Hardware mold roughing's main goal is to pursue the material removal rate per unit time, and for semi-finishing workpiece geometry. Because of cutting layer metal in the process of cutting area change, lead to changes in hardware tool carry the load, the cutting process is unstable, uneven hardware tool wear rate, machining surface quality.
Current many CAM software development through the following measures to maintain a constant cutting condition, in order to gain good processing quality. Constant cutting load. Through calculation of constant cutting area and the material removal rate, keep cutting load and tool wear rate equilibrium, in order to improve the tool life and processing quality. Avoid sudden change of tool feed direction. Avoid buried tool workpiece. Such as the mold cavity machining, should avoid tool vertically inserted into the workpiece, and should adopt tilt knife under way (slope Angle of 20 ° to 30 °) is commonly used, had better use the knife to cut spiral cutter load; When processing mould core, should first as far as possible from the workpiece under the external knife and horizontal cut into the workpiece. Cutter cut, cut out to work should be used as tilting when cutting, cut out (or arc), avoid vertical cut, cut out. The climb type cutting (Climbcutting) can reduce the cutting heat, tool stress and work hardening the extent, improve the quality of machining. Semi-finishing mould semi-finishing's main goal is to make the workpiece contour shape formation, surface finish machining allowance even, this is particularly important for tool steel mold, because it will affect the finishing tool cutting layer area change and the change of the load, thus affecting the stability of cutting process and machining surface quality. Rough machining is based on volume model (Volumemodel), finish machining is based on surface model (Surfacemodel). And previously developed CAD/CAM system is discontinuous geometric description of parts, because there is no description after rough machining, finish machining before the middle of the information processing model, so the remaining on the surface of the rough machining allowance distribution and maximum residual machining allowance are unknown. So to finish machining strategy is optimized to ensure the half after finishing the rest of the workpiece surface is uniform machining allowance.
Optimization process including: after rough machining contour of calculation, the largest remaining machining allowance calculation, the determination of maximum allowable machining allowance, for the rest of the machining allowance is greater than the maximum permissible machining allowance type surface partition (such as sockets, corner transition radius less than the area of rough machining cutter radius) and the semi finishing tool path calculation, etc. Existing mold high-speed machining CAD/CAM software are mostly have remaining machining allowance analysis function, and can according to the size of the remaining machining allowance employing reasonable semi-finishing and distribution strategy. If OpenMind HyperMill and HyperForm software provides a beam milling (Pencilmilling) and residual milling (Restmilling), and other methods to remove residual after rough machining allowance large corner uniform machining allowance in place to ensure that subsequent working procedure. The local milling of Pro/Engineer software (Localmilling) with similar functions, such as local milling process for the rest of machining allowance value equals the rough machining, the process only a small diameter cutter to remove the rough machining is not cut to the corner, and then for semi-finishing; Local milling process if you take more than the rest of the processing quantity as the remaining semi-finishing machining allowance is the process not only can remove roughing cut to the corner, but also can complete semi-finishing.
Finishing the mould high speed finish machining strategy depends on the contact point, cutting tool and the workpiece and cutting tool and workpiece contact point with the processing surface on the surface of the slope and effective radius of tool changing. For a combination of multiple surface of complex curved surface processing, should as far as possible in a process of continuous processing, rather than to carry on the processing for each surface, in order to reduce the number of lifting knife, the knife. However, due to the change of the surface of the slope in the process, if only defines the processing side turning (Stepover), may cause on the surface of the slope in different from actual step uneven, which affects the processing quality. Pro/Engineer to solve the above problem is in defining the side turning at the same time, to define processing surface residual area height (Scallopmachine); HyperMill are provided, such as interval processing (Equidistantmachine), to ensure uniform feeding path between turning to the side, but not limited by surface slope and curvature, guarantee of cutting tool in cutting process is always under uniform load.
Under normal circumstances, the finish machining of curved surface should be greater than 1.5 times that of tool radius of curvature radius to avoid the sudden change of direction of feed. In the high speed finish machining of mould, at every time of cut, cutting work pieces, the change of the direction of feed should transfer using circular arc, or curve, as far as possible avoid using linear transfer, to maintain the stability of cutting process. Feed rate optimization at many CAM software has feed rate optimization adjustment function: in the process of semi-finishing, reduce the feed speed when cutting layer of large area, increasing the feed speed and cutting layer area hours. Application of feed rate optimization adjustment can make the process smoothly, improve the quality of processing surface. The size of cutting layer completely automatic calculation by CAM software, the adjustment of the feed speed can be set by user according to processing requirements.
conclusion
Mold high speed machining technology is a integration of a variety of advanced processing technology, not only involves the high-speed machining technology, but also high speed machine tools, CNC system, high speed cutting tools, CAD/CAM technology, etc.
