Spraying system and method for optical diffuse scattering coating of oversize free-form surface transparent part

Abstract

The invention discloses an optical diffuse scattering coating spraying system and method for a super-huge free-form surface transparent part. A control system controls a six-degree-of-freedom robot, a workpiece rotary table and a spraying system; the rotary table is fixed to the base, the servo motor drives the outer gear ring through the speed reducer, the outer gear ring is connected with the upper rotating bat, the upper rotating bat is connected with the workpiece positioning device, and the rotary table drives a workpiece to rotate around the Z axis. The spray gun is connected with the robot through a spray gun fixing frame, the spray gun fixing frame is welded by aluminum alloy, outlets of multi-channel nozzles of the spray gun are all chamfered to form R angles, the arc lines of the radiuses are tangent to the hole walls of the channels, and fine sand grinding and cerous polishing powder mixed liquid is pressurized and circularly flows in the nozzle channels for polishing; therefore, seven-degree-of-freedom automatic spraying including six degrees of freedom and a rotary table is carried out on diffusion scattering layers on the outer surfaces of oversize free-form surface transparent organic glass rear projection screens of different models and the inner surfaces of oversize free-form surface transparent organic glass rear projection spherical screens of different models, and high uniformity of the thickness and brightness of the optical diffusion scattering layers is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of screen spraying, and in particular to a spraying system for an optical diffusing coating on a super-large free-form transparent component, and a working method of such a spraying system for an optical diffusing coating on a super-large free-form transparent component. It is mainly used in large-field flight training visual simulators, and can also be applied to fields such as education, entertainment, and commerce, such as classrooms, libraries, cinemas, and commercial advertisements. Background Art

[0002] To improve the immersion of the out-of-cabin visual scene of a flight simulator, the visual display system of a flight simulator for flight training generally uses an off-axis virtual image display system to enhance the accurate judgment of altitude, speed, and status during simulated flight. Among them, a super-large free-form acrylic rear projection screen is an important component of the virtual image visual display system. Its outer surface is sprayed with an optical diffusing layer, and this coating requires a small coating thickness error, high physical resolution, high contrast, good brightness uniformity, good color reproducibility, and a large viewing angle. To meet the above requirements, in addition to the material formula, spraying a uniform diffusing coating on the super-large free-form transparent acrylic rear projection screen has become a major problem.

[0003] To improve the spatial positioning accuracy of the out-of-cabin visual scene image of an air combat flight simulator, major flight simulator manufacturers in Western countries have launched seamless double-curvature acrylic rear projection domes. The inner surface is sprayed with an optical diffusing layer, and this coating requires a small coating thickness error, high physical resolution, high contrast, a large viewing angle, good brightness uniformity, and good color reproducibility.

[0004] Companies such as Rockwell Collins in the United States, CAE in Canada, and Barco in Europe have all launched similar products. According to relevant introductions, they all use intelligent robots equipped with special tooling to complete the spraying of the optical diffusing layer.

[0005] On the outer surface of the super-large free-form acrylic rear projection screen developed domestically, an optical diffusing layer is manually sprayed, and its relevant parameters do not meet the requirements; to meet the requirements, a foreign large-format rear projection soft plane screen is purchased and manually covered on the convex surface for use. For the super-large seamless double-curvature acrylic rear projection dome developed domestically, it is impossible to manually cover the flat rear projection soft screen into an inner concave surface, and only an optical diffusing coating can be manually sprayed, and its relevant parameters do not meet the requirements and cannot meet the use. Summary of the Invention

[0006] To overcome the defects of the prior art, the technical problem to be solved by the present invention is to provide a spraying system for an optical diffusing coating on a super-large free-form surface transparent part, which can automatically spray the diffusing layer on the outer surface of a super-large free-form surface transparent acrylic rear projection screen of different models and the inner surface of a super-large free-form surface transparent acrylic rear projection spherical screen of different models with seven degrees of freedom, so that the optical diffusing coating is sprayed on the outer surface or the inner surface of the super-large free-form surface transparent part to achieve high uniformity of the thickness and brightness of the optical diffusing layer.

