Numerical control machine tool requires drive system, speed, wide speed range and high precision, fast response speed, deceleration performance is good, strong protection function etc.High performance CNC machine ac spindle drive system based on intelligent power module IPM inverter switch components, mainly MCS96 series double single chip microcomputer controller, control algorithm adopts digital slip frequency vector control.Main controller adopts double CPU structure, a CPU speed loop control, monitoring and display, etc.;Another slice of the CPU to control the motor speed, 80 c196mc complete current inner loop control.By sharing RAM to communicate between two pieces of CPU, effectively solves the problems of general CPU capacity is not strong.Composed of intelligent power module IPM is used in the main circuit voltage ac\/rectangular inverter.The system also has a fully functional detection and protection circuit, etc.Experiments show that the system has good static and dynamic performance, and can meet the above requirement of driving system of nc machine tools.1, the main loop of the main circuit USES a rectangular voltage type structure, mainly by the rectifier circuit, filter and inverter circuit, etc.Inverter circuit adopts new power devices & ndash;Intelligent Power Module (Intelligent Power Module, IPM).Intelligent power module IPM is an advanced hybrid integrated intelligent power module, it is composed of high speed, low consumption of IGBT chip and optimize the gate drive and over current, short circuit, undervoltage and overheat protection circuit, after IGBT is another innovative achievements in the field of power electronic technology.Because internal IPM adopted for monitoring the current of IGBT chip devices, realize the efficient over-current protection and short circuit protection;IPM has integrated the internal overheating and under-voltage protection circuit, greatly improving the system reliability;IPM has integrated the internal insulated gate bipolar transistor IGBT and its driver circuit, shorten the product development cycle;Loss of IPM on state and switching loss is low, reduce the heat sink size, reduce the cost.So, compared with IGBT intelligent power module IPM has obvious advantages.2, the control circuit in order to realize the fast real-time and reliable control of nc machine tool, control circuit used 80 c196mc – 80 c196kc double single-chip microcomputer 80 c196mc CPU structure has high computing speed and strong control ability, its task is to complete the current inner loop control of high real-time requirements, generating PWM control signal, complete protection function.Especially 80 c196mc contains three phase waveform Generator WFG (Wave Form Generator).WFG has three synchronous PWM module, each module contains a phase comparison register, a no signal time (dead – time) generator and a pair of programmable output.WFG can produce independent three pairs of PWM waveform, they have a common carrier frequency, no signal time and the operating mode, once started, WFG requires only the CPU in the PWM duty cycle is changed to intervene.If use 16 MHZ crystals, center on the cycle of PWM carrier for 0.15 & mu;S ~ 16 ms, increment of 0.25 & mu;S, no signal time adjusting range of 0.125 ~ 125 & mu;S.Used to keep a pair of complementary PWM signal time effectively at the same time, to ensure the output waveform is not overlapping.WFG greatly simplifies the synchronous pulse width modulation (PWM) used to generate the waveform control software and hardware peripherals, especially suitable for the control of three phase ac induction motor, brushless dc motor can also be used to control and other require multiple PWM output device.Unique feature of WFG80C196MC\/MD.80 c196kc mainly complete the speed control and test, the keyboard interrupt input and modify the important parameters, display information about the vector transformation, offering 80 c196mc command signal, etc.Double microcomputer communication between the Shared RAM method, in order to improve the running speed of the system.80 c196kc will calculate the current loop of the required parameters, such as the excitation current and torque current, rotating angular velocity, etc., and transfer to the Shared RAM corresponding unit, while 80 c196mc is to read the data from the Shared RAM.3, 1) detection and protection circuit, current detection because of nc machine tools for wide speed range, as a result, the frequency of the output current range is larger, the average current transformer can not meet the requirements, the hall current transformer is adopted to test the output current.Hall current transformer is characterized by small volume, fast response speed, high accuracy and linearity.2) speed sampling due to the numerical control machine, high speed control precision required average velocity components is difficult to meet the requirements, therefore adopt 1024 high resolution of the photoelectric pulse encoder, in order to realize the high-speed positioning, high-speed tapping, profile control, etc.3) protection function of intelligent power module IPM has good performance of the built-in protection circuit, in order to avoid the stress and make the system failure or damage of power devices.A protection circuit action, if the IPM module IGBT gate drive unit will shut off drive pulse, and the output of a fault signal.Internal protection function has the following several kinds of IPM module.1) the supply voltage locking (UV) IPM internal control circuit consists of 15 v dc power supply, if for some reason the under-voltage action value of the power supply voltage is lower than (UV), the power will be shut off device and outputs a fault signal;Only when the supply voltage than under