combined forces N1 and N2 change the cross section of the tube. Based on this factor, the main reason for the decline in the quality of Electric Pipe Bender is RX and SX. Therefore, in GBJ235-82, the RX value and the amount of external thinning under various pressure levels are clearly defined for the purpose of control. The values of RX and SX ensure quality.
1. When purely bent, the tube is thinned by the tensile stress &1 under the action of the external force M (as shown in Figure 1), and the inner side is under compressive stress. &2 acts to thicken, and the combined forces N1 and N2 change the cross section of the tube. Based on this factor, the main reason for the decline in the quality of Electric Pipe Bender
is RX and SX. Therefore, in GBJ235-82, the RX value and the amount of external thinning under various pressure levels are clearly defined for the purpose of control. The values of RX and SX ensure quality.
2. As mentioned in the preceding article, the outer side of the material is tensioned when the pipe is bent, and the position of the inner pressed neutral shaft is different from that of the elbow method (as shown in Fig. 2). The neutral axis is operated in the top bending type (compression bending). It is about 1/3 from the outer wall, and the neutral shaft is at 2/3 of the outer wall when working in a turning (back bend). Therefore, the thin-walled Electric Pipe Bender
is curved, and it is beneficial to use the spin bending method.
3, the accuracy of bending tires is also one of the factors affecting the quality of the bend. When manufacturing the bent tires, in addition to the specification and size requirements to be controlled within a certain tolerance range, the user is also required to select the corresponding bending tire according to the curved pipe diameter during use.
4. The bendability and surface corrosion of the pipe itself may also affect the quality of the pipe. During on-site construction, the operator also needs to know the material of the pipe being processed, the processing performance and the judgment of the surface corrosion.
5. R is now available. (Bending radius / tube outer diameter) relationship curve (shown in Figure 3), for the user to refer to the relationship between the diameter of the pipe and the wall thickness. This figure focuses on the relative bending radius and the influence of the relative wall thickness on the quality of the bending pipe. According to the acceptance specification of the pipe processing: the cold-bending steel pipe is 4D for medium and low pressure and 5D for high pressure. Therefore, our bending tire design is R=4D (special case is different), so for the Electric Pipe Bender
produced by our factory, the main wall thickness SX is mainly selected, and the upper part of the figure is the coreless shaft area. For the common mandrel area, the lower part of the figure is a special mandrel area. Due to the difficulty in designing and manufacturing special mandrels and the inconvenience of operation, we generally do not supply them. Special circumstances can be agreed upon separately.