Causes of bolt deformation in hydraulic press
The hydraulic tension pre-tightening technology uses the hydraulic tensioner to complete the pre-tightening work of the bolt. The working principle is that the high-pressure oil output by the electric oil pump is sent to the hydraulic cylinder 4 through the high-pressure hose, and the hydraulic cylinder 4 is pulled under the predetermined pressure. Stretching and acting on the tensioned bolt 6 by the bolt 1, and as the piston rod moves, the bolt 6 is stretched to a certain elongation (within the elastic range of the material), at this time, the bolt 6 is stretched A gap occurs between the nuts 8. After the nut 8 is tightened, the load applied to the bolt is loosened to complete the pre-tightening of the bolt. In order to make the pre-tightening force of the bolts uniform and meet the sealing requirements, it must be ensured that the elongation of each bolt is within the allowable range of calculation. If the elongation of a bolt is out of tolerance, the tensioning operation needs to be adjusted.
Before hydraulic stretching, determine the hydraulic pressure set value of the hydraulic tensioner when the bolt is loaded and stretched, that is, the pressure value that the hydraulic tensioner outputs to the hydraulic cylinder. Obviously, the higher the pressure of the oil in the hydraulic cylinder, the greater the pre-tightening force of the output bolt and the greater the elongation of the bolt. The hydraulic cylinders can be used singly or in combination of two or more. If used in series (using a booster cylinder structure), the multiple of the preload force is equal to the number of series connected to the hydraulic cylinder.
The hydraulic pressure p of the hydraulic cylinder is only related to the relative elongation E of the bolt, the ratio k of the bolt to the cross-sectional area of ​​the piston, and the elastic modulus E of the material. For a given bolt, the hydraulic pressure p of the hydraulic cylinder is proportional to the relative elongation E. Therefore, the preload force F0 of the bolt can be accurately obtained by controlling the oil pressure p of the hydraulic cylinder. The relationship between the hydraulic pressure p of the hydraulic cylinder and the relative elongation E is as shown in FIG. It can be seen from Fig. 2 that when the tensile force applied to the bolt exceeds the elastic limit of the bolt, that is, the relative elongation of the bolt is greater than the elastic elongation Ee, the tensile curve is no longer a straight line, and the deformation of the bolt is not Then elastic deformation. Therefore, when the drawing is performed, if the pressure of the hydraulic cylinder is too large, the tensile deformation of the bolt exceeds the elastic range, and the bolt is damaged.
Economical Plasma Cutting Machine is designed on the basis of the traditional Table Plasma Cutting Machine.
1. Economic Plasma Cutting Machine has the advantages of table plasma Cutting Machine - stable, at the same time, economic Plasma Cutter is suitable for cutting thicker sheet metal.
2. The economical plasma cutting machine needs to weld the cutting table by yourself, the advantage is the plasma cutter won't be affected cutting effect by the deformation of the table, so that the accuracy of cnc cutting machine can be ensure.3. The economical plasma cutting machine is suitable for cutting various thickness metal sheets.
4. Economical and practical.
Economic Plasma Cutting Machine
Plasma Table,Cnc Plasma Cutter,Cnc Plasma,Economic Plasma Cutting Machine
Jinan Huaxia Machinery Equipment CO.,Ltd , https://www.cnformingmachine.com