voltage reset value (UVr) circuit to resume normal work.If the disturbance signal duration is less than the prescribed tDUV, under-voltage protection circuit will be ignored, the normal work of the control circuit, so that we can effectively avoid the interference signal’s influence on the normal work of the circuit.Between UV and UVr should have certain difference, so that you can avoid frequent switching under-voltage protection circuit, ensure the normal operation of the circuit.2) overheating protection (OT) inside the IPM is equipped with temperature sensors, used to detect the working temperature of power device.If the sensors detect the substrate temperature exceeds the overheating action value (OT), IPM internal control circuit as the bridge arm device gate driver, the control input signal is invalid, and the fault signal bridge arm, until the temperature returned to normal, so as to protect the power component.When the temperature dropped below to overheating reset value (OTr), and the control input is high level (off), the power device will accept under a low level (open) the input signal and resume normal work.Also, to avoid overheating protection actions frequently, in overheating action value OT and overheat reset between OTr also has difference of 20 ℃.3) over-current protection (OC) IPM IGBT, with current sensor used to measure the working current of power devices, the current through the IGBT if beyond a time to value (OC), flow is greater than the toff (OC), IGBT will be shut off.But time is more than OC number less than toff (OC) of current pulse, over-current protection circuit will be ignored.When detecting produced current, IPM internal control the IGBT soft circuit is cut off, a breakdown at the same time the output signal.Soft shut off can control shut off when large current generated by the surge voltage, so as to avoid the surge voltage is too high, effectively guarantee the safety of IPM.4) short circuit protection (SC), if the load short circuit or system controller failure resulting in upper and lower bridge arm conduction directly, IGBT make the current more than short circuit protection action value (SC), IPM built-in short-circuit protection circuit will start the soft shut off, shut off the IGBT, and the output of a fault signal.Due to the third generation IPM used the real-time current control circuit (RTC), it is directly monitoring level at the end of the IGBT driver circuit current, between SC detection and shut off the response time of the reduced to less than 0.1 & mu;S, which greatly reduced the short circuit current amplitude stress and peak voltage, power, effectively guarantee the safety of IPM.In order to guarantee the system running safely and reliably, in addition to IPM since the protection function, the system will also include a over-current, short circuit, ac\/dc overvoltage, undervoltage, short of all protection measures and the protection of fuse.4, control algorithm for numerical control machine and high precision requirements, the control algorithm USES the slip frequency vector control.Is to put the ac motor vector control simulation to control dc motor, ac motor stator current vector through coordinate transformation are divided into the two according to the rotor field-oriented dc component, and carries on the control of the two components, can achieve the same as the dc motor speed control performance.In the slip frequency vector control algorithm, used to motor parameters, if do not tally with the actual values given parameter, torque and rotor flux value is not equal to their instructions.Here the error of the rotor time constant is important, it directly affect the dynamic and static characteristics of vector control, so need to make proper compensations to the rotor time constant.Under the load of a certain situation, motor running in the best state, is considered to achieve the field-oriented control.Methods is to select motor error between the actual rotating angular velocity and angular velocity given absolute value as the target function, for the optimization of the rotor time constant.That when current and stable operation, select the appropriate rotor time constant to make the error minimum absolute value.Set speed ring once every 1 ms sampling, and put each 163 sampling points as a set of data, this 163 times the sampling time is about 4 s.Each time constant after optimization, let the motor run 4 s, and then continue sampling optimization.Due to the limitation of length, & other;The ac motor vector transformation control principle & throughout;Go here, please see the relevant references.5, summarize the system adopted the structure of the double CPU control circuit, a CPU to control the speed loop, another slice of CPU is used in the current inner loop control;Inverter circuit adopts intelligent power module;Control algorithm USES the slip frequency vector control, excitation current and torque current control independently.In the experiment choose nc machine tools with ac spindle frequency conversion motor, 11 kw power rating, speed 1500 r\/min.The experimental results show that the motor running smooth, good characteristics at low speed, stator current is close to sine wave, this system very well meet the requirements of the nc machine tools to drive system.
