At production of metal designs in which pipes are applied quite often it is required to receive not direct product, but curved forms. It is possible to change form of profile pipe by means of bending. For this operation special bending mechanisms and devices are used.
It is required to you
- - bending machine.
1. When choosing way of bending of pipe you proceed from its diameter, wall thickness, material and the required bend radius. Also consider specific conditions of production, quality and accuracy requirement.
2. You make bending of product within technology admissions on thickness of wall and on outside diameter. Avoid when bending pipe of the undesirable phenomena, such as breaks on internal part of bend or flattening of cross-section. At change in shape of pipes in cold state there can be also peening of material and arise harmful residual stresses.
3. If it is required to provide the small radius of bend, bend product closer by the ends as in middle part it is more difficult to bend pipe.
4. Use at pipe bending the machine for cold are flexible with stretching. The advantage of such way is that availability of stretching leads to the shift of neutral axis to the direction of bend. It reduces possibility of formation of ridged surface on bend. On the machine the pipe is covered at the edges, is exposed to stretching and at the same time is bent by means of movement of bending template.
5. Use the specified method for bending of thin profile wall pipes, in particular for those which have rectangular cross section. Also the way is suitable for giving of certain form to product when the pipe has to be bent in one plane at considerable admission on outside diameter.
6. If you are faced by task to avoid loss of stability of wall of product on internal part of bend, apply pipe gibka under internal hydrostatic pressure. At this way stubs, one of which has branch pipe for giving in liquid cavity, are put on the ends of profile pipe.
7. After filling of volume tension increasing plasticity of metal arises liquid in walls. Now bring bending template which will bend pipe to the middle of pipe, having given it the necessary form in the required place.