[0007] The technical solution of the present invention is: This spraying system for an optical diffusing coating on a super-large free-form surface transparent part includes: a six-degree-of-freedom robot, a workpiece turntable, a spraying system, and a control system;

[0008] The six-degree-of-freedom robot has 6 movable joints, each joint rotates independently, and after combination, it performs up and down movement along the Z-axis, front and back movement along the Y-axis, left and right movement along the X-axis, rotation around the X-axis, rotation around the Y-axis, and rotation around the Z-axis;

[0009] The control system performs comprehensive control on the six-degree-of-freedom robot, the workpiece turntable, and the spraying system;

[0010] The workpiece turntable includes: a turntable, a base, a servo motor, a reducer, an external gear ring, an upper turntable, and a workpiece positioning device. The turntable is fixed on the base, and the servo motor drives the external gear ring with a diameter of 2000 mm through the reducer. The external gear ring is connected to the upper turntable, and the upper turntable is connected to the workpiece positioning device. The turntable drives the workpiece to rotate around the Z-axis;

[0011] The spraying system includes: a spray gun, a paint supply system, and a spraying control system. The spray gun is connected to the six-degree-of-freedom robot through a spray gun fixing frame. The spray gun fixing frame is processed by aluminum alloy welding. Chamfers are made at the outlets of the multi-channel nozzles of the spray gun, and the arc line of the radius is tangent to the wall of the channel hole. The nozzle channel of the spray gun is polished by pressurized circulating flow of a mixture of fine sand and high-cerium polishing powder.

[0012] The present invention performs comprehensive control on a six-degree-of-freedom robot, a workpiece turntable, and a spraying system through a control system; the turntable is fixed on a base and driven by a servo motor through a reducer to drive an external gear ring with a diameter of 2000 mm. The external gear ring is connected to an upper turntable flap, and the upper turntable flap is connected to a workpiece positioning device. The turntable drives the workpiece to rotate around the Z axis; the spray gun is connected to the six-degree-of-freedom robot through a spray gun fixing bracket. The spray gun fixing bracket is processed by aluminum alloy welding. Chamfers with a radius are made at the outlets of the multi-channel nozzles of the spray gun. The arc line of the radius is tangent to the inner wall of the channel hole, and a polishing process is carried out by pressurizing and circulating a mixture of fine sand and high-cerium polishing powder in the nozzle channel of the spray gun; Therefore, it is possible to automatically spray the outer surface of a super-large free-form transparent acrylic rear projection screen of different models and the inner surface diffusion layer of a super-large free-form transparent acrylic spherical projection screen of different models with a total of seven degrees of freedom including six degrees of freedom of the robot and one degree of freedom of the turntable, so that the optical diffusion coating is sprayed on the outer surface or the inner surface of the super-large free-form transparent part to achieve high uniformity in the thickness and brightness of the optical diffusion layer.

[0013] A working method for a spraying system of an optical diffusion coating for a super-large free-form transparent part is also provided, which includes the following steps:

[0014] (1) Polishing is carried out by pressurizing and circulating a high-cerium polishing powder mixture in the nozzle channel of the spray gun for 36 hours to reduce the frictional resistance between the coating and the inner wall of the channel hole and minimize the influence of turbulent flow at the edge of the spray spot;

[0015] (2) Place the rear projection screen corresponding to different models of spherical mirrors or different models of free-form rear projection spherical screens on the workpiece turntable. The workpiece positioning device adjusts the rotation centers of the rear projection screen or the free-form rear projection spherical screen corresponding to the positioning spherical mirror to coincide and ensure the relative position relationship with the robot;

[0016] (3) Automatically spray the outer surface of a super-large free-form transparent acrylic rear projection screen of different models and the inner surface diffusion layer of a super-large free-form transparent acrylic spherical projection screen of different models with seven degrees of freedom, so that the optical diffusion coating is sprayed on the outer surface or the inner surface of the super-large free-form transparent part to achieve high uniformity in the thickness and brightness of the optical diffusion layer; for the outer surface of a super-large free-form transparent acrylic rear projection screen of different models, spray the optical diffusion coating to achieve high uniformity in the thickness and brightness of the optical diffusion layer; for the inner surface of a super-large free-form transparent acrylic spherical projection screen of different models, spray the optical diffusion coating to achieve high uniformity in the thickness and brightness of the optical diffusion layer. Description of the Drawings

[0017] Figure 1 It is a schematic diagram of a rear projection screen.

[0018] Figure 2It is a schematic diagram of a rear projection spherical screen.

[0019] Figure 3 It is a schematic diagram of a six-degree-of-freedom robot.

[0020] Figure 4 It is a schematic diagram of a turntable.

[0021] Figure 5 It is a schematic diagram of the spraying of a rear projection screen.

[0022] Figure 6 It is a schematic diagram of the spraying of a rear projection spherical screen.

