Selection and Configuration of CNC System of Jiangling Automobile Factory EQZ517 Machining Center

At present, the rapid development of domestic economic construction, the degree of automation of the machinery industry has not significantly improved. The overwhelming majority of enterprises in China have the problems of outdated equipment and backward technology, which seriously restricts the development of enterprises. The upgrading of equipment is the first step in improving the development capabilities of enterprises. How to select and configure the CNC system is the most important issue in the transformation of CNC equipment. How to reduce the cost of renovation and make the comprehensive index of the reform project the best is the issue that people are most concerned about and most worried about. This article introduces the selection and configuration of EQZ517 machining center numerical control system, the actual configuration of the situation, to analyze the importance of the selection and configuration of the CNC system in the transformation of mechanical equipment, demonstrate the merits of the choice of the configuration system and the success of the project. , increase the relationship between comprehensive indicators of transformation projects.
I. Comments on the determination of the reconstruction plan:

The so-called transformation is to maintain the original function and performance, based on the addition of new features, or to improve performance, or to improve technical indicators, in order to achieve the purpose of increasing productivity and increasing economic efficiency, which is the principle of transformation projects. Since it is a transformation, what is the reason for the transformation? For example, after the CNC system of the EQZ machining center at the Jiangling Plant suffered an accidental damage, it could not be repaired, and the original design had some problems. In order to repair the machine tool and overcome the deficiencies of the original design, it is necessary to reform. In addition, the purpose of the transformation and the necessity, efficiency, and technical rationality of the transformation must be fully demonstrated. The actual situation of the case, the subjective and objective conditions, the economic and social benefits, as well as the opinions, methods and measures of the project must all be subject to rigorous scientific argumentation and a feasible conclusion. The first problem in transforming CNC machine tools is how to choose the CNC system. The performance of a CNC device depends on the performance of the CNC system. The equipment after the transformation has been improved and the performance has been improved. This is the purpose of the transformation. To achieve this goal, the performance of the selected CNC system should be improved and the configuration should be improved. The first step in the transformation work is to comprehensively analyze, understand, master the electrical working principle, and initially determine the objectives of the transformation work on the performance, functions, and various technical indicators of the transformed equipment. Based on this goal, a thorough investigation and understanding of the market is conducted. Then, based on the functions, performance and technical indicators of the equipment and the objectives to be achieved, one to three renovation projects are proposed and comprehensive indicators are proposed. Then according to the comprehensive index, the demonstration and review of the transformation plan will be carried out according to the market conditions, so that the comprehensive index of the reform project will be the best. When examining and revising the transformation plan, it is not only simpler to over-regulate and pursue high targets, high performance, and multi-functionality, but also cannot simply consider only the cost reduction. Both must be taken into consideration. This is like a power supply, surge only requires the output of high voltage, can not only output a large current, and requires the best working condition, the maximum output power. What we are seeking is that the best comprehensive indicator is the best combination of technical indicators and economic indicators, that is, the intersection of two primary functions. Furthermore, the review and reconstruction program is a rigorous, thorough and scientific work. It is the scientific reliability review of the reform program, not the review of the investigators. The review emphasizes a scientific attitude and discusses the truth of science. It should be truth-seeking, forward-thinking, full of pioneering spirit, and fully embody the spirit of collectivism.

Second, the original configuration of EQZ machining center:

The machining center is a combined machine tool. The machine tool has four axes and linearly interpolates two axes. Y and Z two-axis linkage are required during work. The machine tool electrical numerical control system uses DYTAPATH's DELTA 10M/20M numerical control device, and the processing unit's axis servo and spindle servo device use Japanese YASKAWA's AC servo device. The machine tool gun drill slide, the chamfer car end slide, the cooling device, and the auxiliary actions are all controlled by PLC's programmable interface control PLC. Once the machine tool is clamped, it can be used for gun drilling, milling, drilling, boring, reaming, chamfering, etc. A working cycle, in which the gun drilling process, the end of the chamfering car processing by two in the vertical Sliding table control in direction and horizontal direction, in which two motors are installed on the top of the gun drill processing slide, one of the motors is equipped with a solenoid valve, and the two motors can realize fast-forward, working-in and working-out machining through the internal wheel train mechanism. , And in the work into the fast forward motor locked by the solenoid valve to ensure safety. Gun drill bit has another motor to drive high speed. Chamfering, car end slide feed movement controlled by a hydraulic cylinder to achieve fast forward, retreat, work into, back and forth processing, the tool holder of the clamping tool mounted on two knives, a car end face, a chamfer . The order of work is to chamfer first and then hydraulically control the end face from the outside to the inside. The knife-loading rotary tool holder is mounted on a high-speed rotating car end face and a corner motor to carry out a rotary motion.

The processing control process of these two slides can be controlled by the M code during the automatic processing, and can also be manually adjusted and controlled in the manual mode. On the occasion, the CNC-controlled two axes are mainly for the spindle to move back and forth to complete two actions: one is the tool change action, and the other is the additive control (milling face, drilling, boring, reaming). The tool change is achieved by the following way: the spindle is moved to the loose knife position by the Y and Z axes - spindle orientation - magazine entry - spindle release - spindle to grab position - spindle grab - spindle Directional release - knife withdrawal. Among them, the spindle is loose and the gripper is a spring jaw that is mounted on the spindle and controlled by hydraulic pressure. The working principle is that when the gripper is moved, the hydraulic cylinder moves left and right, and the claw is left by the internal mechanism. The right movement, to achieve relaxation and tensioning action, and in order to ensure that the tool tension is reliable, by the monitor (pressure gauge) to measure the hydraulic pressure when the tension and the hydraulic cylinder movement distance is in place. If both of them reach the required value, it means the tension is in place, so the tension will be automatically stopped and the hydraulic valve will be powered off. This is controlled by the PLC. The spindle is oriented by a magnetic sensor probe mounted on the spindle box. The measured current signal is amplified by the amplifier and sent to the spindle servo unit to control the orientation. The other control is based on the spindle speed control, a position control loop is added, and the control block diagram can be understood as follows: The tool magazine is controlled by the hydraulic in and out of the magazine. The magazine is an upright magazine, and up to four can be installed on the magazine. The tool can be completed in turn.

Third, the choice of CNC system:

After the transformation, the machine tool uses Huazhong CNC "Century Star" CNC system. The system uses a PC as the hardware and software platform of the CNC system and directly connects the real-time control unit (the real-time control board is inserted into the bus slot) on its standard bus to form a complete CNC system. Among them, the PC mainly completes some of the top-level tasks of the CNC system that are not very real-time and coordinates and manages the operation of the entire system. The real-time control unit completes the task of high-level real-time tasks. The real-time control unit can be a complete CNC unit with track interpolation calculations, position control, switching control (PLC), etc. It can also be a digital pulse conversion card with a simple position control card and a digital servo interface with only a position control function. However, there is also a drawback: the exchange of information between the real-time control unit and the servo drive unit. It is easy to interfere with information transmission. Such as analog mouth voltage signal temperature drift, zero drift and so on. The use of a new high-performance CPU as the core of the system's operation and control, and to use software to achieve all the functions of the CNC. In addition, high-reliability reliability design and manufacturing techniques are used in software design, power supply design, connector design and selection, grounding and shielding design. And on the PC platform based on high-performance CPU can not only complete the basic functions of the CNC system (such as information processing, tool compensation calculation, interpolation calculation, acceleration and deceleration control, etc.) and the switch control function, but also can complete the servo control function.