Application of the hottest time servo system in au

Application of time servo system in automatic welding machine project

1. Project introduction

the circumferential seam automatic welding machine of this project is mainly a process device that places the workpiece in any convenient welding position through the tilting and rotary action of the workbench, which is used for the assembly, automatic welding, cutting, etc. of circumferential seam welding (frame, base, flange, spherical container, head, top cover, etc.) of rotary body weldments

before the transformation, the driving part used stepping motor, which has the following disadvantages: unstable speed, low precision, no positioning automatic welding function, and single function. After the transformation, its basic action is that the workpiece is directly driven by the AC asynchronous motor through the reducer, the welding gun is fixed, and the arc starting and arc extinguishing of the welding gun are controlled through the output port. The welding workbench is shown in Figure 1

the functions required to be realized by the reformed circumferential seam automatic welding machine are as follows:

① automatic welding, that is, after pressing the start button, the welding machine automatically realizes all functions

② manual welding, manually control the rotary head by pressing the forward rotation, reverse rotation and stop buttons on the touch screen

③ segmented welding, a circle can be divided into N equal parts through parameter setting, and the angle to be welded in each equal part can be set through parameters

④ the three welding methods can be switched arbitrarily

⑤ through the touch screen, you can modify the welding speed, lap amount, number of welding circles, number of segments, etc. at any time

2. Solution

the whole operation is completely programmed and controlled by the servo controller, using positioning control. The input and output ports of the controller are used to process and control external signals and equipment. 422 communication is used between the touch screen and the controller to modify the operating parameters of the controller. The principle block diagram is shown in Figure 2

principle block diagram

hardware configuration: 400V 200W IMS series servo controller

200w AC asynchronous motor

2500 line photoelectric encoder

hitech pws-1711 touch screen

parameter setting screen

3. After the project implementation

system is powered on for the first time, all welding parameters are in the state to be set, and their initial values are 0. Enter the parameter setting screen (as shown in Figure 3). Set the welding parameters as shown in the picture. Return to the monitoring screen (as shown in Figure 4). At this time, the parameters are displayed according to the settings. Next time you power on, directly enter the monitoring screen to display the parameters set last time

parameter monitoring screen

· manual operation: enter the manual operation interface, as shown in Figure 5, press "forward rotation", and the machine head rotates forward

; Press "stop" with high accuracy, and the machine head stops; Press "reverse" and the nose rotates in reverse

· automatic welding: when continuous welding is selected, install the workpiece manually, press the "start" button on the control panel, and the system will automatically complete the following functions: start the welding procedure → arc striking of the welding machine → after reaching a certain welding current, the workpiece will automatically rotate and start normal welding → after reaching the required number of welding turns and lap, the welding machine will stop the arc according to the arc stopping time, The machine head stops rotating → the workpiece is removed manually → the automatic welding procedure is completed

in automatic welding, there are "locked" and "non locked" options for different welders

-- picture mark 5--

· segmented welding: a special function of automatic welding. The total length of welding is one circle during segmented welding. After selecting

segment welding, the system divides a circle into N equal parts according to the set number of welding segments, and welds at the starting point of each equal part according to the set segment length. As shown in Figure 6, n = 2, and the overlap is 90 degrees. After pressing the "start" button, the machine head rotates and arcs at the same time. After rotating the set segment length, the machine head does not stop and extinguishes the arc at the same time until the starting point of the next segment, and the welding of one segment is completed. At the same time, the welding of the next segment is started until the set number of segments is completed. One stage automatic welding is completed

example of segmented welding

during the welding process of automatic welding and segmented welding, press the "emergency stop" button, the welder stops the arc and the machine head stops. Restore the "emergency stop" button, and then press the "start" to complete the remaining actions according to the state before the emergency stop

4. Project effect

before the transformation, the welding machine uses the drive of the stepping motor to complete the rotation of the workpiece, and can only complete some simple manual welding functions. After the transformation, the functions are enriched and the performance is improved

· when the motor running speed is lower than 60Hz, it can achieve three times of the motor. 5. The maximum axial compression force of the driven plate: 20000n rated torque output, especially when the welding machine works at low speed for a long time, which effectively solves the weakness of insufficient torque output of the frequency converter at low speed

· IMS servo controller adopts encoder feedback for positioning control. The maximum accuracy of position control is ± 1 pulse number, and the positioning accuracy is high

· after each restoration of the emergency stop state, press the start button to continue the state before the emergency stop and complete the rest of the actions, that is, the state of technical requirements for the cylinder configuration of the welding hydraulic system before the emergency stop and the state of welding after restoration; Before the emergency stop, it is in the arc extinguishing and idling state, and after the recovery, it is in the arc extinguishing and idling state, and the remaining length is completed at the same time

the operating parameters of the modified welding machine are as follows: