Abstract: This paper mainly analyzes how to use the MasterCAM software to prepare a reasonable tool path from the surface characteristics of the triangular switch punch and the processing difficulties, so that the processing quality is greatly improved. Foreword: Using CAM software programming, whether the path of the tool is reasonable or not directly affects the processing quality. MasterCAM's surface finishing tool path is difficult to ensure the processing quality of flat and steep surfaces at the same time. In addition, machining center machining is not suitable for using small tools, so for parts that are difficult to machine and parts that have both flat and steep faces. How should the tool path be programmed to meet the processing quality requirements? MasterCAM is a widely used CAD/CAM software developed by CNC Software of the United States, which is easy to use and practical. MasterCAM 8.0 offers a wide range of roughing techniques and a wealth of surface finishing capabilities. The precision machining form directly affects the surface quality of the machine. To achieve the dimensional accuracy and surface accuracy required by the drawings, it is necessary to select the cutting method for the surface characteristics when programming the tool path. For the same part, different ways of walking may be required in different parts. For the joint between the two sides of the part, a special clearing path is also needed. In addition, it is necessary to select the tool reasonably, optimize the path of the tool, reduce the number of knives, empty knives and unnecessary repetitive paths, and improve the processing efficiency while improving the processing quality. First, the surface characteristics and technical requirements (1) Surface features: The triangular switch is a typical part, and the outer shape of the curved surface is 50x60x15.6mm. The upper part of the graph has a flat surface and is called a shallow plane in MasterCAM. This surface is suitable for selecting parallel cutter paths. The lower part of the surface is steep and is called a steep bevel in MasterCAM. This surface is suitable for selecting contour paths. Between the surface and the surface is a R2mm rounded transition. Here, the fillet radius is R0.4mm and the height is 1.15mm. (2) Technical requirements for processing triangular switch punches: 1. All surface roughness requirements Ra3.2; Second, processing triangle switch punch process analysis 1. Material: 45# steel, this steel has high strength and good machinability. After quenching and tempering, it can obtain good comprehensive mechanical properties and is one of the most widely used steel molds in plastic molds. Blank size: 70x80x30mm. The overall idea of ​​the triangular switch punching process is roughing, semi-finishing, finishing, and finally clearing the corner. The specific analysis is as follows: (1) Roughing and roughing is to improve the production efficiency and quickly remove excess material. The curved surface is thickened together with the parting surface. The tool requires sufficient strength. Therefore, choose a larger tool according to the workpiece material and surface shape. Size 50x60x15.6mm and blank size Select a round nose knife with a round radius R1mm diameter ï†10mm. (2) Semi-finishing Due to the large distance between the roughing knives and the cutting depth, the residual material is too much. The semi-finishing is to remove too much residual material, so that the finishing allowance is uniform, and the tool selection should be considered to be subjected to roughing. Residues do not break the knife, and do not leave too much residual material to cause difficulties in finishing. The parting surface is a flat surface, which is processed by a flat knife and the curved surface is processed by a ball cutter. Therefore, the curved surface and the parting surface are separately semi-finished and finished. Semi-finishing of the surface, choose ï†6mm ball knives, less residual material on the parting surface and uniform margin, no need to do semi-finishing. (3) Finishing and finishing need to achieve the required dimensional accuracy and surface precision, while taking into account the efficiency. When selecting the tool, the tool strength should be considered and whether there will be residual material or overcutting. There are many R2mm rounded corners on the surface. The ï†3mm ball cutter is used to finish the curved surface, and the split surface finish is ï†4mm flat cutter. (4) Clearing angle processing is to remove the residual material left in the small rounded corner or right angle due to the incision of the finishing tool. The tool selection should consider the processing efficiency, the tool strength and whether the residual can be removed. material. R0.4mm round corners are selected with a round nose knife with a fillet radius of R0.3mm and a diameter of mm4mm. The curved surface and the parting surface are cleaned with a ï†4mm flat knife. Third, the analysis of processing difficulties Based on the above process analysis, surface characteristics and technical requirements, there are two difficulties in processing the triangular switch punch: one is the shallow plane and the steep slope, and the other is the clear angle problem. 