The application of the welding technology of nc machine tool industry is developed as the imported product technology.At the same time, the domestic welding technology has promoted the development of the application of the machine tool industry welding technology.At present, the main welding technology used in machine tool industry has the following several aspects: steel plate pretreatment technology application of the machine tool industry steel pretreatment line, is the second machine tool plant began using in 1993 by jinan, it is used in the shipbuilding industry, juki industry, mining industry on the basis of the beginning.The pretreatment processing line is developed jointly by the factory and Qingdao third casting machinery factory production, the main process for: steel plate leveling, preheating, shot blasting derusting, automatic spray paint, drying, total length of 60 meters.Main technical parameters as follows: thickness of 8 ~ 40 mm steel plate leveling, leveling width of 3 m;Pretreatment of 8 ~ 160 mm steel plate thickness, the effective width of 3 m;Dealing with structural specifications for the 1500 largest (wide) & times;800 (high);The preprocessing speed of 0 ~ 4 m\/min;Annual processing capacity of 40000 tons\/year;Using the PC automatic control and manual control in two ways.The steel pretreatment line, solve the raw materials of adverse factors such as rust, scale, improve the quality of the numerical control cutting blanking and the appearance of the machine tool product quality.Nc cutting technology application in 1982 by the jinan second machine tool plant began to apply domestic nc cutter Yu Gangban parts cutting blanking, in 1988 began to apply computer automatic programming nesting technology, make the steel utilization ratio from 70% to 70%;Jinan first machine tool plant in 1992 introduced the plasma CNC cutting machine and CNC laser cutting machine, start the application of numerical control plasma and laser cutting machine tool industry, the thickness of 0.5 ~ 8 mm steel sheet cutting accuracy reached 0.5 ~ 1 mm.& quot;> & quot;Period, jinan second machine tool plant development research the thick steel plate CNC precision cutting technology, make the thick steel plate CNC precision cutting thickness up to 275 mm, the project won the prize of the machine tool industry & quot;> & quot;Technology prize.In 1993, jinan second machine tool plant, through the introduction of CNC underwater oxygen plasma cutting machine, the machine tool industry CNC plasma cutting thickness carbon steel raised by 8 mm to 25 mm, reduce the plate cutting deformation, improve the cutting precision of the medium plate parts and cutting quality.Gas shielded welding efficiency, such as the application of welding technology with the introduction of foreign technology, in 1981 by the jinan second machine tool plant is the first application & Phi;1.6 solid CO2 gas shielded arc welding technology for American VERSon all steel mechanical press company & Phi;2.4 cored rich argon welding process, the press large weldments welding technology for the research, and achieved success.The project won the prize of advance of science and technology achievements won third prize.In 1986 qiqihaer second machine tool plant application & Phi;1.2 solid core technology of argon shielded arc welding, the welding problems of large weldments, solved the press by copper wire electrode argon arc welding technique, the piston and cylinder workpiece surface copper layer surfacing, replace the traditional copper set of success.Jinan first machine tool plant in 1992 in application for the first time on the cover plate and shell structure of machine tool & Phi;0.8 solid CO2 gas shielded welding.& quot;> & quot;During, jinan second machine tool plant will also be applied to CO2 gas shielded welding press tension bolt extended welding, the project won the second prize machine tool industry & quot;> & quot;Technological achievements second prize.At present, the high efficiency welding technology such as gas protection welding, has widely used in machine tool lathe bed, the gear, the eccentric body, rocker shaft, cylinder block, not processing after welding of pipe flange and cover parts, such as has become one of the main process of welding machine industry.Vibration aging technology is developed in the 60 s of the 20th century new technology, the technology has strong applicability, save energy and reduce environmental pollution, shorten the production cycle, improve production efficiency, etc.The second machine tool plant, jinan in 1981 began the process applied to the introduction of product components, has obtained the good effect.Yellowstone forging machine tool plant in & quot;> & quot;During the research and application of vibration aging process carried on the thorough, and won the prize of machine tool industry & quot;> & quot;Technological achievements second prize.At present, the technology is widely used in the machine tool industry.Welding automation, mechanization technology application of welding automation in addition to the CO2 semi-automatic welding machine industry, mainly on the application of automatic submerged arc welding, the main application of Yu Gangban on barrel of pressure vessel welding and welding.The second machine tool plant, jinan in 1993 by introducing the weld automatic tracking system and the welding power source, reforming the 1988 purchase of domestic cross operation of automatic submerged arc welding equipment, realize the pressure vessel under 18 mm thick cylinder, head don’t open groove butt double-sided submerged arc weld automatic tracking, garden full success.Welding mechanization, mainly is the application of displacement of welding machine, jinan second machine tool plant in 1981, began to introduce the product welding gear shift machine applied research, but didn’t get the promotion, only will be the modification of the deflection of the gear wheel disk automatic cutting equipment.1988 years later, the corresponding displacement of welding machine in Shanghai forging machine tool plant, yingkou metalforming machine tool plant, Yellowstone forging machine tool plant, the application of improved welding mechanization