飛剪機剪切機構(gòu)設計【5張CAD圖紙】

喜歡這套資料就充值下載吧。資源目錄里展示的都可在線預覽哦。下載后都有，請放心下載，文件全都包含在內(nèi)，【有疑問咨詢QQ:414951605 或 1304139763】=喜歡這套資料就充值下載吧。資源目錄里展示的都可在線預覽哦。下載后都有，請放心下載，文件全都包含在內(nèi)，【有疑問咨詢QQ:414951605 或 1304139763】= Development and maintenance of CNC technologyNumerical control technology and equipment is the development of new high-tech industry and cutting-edge enabling technology, industry and the most basic equipment. The world information industry, biological industry, aviation, aerospace and other defense industry widely used numerical techniques to improve manufacturing capacity and level, to improve the adaptability of the market and competitiveness. Industrial countries and CNC numerical control technology and equipment will also be listed as countries of strategic materials, not only to develop their own numerical control technology and industry, and in sophisticated technology and equipment, numerical control key aspects of the policy of closures and restrictions. Therefore, efforts to develop advanced numerical control technology as the core manufacturing technology has become the worlds developed countries to accelerate economic development, enhance the comprehensive national strength and an important way to statehood.The NC system consists of the following components：data input，the tape reader with the control unit，feedback devices，and the metalcutting machine tool or other type of NC equipmentData input，also called“mantocontrol link”，may be provided to the machine tool manually，or entirely by automatic meansManual methods when used as the sole source of input data are restricted to a relatively small number of inputsExamples of manually operated devices are keyboard dials，pushbuttons，switches，or thumbwheel selectorsThese are located on a console near the machineDials ale analog devices usually connected to a syn-chro-type resolver or potentiometerIn most cases，pushbuttons，switches，and other similar types of selectors aye digital input devicesManual input requires that the operator set the controls for each operationIt is a slow and tedious process and is seldom justified except in elementary machining applications or in special casesIn practically all cases，information is automatically supplied to the control unit and the machine tool by cards，punched tapes，or by magnetic tapeEightchannel punched paper tape is the most commonly used form of data input for conventional NC systemsThe coded instructions on the tape consist of sections of punched holes called blocksEach block represents a machine function，a machining operation，or a combination of the twoThe entire NC program on a tape is made up of an accumulation of these successive data blocksPrograms resulting in long tapes all wound on reels like motion-picture filmPrograms on relatively short tapes may be continuously repeated by joining the two ends of the tape to form a loopOnce installed，the tape is used again and again without further handlingIn this case，the operator simply loads and unloads the partsPunched tapes ale prepared on type writers with special tapepunching attachments or in tape punching units connected directly to acomputer systemTape production is rarely error-freeErrors may be initially caused by the part programmer，in card punching or compilation，or as a result of physical damage to the tape during handling，etcSeveral trial runs are often necessary to remove all errors and produce an acceptable working tapeWhile the data on the tape is fed automatically，the actual programming steps ale done manuallyBefore the coded tape may be prepared，the programmer，often working with a planner or a process engineer, must select the appropriate NC machine tool，determine the kind of material to be machined，calculate the speeds and feeds，and decide upon the type of tooling needed. The dimensions on the part print are closely examined to determine a suitable zero reference point from which to start the programA program manuscript is then written which gives coded numerical instructions describing the sequence of operations that the machine tool is required to follow to cut the part to the drawing specificationsThe control unit receives and stores all coded data until a complete block of information has been accumulatedIt then interprets the coded instruction and directs the machine tool through the required motionsThe function of the control unit may be better understood by comparing it to the action of a dial telephone，where，as each digit is dialed，it is storedWhen the entire number has been dialed，the equipment becomes activated and the call is completedSilicon photo diodes，located in the tape reader head on the control unit，detect light as it passes through the holes in the moving tapeThe light beams are converted to electrical energy，which is amplified to further strengthen the signalThe signals are then sent to registers in the control unit, where actuation signals are relayed to the machine tool drivesSome photoelectric devices are capable of reading at rates up to 1000 characters per secondHigh reading rates are necessary to maintain continuous machinetool motion；otherwise dwell marks may be generated by the cutter on the part during contouring operationsThe reading device must be capable of reading data blocks at a rate faster than the control system can process the dataA feedback device is a safeguard used on some NC installations to constantly compensate for errors between the commanded position and the actual location of the moving slides of the machine toolAn NC machine equipped with this kind of a direct feedback checking device has what is known as a closed-loop systemPositioning control is accomplished by a sensor which，during the actual operation，records the position of the slides and relays this information back to the control unitSignals thus received ale compared to input signals on the tape，and any discrepancy between them is automatically rectifiedIn an alternative system，called an openloop system，the machine is positioned solely by stepping motor drives in response to commands by a controllersThere are three basic types of NC motions, as follows:Point-to-point or Positional Control In point-to-point control the machine tool elements (tools, table, etc.) are moved to programmed locations and the machining operations performed after the motions are completed. The path or speed of movement between locations is unimportant; only the coordinates of the end points of the motions are accurately controlled. This type of control is suitable for drill presses and some boring machines, where drilling, tapping, or boring operations must be performed at various locations on the work piece. Straight-Line or Linear Control Straight-Line control systems are able to move the cutting tool parallel to one of the major axes of the machine tool at a controlled rate suitable for machining. It is normally only possible to move in one direction at a time, so angular cuts on the work piece are not possible, consequently, for milling machines, only rectangular configurations can be machined or for lathes only surfaces parallel or perpendicular to the spindle axis can be machined. This type of controlled motion is often referred to as linear control or a half-axis of control. Machines with this form of control are also capable of point-to-point control.Continuous Path or Contouring Control In continuous path control the motions of two or more of the machine axes are controlled simultaneously, so that the position and velocity of the can be tool are changed continuously. In this way curves and surfaces can be machined at a controlled feed rate. It is the function of the interpolator in the controller to determine the increments of the individual controlled axes of the machines necessary to produce the desired motion. This type of control is referred to as continuous control or a full axis of control.Some terminology concerning controlled motions for NC machines has been introduced. For example, some machines are referred to as four-or five-or even six-axis machines. For a vertical milling machine three axes of control are fairly obvious, these being the usual X, Y, Z coordinate directions. A fourth or fifth axis of control would imply some form of rotary table to index the work piece or possibly to provide angular motion of the work head. Thus, in NC terminology an axis of control is any controlled motion of the machine elements (spindles, tables, etc). A further complication is use of the term half-axis of control; for example, many milling machines are referred to as 2.5-axis machine. This means that continuous control is possible for two motions (axes) and only linear control is possible for the third axis. Applied to vertical milling machines, 2.5axis control means contouring in the X, Y plane and linear motion only in the Z direction. With these machines three-dimensional objects have to be machined with water lines around the surface at different heights. With an alternative terminology the same machine could be called a 2CL machine (C for continuous, L for linear control). Thus, a milling machine with continuous control in the X, Y, Z directions could be termed be a three-axis machine or a 3c machine, Similarly, lathes are usually two axis or 2C machines. The degree of work precision depends almost entirely upon the accuracy of the lead screw and the rigidity of the machine structureWith this systemthere is no self-correcting action or feedback of information to the control unitIn the event of an unexpected malfunction，the control unit continues to put out pulses of electrical currentIf，for example，the table on a NC milling machine were suddenly to become overloaded，no response would be sent back to the controllerBecause stepping motors are not sensitive to load variations，many NC systems are designed to permit the motors to stall when the resisting torque exceeds the motor torqueOther systems are in use，however，which in spite of the possibility of damage to the machine structure or to the mechanical system，ale designed with special hightorque stepping motorsIn this case，the motors have sufficient capacity to“overpowerthe system in the event of almost any contingencyThe original NC used the closedloop systemOf the two systems，closed and open loop，closed loop is more accurate and，as a consequence，is generally more expensiveInitially，openloop systems were used almost entirely for light-duty applications because of inherent power limitations previously associated with conventional electric stepping motorsRecent advances in the development of electro hydraulic stepping motors have led to increasingly heavier machine load applicationsPart I: the development of CNC machine tools trends in individual1. High speed, high accuracy, high reliability High speed: To improve the speed and increase feed spindle speed.High precision: the precision from micron to sub-micron level, and even the nano-level (high reliability: the reliability of numerical control system generally higher than the reliability of numerical control equipment more than an order of magnitude, but not the higher the better reliability because the goods by the cost performance constraints.2. Composite Composite function CNC machine tool development, its core is in a single machine to complete the turning, milling, drilling, tapping, reaming and reaming and other operating procedures, thereby increasing the efficiency and precision machine tools to improve production flexibility.3. Intelligent Intelligent content included in all aspects of the numerical control system: the pursuit of processing efficiency and processing quality of intelligence; to improve the performance and the use of convenient connections and other aspects of intelligence; simplify programming, simplifying operational intelligence; also like the intelligent automatic programming, intelligent man-machine interface, as well as intelligent diagnostics, intelligent monitoring and other aspects, to facilitate system diagnostics and maintenance.4. Flexible, integrated The world of CNC machine tools to the development trend of flexible automation systems are: from the point (CNC single, composite machining centers and CNC machine tools), line (FMC, FMS, FTL, FML) to the surface (Section workshop independent manufacturing island FA) , body (CIMS, distributed network integrated manufacturing system) direction, the other to focus on applied and economic direction. Flexible automation technology is the industry to adapt to dynamic market demands and quickly update the primary means of product is the main trend of national manufacturing industry is the basis for the field of advanced manufacturing technology. Second, personalization is the adaptability of the market trendsTodays market, gradually formed the pattern of international cooperation, the products becoming more competitive, efficient and accurate processing of the escalating demand means, the users individual requirements become increasingly strong, professional, specialization, more and more high-tech machine tools by the users of all ages.Third, the open architecture trend is The core of a new generation of CNC system development is open. Open software platform and hardware platforms are open systems, modular, hierarchical