SolidWorks 2010 bible phần 9 pdf

Part VII: Working with Specialized Functionality 900 The specific formulas for finding these numbers are not as important as an intuitive grasp of what the numbers mean and how they are used, at least in relation to using SolidWorks to model sheet metal parts. The numbers used to fill out Bend Tables using K, BA, or BD values are typically taken from experimentally developed tables. Auto Relief Auto reliefs were formerly called Bend reliefs. You can specify three different Auto relief options to be applied automatically to bends that end in the middle of material. These options are illustrated in Figure 29.7. FIGURE 29.7 The three Auto relief configurations: Rectangular, Tear, and Obround Rectangular Tear Obround For the Rectangular and Obround types, you can control the width and the distance past the tan- gent line of the bend through the Relief Ratio selection box, which is immediately below the type selection box in the Sheet Metal PropertyManager. This ratio is the width of the relief divided by the part thickness. For the Rectangular relief, a ratio of .5 and a thickness of .050 inches means that the relief is .025 inches wide and that it goes .025 inches deeper into the part beyond the tan- gent line of the bend. The Obround relief goes slightly deeper because it has a full radius after the distance past the tangent line of the bend, and so it essentially goes a total of one full material thickness past the tangent line. The Tear relief is simply a face-to-face shear of the material with no gap. Flat Pattern feature The Flat Pattern feature is added automatically to the end of the tree when the Base Flange feature is added. This feature is used to flatten the sheet metal part when the feature is unsuppressed. The Flatten toolbar button acts as a toggle to unsuppress or suppress the Flat Pattern feature in the tree. It may be a little confusing, but the Flatten toolbar button and the flat-pattern feature in the FeatureManager refer to the same functionality. As mentioned earlier, the Flat Pattern has a couple Chapter 29: Using SolidWorks Sheet Metal Tools 901 of special properties that are not seen in other features. The first is that it remains at the bottom of the FeatureManager when other Sheet Metal features are added. The second property of the Flat Pattern feature is that it is added in the suppressed state. When it is unsuppressed, it flattens out the sheet metal bends. By editing the Flat Pattern feature, you can set a few options. The Flat Pattern PropertyManager is shown in Figure 29.8. FIGURE 29.8 The Flat Pattern PropertyManager The Fixed face parameter determines which face remains stationary when the part is flattened out. Generally, the largest face available is selected automatically, but if you want to specify a different face to remain stationary, you can do that here. When the Merge faces option is selected, it causes the Flat Pattern to form a single face rather than being broken up by the tangent lines around the bends. This does a few things. First, selecting the face of the flattened part and clicking Convert Entities (found on the Sketch toolbar) makes an out- line of the entire flattened part, which is easier to use for certain programming applications. Second, the edges around the outside are not broken up. Third, the tangent edges around the bends are not shown. The differences between Flat Patterns with this option selected and unselected are shown in Figure 29.9. Bend lines are shown in both examples in Figure 29.9. When you turn select the Simplify Bends option, it simplifies curved edges that are caused by flat- tening bends to straight lines from arcs or splines. When the option is unselected, the complex edges remain complex. Simple edges can be cut by standard punches, and do not require Computer Numerical Control (CNC) controlled lasers or abrasive water jets. The Corner Treatment option controls whether or not a corner treatment is applied to the Flat Pattern of a part. The corner treatment is illustrated in Figure 29.10. The model used to create this corner used a Miter Flange around the edges of a rectangular sheet. Part VII: Working with Specialized Functionality 902 FIGURE 29.9 The Merge Faces option showing on (selected) and off (unselected) Merge faces on Merge faces off FIGURE 29.10 Using the Corner Treatment setting in the Flat Pattern PropertyManager Corner treatment on Corner treatment off Chapter 29: Using SolidWorks Sheet Metal Tools 903 Note You can export a *.dxf file of the Flat Pattern directly from the model without creating a drawing. n Edge Flange feature The Edge Flange feature is very flexible and can be changed in several ways. If you have not kept up with the changes to Edge Flange for the last couple of releases, then you may find some surprises. Edge Flange is intended to turn a 90-degree flange from a selected straight edge in the direction and distance specified using the default thickness for the part. The default process for this feature is that you select the tool, select the edge, and then drag the distance, clicking a distance reference such as a vertex at the end of another flange of equal length or typing a distance value manually. You can select multiple edges from a part that do not necessarily need to touch one another. That is all there is to a simple default flange, although several options give you some additional options for angle, length, and so on. Figure 29.11 shows the Edge Flange PropertyManager, as well as a simple flange. FIGURE 29.11 The Edge Flange PropertyManager and a simple flange Part VII: Working with Specialized Functionality 904 Edit Flange Profile The Edit Flange Profile button in the Edge Flange PropertyManager enables you to edit a sketch to shape the flange in some way other than rectangular, or to otherwise edit the shape of the flange. Notice in Figure 29.11 that both of the flanges made by a singe flange feature have been edited. You can do this by selecting the flange for which you want to edit the profile before clicking the Edit Flange Profile button. Note If you have added dimensions to the sketch, as shown in Figure 29.11, then you will no longer be able to use the arrow to drag the length of the flange. To edit the length, you will need to edit the sketch or double-click the feature, and then double-click the dimensions that you want to change. n You can add holes to the flange profile as nested loops. This enables you to avoid creating addi- tional hole features, but does not enable you to control suppression state independently from the flange feature. You can make flanges go only part of the way along an edge by pulling one of the end lines back from the edge. This works even though the end lines appear black and fully defined. A situation where the sketch has been edited this way is shown in the image to the right in Figure 29.11. Use default radius This option enables you to override the default inside bend radius that is set for the entire part for this feature. The bend radii for individual bends within an Edge Flange that has multiple flanges cannot be set; the only override is at the feature level. If you need individual bends to have differ- ent bend radii, then you need to do this using multiple Edge Flange features. Gap distance The gap distance is illustrated in Figure 29.12. The Gap Distance selection box is only active when you have selected multiple edges in the main selection box for this feature. The gap refers to the space between the inside corners of the perpendicular flanges. Angle Because the Edge Flange is not dependent on a sketch for its angle like the Base Flange is, you can set the angle in the Angle panel of the PropertyManager. The values that this selection box can accept range from any value larger than zero to any value smaller than 180. Of course, each flange has practical limits. In the flange shown in Figure 29.13, the limitation is reached when the bend radius runs into the rectangular notch in the middle of the flange to the right, at about 158 degrees. The angle affects all the flanges that are made with the feature. To create a situation where different flanges have different angles, you need to create separate flange features. Chapter 29: Using SolidWorks Sheet Metal Tools 905 FIGURE 29.12 Specifying the gap distance Gap FIGURE 29.13 Establishing the limit of the flange angle Flange Length As mentioned earlier, if you have edited the Flange Profile sketch and a flange length dimension is applied in the sketch, then the flange length is taken from that sketch dimension. If this dimension has not been added to the profile sketch, then the options for this setting in the PropertyManager Flange Length panel are Blind and Up To Vertex. Using Up To Vertex is a nice way to link the lengths of several flanges. Flange Position The small icons for Flange Position should be fairly self-explanatory, with the dotted lines indicat- ing the existing end of the material. The names for these options, in order from left to right, are l Material Inside l Material Outside l Bend Outside l Bend From Virtual Sharp (for use when an angle is involved) Part VII: Working with