Abstract: five axis machining is a very important part of numerical control machining, which has been widely used in the field of high-precision instrument manufacturing, such as ship, aerospace, automobile, light industry and medical treatment. In traditional mold machining, three-axis machining center and vertical machining center are widely used to finish the milling of workpiece. With the continuous development of mold manufacturing technology in China, some weaknesses of traditional vertical machining centers and three-axis machining centers have gradually emerged. At present, ball end milling cutter is widely used in mold processing. Although the advantages of using ball end milling cutter in mold processing are obvious, if vertical machining center is applied, its bottom line speed is zero, and its finish is poor. The disadvantages of using five axis machining center to process mold can be completely overcome. In this paper, the author analyzes the advantages of five axis machining center in mold processing, and discusses its application in mold processing.
&1. Analyze the advantages of five axis machining
&In the five axis machining, the flat end milling cutter is used to keep the surface of the complex mold in a vertical state, which can greatly reduce the processing time. The principle of five axis machining center is also applicable to the side milling with angle surface, which can eliminate the rib pattern caused by the ball end end milling cutter, make the surface quality of the mold more ideal, and also reduce the workload of manual milling and manual operation due to the need of cleaning the mold surface.
&Through the five axis machining technology, the problem that the workpiece needs to be debugged and clamped many times for re positioning at the complex angle can be solved, which not only shortens the time, but also greatly reduces the error, and saves the large cost of the fixture when installing the workpiece, and the machine tool also achieves the processing of complex parts, such as Drilling, taper machining, cavity recess and so on, which are needed for complex surface, are all impossible by traditional methods.
&The tool used in five axis machining is shorter, and the machining of the whole part can be completed at one time. There is no need to install the card again or use the longer tool needed in three axis machining of the same kind, so the mold can be made in a shorter time, and the surface quality of the part is better.
&2. Analysis of the application of five axis machining center in automobile mold processing
&At present, CAD system is mainly used in the design of automobile parts, and the design of parts is completed through reverse engineering and various tests. CAM software is used to process the complex surface of mold. However, how to ensure the accuracy of design and processing depends on numerical control processing. The author analyzes the response of five axis machining center in mold processing in the following The relationship between using and the quality of automobile mould.
&Machining of deep cavity mould
&In the process of automobile mold manufacturing, if the three-axis machining center is used to process the deep cavity mold, the tool handle and tool must be lengthened to realize. However, if the five axis machining center is used to process the deep and steep cavity, the tool can be made by the additional rotation and swing of the workpiece or the spindle head to create better technological conditions for mold processing The length is properly shortened, so as to prevent the collision between the tool and the tool bar and the cavity wall, reduce the tool jitter and damage during machining, prolong the service life of the tool, and greatly improve the surface quality and machining efficiency of the die.
&Machining of die sidewall
&For the processing of die sidewall, the tool length of three-axis machining center is larger than the depth of sidewall, which is also determined by the depth of sidewall. If the length of tool is increased, its strength will be significantly reduced. If the length of tool is higher than 3 times of diameter, the phenomenon of tool passing will occur, and the quality of workpiece will be difficult to guarantee. For example, if the five axis machining center is used to process the side wall of the mold, the swing of the spindle or workpiece can be used to make the cutter and the side wall of the mold appear vertical. When milling the side wall of the mold, the plane milling cutter can be used, which can improve the quality of the workpiece and extend the service life of the cutter.
&2.3 surface machining with flat die
&When machining the flat surface of the die, the three-axis machining center needs the ball cutter to finish milling to obtain good surface quality. In this case, the tool path needs to be increased, but the center rotation speed of the ball cutter is almost zero. When machining the die, the degree of tool damage is large, the service life of the tool will be shortened, and the surface quality of the die will be poor. By using the five axis machining center to process the flat surface, the cutter can be turned into a certain angle on the workpiece, and then the workpiece can be processed. In this way, the relative linear velocity between the workpiece and the ball head cutter can be increased, not only the service life of the cutter can be improved, but also the surface quality of the workpiece can be greatly improved.
&Machining the irregular surface of mould
&For the mold machining with irregular surface, the three-axis machining center is generally used in the past. The cutting process that the direction of the tool cutting mold is moving along the whole cutting path will not change. At this time, the cutting state of the tool tip can not guarantee the perfect quality of each part of the mold. For example, the mold with frequent curvature change and the mold with deep groove can be processed through five axis machining center. The cutting tool can always make the cutting state better, and the tool can make the direction of the whole machining path greatly optimized. At the same time, the tool can also make straight-line movement, and every part of the mold surface will be more perfect.
&Machining of different geometric shapes of dies
&When the five axis machining center is used to process the mold with three-dimensional curve plane, the cutting of the mold is always protected in a good working state, and the working angle of the tool can be changed in any area of the machine tool processing, so as to complete the processing of several kinds of mold.
