Transformation of ordinary band sawing machine
The sawing blanking length is realized by adjusting the relative position between ruler 14 and return to the position switch. The amount of blanking is realized by the counter, and the completion of each action is detected by the position switch. Sawing speed is controlled by adjusting oil supply pressure by pressure regulating valve. The logical relation of each action is completed by relay, the drive is completed by power cylinder, and the control is completed by electromagnetic valve.
For ordinary band sawing machine, due to the change of the pressure, the hydraulic oil temperature change and the electromagnetic valve and relay the lag effect of the precision of cutting feed, thus cutting precision, batch consistency of blanking is not good. In addition, when changing the blanking length of ordinary band sawing machine, it is quite complicated to adjust the feeding length scale.
Due to the difference of sawing materials and sawblade performance, it is best to adjust the sawblade speed and sawing speed automatically in real time. For example, when the saw blade bends to a certain threshold of the system, the system reduces the speed of adaptive or closed feed. This requires major changes on the basis of the original ordinary band sawing machine, such as changing the original hydraulic unit and adding the saw blade bending monitor. The position measurement is carried out by installing grating ruler on the original ordinary sawing machine, and the original hydraulic system remains unchanged. Software security control system function design, including bin, storage retrieval, saw a classification management, material management, the material compaction, the saw blade saw blade bending monitoring speed, cutting feed speed of adaptive control, etc. In order to meet the requirement of not changing the original hydraulic system, the position control module based on the general electromagnetic valve is added.
System control reform
The closed – loop position control of servo system is easy. Ordinary solenoid valve only “on”, “off” two states, and with electromagnetic mechanical hysteresis. The temperature and pressure change of the hydraulic oil affect the positioning of the feed slide, so it is difficult to adopt the traditional control theory. In order to close the feed cylinder hydraulic feed before reaching the target position, it is the key problem to make the feed cylinder stop exactly at the target position.
The system servo position control module adopts the position control combining sampling interpolation and predictive control (the specific control is omitted). And ordinary electromagnetic valve cylinder position control module USES the learning and control, through the system experience and the current state, decided to close down the location of the feed oil cylinder, the feed cylinder stops just reached the target location. Due to the hysteresis of electromagnetic machinery and the inertia of motion, it is almost impossible to control the movement of feeding sliding platform by “on” and “off”. In order to ensure the minimum feeding length and feeding accuracy, the rear tongs make the feeding slide back to LK position and then move forward to the predicted position LT close the feeding electromagnetic valve. The tongs are clamped when the feed cylinder movement stops. The former is loosened when the latter clamping is in place, and the feeding begins when the former clamping is in place. Tongs are clamped before feeding is in place. The front tongs are loosened when the clamping is in place. After the tongs are loose in place, start to back up to prepare for the next feeding. Although the positioning system moved more than 2X (LK-L), the whole process was carried out in parallel with the sawing process.