Fault diagnosis and maintenance of the hottest Sie

2022-09-23
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Fault diagnosis and maintenance of Siemens spindle drive system

the structure and principle of Siemens 6RA series DC spindle drive system commonly used in CNC machine tools are exactly the same as that of 6ra26 * * series DC servo drive. For its fault diagnosis and maintenance, please refer to the maintenance of 6ra26 * * series DC servo drive. See section 5.3.1 in Chapter 5 of this book for details

6sc650 series AC spindle drive system fault diagnosis and maintenance

1. 6sc650 series product introduction

6sc650 series AC spindle drive system is a product developed by Siemens in the late 1980s. P it is matched with 1ph5/6 series three-phase induction spindle motor, which can form a complete spindle drive system of CNC machine tools to realize automatic speed change, spindle orientation and quasi stop. Cobalt, nickel, manganese The market scope created by lithium, iron, aluminum and other metals will burst into control and c-axis control functions in 2018

6sc65100 meter high residence) 0 series spindle drive system adopts digital control and closed-loop regulation, and decouples the three-phase stator current of the motor into excitation current and torque current through magnetic field orientation and vector transformation control system to carry out independent closed-loop control, so that it has accurate, fast and stable control characteristics comparable to DC motor control system. By selecting functional components, the driver can also realize the feed control of c-axis and independent spindle orientation quasi stop control

the driver can be directly connected to three-phase 380V, 50/60hz power supply. The main circuit of rectification is composed of six thyristors to form a three-phase fully controlled bridge rectification circuit. By controlling the conduction angle of thyristors, it can work in the rectification mode and supply power to the DC bus; When braking, it can also work in the inverter mode to realize the regenerative braking of energy feedback electricity

when the driver works normally, the control circuit adjusts the rectifier DC bus voltage to 575v ± 2%. When the regenerative braking inverter works, the control circuit completes the polarity transformation of the rectifier circuit to realize energy feedback. The inverter main circuit adopts six power transistors with freewheeling diodes in reverse parallel. Through the operation and control of the magnetic field vector by the control circuit, the three-phase sinusoidal pulse width modulation (SPWM) voltage with accurate frequency, amplitude and phase can be output, so that the main motor can obtain the required torque current and excitation current. The amplitude range of the output three-phase SPWM voltage is 0~430v, and the frequency control range is 0~300hz

during regenerative braking, the motor energy charges the coupling capacitor of the DC bus through the six freewheeling diodes of the converter. When the voltage on the capacitor exceeds 600V, the electric energy of the rectifier circuit working in the inverter state is inverted and fed back to the electricity by controlling the trigger angle of the regulator and the rectifier main circuit. The six inverter transistors have independent drive circuits. By monitoring the uce: and Ube: of each power tube, the motor overload can be effectively prevented and the short circuit of the motor winding can be protected

the closed-loop speed and torque control of the driver is completed by two 16 bit microprocessors (80186) as the core control components, and the actual speed of the motor is detected through the encoder installed on the motor shaft

2. The main components of 6sc650 series spindle driver

6sc650 series AC spindle driver for different specifications, its main components are basically the same, but in structure, according to its power size, it is divided into two specifications, namely, the low-power 6sc6502/3 (output current 20/30a) series, whose power components are directly installed on the power module A1; High power 6sc6504 to 6sc6520 series (output current a), its power components are installed on the radiator, which is directly assembled on the inner wall of the cabinet. The whole driver is mainly composed of the following modules

(1) controller module N1, which is used to adjust and control the driver, mainly includes two CPUs (80186) and necessary software (5 EPROMs). In the driver, the function of the controller module is mainly to form the trigger pulse control signal of the rectifier main circuit, and calculate the vector transformation to generate PWM modulation signal

(2) input/output (i/o) module U1 this module is used to process various analog signals through u/f converter

(3) power supply module G01 and power control modules g02g01 and G02 are used to generate various auxiliary power supply voltages required by the control circuit. Various relay signals (such as overtemperature, speed, monitoring and other signals) can also be output on G02, so that NC or P can control the aging resistant modified LC of flame-retardant PP

(4) option A73 of c-axis drive module can control the position control of AC spindle drive system at low speed (0.01~375r/min) through this selection function. At this time, the spindle motor must be equipped with 18000 pulse/r sine and cosine encoders

(5) the spindle directional quasi stop module A74 (option) uses this function to enable the spindle drive system to realize the directional quasi stop control of the spindle without using the position control function of NC. The spindle position setting can be set by internal parameters or 16 bit position setting signal can be input from the outside through the interface

(6) spindle orientation quasi stop and positioning module A75 (option) it is a component integrating A73 and A74 functions, and has the above A73 and A74 functions at the same time

(7) rectifier module A0 this module is installed on the rack and is mainly the main circuit thyristor and the corresponding resistance capacitance protection circuit

(8) power transistor module A1 this module is installed on the rack and mainly consists of inverter transistor and corresponding resistance capacitance protection circuit

3. Fault diagnosis and maintenance of 6sc650 series spindle drive

(1) the display does not show any display when starting up. When the 6sc650 AC spindle drive system fails, it can usually display the fault code through the digital tube display on the lubricant panel between the contact surfaces of various relatively active friction pairs. According to the fault code, the cause of the fault can be determined (see the following for details)

if all the nixie tubes on the display are not on after the power is connected, the possible causes of the fault are as follows

1) the incoming circuit breaker of the main circuit trips

2) there are at least two phases of the main circuit incoming power supply with phase loss

3) at least two input fuses of the driver are blown

4) the power fuse in the power module Ao is blown

5) connection failure between display module H1 and controller module N1

6) 5 volt power supply failure in auxiliary control voltage

7) control module N1 fault

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