Operating Instructions for the Power Press

Mechanical Work

Due to the poor lubrication of the punch press, the frictional resistance increases when the table moves. When the motor is driven, the table does not move forward, so that the ball screw is elastically deformed, and the energy of the motor is stored in the deformation. The motor continues to drive, and when the elastic force generated by the stored energy is greater than the static friction force, the punching table creeps forward, and moves in this way over and over again, resulting in the phenomenon of crawling. However, this is not the case. If you look closely at the lubrication of the guide rail surface, you can conclude that this is not the problem. Punch crawling and vibration problems are speed problems. Since it is a problem of speed, we need to find the speed loop. The entire adjustment process of the speed of the punch is completed by the speed regulator.

The operation and monitoring of the CNC punch are all done in this CNC unit, which is the brain of the CNC punch. High machining accuracy and stable machining quality; multi-coordinate linkage can process parts with complex shapes; when machining parts are changed, generally only the CNC program needs to be changed, which can save production preparation time; the bed itself has high precision and high rigidity, Favorable processing dosage can be selected, and productivity is high. For speed-related problems, you can only go to the speed regulator. Therefore, the vibration problem of the punch press also needs to find the speed regulator. The fault of the speed regulator can be found from the following places: one is the given signal, the other is the feedback signal, and the other is the speed regulator itself.

Because the vibration frequency of the punch press is proportional to the motor speed, first check whether the motor is faulty, check its carbon brushes, the surface condition of the commutator, and the mechanical vibration, and check the lubrication of the ball bearings. For inspection, it is not necessary to disassemble it all, but it can be observed by an inspector, and the bearing can be inspected by listening to the sound. If there is nothing wrong, check the tachogenerator. Tachogenerators are generally DC.

The punch tachometer generator is a small permanent magnet DC generator, and its output voltage should be proportional to the speed, that is, the output voltage and speed are linear. As long as the rotation speed is constant, its output voltage waveform should be a straight line, but due to the influence of the cogging and the commutation of the commutator, a tiny alternating variable is attached to this straight line. For this reason, a filter circuit is added to the speed measurement feedback circuit, and this filter circuit is to weaken the AC component attached to the voltage.

The punch feedback signal and the given signal are the same for the regulator. Therefore, the fluctuation of the feedback signal will inevitably cause the reverse adjustment of the speed regulator, which will cause the vibration of the punch.

When this happens, it is very easy to deal with, as long as the back cover of the motor is removed, the commutator of the tachogenerator is exposed. At this time, there is no need to do any disassembly, just use a sharp hook to carefully hook each slot, then use fine sandpaper to lighten the burrs, wipe the surface of the fairing with anhydrous alcohol, and then put the charcoal Just brush it. Special attention here is that when using a sharp hook to hook the slot between the commutation slices, do not touch the winding, because the winding wire is very thin, once it is broken, it cannot be repaired, and only the winding can be replaced. Also, don't wipe it with water-based alcohol, so that the insulation resistance drops and cannot be dried, which will delay the repair period.

A closed-loop system may also cause system oscillation due to poor parameter setting, but the method to eliminate this oscillation is to reduce its magnification, adjust RV1 in the FANUC system, and rotate counterclockwise. It has become better, but because the range of the RV1 adjustment potentiometer is relatively small, sometimes it cannot be adjusted, and only the shorting bar can be changed, that is, the value of the feedback resistance is removed, and the magnification of the entire regulator is reduced.

Mechanical Use

Press for blanking, forming should comply with the following regulations. When operating with more than two people, you should appoint someone to drive, and pay attention to coordination. Before leaving get off work, the mold should be dropped, the power supply should be disconnected, and necessary cleaning should be carried out. The transmission parts exposed to the outside of the press must be equipped with protective covers, and it is forbidden to drive or test the car with the protective covers removed. If necessary, the empty vehicle can be tested. When installing the mold, the slider must be opened to the bottom dead center, the closing height must be correct, and eccentric load must be avoided as much as possible; the mold must be fastened firmly and checked by pressure test.

Attention should be paid to the work. It is strictly forbidden to put hands, tools and other objects into the dangerous area. If the press is running abnormally or there is abnormal sound, the feeding should be stopped and the cause should be checked. If the rotating parts are loose, the control device fails, and each workpiece is finished, the hand or foot must leave the button or pedal to prevent misoperation. Before starting work, check whether the punch guards are complete, whether the flywheel runs smoothly; whether the upper and both sides of the pedal device are protected, and whether the operation is reliable and flexible; and remove the objects that hinder the operation in the workplace.

The punching force must be approved, and overload operation is strictly prohibited. When installing or removing the mold, the power must be cut off first. The mold installation must be firm and reliable. When adjusting the height of use, use manual or moving methods, and do it step by step. Before confirming the adjustment, it is forbidden to connect cars. When operating, it is necessary to concentrate on thinking, and it is strictly forbidden to talk and do it. It is necessary to cooperate with each other to ensure safe operation. It is generally forbidden for more than two people to operate the punch at the same time. If necessary, a special person must be instructed and responsible for the operation of the pedal device. It is strictly forbidden to carry out any part of the body during work, and special tools should be provided for feeding and unloading of the mold range.

The interlayer feeding stamping is prohibited, and the second feeding can only be carried out after the first punching part or the remaining material must be removed. The installation of the mold must be checked regularly, and if it is loose or slipped, it should be adjusted in time. Before the knife edge is worn to the point where the burr exceeds the standard, the knife edge should be sharpened in time. When disassembling the mold, it must be done in the closed state. Take care of stamping equipment, dies, tools, gauges and instruments. After the work is completed, the mold and punch should be wiped clean and ready to be sorted. In the formal punching process, since the static difference rate of the main motor varies with different loads, the electromagnetic counter set on the control board can be used to correct the rotational speed when punching different parts.