Specialized Functionality 906 Trim side bends In situations where a new flange is created next to an existing flange, and a relief must be made in the existing flange to accommodate the new flange, you can select the Trim side bends option to trim back the existing flange. Leaving this option unselected simply creates a relief cut, as shown in Figure 29.14. This is functionality that requires some imagination from the user. A real sheet metal part manufactured like this would have an area at the corner where the deformation from the bends in different directions overlaps. This overlapping bend geometry is too complex for SolidWorks to create automatically, so it offers you a couple of options for how you would like to visually represent the corner. The Flat Pattern is correct, but the formed model requires some imagination. FIGURE 29.14 Using the Trim side bends option Trim Side Bends off Trim Side Bends on Curved edges Edge Flanges can be created on curved edges, but the curved edge must be on a planar face. For example, if the part were the top of a mailbox, then an Edge Flange could not be put on the curve on the top of the mailbox. The flange would have to be made as a part of the flat end of the mail- box, instead. Figure 29.15 shows Edge Flanges used on a part. Notice that reliefs are added to the ends of the bends, although they are not really needed. Chapter 29: Using SolidWorks Sheet Metal Tools 907 FIGURE 29.15 Curved Edge Flanges on a part Notice bend reliefs where they are not needed All the edges that you select to be used with a curved Edge Flange must be tangent. This means that in Figure 29.15, neither of the Edge Flanges could have been extended around the ends of the part. You would need to create separate Edge Flange features for those edges. Because these Edge Flanges are made in such a way that they are developable surfaces, they can be (and are) flattened in such a way that they do not stretch the material of the flange when the flat is compared to the formed shape. Doubtless there is some deformation in between the two states in the actual forming of this flange, and so its manufacturing accuracy may not be completely reliable. Miter Flange feature The Miter Flange feature can create picture frame–like miters around corners of parts, and cor- rectly recognizes the difference between mitered inside corners and mitered outside corners. The PropertyManager and a sample Miter Flange are shown in Figure 29.16. A Miter Flange feature starts off with a sketch that is perpendicular to the starting edge of the Miter Flange feature. Tip A quick way to start a sketch for a Miter Flange that is on a plane perpendicular to a selected edge is to select the edge, and then click a sketch tool. This automatically creates a plane perpendicular to the edge at the near- est endpoint. n Miter Flange sketches can have single lines or multiple lines. They can even have arcs. Still, remember that just because you can make it in SolidWorks does not mean that the manufacturer can make it. It is often a good idea to check with the manufacturer to ensure that the part can be made. Also, you usually learn something from the experience. Part VII: Working with Specialized Functionality 908 FIGURE 29.16 The Miter Flange PropertyManager and a sample part Tip When selecting edges for the Miter Flange to go on, be sure to remain consistent in your selection. If you start by selecting an edge on the top of the part, then you should continue selecting edges on the top of the part. If you do not, then SolidWorks prompts you with a warning message in a tool tip that says that the edge is on the wrong face. n Some of the controls in the Miter Flange PropertyManager should be familiar by now, such as Use default radius, Flange Position, Trim side bends, and Gap Distance. You have seen these controls before in the Edge Flange PropertyManager. The Start/End Offset panel enables you to pull a Miter Flange back from an edge without using a cut. If you need an intermittent flange, then you may need to use cuts or multiple Miter Flange fea- tures, as shown in Figure 29.17. Hem feature The Hem feature is used to roll over the edge of a sheet metal part. This feature is often used to smooth over a sharp edge or to add strength to the edge. You can also use it for other purposes, such as to capture a pin for a hinge. SolidWorks offers four different hem styles — Closed, Open, Tear Drop, and Rolled — which are shown as icons on the Hem PropertyManager. The PropertyManager for the Hem feature is shown in Figure 29.18. [...]