The following four types of process measures are commonly used to increase machining productivity:
Single-piece work time reduction
The procedure attempts to reduce the overall time. Because basic time in the unit of time accounted for a larger share of mass production, reducing basic time can increase productivity. The following are the primary methods for reducing the basic time:
1. Increasing the cutting quantity, cutting speed, feed, and backdraft can reduce the basic time, which is widely used in machining to boost productivity in effective ways. However, the amount of cutting that can be improved is limited by tool durability, machine power, process system stiffness, and so on. Cutting speed has significantly increased as a result of the development of new tool materials; at the moment, carbide turning tools can cut at speeds of up to 200 m/min, and ceramic tools can cut at speeds of up to 500 m/min. Polycrystalline artificial diamond and polycrystalline cubic boron nitride cutting tools have recently come into use, increasing the speed at which regular steel can be sliced to 900 m/min. High-speed and powerful grinding is a new development trend in the grinding industry.
2. Cutting with multiple instruments at the same time.
3. Milling multiple parts By shortening the tool's cutting-in and cutting-out periods or synchronizing the basic times, this technique reduces the basic time required to machine each item. Sequential multi-part machining, parallel multi-part machining, and parallel sequential multi-part machining are the three different methods of multi-part machining.
4. Lower the allowance for machining. Precision casting, pressure casting, precision forging, and other cutting-edge techniques can greatly increase productivity by increasing blank manufacturing accuracy, decreasing machining margins to reduce basic time, and sometimes even without additional mechanical processing.
Second, cut the auxiliary time shorter. A huge chunk of a single piece of time is taken up by auxiliary time as well. This is especially true following a significant increase in the cutting amount when the basic time is drastically reduced and the proportion of auxiliary time increases even more. At this point, reducing auxiliary time has become a key strategy for boosting production. There are two ways to reduce the auxiliary time: one is to automate and mechanize the auxiliary action, which reduces the auxiliary time directly; the other is to make the auxiliary time and the basic time overlap, which reduces the auxiliary time indirectly.
1. Directly cutting back on auxiliary time. The time it takes to load and unload the workpiece can be sped up by using customized fixtures to clamp the workpiece, which eliminates the requirement for the workpiece to locate the correct position. High-efficiency pneumatic and hydraulic fittings are frequently used in mass production to speed up the loading and unloading of workpieces. Due to the high manufacturing costs of specific fixtures, combining fixtures and adjustable fixtures can be utilized in single-piece small-batch production to reduce the time required for loading and unloading workpieces. Moreover, active inspection devices or digital display devices can be employed to conduct real-time measurements during processing to reduce the measurement time necessary during processing. This will cut down on the auxiliary time for halting and measuring during processing. Active inspection equipment, such as automatic grinding measuring devices, may measure the precise dimensions of the machined surface while it is being machined. The machine will then automatically modify itself based on the measurement results and work cycle control. Digital display systems can correctly and continuously show the movement of the machine tool during machining or tool adjustment, which significantly reduces the amount of time needed to monitor downtime.
2. Reduce auxiliary time indirectly. For multi-station fixtures and continuous processing techniques, it is possible to make the coincidence between the auxiliary time and the basic time total or partial.
3. Reduce the duration of setup. It is vital to decrease the frequency of tool changes as well as the time needed for each tool change because changing tools take up the majority of the time needed to set up work. The use of tool loading fixtures and better tool installation techniques are the key ways to cut down on tool changing times. Such as the use of a range of quick-change tool clamps, tool fine adjustment mechanisms, unique tooling samples or tooling samples, and automatic tool changing devices to reduce tool loading and unloading and toolset time. Indexable carbide insert tools, for example, can reduce the number of tool changes and the time required for tool loading and unloading, tool set, and sharpening on lathes and milling machines.
4. Process improvements to shorten preparation and completion times There are two ways to minimize the preparation and end time: first, enlarge the manufacturing batch to reduce the preparation and end time allocated to each part; second, reduce the preparation and finish time directly. The standardization and generalization of parts, which can be organized into groups, can be used to expand the production batch.
The use of multiple machine tool supervisors is being implemented.
A sophisticated measure of labor organization is multiple-machine tool management. A worker can control multiple machine tools at the same time to increase production, but he or she must meet two conditions: first, if a person is in charge of M machine tools, any M-1 machine tools on the aggregate of the worker's operating time should be less than another machine tool maneuvering time; and second, each machine tool should have an automated stopping device.
The use of advanced technology methods
1. Blank preparation. The use of cold extrusion, hot extrusion, powder metallurgy, precision forging, explosive forming, and other new processes, can greatly improve the accuracy of the blank, reduce the machining workload, save raw materials, can significantly improve productivity.
2. Special processing. For extra hard, tough, brittle, and other difficult-to-process materials or complex surfaces, the use of special processing methods can greatly improve productivity. Such as the electrolytic processing of general forging die, the processing time can be reduced from 40 to 50 hours to 1 to 2 hours.
3. Using less cutting processing Such as cold extrusion gear, rolling screw, etc.
4. Improve processing methods, and reduce manual and inefficient processing methods. Such as mass production to broaching, rolling instead of milling, reaming, grinding, fine planing, fine grinding, diamond boring instead of scraping, etc.
Adopt an automated manufacturing system
An automated manufacturing system is an organic whole composed of a certain range of processed objects, a certain level of flexibility, and automation of various equipment and highly qualified people, which accepts external information, energy, funds, supporting parts, and raw materials, etc., and realizes a certain degree of flexible automated manufacturing under the joint action of human and computer control systems, and finally outputs products, documentation, waste amplification, and so on. The adoption of automated manufacturing systems has the potential to greatly improve labor conditions, significantly enhance labor productivity, significantly improve product quality, significantly shorten the production cycle, and significantly lower manufacturing costs.
