Any faults may result in a stop of the processing of die castings, not to mention the cutting tools. The tool with the longest cutting time has a greater impact on the production cycle. What should you consider when selecting cutting tools for processing zinc alloy die casting parts?
1. Machine tool
Tools are divided into right-hand tools and left-hand tools, so it is very important to select the correct tools. Generally, right-hand tools are suitable for machine tools with counterclockwise rotation; The left-hand tool is suitable for machine tools with clockwise rotation. If you have several lathes, some hold left-hand tools, and others are compatible with left and right hands, please choose left-hand tools. As for milling, people tend to choose more versatile tools. However, although this kind of tool includes a larger processing scale, it also loses the rigidity of the tool, increases the tool deformation, reduces the cutting parameters and causes machining oscillation. In addition, the manipulator that replaces the tool of the machine tool also has constraints on the size and weight of the tool. If you buy a machine tool with an internal cooling through a hole in the spindle, please also choose a tool with an internal cooling through the hole.
2. Materials to be machined
Carbon steel is the most common material in machining, so most tools are based on optimized carbon steel machining planning. The blade trademark shall be selected according to the processed data. Tool manufacturers provide a series of tool bodies and matched blades for processing non-ferrous materials such as superalloys, titanium alloys, aluminum, composite materials, plastics, and pure metals. When you need to process the above data, please select the tool with matching raw materials. Most brands have various series of cutting tools, indicating what materials are suitable for processing.
3. Specification of machining tools
The common fault is that the selected turning tool specification is too small and the milling tool specification is too large. Large standard turning tool has better rigidity; The large standard milling cutter is not only more expensive but also has a long empty cutting time. On the whole, the price of large specification tools is higher than that of small specification tools.
4. Select replaceable blade type or regrinding type tools
The rule to follow is simple: try to avoid grinding the tool. In addition to a small number of drill bits and end milling cutters, try to choose replaceable blades or replaceable head cutters. This will save you labor costs and achieve stable processing results.
5. Cutting tool material and manufacturer
The selection of tool data and trademark is closely related to the function of processed data, the maximum speed and feed rate of the machine tool. Select a more general tool trademark for the processed data group, and generally select the coating alloy trademark. In practice, the common fault is to try to deal with the problem of tool life by replacing similar data trademarks of other tool manufacturers. If your existing tools are not ideal, reorganizing the trademarks of other manufacturers close to you is likely to bring similar results. To solve the problem, the cause of tool failure must be clear.
6. Processing power requirements
The guideline is to make the best use of everything. If you buy a milling machine with a power of 20HP, select the appropriate tools and processing parameters when the workpiece and fixture are allowed, so that it can complete 80% of the power of the machine tool. Pay special attention to the power/tachometer in the user manual of the machine tool, and select the tool that can complete better cutting according to the useful power scale of the machine tool power.
7. Number of cutting edges processed
The rule is, more is better. Buying a turning tool with twice the cutting edge does not mean paying twice the cost. With advanced planning, the number of cutting edges of the grooving cutter, blocking cutter, and some milling insert has also been doubled. It is not uncommon for an advanced milling cutter with 16 cutting edges to replace the original milling cutter with only 4 cutting edges. The number of useful cutting edges also directly affects the feed and yield of the worktable.
8. Select integral tools or modular tools
Small standard cutting tools are more suitable for overall planning; Large standard cutting tools are more suitable for modular planning. For large specification tools, when the tool fails, users often expect to regain the new tool by replacing small and inexpensive parts. This is especially true for grooving cutters and boring cutters.
9. Select single tool or multi-functional tool
The smaller the casting, the more suitable it is for compound tools. For example, a multifunctional tool can be used for compound drilling, turning, inner hole processing, thread processing, and chamfering. Of course, the more messy the workpiece is, the more suitable it is for multi-functional tools. The machine tool can bring you benefits as long as it is cutting, not when it is stopped.
10. Select standard tools or non-standard special tools
With the popularization of numerical control machining center (CNC), it is generally believed that the casting shape can be completed by programming instead of relying on tools. Therefore, non-standard special tools are no longer required. In fact, today’s non-standard tools still account for 15% of the total tool sales. Special cutting tools can be used for fine zinc alloy die-casting parts to meet the dimensional requirements, reduce the process and shorten the processing cycle. For mass production, non-standard special tools can shorten the processing cycle and reduce the cost.
11. Machining chip handling
Remember, your intention is to process the workpiece rather than chips, but chips can clearly reflect the cutting condition of the tool. On the whole, people have stereotypes about chips because most people do not interpret the practice of chips. Remember the following rule: good chips will not damage the machining, and bad chips are the opposite. Most blades are planned with chip-breaking grooves, which are planned according to the feed rate, whether it is the finishing of light cutting or the rough machining of heavy cutting. The smaller the chip, the harder it is to break. Chip handling is a difficult problem for difficult machining data. Although the processed data cannot be replaced, the tool can be updated and the cutting speed, feed rate, cutting depth, tooltip fillet radius, etc. can be adjusted. Optimizing chip and machining is a result of induction and selection.
12. Machining programming
Facing cutting tools, workpieces, and NC machining machines, cutting tools are often needed. Understand basic machine code and have an advanced CAM software package. Tool path must take into account tool characteristics, such as slope milling angle, rotation direction, feed, cutting speed, etc. Each tool has corresponding programming skills to shorten the machining cycle, improve the chip and reduce cutting force. A good CAM software package can save labor and improve productivity.
13. Tool price
Although the price of cutting tools is important, it is not as important as the production cost paid for cutting tools. Although the knife has its corresponding price, the real value of the knife lies in the responsibility for the production rate. Generally, the tool with the lowest price is the tool with the highest production cost. The price of cutting tools accounts for only 3% of the cost of parts. Therefore, please pay attention to the production rate of cutting tools, not their purchase price.