&Machining of inclined hole on the inclined surface of die
&When machining the inclined hole of the die inclined plane, the five axis machining center can place the spindle in the aspect of the workpiece inclined plane vertical by the action of the swinging machine tool, and locate the exact hole position. In order to process the inclined hole on the mould accurately, it needs at least two linear axes to interpolate, and the accuracy of the hole position is obviously reduced in this process. If a five axis machining center with a swing table is used to process the inclined hole, the action is to place the inclined plane of the mold in the position perpendicular to the main shaft through the machine tool swing table. The processing of a single moving inclined hole of one linear axis of the main shaft can be completed, which can significantly improve the accuracy of the hole.
&Milling of straight line without direction change of die
&If you want to mill a straight line without direction change, you only need to draw a straight line on the tool tip. If you need to change the direction, you can draw a curve on the tool tip, and the direction of the tool tip is changed. If you want a straight line again, you need to compensate the curve. It is very important to apply the five axis machining center. If the length of the tool is not taken into account in the control system, the tool rotates around the axis center, the tool tip cannot be fixed, and it is likely to move out of the current working position. However, the five axis control function is available in the five axis machining center system. In the operation of the machining die, the use of the five axis control system can guarantee the position of the tool tip although the direction of the tool is changed In this process, the necessary compensation motion of XYZ axis is calculated automatically, and the machining accuracy is improved obviously.
&In a word, in mold processing, the application of five axis machining center can avoid the interference of tools, and can process complex parts that are difficult to be processed by common three-axis machine tools. For the processing of molds with ruled surface, the side milling one knife forming technology can be used, which has good processing quality and high efficiency. For the solid surface, especially for the large flat surface, it can be processed by the large diameter end milling cutter close to the large surface. The times of cutting will be reduced, the residual height is small, and the machining efficiency and surface quality can be effectively improved. Multi process and multi surface machining can be carried out by clamping multiple space surfaces of the die at one time, which can improve the machining efficiency and the accuracy of the mutual positions of various surfaces. When the five axis machining center is applied to mold machining, for the workpiece, the cutter can always be in an effective cutting state. In some machining fields, large-size cutters can be used to avoid mutual interference. This kind of cutter has good rigidity, and the machining accuracy and efficiency can be improved. Therefore, the five axis machining center has a wide range of processing adaptability and is worth popularizing.
&The company is a manufacturer of large five axis CNC machine tools. The CNC machining center produced by the company specializes in machining various molds, foam molds, large ship models, aviation molds, and train wooden models. The accuracy of the production and processing of machine tools can reach up to + 0.03mm. All machine tools can be customized according to customer needs, and you are welcome to call at any time.
&1. Analyze the advantages of five axis machining
&In the five axis machining, the flat end milling cutter is used to keep the surface of the complex mold in a vertical state, which can greatly reduce the processing time. The principle of five axis machining center is also applicable to the side milling with angle surface, which can eliminate the rib pattern caused by the ball end end milling cutter, make the surface quality of the mold more ideal, and also reduce the workload of manual milling and manual operation due to the need of cleaning the mold surface.
&Through the five axis machining technology, the problem that the workpiece needs to be debugged and clamped many times for re positioning at the complex angle can be solved, which not only shortens the time, but also greatly reduces the error, and saves the large cost of the fixture when installing the workpiece, and the machine tool also achieves the processing of complex parts, such as Drilling, taper machining, cavity recess and so on, which are needed for complex surface, are all impossible by traditional methods.
&The tool used in five axis machining is shorter, and the machining of the whole part can be completed at one time. There is no need to install the card again or use the longer tool needed in three axis machining of the same kind, so the mold can be made in a shorter time, and the surface quality of the part is better.
&2. Analysis of the application of five axis machining center in automobile mold processing
&At present, CAD system is mainly used in the design of automobile parts, and the design of parts is completed through reverse engineering and various tests. CAM software is used to process the complex surface of mold. However, how to ensure the accuracy of design and processing depends on numerical control processing. The author analyzes the response of five axis machining center in mold processing in the following The relationship between using and the quality of automobile mould.
&Machining of deep cavity mould
&In the process of automobile mold manufacturing, if the three-axis machining center is used to process the deep cavity mold, the tool handle and tool must be lengthened to realize. However, if the five axis machining center is used to process the deep and steep cavity, the tool can be made by the additional rotation and swing of the workpiece or the spindle head to create better technological conditions for mold processing The length is properly shortened, so as to prevent the collision between the tool and the tool bar and the cavity wall, reduce the tool jitter and damage during machining, prolong the service life of the tool, and greatly improve the surface quality and machining efficiency of the die.