degree.In addition, in 1998, jinan second machine tool group co., LTD., in cooperation with Japan komatsu successful displacement machine was applied to 40 grmo high alloy welding gear.Propane high efficiency and energy saving, environmental protection, such as the application of cutting gas propane gas liquefaction cut is national & quot;Weaving & quot;, & quot;The ninth & quot;Promotion of energy-efficient and environmentally friendly gas.Jinan 2 machine tool group co., LTD. Started in 1993 the industrial application of propane liquefied gas was studied, after a lot of contrast experiments, with 1998 C3 series of liquefied gas fully replace acetylene gas, greatly reduces the production cost, improve the quality of the production safety and cutting, with new gas nozzle, improve the production efficiency.The application of nondestructive flaw detection technology of machine tool industry application of NDT technology first container parts from the machine tool main weld.Such as set up in 1975, jinan second machine tool plant in welding workshop at the same time, set up the X-ray flaw detection room.In 1989, according to national standards to establish quality assurance system, perfect the pressure vessel to fully implement the GB150 “steel pressure vessel” standard and JB4730 standard for pressure vessel NDT.Machine tool industry in the early 90 s 20th century began using ultrasonic testing technology of machine tool product main structure of the welds are 20% sampling inspection, performed the gb GB11345-89 “steel weld manual ultrasonic testing method and testing results of classification.Check the main parts of weld is press base, beams and the slider of the main vertical plate weld;Columns, sliding block guide rail weld;Beam axle sleeve seam;Base, beams, the workbench face up and down all weld and weld splice plate and gear circumferential weld.Gas supply technology application of CO2 gas supply mode, in the welding production of machine tool industry has also been seriously.At present, the domestic many manufacturers generally adopts single bottle single gas, the gas supply mode not only restricts the expansion of production scale, as well as the production management and quality of welding has great influence.CO2 gas and gas centralized supply, improve the efficiency of the welding production, but also to improve purity of CO2 gas by 0.4 ~ 0.6%, a 0.25% drop in gas water content, ensure the welding quality, also get application in welding production of machine tool industry.As in 1992, jinan second machine tool group co., LTD. At the same time of building new metal structure factory, built the CO2 gas gas supply device.Total work pressure 0.15 MPa, and intermediate storage barrel capacity of 2 m3, can be continuous stable gas supply to the plant more than 120 CO2 welding machine, at that time, the annual production capacity of 12000 tons of welding, by 2002 to meet the annual production capacity of 15000 tons of welding requirements.
Roller roller types of nc machine tool is used in the processing industry, various types of CNC machine tool because of its function, structure and the system of different, each has its different characteristics.Its maintenance content and rules also has its distinguishing feature each, concrete should be based on the machine type, model and actual usage, and with reference to the machine specification requirements, to develop and establish the necessary maintenance regularly, grading system.China roller industry network compiled under the roller device of nc machine tools system maintenance is for your reference.1 CNC system maintenance 1) strictly comply with operation procedures and maintenance system (2) should be less as far as possible open numerical control cabinet and heavy current cabinet door in the machining workshop will typically have oil mist in the air, dust, and even metal powder, once they fall in the numerical control system in the circuit board or electronic device, easy to cause the insulation resistance between the components to drop, even cause the damage of components and circuit board.Some users in order to make the numerical control system in the summer can overload long-term work, take the door of the open numerical control cabinet to heat dissipation, which is a highly desirable method, it will eventually lead to damage of the acceleration of CNC system.3) regular cleaning the cooling ventilation system of numerical control ark should check whether the CNC on the cooling fan is working normally.Once every half a year or every quarter to check air duct filters are blocking phenomenon, if the filter dust accumulation is overmuch, not clear in time, will cause in numerical control cabinet temperature too high.4) the regular maintenance of CNC system input\/output devices in the 80 s before the production of CNC machine tools, mostly with photoelectric paper tape reader, if read part with contaminated, will lead to read error information.Therefore, must be in accordance with the provisions of photoelectric reading machine maintenance.5) regular inspection and replacement of the dc motor brush dc motor brush the transition of wear and tear, will affect the performance of the motor, motor damage even.Therefore, to deal with motor brush for regular inspection and replacement.CNC lathe, CNC milling machine, machining center, etc., should be checked once a year.6) regular change storage batteries in general nc system for CMOSRAM storage device is equipped with rechargeable battery circuit maintenance, to ensure that the system can maintain its storage contents during without power.In general, even failure, should also be replaced once a year, to ensure the system to work normally.Battery replacement shall be carried out in