[0023] Figure 7 It is a schematic diagram of an adjustable-height base.

[0024] Figure 8 It shows a spray gun extension bracket.

[0025] Figure 9 It is a schematic diagram of the chamfering of the paint outlet hole.

[0026] Figure 10 It is a schematic diagram of the positioning and installation of rear projection screens of various models.

[0027] Figure 11 It is a schematic diagram of a waste paint recovery system.

[0028] Among them, 1, 2, 3, 4, 5, and 6 are rotatable rotating shafts, 7 is a spray gun extension bracket, 8 is a six-degree-of-freedom robot, 9 is a base, 10 is a rear projection screen, 11 is a workpiece turntable, 12 is a rear projection spherical screen, 13, 14, and 15 are rear projection screens of different types, 16 is a paint suction head, 17 is a paint suction pipeline, and 18 is a paint discharge fan. Specific implementation mode

[0029] This super-large free-form transparent optical diffusing coating spraying system includes: a six-degree-of-freedom robot (as Figure 3 shown, 1, 2, 3, 4, 5, and 6 are rotatable rotating shafts), a workpiece turntable, a spraying system, and a control system;

[0030] The six-degree-of-freedom robot 8 has 6 movable joints 1-6, and each joint rotates independently. After combination, it performs up and down movement along the Z axis, front and back movement along the Y axis, left and right movement along the X axis, rotation around the X axis, rotation around the Y axis, and rotation around the Z axis;

[0031] The control system performs comprehensive control on the six-degree-of-freedom robot, the workpiece turntable, and the spraying system;

[0032] Such as Figure 4As shown in the figure, the workpiece turntable includes: a turntable 11, a base 9, a servo motor, a reducer, an external gear ring, an upper rotating plate, and a workpiece positioning device. The turntable is fixed on the base and driven by the servo motor through the reducer to drive the external gear ring with a diameter of 2000 mm. The external gear ring is connected to the upper rotating plate, and the upper rotating plate is connected to the workpiece positioning device. The turntable drives the workpiece to rotate around the Z-axis;

[0033] The spraying system includes: a spray gun, a paint supply system, and a spraying control system. The spray gun is connected to the six-degree-of-freedom robot through a spray gun fixing bracket. The spray gun fixing bracket is processed by aluminum alloy welding. Chamfers are made at the outlets of the multi-channel nozzles of the spray gun (as Figure 9 shown), the arc line of the radius is tangent to the channel hole wall, and polishing is carried out by pressurizing and circulating a mixture of fine sand polishing and high-cerium polishing powder in the nozzle channel of the spray gun.

[0034] The present invention performs comprehensive control on the six-degree-of-freedom robot (realizing six degrees of freedom), the workpiece turntable, and the spraying system through the control system; the turntable is fixed on the base and driven by the servo motor through the reducer to drive the external gear ring with a diameter of 2000 mm. The external gear ring is connected to the upper rotating plate, and the upper rotating plate is connected to the workpiece positioning device. The turntable drives the workpiece to rotate around the Z-axis (realizing the seventh degree of freedom); the spray gun is connected to the six-degree-of-freedom robot through a spray gun fixing bracket. The spray gun fixing bracket is processed by aluminum alloy welding. Chamfers are made at the outlets of the multi-channel nozzles of the spray gun (to ensure uniform atomization of the spray spots, chamfers need to be made on the spray gun, and high-cerium powder is used for pressurized circulating polishing with water), the arc line of the radius is tangent to the channel hole wall, and polishing is carried out by pressurizing and circulating a mixture of fine sand polishing and high-cerium polishing powder in the nozzle channel of the spray gun; Therefore, automatic spraying with a total of seven degrees of freedom of six degrees of freedom plus a turntable can be realized on the outer surface of the extra-large free-form transparent acrylic rear projection screen 10 of different models and the inner surface diffusion layer of the extra-large free-form transparent acrylic rear projection dome 12 of different models, so that the optical diffusion coating is sprayed on the outer surface or the inner surface of the extra-large free-form transparent part to achieve high uniformity of the thickness and brightness of the optical diffusion layer.

[0035] Preferably, as Figure 7 shown, the base is a base with adjustable height, the length of the wrist section is lengthened, and sealing covers and robot protective suits are installed at each joint.

[0036] Preferably, the R of the chamfer is 2 mm.