Mould high speed machining technology has been widely used in the die and mould industry in developed countries, while in our country level remains to be improved and the application scope of application, developing and popularizing the mold high speed machining technology to promote our country to improve the economic benefits of the die and mould industry overall technical level and is of great significance.
Current many CAM software development through the following measures to maintain a constant cutting condition, in order to gain good processing quality. Constant cutting load. Through calculation of constant cutting area and the material removal rate, keep cutting load and tool wear rate equilibrium, in order to improve the tool life and processing quality. Avoid sudden change of tool feed direction. Avoid buried tool workpiece. Such as the mold cavity machining, should avoid tool vertically inserted into the workpiece, and should adopt tilt knife under way (slope Angle of 20 ° to 30 °) is commonly used, had better use the knife to cut spiral cutter load; When processing mould core, should first as far as possible from the workpiece under the external knife and horizontal cut into the workpiece. Cutter cut, cut out to work should be used as tilting when cutting, cut out (or arc), avoid vertical cut, cut out. The climb type cutting (Climbcutting) can reduce the cutting heat, tool stress and work hardening the extent, improve the quality of machining. Semi-finishing mould semi-finishing's main goal is to make the workpiece contour shape formation, surface finish machining allowance even, this is particularly important for tool steel mold, because it will affect the finishing tool cutting layer area change and the change of the load, thus affecting the stability of cutting process and machining surface quality. Rough machining is based on volume model (Volumemodel), finish machining is based on surface model (Surfacemodel). And previously developed CAD/CAM system is discontinuous geometric description of parts, because there is no description after rough machining, finish machining before the middle of the information processing model, so the remaining on the surface of the rough machining allowance distribution and maximum residual machining allowance are unknown. So to finish machining strategy is optimized to ensure the half after finishing the rest of the workpiece surface is uniform machining allowance.
Optimization process including: after rough machining contour of calculation, the largest remaining machining allowance calculation, the determination of maximum allowable machining allowance, for the rest of the machining allowance is greater than the maximum permissible machining allowance type surface partition (such as sockets, corner transition radius less than the area of rough machining cutter radius) and the semi finishing tool path calculation, etc. Existing mold high-speed machining CAD/CAM software are mostly have remaining machining allowance analysis function, and can according to the size of the remaining machining allowance employing reasonable semi-finishing and distribution strategy. If OpenMind HyperMill and HyperForm software provides a beam milling (Pencilmilling) and residual milling (Restmilling), and other methods to remove residual after rough machining allowance large corner uniform machining allowance in place to ensure that subsequent working procedure. The local milling of Pro/Engineer software (Localmilling) with similar functions, such as local milling process for the rest of machining allowance value equals the rough machining, the process only a small diameter cutter to remove the rough machining is not cut to the corner, and then for semi-finishing; Local milling process if you take more than the rest of the processing quantity as the remaining semi-finishing machining allowance is the process not only can remove roughing cut to the corner, but also can complete semi-finishing.
Finishing the mould high speed finish machining strategy depends on the contact point, cutting tool and the workpiece and cutting tool and workpiece contact point with the processing surface on the surface of the slope and effective radius of tool changing. For a combination of multiple surface of complex curved surface processing, should as far as possible in a process of continuous processing, rather than to carry on the processing for each surface, in order to reduce the number of lifting knife, the knife. However, due to the change of the surface of the slope in the process, if only defines the processing side turning (Stepover), may cause on the surface of the slope in different from actual step uneven, which affects the processing quality. Pro/Engineer to solve the above problem is in defining the side turning at the same time, to define processing surface residual area height (Scallopmachine); HyperMill are provided, such as interval processing (Equidistantmachine), to ensure uniform feeding path between turning to the side, but not limited by surface slope and curvature, guarantee of cutting tool in cutting process is always under uniform load.
Under normal circumstances, the finish machining of curved surface should be greater than 1.5 times that of tool radius of curvature radius to avoid the sudden change of direction of feed. In the high speed finish machining of mould, at every time of cut, cutting work pieces, the change of the direction of feed should transfer using circular arc, or curve, as far as possible avoid using linear transfer, to maintain the stability of cutting process. Feed rate optimization at many CAM software has feed rate optimization adjustment function: in the process of semi-finishing, reduce the feed speed when cutting layer of large area, increasing the feed speed and cutting layer area hours. Application of feed rate optimization adjustment can make the process smoothly, improve the quality of processing surface. The size of cutting layer completely automatic calculation by CAM software, the adjustment of the feed speed can be set by user according to processing requirements.
conclusion
Mold high speed machining technology is a integration of a variety of advanced processing technology, not only involves the high-speed machining technology, but also high speed machine tools, CNC system, high speed cutting tools, CAD/CAM technology, etc.
Mould high speed machining technology has been widely used in the die and mould industry in developed countries, while in our country level remains to be improved and the application scope of application, developing and popularizing the mold high speed machining technology to promote our country to improve the economic benefits of the die and mould industry overall technical level and is of great significance.