PLC-based multi-axis motion precise control tooling

Abstract

The utility model belongs to the field of aviation manufacturing technology relates to a kind of multi-axis movement accurate control tool based on PLC, it mainly includes base body, lifting platform, electrical control cabinet, touch screen, industrial computer, the automatic control of PLC control system is realized the accurate control of multi-axis load movement, highest precision reaches ±0.01mm.Effectively solve the positioning assembly demand of product under the condition of multi-axis multidirectional, and improve product positioning accuracy, reduce worker's labor intensity, realized the smooth controllable of product component extension directional movement, and the automatic compensation of fixed point displacement, movement process time is significantly less than the time consumed by manual adjustment, one-key start after the parameter setting of speed, direction, simple and reliable operation, significantly improve product component assembly efficiency and quality.

Description

Technical Field

[0001] This utility model belongs to the field of aerospace manufacturing technology and relates to a PLC-based multi-axis motion precision control tooling. Background Technology

[0002] In the process of assembling product parts and components, in order to ensure the correctness of the assembly or docking coordination, the orderliness of the assembly steps, and the positioning accuracy of the relative positions, it is necessary to use assembly tooling to complete clamping, positioning, fixing and support, and orderly assembly.

[0003] The existing method for assembling product parts and components involves using traditional mechanical assembly fixtures. Following the assembly process and the structural characteristics of the product components, the parts are clamped and positioned separately, then manually adjusted to their theoretical assembly positions before coordinated assembly. For parts requiring single-axis orientation assembly, the reciprocating motion of the lead screw or guide rail is manually adjusted to achieve axial movement and positioning. Positioning accuracy can be verified using calipers or a laser tracker. For parts requiring orientation assembly along two or more axes, manual adjustment mechanisms are needed in each axis's direction of movement. After the overall assembly is completed according to the assembly process, a laser tracker or inspection fixture is used for conformity checks. For parts and components requiring multi-axis orientation assembly, manual adjustment of the orientation movement suffers from drawbacks such as unstable and uncontrollable speed, low and difficult-to-adjust positioning accuracy, lack of displacement data feedback, and cumbersome operation.

[0004] To effectively address the positioning and assembly requirements of components under multi-axis and multi-directional conditions, improve product positioning accuracy, and reduce worker labor intensity, this invention proposes a multi-axis motion precision control fixture based on a PLC control system. This fixture combines the mechanical structure of existing assembly fixtures of this type with a manual adjustment and control method for motion. Utility Model Content

[0005] 1. Technical problems to be solved

[0006] This invention addresses the shortcomings of existing technologies, such as low positioning accuracy of single-axis load motion, inability to adjust speed, and inability to link multi-axis load motion. It provides a novel tooling structure, incorporating the design concept of mechatronics tooling and adopting an electronic control mode. The original manual adjustment of linear motion is replaced by PLC-based automatic feedback adjustment. Whether it is single-axis motion or multi-axis linkage, it achieves stable and controllable directional motion speed and automatic compensation of fixed-point displacement. The motion process time is significantly less than the time consumed by manual adjustment. After setting the speed and direction parameters, it can be started with one key. The operation is simple and reliable, significantly improving the assembly efficiency and quality of product parts and components.

[0007] 2. Technical Solution

[0008] A PLC-based multi-axis motion precision control fixture is characterized by comprising a base 1, a lifting platform 2, an electrical control cabinet 3, a touch screen 4, and an industrial computer 5. The base 1 is a rectangular welded frame structure. L-shaped baffles are welded to the four columns at the top of the base 1. A flat plate is laid on the bottom of the base 1, and four guide pillars 6 are bolted to the four corners of the plate. A hydraulic lift 7, an electric oil pump 8, a drive motor 9, and a hydraulic system control cabinet 10 are installed in the middle of the plate. The inlet and outlet oil pipes of the hydraulic lift are connected to the electric oil pump, and the drive motor and hydraulic control cabinet are connected through the oil pump's data cable and solenoid valve. Together, they constitute a hydraulic lifting mechanism in the vertical direction (i.e., the Z-axis). The lifting platform 2 is equipped with an adjustment plate 11, a slide rail 12, a slider 13, a ball screw linear module A14, and a servo motor A15. The lower part of the adjustment plate 11 is connected to the platform 2 by screws, and the upper part is connected and fixed to the slide rail 12 by slide rail screws. The slider 13 is connected to the slide rail 12 by ball engagement, so that the slider 13 slides linearly along the slide rail 12. The ball screw linear module A14 is set at the symmetrical center of the two sets of slide rails 12, and one end is connected to the servo motor A15 through a coupling and a reducer, together forming a linear motion mechanism in the length direction (i.e., the Y-axis).

