Bending process can be divided into many kinds, there are bending, bending and other means to push, these methods can be divided into two kinds of cold bending and bending bending state. For different bends of the processing technology used is different, different characteristics of the elbow is not the same.
The main reason that causing the quality of elbow decline and the attention method:
1, Pure bending, the tube under the action of the external force M in the outer layer of the lateral arm wall tensile stress and thinning, the inner stress, the role of thickening, resultant N1 and N2 to the tube cross-section changes. Therefore, GBJ235-82, for a variety of pressure levels under the conditions of the RX value and the amount of thinning outside are clearly defined, the purpose is to control the RX and SX To ensure quality.
2, The previous article has been mentioned, the elbow when the lateral tension of the material, the medial position of the neutral axis of pressure and bending method is different from the top bend (compression bending) work in the neutral axis from the outer wall of about 1/3, in the bending (bending) work, the neutral axis from the outer wall 2/3. Therefore, the thin-walled pipe is bent, and it is advantageous to use a bending method.
3, The accuracy of curved tire is also one of the factors affecting the quality of elbow. We bend fetal production, in addition to size requirements to control in a certain tolerance range, but also requires users to use in accordance with bending pipe diameter to select the corresponding bending tire.
4, The pipe itself, the bending performance and surface corrosion, may also affect the quality of elbow. On-site construction, the operator should also be aware of the material being processed pipe, processing performance and surface corrosion to make production judgments.