... tooltips: Butt, Overlap, and Underlap 91 2 Chapter 29: Using SolidWorks Sheet Metal Tools Faces to Match The faces selected in the Faces to Match selection box act as an “up to” end condition for the faces to extend Prior to SolidWorks 2010, the Closed Corner feature always automatically selected a matching face to extend for each face selected, when appropriate SolidWorks 2010 enables you to manually select... everything to work out properly This part is in the same location as the Cross Break file, and is called Chapter 29 – Form Across Bends Sheet Metal.sldprt Figure 29. 29 shows the tool and a part to which it has been applied FIGURE 29. 29 Forming across bends Stopping face Faces to remove (both ends) 91 9 Part VII: Working with Specialized Functionality Lofted Bends feature The Lofted Bends feature enables you... geometry to the Flat Pattern The three available options are Circular, Square, and Bend Waist These options are shown in Figure 29. 24 91 4 Chapter 29: Using SolidWorks Sheet Metal Tools FIGURE 29. 24 Applying the Corner Trim Relief options Forming Tool feature Forming tools in SolidWorks enable you to place features that are not formed on a brake press These are features that are not straight-line bends,... in the PropertyManager FIGURE 29. 30 The Lofted Bends PropertyManager, a sample, and a Flat Pattern with bend lines 92 0 Chapter 29: Using SolidWorks Sheet Metal Tools Like the forming tools, you can also use Lofted Bends in situations for which they were probably not intended Figure 29. 31 shows how lofting between 3D curves can also create shapes that can be flattened in SolidWorks In this case, a couple... select a flat face to remain fixed when the part is flattened Instead, you can use a straight edge along the revolve gap, as shown in Figure 29. 39 FIGURE 29. 39 Selecting a straight edge for a conical part Select one of these edges in the Fixed Face/edge selection box 92 9 Part VII: Working with Specialized Functionality Note When a conical sheet metal part is created, it does not receive the Flat Pattern... this are shown in Figure 29. 44 93 3 Part VII: Working with Specialized Functionality FIGURE 29. 44 Using the Normal cut option 9 Click the Flatten button on the Sheet Metal toolbar Notice that the Flat Pattern feature becomes unsuppressed and that the Bend Lines sketch under it is shown This works just like it did in the Base Flange method The finished part is shown in Figure 29. 45 93 4 ... this chapter in the section on mixing methods 92 6 Chapter 29: Using SolidWorks Sheet Metal Tools FIGURE 29. 37 Using the Process Bends feature Bend lines drawn in Flat Sketch to add bends to part Bends added to part by bend lines Added by bend lines added to the Flat Sketch Convert to Sheet Metal feature The Convert to Sheet Metal feature can use either SolidWorks native data or imported data It can...Chapter 29: Using SolidWorks Sheet Metal Tools FIGURE 29. 17 The Start/End Offset settings for a Miter Flange End Offset Sketch for Miter Flange Start Offset FIGURE 29. 18 The Hem PropertyManager and a sample hem One of the limitations to keep in mind with regard to hems is that SolidWorks cannot fold over a part so that the faces touch perfectly... picking the middle of the base of the part for the fixed face 7 Draw a rectangle on one of the vertical faces of the part, as shown in Figure 29. 43 93 2 Chapter 29: Using SolidWorks Sheet Metal Tools FIGURE 29. 42 Ripping the corners Completed rip FIGURE 29. 43 Adding a sketch for the cut 8 Use the sketch to create a Through All cut in one direction Notice that the Normal cut option is on by default Examine... button below the Edges selection box in the Hem PropertyManager, shown in Figure 29. 18 Jog feature The Jog feature puts a pair of opposing bends on a flange so that the end of the flange is parallel to, but offset from, the face where the jog started The Jog PropertyManager and a sample jog are shown in Figure 29. 19 FIGURE 29. 19 The Jog PropertyManager and a sample jog The Jog feature is created from a . Figure 29. 18. Chapter 29: Using SolidWorks Sheet Metal Tools 90 9 FIGURE 29. 17 The Start/End Offset settings for a Miter Flange End Offset Start Offset Sketch for Miter Flange FIGURE 29. 18 The. are shown in Figure 29. 24. Chapter 29: Using SolidWorks Sheet Metal Tools 91 5 FIGURE 29. 24 Applying the Corner Trim Relief options Forming Tool feature Forming tools in SolidWorks enable you. 29: Using SolidWorks Sheet Metal Tools 91 3 Faces to Match The faces selected in the Faces to Match selection box act as an “up to” end condition for the faces to extend. Prior to SolidWorks 2010,