1. Prepare the auxiliary surface of the bottom surface of the workpiece, which is also the parting surface of the upper and lower dies. The size of the auxiliary surface is the size of the blank workpiece. Sometimes you can modify the size of the auxiliary surface to facilitate tool path weaving.

2. Make the bounding box of the workpiece, and move the center point of the upper surface of the workpiece to the origin defined in MasterCAM system.

3. Analyze the material and size of the workpiece, the minimum distance between boundaries and the minimum arc radius. These data are the basis of tool parameter selection. Tool parameters include tool type (flat knife, round head knife, ball end mill, etc. ), tool material, tool diameter, blade length and clamping length.

4. Analyze the distribution of blank allowance and observe whether the blank allowance is evenly distributed. If the uniformity of blank allowance distribution is quite different, it is necessary to coarsen the part with large allowance first, and then coarsen the whole workpiece.

Second, the idea of weaving tool path:

If the machining accuracy requirements are general, the optional machining processes are: rough machining-finish machining; If the machining accuracy is high, the machining process includes: rough machining-semi-finish machining-finish machining.

Rough machining: remove most of the allowance of the blank.

Semi-finishing: on the basis of rough machining, further process the blank allowance to make the allowance uniform, and the processing quality after finishing should be close to the requirements.

Finishing: the processing capacity is very small, and the quality requirements are met after processing.

Surface finish:

(1) Rough machining: 1, parallel milling 2, radial machining 3, projection machining.

4. Surface streamline 5. Contour. Contour 6. Trenching rough machining 7. Drilling processing.

1. Parallel milling: the workpiece is processed in layers along the Z axis, and the tool paths of each layer are generated in parallel and coarsened quickly, but there is no contour finish machining, and there are many residues after machining. Because its cutting mode is linear cutting mode, it is determined that it is only suitable for the whole broaching or local broaching of completely stamped workpieces (that is, workpieces without cavities).

2. Radial machining: the workpiece is processed in layers along the Z axis, and the tool path of each layer is generated by increasing the angle. The tool path will produce a lot of tool lifting and cutting actions. Moreover, because its path radiates at a certain angle, the residue of the tool path is uneven, that is, the residue far from the radiation center point is greater than that near the radiation center point. Therefore, it is only suitable for rough machining or semi-finish machining of small workpieces. It is rarely used in practical applications.

3. Projection machining: the projection modes are 1, NCI (tool path), 2, curve 3 and point.

Projection NCI: the workpiece is processed in layers along the Z axis, and the tool path of each layer is processed according to the existing tool path. The existing tool path is a 2D tool path. Therefore, it is necessary to compile a two-dimensional tool path as a reference for the tool feed mode. It is not applicable in terms of operation process and actual effect. Therefore, it is rarely used in practical applications.

Projection curve: project the curve onto the surface and generate the tool path along the projection curve. Used in sculpture. Such as carving words or patterns.

Projection point: the point is projected on the surface, and the tool cuts along the Z axis where the point is located, similar to drilling. It is rarely used in practical applications.

4. Surface streamline: cutting along the direction of surface generation (cutting direction and cutting direction). Advantages: The height of the tool mark can be accurately controlled, so as to obtain a higher surface accuracy.

Note: It will be difficult to process multiple surfaces at the same time due to the inconsistent streamline direction.

5. Contour contour: The workpiece is processed by Z-axis layering, and the spacing between layers is equal. After layering, the workpiece contour is generated along each layer. Therefore, it is suitable for semi-finish machining after rough machining of workpieces, or rough machining or semi-finish machining of formed blanks. Commonly used in practical processing. The spiral cutting mode is added in MILL9, which solves the cutting problem in MILL8 and other high-profile machining methods.

6. Trenching rough machining: the workpiece is processed by Z-axis layering, and the inner and outer boundary contours are automatically generated after layering. The system can dynamically generate the tool path to clear the material at the boundary, and can complete the machining of internal and external contours. It also provides multiple cutting modes, which can be applied to the overall rough machining and semi-finish machining of any workpiece. It is often used in practical applications.

7. Drill-type machining: It is similar to the method of surface rough machining through layered drilling, and it is a way to quickly remove the blank allowance, which is suitable for deep cavity parts and not for shallow plane machining. Keyway milling cutter or drill can be selected. This method is not supported by all CNC machine tools, and it requires high rigidity of machine tools and high requirements for tools, so it is rarely used.

(2) Semi-finishing and finishing of curved surfaces are characterized by only one feed in Z direction, and all feeds are as follows:

Tool path of surface finishing: 1, parallel milling 2, steep slope machining 3, radial machining 4, projection machining 5, outline 6, surface streamline 7, shallow plane machining 8, circumferential equidistant 9, intersection angle clearance 10, and leftover angle clearance.

1. Parallel milling: Tool path layers are generated in parallel.

2. Steep bevel machining: After parallel tool paths are used, a finishing tool path is generated, which is used to cut the allowance on the bevel of the curved surface.

3. Radial machining: generate a layer of tool path by increasing the angle.

4. Projection machining: key points of construction-the machining depth is determined by the remaining allowance (not greater than the tool radius).

5. Streamline of curved surface: Streamline machining is similar to parallel milling, but the height of residual material on the machined surface can be controlled by the residual height in streamline machining. On steep slopes, the density of the tool path will automatically increase to ensure that the remaining height meets the set requirements.

6. Shallow plane machining: mainly used for relatively flat surfaces, usually used after contour machining to obtain accurate machining range.

7. Clearance of intersection angle: used to handle the intersection angle between two or more surfaces.

8. Waste cleaning: used to remove the waste left by large-scale tool processing before. It is mainly to determine the diameter of the front machining tool and the cooperation with other tool paths.

9. Circumferential equidistant: When machining multiple surfaces, the tool mark height (residual ridge height) remains relatively constant, similar to the streamline machining of surfaces.