Selection of cutting tools
In order to ensure the balance between equipment efficiency and production line rhythm, it is necessary to consider the matching of suitable tools and equipment on the production line. Therefore, whether the tool selection is reasonable will directly affect the workpiece quality and processing efficiency, so the tool selection should be carried out from the following aspects:
1, processing equipment
First of all, we must understand the performance of processing equipment. Only by knowing the performance of the equipment can we choose the appropriate tools to match it. Otherwise, no matter whether we choose equipment or tools alone, its efficiency will not be brought into play. Relevant data in recent years show that a tool worth tens of thousands of yuan may affect the efficiency of a device worth millions of yuan. The design and arrangement of tools in the planning process largely determines the manufacturing cost and tool cost in the production stage.
2. Tool materials
With the rapid development of manufacturing technology, the requirements for cutting tools are getting higher and higher. In order to meet the requirements of high-speed cutting degree, new material tools have been widely used. The use of new material tools greatly improves the cutting efficiency. The durability of high-performance high-speed steel cutter with high cobalt and high vanadium is 1.5 ~ 3 times higher than that of ordinary high-speed steel, and the strength of powder metallurgy high-speed steel can be improved by 20% ~ 30%. The toughness is increased by 1.5 ~ 2 times, and the reliability is obviously improved compared with that of ordinary high-speed steel. The cutting speed of superhard tools such as CBN (cubic boron nitride), PCD (polycrystalline diamond) and ceramic tools, which represent the current technical development level, is several times higher than that of cemented carbide, and the machining efficiency is greatly improved.
3. Tool handle
With the increase of cutting speed, the connection performance of spindle/tool holder has changed greatly under the action of centrifugal force, which directly affects the machining accuracy and surface roughness of workpiece. Therefore, tool clamping and its connection with machine tools, such as HSK tool holder, hot sleeve tool holder and hydraulic tool holder, are widely used to meet the needs of CNC machine tools and high-speed machining.
4. Tool structure
In order to improve production efficiency and reduce tool changing time, more and more compound tools are used in the processing of automobile parts, such as drilling and boring compound, drilling and hinge compound, drilling and threading compound and so on. The deployment tools with complex structure meet many special processing requirements, and some tools have even developed into mechanical, electrical and hydraulic integrated devices, which have gone far beyond the traditional concept of tools. Because a large number of assembly lines are used in powertrain processing, the production of the previous process directly affects the production of the next process. In order to improve production efficiency and reduce production cost, a large number of combined tools and non-standard tools are used.
5, the cost of tools
Tool consumption is related to many factors and needs specific analysis. While looking at the total cost of tools, it is more important to look at the tool cost consumed by a single piece of processed products, not only the direct tool cost, but also the impact of tools on production efficiency and the changes in the total manufacturing cost caused by it. The performance, service life and purchase price of new tools have great influence on the tool cost, while the number of regrinding tools, regrinding times and grinding cost also have significant influence on the total tool cost. Therefore, the relationship between disposable equipment and tool input and long-term tool consumption cost needs to be considered and balanced comprehensively.
6. Process method
In order to give full play to the role of high-efficiency flexible line, tools put forward many new requirements for technology, such as trying to consider that the same tool can complete more processing of the same workpiece in different processes, trying to reduce tool inventory, limiting tool change frequency and reducing manufacturing costs. At the same time, in view of some technical difficulties, special tools, compound tools or intelligent tools are designed to solve the problem between machining accuracy and machining efficiency.
7. Tool suppliers
Tool selection includes the determination of tool suppliers. Because cutting is a systematic problem, process change, machine tool, fixture, cutting fluid and cutting parameters all have significant effects on tool life, and the determination of tool structure, tool material and surface coating that affect machining performance is closely related to process, cutting parameters and cutting fluid. The selected tool must pass the cutting test, and the selected tool and its supplier must be determined after the cutting test. At the same time, modern automobile manufacturing industry also requires tool suppliers not only to provide overall cutting solutions, but also to provide timely and effective on-site technical support and form a cooperative partnership with automobile manufacturing enterprises.