the numerical control system of power supply condition, when the replacement in case loss of information in RAM.7) standby circuit board maintenance spare copies of the printed circuit board for a long time need not when, should be installed on a regular basis to the electricity in the numerical control system for a period of time, in case of damage.2 mechanical parts maintenance 1) of the main drive chain maintenance regularly adjust tightness of the spindle drive belt, turn to prevent lost caused by belt skid phenomenon;Check the spindle lubrication of constant temperature tank, adjust temperature range, timely supply of oil, and cleaning the filter;Cutter clamping device in the field of the spindle after long time use, can produce clearance, affect the tool clamping, need to adjust the hydraulic cylinder piston displacement.2) ball screw thread deputy vice of maintenance periodically check, adjust the screw thread axial clearance, ensure accuracy of reverse transmission and axial stiffness;On a regular basis to check whether there is loose screw and lathe bed connection;Screw protective device with a damage to change in time, to prevent dust or chip in.3) maintenance knife library and change the knife manipulator are strictly forbidden to put the overweight, super long knives into knife library, to avoid a manipulator tool change when off a knife or cutting tool and the workpiece and fixture collision;Check the back to the zero position of the tool storage is correct, check the spindle back in knife point location is in place, and timely adjustment;When turned on, should make knife library and manipulator empty running, check whether the parts work is normal, especially the travel switch and solenoid valve can normal action;Check and reliable tool in manipulator locked tight, found abnormal should be handled in time.3 hydraulic, pneumatic system maintenance on a regular basis on the lubrication, hydraulic, pneumatic system of filter and clean or replace filters or points;Regular inspection and replacement of oil test for hydraulic system of hydraulic oil.On a regular basis to the pneumatic system points * gas filter water;4 precision machine tool maintenance level of machine tool on a regular basis and mechanical precision check and correction.Mechanical precision calibration method has two kinds of hard and soft.Its soft compensation method is mainly through the system parameters, such as screw backlash compensation, the compensation, machine tool coordinate position precision fixed-point return reference point position correction, etc.;When hard method will make the machine overhaul, the guide rail was carried out such as scraping, ball screw nut pair preload adjustment reverse clearance, etc.
Numerical control machine tool is a kind of high technical content machine, electric, instrument integration of efficient automatic tools, a combination of computer technology, automation technology, servo drive, precision measurement and precision machinery and other fields of new technological achievements, is an emerging industrial control technology.Although different nc system on the structure and performance, but has its generality on fault diagnosis, combined the actual work now talk about the numerical control system and the method of fault analysis and repair.Numerical control system fault maintenance usually according to: field of fault diagnosis and analysis, fault measurement, system commissioning to repair and eliminate the three big step.1, nc machine tool fault diagnosis in the fault diagnosis should grasp the following principles: 1.1 after the first external internal modern numerical control system can be * sex is higher and higher, the numerical control system itself more and more low failure rate, while most of the fault is caused by the system itself.Due to the numerical control machine tool is integrating mechanical, hydraulic, electric machine, its failure will be reflected by the three integrated.Maintenance personnel should be outside-in on a screen.Avoid unsealed at random, disassembly, otherwise it will enlarge the fault, reduce loss of machine tool accuracy, performance.System of external fault is mainly due to the detection switch, hydraulic components, pneumatic components, electric actuators, and cause the problems of mechanical device and so on.1.2 after the first mechanical electrical in general, mechanical failure find more easily, and numerical control system and electrical fault diagnosis is difficult.Before troubleshooting, first of all, pay attention to rule out the failure of mechanical.1.3 first after static dynamic, first in the stationary state of power machine, through understanding, observing, testing, analysis, confirm will not result in a failure to expand after the power supply, after the accident, may give machine electricity.In running state, dynamic observation, inspection and testing, to find fault.For the destructive failure will happen after the power supply, you must first, after eliminating the risk before electricity.1.4 after simple first when there is a variety of complex fault interweave each other, at that time do not know how to start, should first solve the problem of easy, after solve difficult problems.Often after solve simple problem, difficult problem may also be easier.2, numerical control machine tool numerical control system fault diagnosis technology is the high technology-intensive product, if you want to quickly and find out the reason and to determine the fault parts of the right, to the use of diagnostic techniques.With the continuous development of the microprocessor, and diagnosis technology is also by simple diagnostic towards versatile senior or intelligent direction.Diagnostic ability strong and the weak is