1, shallow plane and steep slope problem Finishing should ensure the machining accuracy of the entire surface, solve the problem of shallow plane and steep slope, and the longest time for finishing, and also pay attention to efficiency while solving the problem of processing quality. Therefore, a reasonable choice of finishing methods is essential. MasterCAM 8.0 provides ten surface finishing methods. For this problem, the following methods are often used to program tool paths: (1) Parallel milling + steep bevel machining Parallel milling uses the maximum spacing in the X and Y directions to control the fineness of the tool path. Because the slope of the steep bevel is steep, the same cutting pitch, the tool marks formed on the steep bevel It is much larger than on a flat or flat surface, making the processing quality of the steep bevel worse. Therefore, a steep beveling tool path is added after the parallel milling process. If the cutting mode of the steep bevel path is selected to be bidirectionally cut, the machining quality is degraded due to the uneven force of the tool when the tool is raised along the Z axis. In one-way cutting, there are too many paths in the tool path, which seriously affects the machining efficiency. (2) Contour shape + shallow plane machining The contour machining method uses the maximum Z-axis feed to control the degree of density of the tool path. On a relatively flat surface, the Z is the same distance as the steep surface. Much, the surface quality of the shallow plane cannot be guaranteed. Therefore, when the tool path is programmed, the shallow plane machining tool path is often added after the contour shape processing. Because the shallow plane area on the curved surface is discontinuous, the processing order is not ideal, which affects the processing quality. And there are many tool path in the shallow plane tool path, this method has low processing efficiency. (3) Surround equidistant machining Surrounding equidistant machining is to generate a set of tool paths around the workpiece surface. The path calculation time is long and the generated NC file is large. For irregularly shaped surfaces, the path spacing at the path of the path is greater than the path spacing at other locations, which creates tool marks on the surface of the workpiece that turn the tool path, affecting the quality of the machining. All of the above three processing methods make the surface of the workpiece not meet the processing quality requirements. According to the characteristics of the surface and the characteristics of the MasterCAM finishing toolpath, sub-regional machining can be adopted, that is, the shallow plane and the steep slope are processed separately, the flat surface is selected for parallel cutter processing, and the steep surface selection is equal to the high cutter processing. The triangular switch surface is partially flat and the lower part is steep. The cutting depth can be used to determine the machining area of ​​parallel milling and contour. Compared with the above three methods, this processing method has the best processing quality and improved processing efficiency when the processing parameters are selected the same. 2, clear angle problem (1) For the rounded corners of R0.4, a flat knife or a round nose knife with a radius of less than 0.4 mm can be used for machining. The following processing methods are often selected: â—‹1 Use the intersection line clear angle processing, the tool selects the round nose knife of R0.4mm, because the intersection line clear angle can only take a knife along the intersection of the curved surface, if the tool radius used for finishing is greater than 0.4mm, it will be in two The area where the knives cannot be processed leaves a residue. â—‹2 Using the radial machining setting, the initial correction distance is 4.4 mm, the cutting range is set, and only the residual material area is processed. This method can meet the processing quality requirements, but the machining path has many round trips. â—‹3 The cutting range can be set by using the circumferential equidistant machining. The round nose knife with a round radius of R0.3mm can remove all the residual materials, the path is continuous, and the number of lifting tools is small, which can meet the surface quality requirements and high efficiency. Through the above analysis, it is more reasonable to process the R0.4mm rounded corners to select the equidistant cutter path. (2) After the ball cutter is finished, it will leave a rounded corner at the intersection of the curved surface and the parting surface. The flat knife should be used to clear the corner. The surface has a draft angle of 5°, which is the same as the above, so the surround is selected. Isometric or contoured tool path, the machining depth is limited by the cutting depth, and only the residual material is processed. Here, the residual material height is the radius of the tool nose radius used for finishing, so the cutting depth range is slightly larger than the radius value. can. Fourth, the preparation of the tool path Based on the above analysis, compare several processing methods and propose the following processing schemes. Conclusion: According to the triangular switch convex model point and the processing difficulty, the path of the tool is analyzed and compared, and the best processing scheme is proposed. By using the above method, the surface precision of the whole part can reach Ra3.2, and the processing efficiency is slightly improved when the processing parameters are set to be the same. Since the path of the tool is reasonable, the feed rate can be increased, and the processing efficiency can be further improved under the premise of ensuring the processing quality. Roll Up Door Servo Motor,Automatic Roller Shutter Door Opener,Roller Shutter Door Servo System,Glass Sliding Door Motor Shenzhen Hongfa Automatic Door Co., Ltd. , https://www.pvchighspeeddoor.com
2. There is no defect on the surface of the workpiece, and there is no residual material in the rounded part;
3. The root is required between the curved surface and the parting surface.
2, tool material: According to the processing materials, choose YT15 carbide tool.
3. Equipment: Machining Center, Model: VMC800
4. Process analysis and tool selection:
Tool Path Analysis Based on MasterCAM Machining Triangle Switch Punch