Foreword PLC with its dependability tall, logic controls a function small, adaptability mixes strong, bulk by force to go to the lavatory with computer interface wait for an advantage to be measured in industry accuse a domain to be applied extensively, already replaced the traditional electric equipment that waits for composition by auxiliary relay and time relay to control a system in great quantities. In recent years, PLC technology development is swift and violent, new product emerges in endlessly. High-end PLC is good at switch the quantity detects and be being controlled logically not only, and can process imitate signal, undertake positional control and loop are controlled, still can join interfaces of all sorts of feeling screen man-machine have powerful network function. High-end PLC deploys proper place to control unit and interface of feeling screen man-machine, and according to the CIMS (CIMS) or flexible production system (the specific requirement of FMS) , configure corresponding network module or network unit, can realize a network to interrelate, make open numerical control system. Article introduction is based on the system of grinding numerical control of PLC of OMRON high end one kind, the position that system of this kind of numerical control equips controls unit to be able to achieve two axes linkage, and but the basis needs actually, interface of man-machine of screen of feeling of; of number of axle of aleatoric and patulous control can need to design; to still can pass DeviceNet, Controllerlink and TCP/IP agreement unit to undertake mutiple level network interrelates neatly according to the operation. System of this kind of numerical control already was at present in technical reformation of 3MZ2120 grinder numerical control win success application. 1.
The open feature of numerical control system and typical pattern open system of type numerical control to be based on PC platform commonly, have modular, standardization, platform to have nothing to do gender, can be developed 2 times and get used to the feature such as couplet net job. The system of open mode numerical control that is based on PC platform has 3 kinds of typical pattern at present. The first kind is derive model (special NC+PC) , the interface that inserts special development in traditional CNC board, make traditional special CNC contains the characteristic of PC. Because manufacturer of numerical control system cannot be in,this kind of mode is short-term inside the special CNC technology that abandons a tradition and the compromise proposal of generation, what have not realize NC kernel is open, have; of primary and open sex only the 2nd kind is built-in model (PC+NC control blocks) , the high speed that is based on DSP motion controls card (NC controls card) the standard that is inserted in PC is patulous in groove, carry out all sorts of blame by the PC real time task, NC controls card to handle real time task. The mainstream; that is the system of open mode numerical control that is based on PC platform at present is system of complete software numerical control the 3rd kind, the PC can finish the blame such as management not only real time task, also can be below the support of real time operating system, the task of real time sex such as control of control of interpolation of executive real time, servo, machine tool electric equipment. What the numerical control system of this kind of mode realized NC kernel is open what operate an interface with the user is open, OK and direct or run all sorts of application software through the network, it is the system of open mode numerical control on real significance. With PC platform photograph of system of open mode numerical control is compared, the open sex of the numerical control system that is based on high-end PLC basically is reflected in network level and systematic expansion level. High-end PLC uses the bus line structure that is similar to PC and the process designing of echelon graph language that face an operation, the high-end component such as module of unit of imitate quantity processing, positional control unit, loop control unit, network or network unit has special control sentence, have systematic compose to build capacity of agile, augment design of strong, application software is convenient wait for an advantage. Programming language is standardized and the component can increase of interchangeability ceaselessly, use generally of technology of spot bus line and standard of industrial aether network, make the numerical control system that is based on high-end PLC becomes more open, the main component that makes the equipment layer that faces CIMS or FMS. 2.
If the graph is shown 1 times,the system of grinding numerical control that is based on the system of grinding numerical control of high-end PLC to be based on high-end PLC forms a structure. Graph structure of composition of system of 1 grinding numerical control pursues 2.
1 switch signal monitors as current as logistic control system to input the main component that output unit is PLC, be monitored in what all switch signal assumes in system of grinding numerical control and control a function logically entirely. Does the signal that monitor basically have: ? All sorts of working status signal that ⒘ of grand of shipboard of childish of stool of of ⒒ of an ancient wine vessel made of horn of of stool paper frightens equipment of grinding of? of lotus root of narrow one's eyes of extensive of Nai of Jian of of discuss of Lai of Xian of kneecap of of Pan of ⑿ of of contented vinegar and auxiliary unit to go up and unusual alarm signal. Systematic output unit controls all electromagnetism a powerful person on grinding equipment and system of machine tool electric equipment to wait, adopt the hydraulic pressure system on grinding equipment, axis of chuck of control manipulator, charging tray, workpiece, emery wheel, lathe bed, nap implement etc main part and refrigeration, lubricant, filter wait for auxiliary unit to be mixed according to grinder movement grinding craft asks to work, implementation grinding machines the automation of the process. 2.
2 workpiece and control of speed of emery wheel movement maintain workpiece and emery wheel roll rate is constant, very advantageous to raising grinding to machine quality. Deployed 2 to take RS-485 to string together buccal transducer for this system, part drive workpiece axis and arenaceous axle. PLC uses online follow-up control to assure both between of speed cooperate with stability. Grinding of operation personnel basis machines parameter of speed of transducer of axis of requirement set workpiece, after PLC receives this parameter, consult emery wheel diameter (set or memorial value) concern with rotational speed scale, calculate and the speed parameter of transducer of axis of automatic set emery wheel. In grinding treatment process, PLC reachs the loss in nap process to offer speed automatic compensation in grinding to emery wheel. PLC can control 32 transducer at most, the transducer of different manufacturer can use an agreement grand communication connection. PLC according to transducer address (code of 0-31) , instruction and relevant data order convey to transducer command, move to transducer, stop, turning, invert wait for executive control;PLC to still can monitor transducer runs state, cross overload of electric current, overvoltage, transducer, hardware when transducer happening overload of unusual, electric machinery, cross pitching moment to detect, power source the circumstance such as overtime of unusual, communication, can transmit unusual parameter PLC, make corresponding processing by PLC. 2.