[0009] A rectangular moving stage 16 is connected to four sliders 13. The rectangular moving stage 16 is equipped with a reference plate 17, a ball screw linear module B18, a docking joint 19, a reference joint 20, and a servo motor B21. The lower part of the reference plate 17 is connected to the rectangular moving stage 16 by bolts, and the upper part is connected and fixed to the ball screw linear module B18 and the reference joint 20 by pins and screws. One end of the ball screw linear module B18 is connected to the servo motor B21 through a coupling and a reducer, and the upper part is connected to the docking joint 19, which together form a linear motion mechanism in the width direction (i.e., the X-axis).

[0010] The entire tooling is connected to the electrical control cabinet 3 via power cables and data cables. The touch screen 4 is embedded in the panel of the electrical control cabinet 3. The electrical control cabinet 3 is connected to the industrial control computer 5 via signal transmission lines. The industrial control computer 5 acts as a host computer and is connected to a regular computer monitor for editing and debugging of the control program.

[0011] The L-shaped baffle on the base 1 is connected and fixed to the lifting platform 2 by a quick-release pin. When lifting is required, the quick-release pin is removed; the accuracy of the Y-axis linear motion is ±0.05mm.

[0012] Furthermore, screw holes are reserved on the L-shaped baffle. After the Z-axis lifting motion is completed, in order to prevent relative slippage during the X-axis and Y-axis movements, the lifting platform 2 is connected and fixed to the base 1 by screws.

[0013] The frame of the lifting platform 2 is a two-layer structure. The lower layer is a rectangular welded frame. The upper working platform is fixed to the frame with screws. Adjustment plates 11 are set on both sides of the working surface of the working platform for installing linear motion mechanisms. To ensure the overall rigidity and stability of the motion mechanism, the adjustment plates are formed by CNC machining and the material is 45 steel.

[0014] Furthermore, a slide rail 12 and a slider 13 are provided above the adjustment plate 11. To ensure the stability and accuracy of linear motion, the slide rail 12 and the slider 13 are used in combination. The straightness of the slide rail is 0.05, and the repeatability of the slider is ±0.01mm. A ball screw linear module A14 is provided at the symmetrical center position of the two adjustment plates 11.

[0015] Furthermore, the slider on the ball screw linear module A14 is connected and fixed to the rectangular moving stage 16. The reciprocating motion of the ball screw drives the rectangular moving stage 16 and the X-axis linear motion mechanism to perform linear motion along the Y-axis, with a motion accuracy of ±0.01mm.

[0016] Furthermore, the slide rail 12 is provided with a mechanical zero-position block 22 and a mechanical limit block 23 on its side; together with the positioning pin, it not only serves as a mechanical protection measure when the electronic control system fails, but also as a means of checking the displacement accuracy during electronic control operation.

[0017] The rectangular moving stage 16 has a frame divided into two sides. The lower layer is a rectangular welded frame. The upper part of the frame is connected and fixed to the reference plate 17 with screws. Two sets of X-axis ball screw linear modules C21 are set on the reference plate 17, which can realize synchronous and asynchronous movement in the X-axis direction with a movement accuracy of ±0.01mm. Therefore, the two sets of modules are defined as X1 axis and X2 axis respectively.

[0018] The ball screw linear module B18 is connected to the servo motor B21 via a coupling on one side, and a reference joint 20 is provided on the other side. A fixed docking joint 19 is connected to the module slider.

[0019] Furthermore, the docking joint 19 and the reference joint 20 can be used as a precision testing device for motion displacement. The slider drives the docking joint 19 to make linear motion. After moving to the positioning hole on the reference joint, the positioning pin is inserted for verification. After the docking joint 19 is disassembled, it can be connected to other motion loads. Similarly, after the reference joint is disassembled, it can be designed as other docking devices.

