotation functions. The robot arm 8 can be a conventional device in the mechanical field. Its structure and operating principle are well known in the art and will not be described in detail.

[0031] Three ultrasonic sensors are provided: ultrasonic sensor 1 5, ultrasonic sensor 2 6, and ultrasonic sensor 3 7. All three sensors are located downstream of the conventional spraying station on the conveyor belt 1 to detect the coating thickness on the surface of the lampshade 3. Ultrasonic sensor 1 5 is located above the lampshade 3 supported by the conveyor belt 1, while ultrasonic sensor 2 6 and ultrasonic sensor 3 7 are located on the left and right sides of the lampshade 3 (relative to the conveyor direction). The three ultrasonic sensors emit ultrasonic waves of three different frequencies from three different directions. These frequencies precisely cover the outer surface of the lampshade 3 along the circumference of the cross section. The structure and support locations of the support arm 4 do not affect the ultrasonic irradiation of the lampshade 3. The ultrasonic echoes received by each ultrasonic sensor can be used to measure the thickness of the UV coating on the irradiated surface of the lampshade 3. As the conveyor belt 1 moves, each ultrasonic sensor detects the UV coating thickness of the corresponding irradiated surface and transmits the detection signal to a controller connected to each ultrasonic sensor. The controller processes the detection signal and calculates the UV coating uniformity across the entire outer surface of the lampshade. The three ultrasonic sensors use three different frequencies to avoid mutual interference.

[0032] The controller receives signals from the three ultrasonic sensors and calculates the uniformity of the UV coating on the entire surface of the lampshade 3. The controller controls the activation time of each nozzle on the production line according to the set parameters. The controller controls the pumping pressure of the hydraulic pump according to the set parameters to control the paint flow rate at the nozzle, and coordinates with the activation time of each nozzle to accurately control the volume of paint sprayed by the nozzle within the set time. When the lampshade 3 on the top of the support arm 4 of the conveyor belt 1 needs to be removed, the controller controls the robot 8 to clamp the lampshade 3, remove it from the top of the support arm 4, and transfer it to the cleaning station, drying station, or additional spraying station.

[0033] Preferably, there are multiple robotic arms 8, and each workstation is equipped with a robotic arm 8 to clamp the lampshade 3 to be processed and send it to the workstation and / or send the processed lampshade 3 out of the workstation.

[0034] Example 2: Figure 3 As shown, the control system of the through-type automobile lampshade UV coating line of the present invention has a specific control method, which includes the following steps:

[0035] 1. Controller initialization;

[0036] 2. Enter the conventional spraying mode, which is an existing conventional spraying scheme formulated according to the material, size and type of paint of the lampshade 3;

[0037] 3. Use the conventional spraying mode to remove dust and static electricity from the lampshade 3;

[0038] 4. The controller controls the corresponding nozzles and hydraulic pumps according to the parameters set in the normal mode to spray paint on the lampshade;

[0039] 5. Detect coating thickness. When the lampshade 3 passes ultrasonic sensor 1 5, ultrasonic sensor 2 6 and ultrasonic sensor 3 7 on the conveyor belt 1, the three ultrasonic sensors detect the coating thickness on its outer surface and send feedback signals to the controller. The controller calculates the coating thickness and sets the maximum coating thickness U on the lampshade surface. max Compare and judge with the set unqualified thickness. In this embodiment, the unqualified thickness of the coating is set to 20μm:

[0040] (1)If U max >20μm, go to step 8;

[0041] (2)If U max ≤20μm, go to step 6;

[0042] 6. The controller uses the data from each ultrasonic sensor to calculate the uniformity of the lampshade surface coating. When calculating the uniformity, the surface coating uniformity Q is defined as:

[0043]

[0044] Among them, U max is the maximum thickness of the lampshade surface coating, U min is the minimum thickness of the lampshade surface coating, U ST is the designed coating thickness of the lampshade, in this embodiment, U ST Select 15 μm;

[0045] 7. Analyze and judge the surface coating uniformity calculated in step 6:

[0046] (1) If the surface coating uniformity is 20% ≤ Q ≤ 50%, it is necessary to further determine the numerical range of the maximum thickness of the coating:

[0047] ①U max >15μm, go to step 8;

[0048] ②U max ≤15μm, the controller controls the robot 8 to remove the corresponding lampshade 3 from the conveyor belt 1 and transfer it to the supplementary spraying station. Based on the previous ultrasonic detection information, the controller controls the nozzle of the supplementary spraying station to aim at the corresponding part of the surface of the lampshade 3, such as the part with the thinnest coating or multiple parts with a coating thickness less than the set value, and performs supplementary spraying. Then the controller controls the robot 8 to place the lampshade 3 with the outer surface facing up on the idle support arm 4 that is about to enter the detection range of each ultrasonic sensor, and then enters step 5;