also an important index for CNC numerical control system performance evaluation.The diagnosis technology of various kinds of CNC systems in use today can be roughly divided into the following categories: 2.1 starting diagnostic starting refers to each from the beginning of the electricity, the CNC system internal diagnostic procedures will automatically perform.The content of the diagnosis for the key in the system hardware and system control software, such as CPU, memory and I\/O module, and MDI\/CRT unit, paper tape reader, device or an external device such as a floppy disk unit.Only when the whole project after confirmation is correct, the system can enter into the normal operation of the ready state.Otherwise, will be in the CRT screen or leds indicate fault information in alarm mode.At this point starting diagnosis process cannot end, system cannot be put into operation.2.2 on-line diagnosis on-line diagnosis is to point to by the inside program of CNC system, when the normal operation of the system of the CNC system and CNC device connected to the servo unit, servo motor, spindle servo unit and the spindle motor and external equipment for automatic diagnosis and examination.As long as the system outage, on-line diagnosis will not stop.Online diagnosis generally includes state show that there are thousands of self-diagnosis function, often in binary 0 and 1 to display its state.For positive logic 0 means off state, said on state, with the help of status display can judge the failure parts.Commonly used interface state and internal status display, such as the use of I\/O interface status display, combining PLC ladder diagram and the high voltage control circuit diagram, the reasoning method and the method can determine the position of the point of failure in the real.Fault information mostly take the form of alarm number.Generally can be divided into the following categories: overheating alarm classes;The system alarm classes;Storage alarm classes;Programming\/set class;Servo classes;Travel switch alarm classes;The connection between the printed circuit board fault class.2.3 off-line diagnosis index of diagnosis is a control system malfunction, numerical control system manufacturer or professional repair center by using special diagnostic software and test device to stop (or offline).Make the fault location to as small as possible, within the scope of the part such as narrowed to a function module, circuit, or even a chip or components, the more accurate fault location.2.4 modern diagnostic technology with the development of telecommunications technology, IC and microcomputer price rise, in recent years abroad have put some new concepts and methods succeeded in reference to the diagnosis.(1) communication diagnosis also calls the remote diagnosis, the use of telephone communication line with faults of CNC system and professional repair centers dedicated communication diagnostic computer through the connection test.Such as Siemens ag in the diagnosis of CNC system adopted the diagnosis function, the user in the CNC system dedicated & other;Communication interface & throughout;Connection on the ordinary telephone lines, and two doors company special newsletter diagnosis of computer maintenance center & other;Data throughout the phone &;Also connected to the phone lines, and then sent to the CNC system by computer diagnostic procedures, and the test data back to the computer is analyzed and concluded that then diagnosis and treatment way to notify the user.Communication diagnosis system can also make regular preventive diagnosis for users and maintenance staff don’t need to attend, just to make a series of machine tools according to the predetermined time running examination, analysis of diagnosis in the center of the maintenance data, can be found the problems, so as to take measures as early as possible.Of course, this type of CNC system must have the remote diagnosis interface and networking.(2) the self-healing system is set in the system have a backup module, in the software of CNC system is equipped with the repair procedure, when the software is running once found a module has a failure, the system on the one hand, the fault information is displayed in the CRT, automatically looking for whether there is a spare module at the same time, if there are any spare module, the system can automatically make the fault offline, and through to the standby module the system can quickly enter the normal working condition.This scheme applies to unattended automation work situation.Need to be aware that there are some faults in the machine tools in the actual use without alarm, phenomenon also is not very obvious, in this case, the process is not so simple.After the other there is the equipment failure, not only no alarm information, and the lack of information on maintenance required.For this kind of fault diagnosis processing, must be carefully check according to the concrete situation, carries on the analysis from the phenomenon of tiny, find out the real reason for it.To the cause of such failure was found, you must first find from various surface mount its real failure phenomenon, from confirmed fault phenomenon to find out the reason of occurring.Comprehensive analysis of a fault phenomenon is one of the important factors to determine whether the correct.Before to find the cause of the problem, you must first understand the following situation: the fault is in the normal work or just boot occurs;Mountain is the number of times is the first time or have occurred many times;Confirm the correctness of the machine tool processing program;If anyone else 3, the common troubleshooting methods of the nc machine tools because of nc machine tool fault is more complex, at the same time, nc