[0037] Preferably, the system further includes a waste paint recovery system. In order to avoid the influence of paint mist in the air on the surface of the sprayed parts, a waste paint recovery system is added as Figure 11 shown, which can recover and process the excess waste paint in the air during the spraying process. The waste paint recovery system mainly includes: a paint suction head 16, a paint suction pipeline 17, and a paint discharge fan 18. The paint suction pipeline is connected to the paint suction head and the paint discharge fan through clamps respectively.

[0038] Preferably, the control system includes: robot control and drive, turntable control and drive, and spraying control and drive are interconnected and communicate with each other; responsible for robot motion control, spraying system switch, spray recovery system switch, and turntable linkage control; install an emergency stop button and an alarm device, and the control cabinet is placed separately outside the spraying room. The wiring with the equipment uses a cable bridge, and the circuit is functionally divided into strong electricity and weak electricity blocks for easy maintenance.

[0039] Preferably, the spraying system consists of a spray gun, a paint supply system, and a spraying control system; used for controlling and modifying spraying process parameters, spraying the inner and outer surfaces of workpieces, and the length of the spray gun fixing frame is adjusted according to the trajectory requirements, and a spray gun extension bracket 7 is provided (as Figure 8 shown).

[0040] Preferably, the open end of the positioning plate is connected to the base, and the other end is connected to the workpiece turntable base; according to the relative position relationship between different models of rear projection screens and different models of rear projection spherical screens and the robot, the position of the robot is adjusted through the positioning plate.

[0041] A working method of a spraying system for an optical diffusing coating on a super-large free-form transparent part is also provided, which includes the following steps:

[0042] (1) Pressurize and circulate a mixed solution of high-cerium polishing powder in the nozzle channel of the spray gun for 36 hours for polishing to reduce the frictional resistance between the paint flow and the channel hole wall, and minimize the turbulent flow influence at the edge of the spray spot;

[0043] (2) As Figure 1 、 2 shown, place the rear projection screen corresponding to different models of spherical mirrors or different models of free-form rear projection spherical screens on the workpiece turntable, and the workpiece positioning device adjusts the rotation centers of the rear projection screen or free-form rear projection spherical screen corresponding to the positioning spherical mirror to coincide, and ensure the relative position relationship with the robot;

[0044] (3) As Figure 5 、 6 shown, perform seven-degree-of-freedom automatic spraying on the outer surface of different models of super-large free-form transparent acrylic rear projection screens and the inner surface of different models of super-large free-form transparent acrylic rear projection spherical screens for the diffusing layer, so that the optical diffusing paint is sprayed on the outer surface or inner surface of the super-large free-form transparent part, achieving high uniformity of the thickness and brightness of the optical diffusing layer; spray the optical diffusing paint on the outer surface of different models of super-large free-form transparent acrylic rear projection screens to achieve high uniformity of the thickness and brightness of the optical diffusing layer; spray the optical diffusing paint on the inner surface of different models of super-large free-form transparent acrylic rear projection spherical screens,

[0045] Achieve high uniformity in the thickness and brightness of the optical diffusing layer.

[0046] Preferably, to ensure uniform spraying, in the step (3), control the spray width of the spray gun and the distance and angle of the spray gun relative to the workpiece to be sprayed.

[0047] Preferably, to avoid overlapping patterns caused by pressing the gun, in the step (3), each time the gun is pressed, it is 1 / 3 of the previous shot, and the starting point of each time the gun is lifted is shifted up by 15 mm.

[0048] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. Optical Diffuse Scattering Coating Spraying System for Extra-Large Free-Form Transparent Parts, Characterized in that: It includes: A six-degree-of-freedom robot (8), a workpiece turntable, a spraying system and a control system; The six-degree-of-freedom robot has 6 movable joints (1-6), each joint rotates independently, and after combination, it performs up and down movement along the Z-axis, forward and backward movement along the Y-axis, left and right movement along the X-axis, rotation around the X-axis, rotation around the Y-axis, and rotation around the Z-axis; The control system performs comprehensive control on the six-degree-of-freedom robot, the workpiece turntable and the spraying system; the workpiece turntable includes: a turntable (11), a base (9), a servo motor, a reducer, an external gear ring, an upper rotating plate, a workpiece positioning device. The turntable is fixed on the base and drives the external gear ring with a diameter of 2000mm by the servo motor through the reducer. The external gear ring is connected to the upper rotating plate, and the upper rotating plate is connected to the workpiece positioning device. The turntable drives the workpiece to rotate around the Z-axis; The spraying system includes: a spray gun, a paint supply system and a spraying control system. The spray gun is connected to the six-degree-of-freedom robot through a spray gun fixing bracket. The spray gun fixing bracket is processed by aluminum alloy welding. Chamfers with an R angle are made at the outlets of the multi-channel nozzles of the spray gun. The arc line of the radius is tangent to the wall of the channel hole, and polishing is carried out by pressurizing and circulating a mixture of fine sand and high-cerium polishing powder in the nozzle channel of the spray gun.

