At present, the processing equipment and processing production lines of mechanical springs are developing towards the depth and breadth of numerical control (NC) and computer control (CNC). However, with the changes in spring materials and geometric new shapes, the processing technology has also developed.
Variable spring outer diameter, variable pitch and variable wire diameter (three-variable) suspension springs have realized moldless plastic processing. Since the development of three-variable springs, tapered steel bars have been used for winding processing on CNC lathes, but the yield rate And the price is not ideal.
is now replaced by a spring coiling machine in a heated state to control the roll speed and drawing force to obtain the required cone shape, and use the processing waste heat for quenching. The hollow stabilized spring rod is formed by rolling and welding of low carbon boron steel plate.
The torsion bar is made of high-purity 45 steel, which has high surface hardness and large residual compressive stress through high-frequency quenching, thereby improving fatigue life and relaxation resistance. The leaf springs widely used in electronic products basically use stamping and automatic bending processing Forming. At present, it is mainly to develop the joining technology of composite materials.
The cold forming process of the spring has the one-time automation capability. The cold forming machine has been developed to 12 jaws. The steel wire in the range of (0.3~14) mm can basically be formed at one time by the 8-jaw forming machine.
At present, the development direction of forming process equipment is to increase the forming speed. The main development trend is to increase the forming speed of the equipment, that is, the production efficiency; improve the durability of the equipment by improving the precision of the equipment parts and strengthening the heat treatment effect; increase the length sensor and laser ranging Instrument, to the CNC forming machine for automatic closed-loop control of the manufacturing process.
Cold forming process range capability. At present, the maximum specification of large wire diameter spring coiling machine can reach 20mm, =2000MPa, and the winding ratio is 5. The cold forming process of variable diameter or equal diameter material Minic-Block spring and eccentric spring still has limitations.
The hot forming process speed capability of springs. At present, my country only has CNC2-axis hot coiling machine for forming on (9~25)mm specifications, with a maximum speed of 17 pieces per minute. Compared with developed countries, there is a big gap.
Large spring hot forming process control ability. Because there is only a CNC2-axis hot coil spring machine, the shape control has less three directions and poor accuracy; and there is no automatic bar rotation control and adjustment mechanism, so the hot coil spring forming process level is The capacity is low, so the accuracy level of the spring and the level of surface oxidation and decarburization are also low.