Punching machine operating instructions

Punching machine operating instructions

Mechanical work

Due to poor lubrication of the punch press, frictional resistance increases when the worktable moves. When the motor is driven, the worktable does not move forward, so that the ball screw is elastically deformed, and the energy of the motor is stored in the deformation. When the electric motor continues to drive and the elastic force produced by the stored energy is greater than the static friction force, the punch work table creeps forward and moves like this again and again, resulting in a crawling phenomenon. 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 issues are speed issues. Since it is a speed problem, we must look for the speed loop. The entire adjustment process of the speed of the punch is done by the speed regulator.

The operation and monitoring of the CNC punching machine are all completed in this CNC unit, which is the brain of the CNC punching machine. High machining accuracy and stable machining quality; multi-coordinate linkage can process parts with complex shapes; when machining parts change, generally only need to change the CNC program, which can save production preparation time; the bed itself has high precision and rigidity. You can choose a favorable processing amount, and the productivity is high (generally 3 to 5 times that of ordinary machine tools). For speed-related issues, you can only look for the speed regulator. Therefore, the problem of press vibration should also look for the speed regulator. You can find the fault of the speed regulator from the following places: one is the given signal, one is the feedback signal, and the other is the speed regulator itself.

Because the vibration frequency of the punch press is in a certain ratio to the motor speed, first check whether the motor is faulty, check its carbon brush, commutator surface condition, and mechanical vibration, and check the lubrication of the ball bearing. The inspection does not need to be completely disassembled, it can be observed by the inspector, and the bearing can be inspected by listening to the sound. If there is no problem, 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 the speed have a linear relationship. As long as the speed is constant, its output voltage waveform should be a straight line, but due to the influence of cogging and commutator commutation, a tiny alternating variable is attached to this straight line. For this reason, a filter circuit is added to the speed measurement feedback circuit. This filter circuit is to weaken the AC component attached to the voltage.

The punch feedback signal and the given signal are exactly the same for the regulator. Therefore, the fluctuation of the feedback signal will inevitably cause the speed regulator to adjust in the opposite direction, which will cause the vibration of the punch press.　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 will be exposed. At this time, there is no need to do any disassembly, just use a sharp hook to carefully hook each slot, and then use fine sandpaper to smooth the burrs, rub the surface of the commutator with anhydrous alcohol, and put on the charcoal. Just brush it. Special attention should be paid here when using a sharp hook to hook the notch between the commutator segments, do not touch the winding, because the winding wire is very thin, once it is broken, it cannot be repaired, only to replace the winding. Don’t use water-alcohol to wipe again. If the insulation resistance drops, it will not be able to be dried, which will delay the repair period.

A closed-loop system may also cause system oscillation due to poor parameter settings, but the way to eliminate this oscillation is to reduce its magnification. Adjust RV1 in the FANUC system and rotate it counterclockwise. It can be seen that it will be immediately obvious. It becomes better, but because the range of the RV1 adjustment potentiometer is relatively small, sometimes it can’t be adjusted, and only the short-circuit bar can be changed, which is to cut off the feedback resistance value and reduce the magnification of the entire regulator.

Mechanical use

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

Attention must be paid during work, and it is strictly forbidden to extend hands and tools into the danger zone (see item 4 of the safety production regulations). If the press is running abnormally or there is abnormal sound, (such as battering, cracking) should stop feeding , Check the reason. If the rotating parts are loose, the control device is out of order, (see introduction) every time a workpiece is punched, the hands or feet must leave the button or pedal to prevent misoperation. Before work, check whether the punch protection device is complete, whether the flywheel is running 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 operation on the work site.

The arbitration power must be verified and overloaded operation is strictly prohibited. When installing or disassembling the mold, the power must be cut off first. The mold installation must be firm and reliable. Use manual or moving methods to adjust the combined height, and proceed gradually. Before confirming the adjustment, it is forbidden to connect cars. When operating, you must concentrate your thoughts, and it is strictly forbidden to talk while doing, and cooperate with each other to ensure safe operation. Generally, it is forbidden for more than two people to operate the press at the same time. If necessary, a person must be assigned to direct and be responsible for the operation of the pedal device. It is strictly forbidden to carry out the feeding and unloading of any part of the body during the work. Special tools should be provided.

It is forbidden to press the interlayer feed material, and the second feed material can only be carried out after removing the secondary punching parts or remaining material. The installation of the mold must be checked regularly, and if there is any looseness or slippage, it should be adjusted in time. Before the knife edge is worn until 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, measuring tools and instruments. After the work is completed, the mold and punch should be wiped clean and ready to be put in order. In the formal punching process, since the static error rate of the main motor varies with different loads, when punching different parts, the electromagnetic counter set on the control board can be used to correct the speed.