system self-diagnosis ability can not all parts of the system test, is often a alarm number to indicate the number of the cause of the problem, make it difficult to start.Below is the maintenance personnel for troubleshooting methods commonly used in production practice.Visual test method is 3.1 maintenance personnel according to the failure of various abnormal phenomena such as light, sound, taste of observation, determine the scope of the fault, the fault can be narrowed to a module or on a piece of circuit board, and then to eliminate.Generally includes: a. ask: ask fault field personnel carefully failure process, failure surface and failure consequences, etc.;B. visual: overall check whether the machine parts working status in normal state, the electric control device for emergency instructions, local burn out, check whether insurance components burnt fall off, craze, wires and cables, each operation element position correctly or not, etc.C. touch: under the condition of the machine power can touch the main circuit board installation condition, the condition of each connector plug, the power and signal connection status of the wire and hand touch and light wave components, especially large volume resistance capacity, semiconductor devices have a loose sense, to check out some of the broken foot, virtual welding, such as poor contact fault;D. power: it is to point to in order to check whether smoking, lighter, with or without abnormal sounds, smells and touch any motor overheating and components exist and electricity, once discovered immediately without electricity for analysis.If there is a destructive failure, must eliminate rear can electricity.Example: a CNC machining center is running after a period of time, the CRT display suddenly show no fault, and the machine also can continue to operate.After downtime to open and everything is ok.Observed that in the process of the equipment operation, failure may occur when in vibration.Preliminary judgment is poor contact element.When checking for a display panel, the CRT display suddenly disappeared.Inspection found a crystal vibration of two pins are loose virtual welding.After welding, fault elimination.3.2 initialization reset method usually, caused by transient fault alarm system, the available hardware reset or switch power supply, in turn, to clear the fault.Because if the system storage area off electricity, chaotic circuit board or the battery voltage, it must be initialized to the system to clear, clear before to make a good record of data copies should be paid attention to, if the fault is still cannot be ruled out after initialization, hardware diagnosis.Example: a CNC lathe when press the run button, a microcomputer refused to carry out the processing procedure, also don’t show breakdown self check tips, the display in the reset state (only display menu).Sometimes manually, editing function is normal, check the user program, various parameters exactly;Sometimes because of the memory cell failure, replace the memory cell and so on, the system displays a certain direction or the size of each direction on the super size by the most (display size more than maximum size of the machine can real jin processing or exceed the maximum size of the system to be able to recognise).Elimination method: initialize the reset method is used to make the system reset reset (usually with a special combination of rehabilitation or password).3.3 since the diagnosis method of CNC system has the function of strong self-diagnosis, and can at any time to monitor the working state of the hardware and software of CNC system.Use of self-diagnosis function, can show the state of the system and the interface between the host information, so as to determine the fault occurred in mechanical parts and CNC, and show the general parts of the fault, fault code).A. hardware alarm indication: refers to, including CNC system, servo system, the various states and fault indicator light on the electrical devices, combined with light state and melody & Phi;The tomb & delta;Qin to martingale accept 1 Shan gansu jiu ChenJing Hang closed show Qi brachial flint pepper m:?BR>B. software alarm indication: system software, PLC program and process of fault alarm display normally, according to the display of alarm, control the corresponding diagnostic manual possible fault causes and elimination method may be revealed.3.4 feature program testing function test method is the numerical control system of G, M, S, T, F function by programming method into a functional test procedure, and stored in the corresponding medium, such as paper tape and tape, etc.Run the program in fault diagnosis, can quickly determine the probable cause of the failure.Functional program testing is often used in the following situations: a. machine tool processing waste caused by uncertain programming is improper operation, or CNC system failure caused b. random failures, CNC system, is difficult to difference between outside interference, or is there a good system stability;C. longer CNC machine idle time before put into use or preventive maintenance of CNC machine tool.Example: a FANUC9 system of vertical milling machine in automatic machining one curve parts appear crawl phenomenon, the surface roughness is poor.When run the test program, linear and circular interpolation stoppage is no creeping, determine the reason in the aspect of programming.To process after careful inspection found that the curve is composed of many small pieces of circular arc, and programming and use the correct positioning check C61 instruction.G61 cancelled from the program, after using G64, eliminate crawl phenomenon.3.5 spare parts replacement method with a good spare parts to replace diagnosed a bad circuit board, which