[0020] The electrical control cabinet 3 is the external control system of the entire tooling set. It is independent of the main structure of the tooling and communicates with the main structure of the tooling through power cables and encoder cables. The electrical control cabinet is equipped with the functional modules of the PLC control system, including CPU, non-adjustable power supply module (5KW and 10KW), servo motor drive module, control module, programmable controller, reactor, filter, relay, contactor, and connecting cables.

[0021] Furthermore, the external dimensions of the electrical control cabinet 3 can be modified according to the site environment of the tooling and the number of functional modules of the PLC control system. Ventilation vents can be installed on either side of the cabinet, and the installation positions of the touch screen 4 and the emergency stop button are determined according to the user's operating habits.

[0022] Furthermore, retractable dust covers are installed on the external parts of the ball screws on the X-axis ball screw linear module B18 and the Y-axis ball screw linear module A14, and are fixed to the ball screw linear module by screws.

[0023] Beneficial effects

[0024] This invention provides a PLC-based multi-axis motion precision control fixture, which effectively solves the problem of inaccurate control and adjustment of linear load motion speed and displacement compared with the existing assembly fixtures that rely on manual adjustment of linear motion. It meets the linkage or differential motion requirements of multi-axis load motion. In addition, it introduces the concept and structure of mechatronics into traditional mechanical fixtures. By combining the PLC-based control system with electrical equipment and mechanical structure, the motion process is smooth, highly controllable and scalable, which can greatly improve the labor intensity of workers, increase production efficiency and assembly manufacturing quality. Attached Figure Description

[0025] This utility model includes four accompanying drawings, and the drawings and their descriptions are as follows:

[0026] Figure 1 This is a schematic diagram of the structure of this utility model;

[0027] The components include: 1. Base; 2. Lifting platform; 3. Electrical control cabinet; 4. Touch screen; 5. Industrial computer;

[0028] Figure 2 This is a schematic diagram of the Z-axis hydraulic lifting mechanism of this utility model;

[0029] Among them: 6. Guide pillar; 7. Hydraulic lift; 8. Electric oil pump; 9. Drive motor; 10. Hydraulic system control cabinet;

[0030] Figure 3 This is a schematic diagram of the Y-axis linear motion mechanism of this utility model;

[0031] Among them: 11. Adjustment plate; 12. Slide rail; 13. Slider; 14. Ball screw linear module A; 15. Servo motor A; 22. Mechanical zero block; 23. Mechanical limit block;

[0032] Figure 4 This is a schematic diagram of the X-axis linear motion mechanism of this utility model;

[0033] Among them: 16. Rectangular moving stage; 17. Reference plate; 18. Ball screw linear module B; 19. Butt joint; 20. Reference joint; 21. Servo motor B. Detailed Implementation

[0034] The present invention will be further described in detail with reference to the accompanying drawings and specific embodiments:

[0035] A multi-axis motion precision control fixture based on a PLC control system is provided, mainly including a base 1, a lifting platform 2, an electrical control cabinet 3, a touch screen 4, and an industrial computer 5. The base 1 contains a hydraulic lifting mechanism that provides vertical (Z-axis) motion, and the lifting platform 2 contains a linear motion mechanism that provides linear motion in the length direction (Y-axis) and a linear motion mechanism that provides linear motion in the width direction (X-axis). The linear motion mechanism in the width direction (X-axis) includes two sets of linear motion mechanisms, namely the X1-axis linear motion mechanism and the X2-axis linear motion mechanism, which can achieve linkage and differential.

[0036] This utility model, as a typical combination structure of mechatronics assembly tooling, is suitable for providing precise control of directional displacement when product components have assembly requirements in single-axis or multi-axis directions. The speed and positioning accuracy adjustment during the movement process is based on a PLC control system, with automatic adjustment achieved through data feedback from an absolute position encoder. Users can independently set parameters such as motion mode, speed, displacement, and time, and control the system via a touchscreen. Single-person operation not only features flexible control and simple operation, but also allows for the addition of suitable load units to the sliders of the ball screw linear module A14 or ball screw linear module B18 according to changes in the load structure at the application site, effectively expanding the scope of application of this utility model.