3 positions control is unit (PCU) and PLC of positional control high end deploy buy of odd position of axle to control unit, enter electric machinery or form a complete set of driver of communication servo electric machinery to use with the pace, can finish open loop or control of position of half closed circuit and speed control, deploy position of two axes linkage to control unit to be able to undertake real time interpolation is controlled, implementation is controlled with the treatment such as circular arc curved surface point-blank. At present each main PLC manufacturer already rolled out the whole world the PCU with high-end PLC form a complete set, the place that has high speed and high accuracy controls a function. The CJ1MCPU of OMRON company is 1kBPS from the positional pulse rate that carries PCU, the speed of advanced PCU can achieve 500kBPS, the pine issues PP2 or the positional control speed of PP4 series is as high as 1MBPS. Use high-end PLC to design numerical control system, the seat that needs to choose to suit according to controlling precision, traversal speed and moving contrail demand controls unit (PCU) . Demand of precision of control of system of grinding numerical control is higher (F1 μ M) , choose digital communication servo commonly. Pulse of control of special and high-quality instruction outputs PLC of OMRON high end, form of optional choose echelon, S or triangular speed-distance curve move, implementation decides Cheng, dot to move, return the athletic control such as origin and origin search. Programming can select opposite coordinate department or world coordinate system, according to the graph 2 shown echelon graph process designing move, can realize all sorts of grinding to machine a moving curve that should abide by. Graph contrail of the 3 speed control that state system of this numerical control allows to show rib of railroad bearing liner to thick, essence, smooth grinding is machined and decline a few level 3MZ2120 grinder speed, quickly really and positional pilot motion. Graph give typical examples of process designing of 2 positions control pursues the contrail of emery wheel motion in 3 grinding treatment 2.
The system of grinding numerical control that design of interface of man-machine of 4 feeling screen is based on high-end PLC can choose interface of feeling screen man-machine (ProgrammableTer2minal, PT) , use configuration tool software and graphical warehouse (switch, lamp, good plan) and animation function, according to grinding technological process the requirement undertakes the system operates interfacial design. With 3MZ2120 grinding numerical control the system operates an interface to be an introduction to design process and effect below. According to operation of grinding numerical control and indication need, this system advocate the interface sets 8 stature pictures (graph 4) . Systematic electrify is entered automatically advocate interface, check an entree sheet is played after operating a password, in advocate the operation is clicked to be able to be transferred on the interface corresponding child interface. Treatment parameter and interface of nap parameter setting provide a setting hand of parameter clew; moves operation and hand to move nap interface to be used at related numerical control grinding fast before, retreat quickly, slow before, retreat slow, return wait for a hand to move positional control and hand to move operation of nap emery wheel, debug for equipment offer convenience; to call the police automatically the warning function design that the interface uses itself of interface of feeling screen man-machine to have, condition of chamfer of system of system of lubricant to oily mist, hydraulic pressure, machine tool electric equipment, makings, cooling system and servo electric machinery carry out monitor and call the police automatically, when malfunction feeling screen is played immediately piece call the police information (call the police code of time, breakdown and answer measure to wait) ; runs an interface automatically (graph 5) uses good plan to show current grinding surplus is worth; to use animation means to show treatment status and treatment position to wait in real time. Still set " urgent jockey " wait for lash-up pushbutton. PT has RS232/422/485 communication opening, can the PLC of compatible and numerous manufacturer. Man-machine interface applies a program to off line weaves and can be debugged, download to move to PT next, PLC is linked together through RS232 interface and PT commonly. A lot of PT still deploy collateral interface, can join with printer directly, real time prints data or undertake screen is copied. Graph sketch map of impact of 4 interfaces move pursues 5 run interfacial sketch map automatically 2.
The network structure with 5 networks structure and couplet net agile function and powerful couplet net function are the main feature of high-end PLC. PLC of OMRON high end deserves to join of standard RS232 interface feels screen man-machine interface, go up a machine or process designing workstation. Still can expand DeviceNet corresponds unit, in making all sorts of products that accord with DeviceNet communication agreement can join a system, the join of the system of; of numerical control system that is based on DeviceNet in order to form to open type spot bus line and computer of workshop management layer and PLC of workshop other high end can use Controllerlink means, communication of patulous in PLC Controllerlink is unit, card of support of Controllerlink of equipment of computer of workshop management layer can come true interrelate, measure by the rock-bottom DeviceNet equipment, numerical control system that is based on high-end PLC or other accuse computer of equipment and workshop management layer to form 3 to give rank structural network is measured control a system. High-end PLC can configure the aether network unit that accords with TCP/IP agreement standard commonly, support the application such as long-range monitoring in the round. 3.
The last word builds a CIMS extensively (CIMS) , raise the important way that production automation level is development of our country manufacturing industry in the round. The strong support that lacks equipment layer however is becoming those who develop CIMS gradually " bottleneck " , research develops all sorts of numerical control equipment that face CIMS to appear very important and pressing. The numerical control system that is based on high-end PLC has systematic compose to build agile, application software design is convenient wait for an advantage. Agile network structure, powerful couplet net function and systematic expansion ability make system of this kind of numerical control has certain open sex, the main component that makes CIMS equipment layer. Article place narrates the system of grinding numerical control that is based on PLC of OMROM high end to apply successfully already at technical reformation of 3MZ2120 grinder numerical control, the grinding equipment that makes original handiwork is operated makes equipment of advanced numerical control grinding, it is in treatment of grinding of rib of railroad bearing liner produced main effect. CNC Milling