in the process of processing mold, the accuracy and surface processing quality requirements are increasingly high, in order to ensure the quality of mold processing, we should consider from the choice of machine tools, toolholder selection, tool selection, processing program, program generation, operator requirements and other aspects.
1. Select high precision high-speed machining center with the improvement of product design requirements and the development of high-speed high-precision machining technology is increasingly mature, thus greatly improving the quality of CNC machining of molds and greatly improving the speed of mold processing, reducing the processing process, shortening the production cycle of the mold and the number of clamping, and sometimes can eliminate time-consuming clamp repair work. Mold high-speed high-precision processing gradually become one of the important elements of the technical transformation of mold production enterprises, high-speed CNC machining center to replace the traditional low-speed processing has become inevitable, and the development of mold manufacturing technology will also bring us a richer product experience.
2. The use of suitable toolholder structure high-speed high-precision machining center, will also drive the update of related process equipment. In particular, the impact of the tool on the quality of CNC machining, toolholder will become prominent. In the rotary class tool processing system, collet and machine tool (or its combination) of a tight connection to ensure that the tool processing performance. Generally often used machine tool and toolholder interface are HSK hollow toolholder and BT type toolholder and other two types. The taper of the machine tool spindle and BT toolholder interface is 24:7, the traditional low-speed machining is suitable for using this toolholder connection, because the BT toolholder and the machine tool spindle is only taper fit, under the action of centrifugal force at high speed will make the taper fit gap increase, thus affecting the quality of CNC machining. Generally when the spindle speed exceeds 16000 rpm, we will need to use HSK hollow shank, HSK toolholder positioning structure for over-positioning, to provide a standard connection with the machine tool, under the action of machine tool pull, to ensure that the short taper and end face of the toolholder and the machine tool are closely matched.
3. Select the right tool for processing the reasonable use and selection of tools will be an important factor affecting the quality of CNC machining. Carbide tools are being more and more widely used, high-speed machining in coated carbide will replace most of the sharp steel tools, including reamers, ball cutters, boring tools and other simple tools, coated carbide will play an important role in high-speed machining tool materials, applied to most of the conventional machining areas. Usually we know that in rough machining we will use large diameter tools for machining, in order to save cost and reduce the difficulty of tool manufacturing, we will use machine clamped carbide inserts , try to make rough machining chip discharge more; in semi-finishing machining use high speed and high feed insert tools to make semi-finishing machining go fast; in finishing machining try to use high precision round head mirror inserts in carbide tool bar to ensure the tool and tool bar This will save the expensive cost of choosing the whole alloy tool while maintaining the machining accuracy. In the processing we also need to pay attention to the finishing parts on the inner contour of the radius must be greater than or equal to the radius of the tool, the choice of radius is less than the radius of the corner of the tool in the way of circular interpolation or diagonal interpolation for processing, so that you can avoid the use of linear interpolation and overcutting phenomenon, to ensure the quality of mold finishing.
4.CNC process scheme in the high-speed high-precision machining CNC process scheme design importance is mentioned to a higher status, must be the whole process of processing control, any error will have a serious impact on the quality of the mold, so the process scheme will play a decisive role in the quality of processing. CNC machining process design can be considered as a system from the part blank to the part processing between the state control of the process plan. A good process solution is difficult to obtain throughout the design process, and requires continuous practical summary and modification. The large amount of information to be considered in the design process and the complex relationship between the information must be ensured by the actual work experience of the program designer. Therefore, the quality of the design of the process program depends mainly on the experience and level of technical personnel. Usually a complete CNC machining process planning, probably including the following: 1) CNC machine selection.
2) processing method selection.
3) Determine the clamping method of the part and select fixture.
4) positioning method.
5) Inspection requirements and inspection methods.
6) Selection of tools.
7) Error control and tolerance control in machining.
8) Define the CNC process.
(9) CNC process sequencing.
(10) cutting parameters selection.
(11) preparation of CNC process program sheet.
5.CAM software a good software can also improve the quality and efficiency of mold processing, such as UniGraphics and CIMIAMTRON, are very good mold processing software, especially the two software rich and practical different processing strategies in CNC milling programming, turning programming, EDM wire cutting programming are widely used to complement each other so that the quality and efficiency of CNC machining has been greatly improved. CIMIAMTRON in the offset area to clear the rough machining can be added to the spiral function, will make the actual cutting become smoother, eliminating the adjacent toolpath connected between the sudden change in the direction of the feed, reduce the acceleration and deceleration of the cutting feed, maintain a more stable cutting load, extend the tool life, the machine also plays a good role in the protection. Software it is also just a tool, an excellent programmer have a wealth of experience in on-site machining and theoretical knowledge, while skilled in software functions of CNC programmers, talent is the decisive factor in mold CNC machining, the quality and efficiency of CNC machining plays a key role. To this end the establishment of a perfect program designer training system. First of all, designers are to first in the CNC operation of the post of internship for a period of time, after strict operation assessment qualified before the CNC program design training. In order to ensure the quality of CNC machining of the mold, it is necessary to have a good CNC program.
6. The operator machining center operator is the executor of CNC machining
, and their control of the quality of CNC machining is also very obvious. They perform machining tasks in the process of machine tools, toolholders, tools, machining processes, software and cutting parameters of the real-time state of the most understanding, their various operations on CNC machining the most direct impact, so the skills and responsibility of the machining center operator is also to improve the quality of CNC machining key factors! To sum up: Although hardware equipment such as machining centers is very critical, but talent is the decisive factor affecting the quality of CNC machining, because the programmer and machine tool operator's professional ethics, skill level, job responsibility to determine how effective a variety of advanced equipment can be. We must pay attention to all aspects of processing, especially the human element, in order to make CNC machining center mold processing more and more extensive.