[0037] After the test module or product components are connected and fixed on the working surface of each axis motion mechanism, power on the electrical control cabinet 3 and the industrial computer 5, turn on the contactor in the electrical control cabinet 3 and the switch of the industrial computer 5. The computer HMI operation screen displays the communication status between the PLC and the driver and encoder. Green indicates normal operation, and red indicates a fault. The touch screen 4 displays the actual speed, actual position, current zero point position of the three servo motion axes, as well as the enable status of each axis. At this time, the position, speed, and jog speed of the three servo axes can be set. Then, operate the button on the screen to start. Each axis performs linear motion and fixed-point displacement according to the set parameters. The button is a pulse button. Releasing the button stops the servo axis. "Emergency Stop" (the emergency stop button is a self-holding button, the opposite of the normal button state) is red and set to 0 the first time it is pressed, and green and set to 1 the second time it is pressed. If a fault occurs, press the emergency stop button to stop the equipment. The button is red and set to 0. After the fault disappears, press the emergency stop button again to reset the button. The button is green and set to 1. "Alarm Confirmation" is an alarm confirmation button and an alarm reset button. After an alarm occurs, the alarm is processed. After processing, press the alarm confirmation button to clear the alarm.

[0038] The "Zero Point" button is for setting the zero point of the servo axis absolute positioning control. The zero point marker name cannot be set; the default is "0". Before resetting the zero point, the soft limit switch must be turned off. After resetting the zero point, modify the negative and positive positions of the soft limit switch according to the effective travel distance. Then, re-enable the soft limit switch and modify the position parameters of each servo axis in the program (they must be within the effective travel distance; if the soft limit switch is enabled and the effective travel distance is exceeded, a soft limit alarm will be triggered, causing the axis to stop. If the soft limit switch is not enabled, the X-axis may run off the slide rail. The Y-axis will trigger the F07900 motor stall alarm). After modification, re-download the program.

[0039] For the hydraulic lifting motion along the Z-axis, the same starting method is used to control it as the X and Y axes on the touch screen 4. However, the difference is that the Z-axis lifting uses a hydraulic pump, motor, solenoid valve, and relay as the drive and control. Unlike the control of the servo axis, the PLC control system does not control the speed and fixed-point displacement of the Z-axis, but only controls the lifting time. Its advantages are: first, it reduces the logic operation of the entire control system and increases the stability of the control system; second, the axis that mainly bears the heavy load uses a hydraulic mechanism, and the power output is greater than the output force provided by the electric servo motor.

[0040] After the work is completed, first disconnect the DC24V power supply on the control cabinet, that is, turn off the power supply path of the PLC power module, then disconnect the contactor switch, that is, turn off the overall path of the control cabinet, and finally turn off the main power supply to complete the work.

Claims

1. A PLC-based multi-axis motion precision control fixture, characterized in that, The main components include a base (1), a lifting platform (2), an electrical control cabinet (3), a touch screen (4), and an industrial computer (5). The base (1) is a rectangular welded frame structure. L-shaped baffles are welded on the four columns at the top of the base (1). A flat plate is laid on the bottom of the base (1). Four guide pillars (6) are bolted to the four corners of the flat plate. A hydraulic lift (7), an electric oil pump (8), a drive motor (9), and a hydraulic system control cabinet (10) are set in the middle of the flat plate. The inlet and outlet oil pipes of the hydraulic lift are connected to the electric oil pump, and the drive motor and hydraulic control cabinet are connected through the data line of the oil pump and the solenoid valve. Together, they form a vertical hydraulic lifting mechanism. The lifting platform (2) is equipped with an adjustment plate (11), a slide rail (12), a slider (13), a ball screw linear module A (14), and a servo motor A (15). The lower part of the adjustment plate (11) is connected to the lifting platform (2) by screws, and the upper part is connected and fixed to the slide rail (12) by slide rail screws. The slider (13) is connected to the slide rail (12) by ball engagement, so that the slider (13) slides linearly along the slide rail (12). The ball screw linear module A (14) is set at the symmetrical center of the two sets of slide rails (12), and one end is connected to the servo motor A (15) through a coupling and a reducer, together forming a linear motion mechanism in the length direction. A rectangular moving platform (16) is connected to four sliders (13). A reference plate (17), a ball screw linear module B (18), a docking joint (19), a reference joint (20), and a servo motor B (21) are set on the rectangular moving platform (16). The lower part of the reference plate (17) is connected to the rectangular moving platform (16) by bolts, and the upper part is connected and fixed to the ball screw linear module B (18) and the reference joint (20) by pins and screws. One end of the ball screw linear module B (18) is connected to the servo motor B (21) through a coupling and a reducer. The upper part of the module is connected to the docking joint (19), which together form a linear motion mechanism in the width direction. The entire tooling is connected to the electrical control cabinet (3) via power cables and data cables. The touch screen (4) is embedded in the panel of the electrical control cabinet (3). The electrical control cabinet (3) is connected to the industrial computer (5) via signal transmission lines. The industrial computer (5) is connected to a regular computer monitor as a host computer to edit and debug the control program.