structure, and through out the form to provide a unified application interface. CNC system to address the closure of the traditional CNC applications and industrial production problems. At present, many countries of open CNC system, CNC system has become an open numerical control system of the future of the road. The open numerical control system architecture specification, communication specifications, configuration specifications, operating platform, function libraries and CNC numerical control system software development tools, system function is the core of the current study. Network numerical control equipment is nearly two years of a new focus. NC network equipment will greatly satisfy the production lines, manufacturing systems, manufacturing information integration needs of enterprises, but also achieve new manufacturing model, such as agile manufacturing, virtual enterprises, global manufacturing the base unit. Some well-known at home and abroad, and CNC CNC machine tools manufacturing company inPart II: Machine Maintenance There are two basic types of numerically controlled machine tools：pointtopoint and continuouspath(also called contouring)Pointtopoint machines use unsynchronized motors，with the result that the position of the machining head Can be assured only upon completion of a movement，or while only one motor is runningMachines of this type are principally used for straightline cuts or for drilling or boringCNC machine tools is electronic technology, measurement technology, automation technology, semiconductor technology, computer technology and electrical technology, and integrated set of automation equipment, high precision, high efficiency and high flexibility. CNC machine tools is a process control equipment and asked him in real-time control of the accuracy of every moment of work, any part of the fault and failure, so that the machine will shut down, resulting in production stoppages, which seriously affected and restricted the production efficiency . CNC machine tools in many industries to work the device is critical, if not after a failure in its maintenance and troubleshooting time, it will cause greater economic losses. Therefore, the principle that complex numerical control system, structure, maintenance of sophisticated equipment is necessary. CNC machine tools to enhance fault diagnosis and maintenance of power, can improve the reliability of CNC machine tools, CNC machine tools is conducive to the promotion and use. CNC machine tools is a mechanical, electrical, hydraulic, gas combination of complex equipment, though the reasons for failure vary, but the failure occurred, the general idea of the steps are the same. Fails, Spindle start below to stop immediately after the fault diagnosis of CNC machine tools as an example the general process.First, the fault-site investigation. The survey content includes 1, 2 types of failure, the failure frequency of 3, 4, external conditions, the operating conditions 5, 6, machine conditions, the functioning of 7, wiring between machine tools and systems 8, CNC equipment visual inspection. After an investigation, such failure is spindle class failure, only once, outside of all normal, the operator of a boot to reflect this situation. Second, the fault information collation, analysis. For some simple fault, because not a lot of time, the method can be used form of logical reasoning, analysis, identification and troubleshooting. After a failed on-site investigation for several reasons we suspect that the system output pulse drive is not enough time to move the state line to control the spindle components damage to the spindle motor short-circuit, causing the spindle thermal relay protection not with self-control loop lock circuits, and the parameter is set to pulse signal output, so that the spindle can not operate normally. Identify possible reasons to rule out one by one. Third, conduct fault diagnosis and troubleshooting.Diagnosis usually follows the following principles: 1, after the first outside inside. Reliable line of modern CNC system increasingly high failure rate of CNC system itself less and less, and most are non-occurrence of failure causes the system itself. The CNC machine is a mechanical, hydraulic, electrical as one of the tools, the occurrence of the fault will be reflected by these three comprehensive, maintenance personnel should be from outside to inside one by one investigation to avoid arbitrary unsealed, demolition, otherwise expand the malfunction, so that the loss of precision machine tools, slow performance, outside the system detected the fault is due to open one by one, hydraulic components, pneumatic components, electrical actuators, mechanical devices caused problems. 2, the first after the electrical machinery. In general, the mechanical failure easier to find, and numerical control system and electrical fault diagnosis more difficult, before the troubleshooting to rule out mechanical failure of the first 3, after the first static dynamic. Power off the machine first, quiescent state, through understanding, observation, testing, analysis, confirm the power failure will not result in expansion of the incident only after the power to the machine, run the state, the dynamic of observation, inspection and testing, to find fault. While after the devastating power failure, you must first rule out the danger, before electricity. 4, after the first simple and complex. When multiple failures are intertwined, and sometimes impossible to start with, we should first solve the problem easily, then solve the difficult problem, often a simple problem to solve, the difficulty of the problem may also become easier. CNC machine tools in the fault detection process, should make full use of numerical control system self-diagnostic features to be judged, but also flexibility in the use of some common troubleshooting methods. Troubleshooting common methods are:1. Routine examination method Routine examination method is mainly of hands, eyes, ears, nose and other organs of the fault occurrence of various light, sound, smell and abnormal observations and careful look at every system, follow the first post outside of the principle of fault diagnosis by looking, listening, smelling, asking, mold and so on, from outside to inside one by one check, the fault can often be narrowed down to a module or a printed circuit board. This requires maintenance personnel have a wealth of practical experience, to the wider multidisciplinary and comprehensive knowledge of the ability to judge.2. Self-diagnostic function method Modern CNC system has yet to achieve a high degree of