In the process of processing molds, mold processing centers have higher and higher requirements for accuracy and surface processing quality. In order to ensure the quality of mold processing, we should choose from machine tool selection, tool holder selection, tool selection, processing plan, program generation, Operator requirements and other aspects are considered:
1. Choose high-precision high-speed machining center.
With the improvement of product design requirements and the development of high-speed and high-precision processing technology, the quality of CNC machining has been greatly improved, the mold processing speed has been greatly improved, the processing time is shortened, the production cycle is shortened, and the mold clamp is loaded The number can sometimes eliminate time-consuming fitter repair work. The high-speed and high-precision processing of molds has gradually become an important part of the technological transformation of mold manufacturing enterprises. It has become an inevitable substitute for the traditional low-speed machining of high-speed CNC machining centers, and the development of mold manufacturing technology will also bring us a richer product experience.
2. Use proper handle structure
The use of high-speed and high-precision machining centers will also promote the update of related process equipment. In particular, the influence of tools on CNC machining quality and tool holders will become prominent. In the rotary tool processing system, the connection between the chuck and the machine tool (or a combination thereof) is tight to ensure tool processing performance. Commonly used machine tool and tool holder interfaces are HSK hollow shank and BT type tool shank. The taper of the machine tool spindle and the taper shank of the BT tool holder is 24:7. Traditional low-speed processing is suitable for this shank connection. Since the BT shank and the machine spindle are only tapered, the cone will be made under the action of high-speed centrifugal force. The surface matching gap increases, which affects the quality of CNC machining. Usually, when the spindle speed exceeds 16000 rpm, we need to use the HSK hollow handle. The HSK spindle positioning structure is located in the excessive position to provide a standard connection with the machine tool. Under the tension of the machine tool, the short taper and end face of the mandrel are closely matched with the machine tool.
3. Choose the right processing tool
Reasonable use and selection of tools will be an important factor affecting the quality of CNC machining. The use of cemented carbide tools is becoming more and more widespread. High-speed machining of coated carbides will replace most of the front steel tools, including reamers, ball-end tools, boring tools and other simple tools. Coated carbide will run at high speeds. It plays an important role in the processing of tool materials.
Suitable for most traditional processing fields. Usually we know that we will use large diameter tools for roughing. In order to save costs and reduce the difficulty of tool manufacturing, we will use the carbide inserts clamped by the machine to maximize roughing and chip removal; semi-finishing high-speed and high-feed tools make semi-finishing through faster.
In the finishing process, use high-precision round mirror blades as much as possible to ensure the strength of the tool and the arbor, so as to ensure the machining accuracy and save the expensive cost of selecting the entire alloy. In processing, we also need to pay attention to the fillet radius of the inner contour on the finished part must be greater than or equal to the radius of the tool. The tool whose radius is smaller than the corner fillet radius is selected by circular interpolation or diagonal interpolation. During processing, this can avoid the use of linear interpolation and over-cutting, and ensure the quality of mold finishing.
4. CNC machining plan
In high-speed and high-precision machining, the importance of numerical control process design has been raised to a higher position, and the entire process must be controlled. Any error will seriously affect the quality of the mold, so the process plan will depend on the quality of the process and play a decisive role. The design of CNC machining process can be considered as the process state of the system from part blank to part processing and forming.
It is difficult to formulate a good process plan during the entire design process. It needs to be summarized and modified after continuous practice. The amount of information to be considered in the design process is very large, the relationship between the information is very complicated, and programming must be carried out. Ensure the actual work experience of employees. Therefore, the design quality of the process plan mainly depends on the experience and level of the technicians.
5.CAM software
A good software can also improve the quality and efficiency of mold processing. Software is just a tool. An excellent programmer has rich experience and theoretical knowledge of on-site machining, and a CNC programmer who is proficient in software functions. Talent is the decisive factor in the CNC machining of molds, and the quality of CNC machining And efficiency play a key role. To this end, establish a complete program designer training system.
6. Operator
Machining center operators are the executors of CNC machining, and their control over the quality of CNC machining is also obvious. They have the best knowledge of the real-time status of machine tools, tool holders, tools, processing technology, software and cutting parameters during the execution of machining tasks. Their various operations have the most direct impact on CNC machining, so the skills and responsibilities of the machining center operators Heart is also a key factor to improve the quality of CNC machining!