&Machining of die sidewall
&For the processing of die sidewall, the tool length of three-axis machining center is larger than the depth of sidewall, which is also determined by the depth of sidewall. If the length of tool is increased, its strength will be significantly reduced. If the length of tool is higher than 3 times of diameter, the phenomenon of tool passing will occur, and the quality of workpiece will be difficult to guarantee. For example, if the five axis machining center is used to process the side wall of the mold, the swing of the spindle or workpiece can be used to make the cutter and the side wall of the mold appear vertical. When milling the side wall of the mold, the plane milling cutter can be used, which can improve the quality of the workpiece and extend the service life of the cutter.
&2.3 surface machining with flat die
&When machining the flat surface of the die, the three-axis machining center needs the ball cutter to finish milling to obtain good surface quality. In this case, the tool path needs to be increased, but the center rotation speed of the ball cutter is almost zero. When machining the die, the degree of tool damage is large, the service life of the tool will be shortened, and the surface quality of the die will be poor. By using the five axis machining center to process the flat surface, the cutter can be turned into a certain angle on the workpiece, and then the workpiece can be processed. In this way, the relative linear velocity between the workpiece and the ball head cutter can be increased, not only the service life of the cutter can be improved, but also the surface quality of the workpiece can be greatly improved.
&Machining the irregular surface of mould
&For the mold machining with irregular surface, the three-axis machining center is generally used in the past. The cutting process that the direction of the tool cutting mold is moving along the whole cutting path will not change. At this time, the cutting state of the tool tip can not guarantee the perfect quality of each part of the mold. For example, the mold with frequent curvature change and the mold with deep groove can be processed through five axis machining center. The cutting tool can always make the cutting state better, and the tool can make the direction of the whole machining path greatly optimized. At the same time, the tool can also make straight-line movement, and every part of the mold surface will be more perfect.
&Machining of different geometric shapes of dies
&When the five axis machining center is used to process the mold with three-dimensional curve plane, the cutting of the mold is always protected in a good working state, and the working angle of the tool can be changed in any area of the machine tool processing, so as to complete the processing of several kinds of mold.
&Machining of inclined hole on the inclined surface of die
&When machining the inclined hole of the die inclined plane, the five axis machining center can place the spindle in the aspect of the workpiece inclined plane vertical by the action of the swinging machine tool, and locate the exact hole position. In order to process the inclined hole on the mould accurately, it needs at least two linear axes to interpolate, and the accuracy of the hole position is obviously reduced in this process. If a five axis machining center with a swing table is used to process the inclined hole, the action is to place the inclined plane of the mold in the position perpendicular to the main shaft through the machine tool swing table. The processing of a single moving inclined hole of one linear axis of the main shaft can be completed, which can significantly improve the accuracy of the hole.
&Milling of straight line without direction change of die
&If you want to mill a straight line without direction change, you only need to draw a straight line on the tool tip. If you need to change the direction, you can draw a curve on the tool tip, and the direction of the tool tip is changed. If you want a straight line again, you need to compensate the curve. It is very important to apply the five axis machining center. If the length of the tool is not taken into account in the control system, the tool rotates around the axis center, the tool tip cannot be fixed, and it is likely to move out of the current working position. However, the five axis control function is available in the five axis machining center system. In the operation of the machining die, the use of the five axis control system can guarantee the position of the tool tip although the direction of the tool is changed In this process, the necessary compensation motion of XYZ axis is calculated automatically, and the machining accuracy is improved obviously.
&In a word, in mold processing, the application of five axis machining center can avoid the interference of tools, and can process complex parts that are difficult to be processed by common three-axis machine tools. For the processing of molds with ruled surface, the side milling one knife forming technology can be used, which has good processing quality and high efficiency. For the solid surface, especially for the large flat surface, it can be processed by the large diameter end milling cutter close to the large surface. The times of cutting will be reduced, the residual height is small, and the machining efficiency and surface quality can be effectively improved. Multi process and multi surface machining can be carried out by clamping multiple space surfaces of the die at one time, which can improve the machining efficiency and the accuracy of the mutual positions of various surfaces. When the five axis machining center is applied to mold machining, for the workpiece, the cutter can always be in an effective cutting state. In some machining fields, large-size cutters can be used to avoid mutual interference. This kind of cutter has good rigidity, and the machining accuracy and efficiency can be improved. Therefore, the five axis machining center has a wide range of processing adaptability and is worth popularizing.
&The company is a manufacturer of large five axis CNC machine tools. The CNC machining center produced by the company specializes in machining various molds, foam molds, large ship models, aviation molds, and train wooden models. The accuracy of the production and processing of machine tools can reach up to + 0.03mm. All machine tools can be customized according to customer needs, and you are welcome to call at any time.