Leveraging CAD Technology to Design Shaped Turning Tools
The blade shape of a turning tool is complex and often requires tedious correction calculations. There is a method called “inverse shape†method for manufacturing a turning tool—that is, a tool with the same shape as a workpiece (referred to as a second type turning tool, which is a shaping turning tool for making a shaping turning tool). The position is to cut and shape the turning tool so that no correction calculation is required. However, due to various limitations in application, this method is rarely used in actual production. Now, the use of a new tooling design method based on the SolidWorks system makes it possible to process the above-described reversed shape. It uses its features modeling, analog assembly, directly generating associated drawings and other functions to realize the parametric design of turning tools. For different workpieces, only by changing its two-dimensional profile and the corresponding tool parameters can directly obtain the corresponding Tool pattern. With the end plane P as the sketch plane, draw the straight line (see figure 2a) by the relative position of the rake face and the workpiece (workpiece r1 = 10mm and γf = 10° at the horizontal plane), and remove the upper part by this straight line. Figure 2b . Manual Forklift,Hydraulic Forklift,Hydraulic Hand Pallet Forklift,Manual Pallet Jack Forklift Baoding KR Earnest I/E Co.,Ltd. , https://www.bdkrearnest.com
Take the workpiece profile and dimension shown in Fig. 1 as an example (take the tool's rake angle γf = 10° and the relief angle αf = 12°) to illustrate the realization process of the parameterized design of the turning tool based on the SolidWorks feature model.
Creating Part Entity To create a new part in SolidWorks, select the horizontal plane to draw the axis and semi-contour for the sketch plane (Figure 1a) and rotate to get the part's body, as shown in Figure 1b.
Figure 1 Workpiece sketches and entities
Designing Tool Entity in an Assembly Create a new assembly in SolidWorks and insert the completed part into the assembly. Insert the new part into the assembly and name it “Toolsâ€. Select the workpiece plane as the sketch plane. Use the entity reference command to get the truncated shape on this plane (see Figure 3a). Remove some irrelevant lines, retain some of the cutting edge lines and extend the additional cutting edge, then draw lines on the outside to form a closed figure. This figure is the truncated shape of the rake face of the tool. After the completion, it is shown in Figure 3b.榫 Not shown, after the excision method is used).
Figure 2 Sketch of rake face and cut off workpiece
Then the end plane P is the sketch plane. Draw a straight line in this sketch to determine the position of the tool flank. In the past, a straight line with a section of a knife face and a position of a flank was used as a path, and a tool entity was created with a scan command.
The bottom edge of the tool is aligned with the vertical face of the flank, and the dovetail is generated by the cut command. The design of the tool body is completed. Figure 4a is an axial side view of the tool, and Figure 4b is a render view of it.
Fig. 3 Generation of tool rake face
Create Tool Drawings Create a new drawing in Solid Works and drag the tool part into the drawing. When the truncated parameters of the tool are required, the desired profile can be obtained directly in SolidWorks by determining the appropriate profile position.
Get the tool face truncated parameters In the CAM environment, you can directly obtain the truncated parameters of the tool face, and then use these parameters to program and cut the flank face of the tool on the online cutting machine. The method for obtaining parameters in SolidWorks is: save the drawing as dxf or dwg format, open the dxf or dwg file in AutoCAD, define the appropriate coordinate system, and use the List query command to obtain each line segment in the facet truncation. The parameters.
Figure 4 Axe side view and rendering of the tool
As shown in the 23rd and 567rd segments of Figure 5, the 23rd part of the parts drawing is a straight line with a tapered surface and the 567th section is an arc. The traditional method of designing a turning tool is simplified on the tool to be a straight line and a circular arc, respectively, which brings about a hyperbolic error. Here we use the List query command to find out that 23 segments are not straight lines and 567 segments are not arcs, but spline curves. A spline is a curve that fits between the coordinates of several control points.
The following table lists the coordinate query results for the 23 and 567 spline control points. The reader should pay attention to the same method when operating, because the coordinates and the position of the graphics will get different coordinate values, but as long as the workpiece and tool parameters are consistent, the relative coordinate values ​​will be the same.
Figure 5 Tool face truncated parameters
SolidWorks is a feature-based parametric solid modeling software that can edit entities by changing their dimensions. Therefore, as long as the assembly file of the above generated workpiece and tool is used as a template file, the function of the part design is used in the assembly drawing to redefine the contour of the part in the sketch plane of the part to generate a new part entity, and then based on the new It is required to redefine tool parameters such as γf and αf to directly obtain a new tool entity.
Since the SolidWorks drawing is associated with an entity, the profile and dimensions on the drawing will change accordingly. To obtain the coordinate parameters of the truncated line segment, simply save the tool drawing as dxf or dwg file, and then use the List command to query in AutoCAD.
Table 23, 567 spline curve control point coordinates
Editor's note:
This article was approved by Professor Ye Weichang and was selected from the author's editor's manual "Concise Manual for Mechanical Engineering and Automation" (Volume 1). The design manual has been officially published by the Machinery Industry Press recently. In this second edition, the design method of reducer based on three-dimensional CAD parameterization technology, mechanical manufacturing process and equipment CAD are added. This article is an excerpt of the new part of the tool design and manufacturing.
This design manual has been approved as an ordinary higher education mechanical and electrical planning textbook. It is designed for the course design and graduation design of mechanical principles and mechanical design, hydraulic and pneumatic transmission, mechanical manufacturing technology and equipment for mechanical design and manufacturing and automation students. And write. At the same time, the book design guidance, reference drawings, design information in one, each chapter has a design example and work plans, and attached design questions, is also quite suitable for factory enterprise engineering and technical personnel use.