based on the analysis of the general situation of the cause of malfunction, maintenance personnel can use spare copies of the printed circuit board, integrated circuit chip replace the questionable parts or components, thus the fault range narrowed to a printed circuit board or chip level.Initializes the starting, and accordingly make the machine tool quickly into normal operation.For the maintenance of modern numerical control, more and more, this method is adopted to improve the diagnosis and then use the spare parts to replace damaged module, make the system work normally.As much as possible to shorten downtime, pay attention to when using this method in the operation must be under the power status, but also carefully check the PCB version, model is the same, all kinds of tag, jumper, if it cannot be replaced.Stitch should be marked and recorded.Generally don’t change the CPU board, memory board and electricity, otherwise may cause program and the loss of the machine parameters, and extend the fault.Example: a using Siemens SINUMERIK SYSTEM 3 SYSTEM of nc machine tools, the PLC in sichuan and S5 & ndash;130 w\/B, a failure occurs, through the function of PC NC system input parameters R, don’t work in the processing, can not be changed by R parameter values in the program.Through the analysis of the NC system working principle and fault phenomena, think there is something wrong with the PLC of the motherboard, with another machine tools motherboard exchange, further identified as PLC board problem.By the professional factory maintenance, fault be ruled out.3.6 pay * transposition method when found fault board or a can determine whether the board and the absence of spare parts, in the system can be the same or compatible two board swap check, for example, the two coordinate instruction board or the exchange of servo board, to judge from failure board or failure parts.Should pay special attention to the pay * transposition method, not only to the hardware connection of the right to exchange, exchange will bring a series of corresponding parameters, otherwise not only cannot achieve the purpose, it will produce new fault cause confusion, must be considered in advance and good exchange scheme of software and hardware design, accurate exchange check again.Example: a CNC lathe to feed normal X, Z to feed a large, poor accuracy, vibration, noise, using manual and hand pulse feed.Observe the driving plate lamp brightness and change the basic normal, doubt is the Z axis stepper motor and its open circuit or lead the Z axis mechanical failure.Hence the Z axis motor change leads to the X axis, the X axis motor running normally, illustrate the Z axis motor lead normal;And X axis motor change leads to the Z axis, the fault is still;Can conclude that the Z axis motor fault or Z axis mechanical failure.Measure motor fuses, find an open circuit.Repair the stepper motor, troubleshooting.3.7 parameters test system is on the basis of system function, parameter setting error may cause system fault or a function is invalid.
The main body of a host is nc machine tool numerical control lathe.It includes the lathe bed, base, column, beam, slide, table, spindle box, feed mechanism, rest, and automatic tool change device, such as mechanical parts.It is on the nc machine tool automatically complete all kinds of cutting processing of mechanical parts.Compared with the conventional machine tools, CNC machine main body has the following characteristics: (1) structure with high stiffness, high shock resistance and small thermal deformation of machine tool of new structure.Usually use improve the static stiffness of the structure system, increasing the damping, adjusting structure quality and the natural frequency method to improve the rigidity and vibration resistance of host machine tool, the machine body can adapt to the needs of the CNC machine tools for automatically machining.To improve the machine tool structure, reducing fever, temperature rise and thermal displacement compensation control measures, such as can reduce the influence of thermal deformation of machine tool host.Using high transmission efficiency, high precision, no clearance of transmission and the moving parts, such as ball screw nut pair, plastic slide guide, linear rolling guide, such as hydrostatic guideway. CNC lathe machine Lord of light transmission adopts frequency control of motor speed technology, on the one hand, the main transmission structure is simple, convenient speed adjustment, stable and reliable, transmission noise;On the other hand with friction drive stall form a complete set of automatic compensation device, when stall appear to slow down, N C system instructions immediately adjust cutting parameters, also can avoid stop play knife phenomenon occurred.The measured results of the radial runout of wheel control in 0. 1 mm.Wheel axial positioning design for each side of a lateral pressure guide wheel, guide wheel can freely rotate in their work, and by which several fold shape spring buffer storage of applying pressure to the vertical earth pressure to the lateral aspect of tyre, to ensure the wheel for axial positioning, at the same time, and can automatically according to the lateral side beat below axial follow up, make the rounds of the axial location is stable and reliable, have the effect of floating anchor point, beam orientation detection, axial displacement of the machine stability control in 0. 02 mm or less.Application of Sweden sandvik tool new craft, new material, new technology, the machine design special blade and tool rest, make a tool with reasonable annotation Angle and working Angle and function of chip breaker, greatly improve the cutting tool and chip breaker conditions, improve the tool life.