1. The development trend of the spring industry in various fields
(1) At present, the processing equipment and production lines of mechanical springs are developing towards the depth and breadth of numerical control and computer control. However, as the spring material and geometry change, processing technology has also evolved. Suspension springs with variable spring outer diameter, variable pitch and variable wire diameter (three variations) have been processed without forming. Since the development of three-variable springs, tapered steel rods have been used for the winding of CNC lathes, but the output and price are not ideal. At present, it is changed to the heating state, the speed and stretching force of the roller are controlled by the spring winding machine to obtain the required cone, and quenched by processing the waste heat.
(2) The hollow stable spring rod is rolled and welded with low carbon boron steel plate.
(3) The torsion bar is made of high-purity 45 steel. High-frequency surface hardness and large residual compressive stress are obtained through high-frequency quenching, thereby improving fatigue life and resistance to relaxation.
(4) The leaf springs widely used in electronic products are basically formed by stamping and automatic bending. At present, it is mainly to develop the bonding technology of composite materials.
Second, the main forming process of the spring industry
1. Spring cold forming process
(1) One-time automation capability in the cold forming process. The cold forming machine has now reached 12 claws. The steel wire in the range of (0.3-14) mm is basically formed by an 8-jaw forming machine at a time. At present, the development direction of molding processing equipment is:
(2) To increase the molding speed, the main development trend is to increase the molding speed of the equipment, that is, production efficiency;
(3) Improve the durability of equipment by improving the accuracy of equipment parts and strengthening the heat treatment effect;
(4) Add a length sensor and a laser distance meter to automatically close the loop control of the manufacturing process of the CNC molding machine.
(5) Cold forming process capability. At present, the maximum size of the large-diameter winding machine can reach 20 mm, = 2000 MPa, and the winding ratio is 5. The cold forming process of micro-block springs and eccentric springs with reduced or equal diameter materials still has limitations.
2. Spring thermoforming process
(1) The speed capability of the thermoforming process. At present, there are only CNC2 axial hot spring winding machines of (9 ~ 25) mm in China, with a maximum speed of 17 pieces per minute. Compared with developed countries, there is a big gap.
(2) The control capability of the large spring thermoforming process. Because there are only CNC 2-axis hot spring winding machines, the shape control is less in three directions and the accuracy is poor. In addition, since there is no automatic bar rotation control and adjustment mechanism, the forming technology level and capability of the hot coil spring are relatively low. Therefore, the accuracy level of the spring and the level of surface oxidative decarburization are also very low.