2. The optical diffuse scattering coating spraying system for extra-large free-form transparent parts according to claim 1, Characterized in that: The base is a base with adjustable height, the length of the wrist section is lengthened, and sealing covers and robot protective clothing are installed at each joint.

3. The optical diffuse scattering coating spraying system for extra-large free-form transparent parts according to claim 2, Characterized in that: The R of the chamfer with an R angle is 2mm.

4. The optical diffuse scattering coating spraying system for extra-large free-form transparent parts according to claim 3, Characterized in that: The system further includes a waste paint recovery system, which includes: a paint suction head (16), a paint suction pipeline (17), a paint discharge fan (18). The paint suction pipeline is connected to the paint suction head and the paint discharge fan respectively through clamps.

5. The optical diffuse scattering coating spraying system for extra-large free-form transparent parts according to claim 4, Characterized in that: The control system includes: robot control and drive, turntable control and drive, and spraying control and drive are interconnected and communicate with each other; responsible for robot motion control, spraying system switch, spray recovery system switch and rotary table linkage control; install an emergency stop button and an alarm device. The control cabinet is placed separately outside the spraying room, and the wiring with the equipment uses a cable bridge. The circuit is functionally divided, with strong electricity and weak electricity divided for easy maintenance.

6. The optical diffuse scattering coating spraying system for extra-large free-form transparent parts according to claim 5, Characterized in that: The spraying system consists of a spray gun, a paint supply system and a spraying control system; used for controlling and modifying spraying process parameters, spraying the inner and outer surfaces of the workpiece. The length of the spray gun fixing bracket is adjusted according to the trajectory requirements, and a spray gun extension bracket (7) is set.

7. The optical diffuse scattering coating spraying system for extra-large free-form transparent parts according to claim 6, Characterized in that: The open end of the positioning clamp is connected to the base, and the other end is connected to the workpiece turntable base; according to the relative position relationship between different models of rear projection screens (10) and different models of rear projection spherical screens (12) and the robot, the position of the robot is adjusted through the positioning clamp.

8. The method of the spraying system for the optical diffusing coating of super-large free-form transparent parts according to claim 1, characterized in that: it includes the following steps: (1) Pressurize and circulate the high-cerium polishing powder mixture in the nozzle channel of the spray gun for 36 hours for polishing to reduce the frictional resistance between the coating and the channel hole wall during flow, and minimize the influence of the turbulent flow at the edge of the spray spot; (2) Place the rear projection screen corresponding to different models of spherical mirrors or different models of free-form rear projection spherical screens on the workpiece turntable, and the workpiece positioning device adjusts the rotation centers of the rear projection screen corresponding to the positioning spherical mirror or the free-form rear projection spherical screen to coincide, and ensure the relative position relationship with the robot; (3) Automatically spray the outer surface of different models of super-large free-form transparent acrylic rear projection screens and the inner surface diffusing layer of different models of super-large free-form transparent acrylic rear projection spherical screens with seven degrees of freedom, so that the optical diffusing coating is sprayed on the outer surface or inner surface of the super-large free-form transparent part, achieving high uniformity of the thickness and brightness of the optical diffusing layer; spray the optical diffusing coating on the outer surface of different models of super-large free-form transparent acrylic rear projection screens to achieve high uniformity of the thickness and brightness of the optical diffusing layer; spray the optical diffusing coating on the inner surface of different models of super-large free-form transparent acrylic rear projection spherical screens to achieve high uniformity of the thickness and brightness of the optical diffusing layer.

9. The method of the spraying system for the optical diffusing coating of super-large free-form transparent parts according to claim 8, characterized in that: in the step (3), the spray width of the spray gun and the distance and angle of the spray gun relative to the workpiece to be sprayed are controlled.

10. The method of the spraying system for the optical diffusing coating of super-large free-form transparent parts according to claim 8, characterized in that: in the step (3), each time the gun is pressed is 1 / 3 of the previous shot, and the starting point of each time the gun is lifted is moved up by 15 mm.

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