Coil springs are generally used as the power for micromachines without electrical energy, such as the power of mechanical clocks and timing systems; the power of mechanical phonograph records; mechanical music boxes; the power of winding toys, etc. What this kind of coil spring driven machinery has in common is that the transmission chain is a speed-increasing mechanism instead of a reducer commonly used in machinery. In addition, when the coil spring is tightened, the output torque is large, but when it is almost completely relaxed, the output torque will drop a lot. In order to reduce the uneven output torque of the mainspring, all these devices have a speed stabilizing mechanism to stabilize the speed of the mechanism. In mechanical watches, in order to reduce this torque difference, the spring is deliberately made into an S shape when in the free state, instead of a flat equidistant spiral, so that the output torque of the coil spring is relatively balanced.
For the design of the coil spring, it is necessary to determine the size of the small driving torque and the size of the large torque that can be used; the torque and speed of the driving actuator; and the total time required to drive and other factors, which should be selected from the relevant design manual. At the same time, the size of the barrel, the size of the gear and the number of modular teeth were determined. After the test, the parameters of each part are determined through correction.
Applications of coil springs
Most coil springs can be used to achieve automatic reset within a certain range. For example, when drilling with a bench drill press, hold down the feed handle to move the drill bit downwards. After drilling, once you let go, the drill bit will automatically rise back to its original position, that is, a coil spring is installed on the shaft of the handle. There are many examples of using coil springs as reset in machinery, and they are widely used in various automatic machines, printing machines, packaging machines, etc. Additionally, coil springs are often used for balancing. For example, there is a component installed on a vertical guide rail that needs to move up and down along the guide rail and can stop stably at any position. The up and down movement of the components is pulled by the chain. As the components are lowered, the chain becomes longer. Because the chain also has weight, it is heavier than the components at the upper end of the guide rail, resulting in different up and down positions of the components, and the total weight of the components plus the chain is also different. For this kind of imbalance in different positions, coil springs can also be added. The commonly used box ruler is also an application example of coil spring, which can reduce the size. Coil springs are not as widely used as torsion springs. The main reason is that the production is complicated and usually made by professional manufacturers. But if the product is done in small quantities and the price is high, the manufacturer still cannot make money and does not want to do it. If you do too much, it will cause a lot of waste and make life difficult for technicians. At the same time, the manufacturing cycle is relatively long, so designers generally try not to use coil springs. In most cases, it is only worthwhile to use coil springs when the product is produced in larger batches.