WILA Catalog GB

WE LIVE PRESS BRAKE PRODUCTIVITY 80 TOOLING TOOLING Custom Style FLATTENING TOOLS Depending on the available tonnage and the sheet to be bent (material type and thickness), the sheet can be pressed closed to a greater or lesser extent. The force table on page 113 lists the tonnages required for closing the sheet for mild steel 42 kN/cm2 and for stainless steel 70 kN/cm2. The values as indicated may deviate slightly in actual practice. A variety of tools in the WILA program can be used to perform this bending operation. If hemming is done only occassionally, a two step operation is often used with the first operation bending to 30° using standard 30° top and bottom tools. The second operation uses top and bottom flattening tools to close the hem (Fig 4.4). Because of the side forces that occur when flattening the sheet, we advise that these tools be used on sheets that are no more than 2 mm. Using the New Standard top tool type BIU-051, for example, combined with bottom tool type OZU-083, a flattening combination can be created that can be used for both pre-bending and flattening (Fig. 4.5). An advantage is that this tool can also be used for universal bending. Because the design configuration is centric, no sliding mechanism is required. We advise a maximum sheet thickness of 1,5 mm. with this tool combination. The spring-action flattening tool, consisting of a holder with a spring- action flattening part, is another option (Fig. 4.6). When combined with a 28° top tool, the sheet can be pre-bent and then hemmed. Because the V opening can be adjusted to suit the sheet thickness, short flange lengths can be bent. This combination however cannot be used for universal bending. The range of products includes a number of standard designs, type DDU (page 86), with different V-openings. TOOLING FLATTENING TOOLS (DD) Flattening tools (often called Hemming or Dutch bending tools) are used to pre-bend the sheet and then press it closed (Fig. 4.3). This technique is used, for example, to finish the sharp edges of the ends of a sheet or to reinforce the sheet and thus strengthen the bent product. 1) bending 2) flattening D D Fig. 4.3 spring top tool flattening part guide part Fig. 4.4 Fig. 4.6 flattening pre-bending bottom tool type OZU 083 top tool type BIU 051 Fig. 4.5 CUSTOM STYLE www.wilatooling.com sales: +31 (0)573 28 98 50