2. The PLC-based multi-axis motion precision control fixture according to claim 1, characterized in that, The L-shaped baffle on the base (1) is connected and fixed to the lifting platform (2) by a quick-release pin. When lifting is required, the quick-release pin is pulled out. The accuracy of the linear motion of the Y-axis is ±0.05mm.

3. The PLC-based multi-axis motion precision control fixture according to claim 2, characterized in that, Screw holes are reserved on the L-shaped baffle. After the Z-axis lifting motion is completed, in order to prevent relative sliding during the X-axis and Y-axis movements, the lifting platform (2) is connected and fixed to the base (1) by screws. The frame of the lifting platform (2) is a two-layer structure. The lower layer is a rectangular welded frame. The upper working platform is fixed by screws on the top of the frame. Adjustment plates (11) are set on both sides of the working surface of the working platform for installing linear motion mechanisms. The adjustment plates are formed by CNC machining and the material is No. 45 steel.

4. The PLC-based multi-axis motion precision control fixture according to claim 1, characterized in that, A slide rail (12) and a slider (13) are set above the adjustment plate (11). In order to ensure the stability and accuracy of linear motion, the slide rail (12) and the slider (13) are used in combination. The straightness of the slide rail is 0.05, and the repeatability of the slider is ±0.01mm. A ball screw linear module A (14) is set at the symmetrical center position of the two adjustment plates (11).

5. The PLC-based multi-axis motion precision control fixture according to claim 4, characterized in that, The slider on the ball screw linear module A (14) is connected and fixed to the rectangular moving stage (16). The reciprocating motion of the ball screw drives the rectangular moving stage (16) and the X-axis linear motion mechanism to perform linear motion along the Y-axis, with a motion accuracy of ±0.01mm.

6. The PLC-based multi-axis motion precision control fixture according to claim 5, characterized in that, Mechanical zero-position block (22) and mechanical limit block (23) are provided on the side of the slide rail (12); In conjunction with the positioning pin, it serves as a mechanical protection measure in case of failure of the electronic control system and as a means of verifying displacement accuracy during electronic control operation; The frame of the rectangular moving stage (16) is divided into two side structures. The lower layer is a rectangular welded frame. The upper part of the frame is connected and fixed with screws to the reference plate (17). Two sets of X-axis ball screw linear modules B (18) are set on the reference plate (17), which can realize synchronous and asynchronous movement in the X-axis direction. The movement accuracy is ±0.01mm. Therefore, the two modules are defined as X1 axis and X2 axis respectively. The ball screw linear module B (18) is connected to the servo motor B (21) on one side via a coupling, and a reference joint (20) is provided on the other side. A fixed docking joint (19) is connected to the module slider.

7. The PLC-based multi-axis motion precision control fixture according to claim 6, characterized in that, The docking joint (19) and the reference joint (20) can be used as a precision testing device for motion displacement. The slider drives the docking joint (19) to make a linear motion. After moving to the positioning hole on the reference joint, the positioning pin is inserted for verification. The electrical control cabinet (3) is the external control system of the entire tooling set. It is independent of the main structure of the tooling and communicates with the main structure of the tooling through power cables and encoder cables. The electrical control cabinet is equipped with functional modules of the PLC control system, including CPU, non-adjustable power supply module, servo motor drive module, control module, programmable controller, reactor, filter, relay, contactor and connecting cable.

8. The PLC-based multi-axis motion precision control fixture according to claim 7, characterized in that, The external dimensions of the electrical control cabinet (3) can be changed according to the site environment of the tooling and the number of functional modules of the PLC control system. Ventilation vents can be set on any two sides of the cabinet. The installation positions of the touch screen (4) and emergency stop button are determined according to operating habits.

9. A PLC-based multi-axis motion precision control fixture according to claim 8, characterized in that, Retractable dust covers are installed on the external ball screws of the X-axis ball screw linear module B (18) and the Y-axis ball screw linear module A (14).

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