Automatic spread of the structure shown in Figure 1. Cable uses lag angle cable, servo motor through roller screw and slide the cable device to promote a certain angle cable. In the closing line of the diameter spool area from side to side when the cable, the entire area is divided into general tracking and tracing for the two regions. In general, the regional fixed-lag tracking angle tracking mode, variable-angle region for the tracking mode. As the Types Of Welding Wiresin the edge layer Raozhi spool, it will automatically layer around the opposite direction, in the process, does not allow a forward angle layer around the wire, otherwise there will be gaps between the wire, the next layer of the defects, layer around the will be forced to interrupt. Therefore, to change the angle of detection and control of the region is essential.
Automatic switching by reversing the direction of movement marked the formation of linear units, set the left switch for the right line to sign left-reset flag; switch set to the right for left-flag, reset right-line flag. Take-back line with the rising edge of the switch unit will be around to walk a straight line sign is inverted. The right to change the closing line, for example, when the right moment for action to the switch, linear units to 6 times the base speed fast forward to β ≤ 0; when the main motor to continue rotating, linear unit to the base rate continues to track, when the wire wound close to work the right-most circle round the word line, the line unit to stop, and reset the unit the right straight line flag, set the left-line flag. Similarly, close to the line in left for the right change to the closing line. Take-left line, angle, center angle + α ≤ maintain lag angle; the right line, angle, center angle α to maintain ≥ - lag angle. For the process to change the angle of the region, such as.
2 control system structure and working principle
2.1 Control System Architecture
Cable device according to cable theory, the control system must first complete real-time detection angle cable. Design uses a 1000-line incremental encoder with the PLC program to achieve the combination of digital cable angle sensor for real-time detection angle, the sensor resolution of 0.09 °, to meet the minimum wire diameter of 0.8mm of the upper perimeter of the spindle angle detection requirements; through the action switches to achieve close to linear unit area normal to the regional and change tracking; output pulse through the PLC control servo motor drive unit to run a straight line .
2.2 linear unit works
Linear units moving speed should match the spindle speed. Installed on the spindle speed sensor, a measurement of the rotation of the spindle angular velocity N (rev / sec). Spool on the wire along the axis of the moving speed V = N * Φ, where Φ for the Cast Iron Welding Wire diameter, the unit mm, V the unit mm / s. In order to maintain the cable wire on the body and the spindle speed of synchronization, that is to maintain a fixed phase angle, linear unit of the advance should be equal to V. To ensure accurate synchronization lag angle, road speed line unit should be equal to the angle loop with the output value V (offset), V into the servo motor speed (pulses / s) to:
Pulse rate = M * N * Φ / d (a / s) (1)
Where, N is the spindle rotation angular velocity (rev / sec), Φ for the wire diameter (mm), M is the servo motor encoder number of lines per circle, d is the lead screw roller (mm / rev) .
According to equation 2-1 servo motor pulse rate of a given formula, the range 0 ~ 25000 P / S, so the MV output saturation limit should be set on a 2500 P / S.
3 programming based on angle control
3.1 cable angle detection
4-octave high-speed counter hardware working mode, the interrupt service routine to achieve zero angle sensor function. If the program 1.
3.2 Spindle Speed ??Detection
With M Velocimetry to a fixed time interrupt (not PLC program scan time) way to measure the spindle speed, that is, every 0.4 seconds by the optical encoder pulse count value of a measurement of the spindle speed.
1, the larger the weld cooling rate, the intensity increased, the weld joints prone to crack under adverse circumstances, the choice of a lower strength than the base metal electrode level. Such as thick multi-layer welding or soldering treatment after normalizing the situation, you need to prevent the low intensity of the situation. 2, the same intensity level of acidity or alkaline welding rod selection. To the requirements of good plasticity, high toughness, low temperature performance, ability to use crack alkaline electrode. Such as the DC power supply difficulties, the choice of AC-DC dual-use alkaline Types Of Welding Electrodes. 3, for low carbon steel and low alloy steel, or between low-alloy and low alloy steel welded joints between dissimilar steels is generally used with a lower strength grade of steel box to adapt the welding material. 4, medium carbon steel welding. As the high carbon content in carbon steel, welding cracks tend to large, low hydrogen electrode can be used or weld metal with good ductility and toughness of the welding rod and welding pieces of gentle warm-cold treatment. 5, steel welding. High carbon content steel, thickness, shape complexity, easy to crack, especially the steel in the higher content of alloying elements. Choice of low hydrogen electrodes, and to take appropriate preheat and alloy process. 6, the workpiece, such as by preheating, welding current can be reduced when compared with no warm-up 5 to 15%; when using DC than AC can be reduced by 10%; Li Yang welding, soldering and welding than the horizontal by 10 to 15%. 7, the indoor welding, the need to pay attention to ventilation; outdoor welding, the operator should be on the outlet to reduce the inhalation of welding fumes. 8, with a grade of "B" (RH) and "Ni" of the Cast Iron Welding Wire, the hydrogen series ultra-low-high toughness electrodes, important structural parts for welding.