Feed servo system fault and diagnosis method - Database & Sql Blog Articles

Brand AVX TPSE226M035R0125 Low impedance tantalum capacitor AVX 22

Electronic scale crystal oscillator 3.2*2.5mm 3225 16M (16.000MHZ) 12PF 10PPM 20PPM 30PPM

SMD aluminum electrolytic capacitor

MOSFET imported original FET

Single chip microcomputer STM32L151CCU6

1 Overtravel When the feed motion exceeds the software limit set by the software or the hardware limit set by the limit switch, an overtravel alarm will occur, and the alarm content will be displayed on the CRT. According to the CNC system manual, You can eliminate the fault and release the alarm.
2 Overload When the load of the feed motion is too large, frequent positive and negative movements and poor lubrication of the transmission chain, it will cause an overload alarm. Alarm information such as servo motor overload, overheating or overcurrent is usually displayed on the CRT. At the same time, on the feed drive unit in the power cabinet, the indicator light or the digital tube will prompt the drive unit to overload, over current and other information.
3 Inciting agitation during feeding:
(1) The speed measurement signal is unstable, such as the speed measuring device failure, the speed feedback signal interference, etc.;
(2) The speed control signal is unstable or interfered with;
(3) Poor contact in the terminal, such as loose screws. When the turbulence occurs in the commutation moment of the forward direction and the reverse motion, it is generally caused by the backlash of the feed chain or the servo system gain being too large.
4 Crawl occurs when starting the acceleration section or low-speed feed, which is generally caused by factors such as poor lubrication of the feed chain, low servo system gain and excessive load. In particular, the coupling between the servo motor and the ball screw is not synchronized with the rotation of the servo motor due to loose coupling or defects in the coupling itself, such as cracks. Give the movement a flickering and creeping phenomenon.
5 Machine tool vibration When the machine is running at high speed, vibration may occur and an overcurrent alarm will occur. Machine vibration problems are generally speed problems, so you should look for the speed loop; and the entire adjustment process of the machine speed is done by the speed regulator, that is, any speed-related problems, you should look for the speed regulator, so the vibration problem Look for the speed regulator. Mainly from the given signal, feedback signal and speed regulator itself to find faults. (Source: http://)
6 Servo motor does not turn the CNC system to the feed drive unit In addition to the speed control signal, there is also an enable control signal, generally DC+24V relay coil voltage. The servo motor does not turn. Common diagnostic methods are:
(1) Check if the CNC system has a speed control signal output;
(2) Check if the enable signal is on. Observe the I/O status through the CRT, analyze the machine tool plc ladder diagram (or flow chart) to determine whether the starting condition of the feed axis, such as lubrication, cooling, etc. is satisfied;
(3) For servo motors with electromagnetic brakes, check whether the electromagnetic brake is released;
(4) The feed drive unit is faulty;
(5) The servo motor is faulty.
In order to make the CNC system better machine parts, it is necessary to strengthen the understanding of the servo system and its fault diagnosis.