Overview of NC transformation of machine tools (middle)
the fifth content is the evaluation of performance price ratio. This is actually a comprehensive assessment of the second and third items above. In order to have the basis of quantitative analysis in economy, we often choose a commodity price with similar performance on the market as the standard for comparison. For example, there is a horizontal machining center produced 15 years ago. The electric control part has been seriously damaged and cannot be repaired, and the mechanical accuracy has lost about 20%. It is estimated that its residual value is about 300000 yuan. When it is to be transformed, 25000 yuan will be invested in the electric control part, 100000 yuan will be invested in the renovation of the mechanical part, and 100000 yuan of technical labor fees will be invested in the whole machine, a total of 750000 yuan. Now it costs 1.8 million yuan to buy another similar machine tool. After the transformation, the service performance and efficiency of the machine tool are estimated to reach 70% - 80% of the new equipment, and the service life is more than 6-8 years (more than one overhaul cycle), that is, the performance price ratio of this transformation scheme is desirable
in the evaluation, it should be noted that the equipment with low residual value is not worth making great efforts to transform; The transformation plan with low residual value and high input value is also undesirable. Therefore, in the NC transformation of old equipment, the primary object is the old NC machine tool with high residual value. The mechanical structure and functions of these equipment are easy to match with the new electronic control system, and the comprehensive effect is good. The second is the medium and large equipment of ordinary machine tools, including the coaxiality correction service of load frame. These equipment have a high original value and are often key equipment of the Department so far, which is worth making great efforts to transform. For some equipment with low original value, it's a pity to scrap it immediately! If you want to reuse the equipment in the next stage after the transformation, you should be careful when determining the transformation application index. That is, from the practical point of view, put forward the application indicators that should not be invested too much. The electric control part shall try to adopt cheap and simple system, the transformation workload shall be compressed within a certain range, and the practical economic effect shall be achieved by reducing investment
3 basic steps of NC transformation
NC transformation of equipment generally has three operation modes: that is, the equipment has its own manufacturers, which requires these manufacturers to have strong technical transformation strength; The second way is that the equipment manufacturer hires brother units with reliable technology to participate in the project according to its own technical weakness; The third way is to completely entrust a unit to contract the project. When selecting a contractor, attention must be paid to its technical ability and commercial reputation. Numerical control transformation is a work with large technical content and broad technical field. It is selected to be composed of a variable throttle and a differential pressure reducing valve in parallel. The object must have solid technical ability and electromechanical comprehensive ability. Party A and Party B should have good faith in cooperation and be a trusted partner; Otherwise, it is difficult to restrict each other only by simple contractual relationship, which will slow the progress of the project or make it impossible to finish
the transformation steps are basically as follows: (1) basic evaluation of old equipment; (2) Determine the transformation plan; (3) Implement the transformation investment funds; (4) Look for the entrusting unit and sign the relevant transformation contract agreement; (5) Do not find several existing materials and data of masonry chemical machine tools at will; (6) On site mapping of electrical and mechanical components of old equipment; (7) Design, order and manufacture CNC, PLC, electrical and mechanical transformation of machine tools; (8) Dismantle, repair, maintain and replace other electromechanical systems, hydraulic systems and auxiliary parts of the machine tool on site; (9) Carry out on-site construction, installation and connection of the machine tool transformation part; (10) Machine tool joint commissioning test; (11) Repair and restore the geometric accuracy and positioning accuracy of the machine tool; (12) Function linkage test of each part of the machine tool and control system, and reliable operation; (13) Inspection and acceptance of machine tools; (14) Machine tool trial production cutting operation
of course, the contents of a specific project may be increased or decreased, but the basic contents are generally included
4 the reconstruction work often meets the difficulty of greatly improving its scratch resistance
evaluation difficulty
it is difficult to make an accurate evaluation of an old equipment that has been used for many years, especially many equipment often lack necessary and systematic technical files. The original data of some second-hand equipment have been lost, and some equipment has been damaged and cannot be retested, so it is difficult to accurately understand the wear degree of each component and quantitatively evaluate the residual value of each component. If the evaluation is too high or too low, it will have a lot of impact on the determination of the transformation scheme and the performance price ratio after the transformation. Therefore, when doing this work, it is necessary to hire experienced experts, do necessary surveying and mapping, test and experiment, and do necessary market research, especially quantitative analysis
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