[0049] (2) If the surface coating uniformity Q ≥ 50%, proceed to step 8;

[0050] (3) If the surface coating uniformity Q is less than 20%, the coating thickness is qualified, the robot arm 8 does not move, and the corresponding lampshade 3 is directly sent to the subsequent UV irradiation coating curing station by the conveyor belt;

[0051] 8. The controller controls the robot 8 to send the unqualified lampshade 3 to the cleaning station, and use the selected solvent to clean and remove the paint that has been sprayed on the surface of the lampshade 3. Then the robot 8 sends the lampshade 3 to the drying station to dry the surface of the lampshade 3. Then the robot 8 sends the lampshade 3 to the front end of the UV coating production line and enters step 2.

[0052] Since the probability of the maximum coating thickness at the adjacent joints between the supplementary sprayed area and the non-supplementary sprayed area exceeding 20μm is higher than 80%, the coating failure rate is too high. Compared with the solution of checking whether the coating thickness meets the standard after supplementary spraying and cleaning and re-spraying the lampshade that does not meet the standard, the present invention has the original coating maximum thickness U maxIf the particle size exceeds 15μm, the lampshade will be directly sent to the cleaning station and then re-sprayed, which saves the time of repeated inspections and improves production efficiency.

[0053] In the present invention, the thickness and uniformity of the secondary coating are detected and judged for the lampshade surface coating after the supplementary spraying, which can ensure that each lampshade produced by the spraying control method of the present invention meets the set qualified standards, that is, U max ≤20μm and Q<20%.

[0054] The above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Those skilled in the art should understand that the specific implementation methods of the present invention can be modified or replaced with equivalents with reference to the above embodiments. Any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention are within the scope of protection of the pending claims.

Claims

1. A coating control method for a through-type automobile lampshade UV coating line, characterized in that: During the spraying process of the lampshade, multiple ultrasonic sensors distributed along the circumferential direction on the side of the lampshade transmission path emit ultrasonic waves of different frequencies from different directions toward the outer surface of the lampshade, so that the ultrasonic waves cover the outer surface of the lampshade, detect the coating thickness on the lampshade surface and send a feedback signal to the controller; the controller then judges the detection results: (1) If the maximum coating thickness is greater than the set unqualified thickness, the corresponding lampshade returns to the cleaning station, removes the surface paint, and re-sprays; (2) If the maximum coating thickness is not greater than the set unqualified thickness, the controller will perform surface coating uniformity analysis; The surface coating uniformity Q is defined as: ; in, U max is the maximum thickness of the lampshade surface coating, U min is the minimum thickness of the lampshade surface coating, U ST Design coating thickness for the lampshade; The surface coating uniformity analysis method is as follows: (1) When Q is within the set uniformity range, if U max > U ST , then the corresponding lampshade returns to the cleaning station, removes the surface paint, and re-sprays; if U max ≤ U ST , then the corresponding lampshade is sprayed again, and then the ultrasonic sensor is used to detect the spraying thickness again; (2) When Q is greater than or equal to the maximum value of the set uniformity range, the corresponding lampshade returns to the cleaning station, removes the surface paint, and re-sprays; (3) When Q is less than the minimum value of the set uniformity range, the coating thickness is qualified and the conveyor belt transports the lampshade to the subsequent workstation.

2. The coating control method of a through-type automobile lampshade UV coating line according to claim 1 is characterized in that: The uniformity range is 20% to 50%.

3. A coating control system for a through-type automotive lampshade UV coating line, used to implement the coating control method according to claim 1, the control system comprising a robot for grasping the lampshade, a spraying device for spraying, and a controller; characterized in that: An ultrasonic sensor is set on the side of the lampshade's conveying path. The ultrasonic sensor is located downstream of the spraying station and is used to detect the coating thickness of the lampshade. The ultrasonic sensor is connected to the controller signal; the robot arm is set on one side of the lampshade's conveying path, and the robot arm is controlled by the controller to perform corresponding actions.

4. A through-type automobile lampshade UV coating line, including a conveying device, characterized in that: It also includes the control system as claimed in claim 3, wherein the conveying device is further provided with a supplementary spraying station, a cleaning station and a drying station.

5. The through-type automobile lampshade UV coating line according to claim 4 is characterized in that: The conveying device is a conveyor belt, and a plurality of pairs of brackets are arranged on the conveyor belt along its conveying direction. A supporting arm for supporting the lampshade is arranged on the top of each bracket.

6. The through-type automobile lampshade UV coating line according to claim 5 is characterized in that: There are multiple robotic arms, and each workstation is equipped with a robotic arm to deliver the lampshades to be processed to or from the corresponding workstation.

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