Please avoid the following improper uses of double torsion springs :
(1) When a large amount of compression is exceeded, pressure will be generated and damage will occur. When used close to the tightening length, the spring wire will gradually close. This is because the higher the fixed number of double torsion springs, the higher the load curve, resulting in high stresses near the breakage of the double torsion spring. Please do not use more than 300000 loops.
(2) When used without preload, the double torsion spring will vibrate up and down due to the gap, causing the spring to deform. If preloaded, the spring is relatively stable.
(3) When the spring is used horizontally, the guide pin and spring will wear and break.
(4) When used without a double torsion spring guide, such as under the guidance of a dancing spring, it is easy to cause deformation of the spring bottom and spring body. The local high pressure in the twisted part of the spring is the main cause of spring breakage. Be sure to use ID guide pins or OD guides and other devices.
(5) When the flatness of the assembly surface is poor, the parallelism difference of the assembly surface will cause the double torsion spring to deform and partially break under high pressure. The spring will deform when the parallelism is poor, and the spring will break when it is reused more than 300,000 times. Please improve the parallelism of the assembly surface without exceeding 300,000 reuses.
(6) If the inner diameter of the double torsion spring and the gap between the guide pin and the guide pin are too small, it will cause collision wear of the inner diameter, and the worn part is the main cause of spring breakage. On the contrary, if the gap is too large, the double torsion spring will twist and break, and the inner diameter of the spring will be about -1.0mm. For springs with a long free length (free length/outer diameter greater than 4), please use steps or guide pins to avoid collision with the guide pins when the spring body is twisted.
(7) If the outer diameter of the spring and the countersunk hole and the gap between the countersunk hole are too small, the compression of the spring will cause the outside to expand and rub against the countersunk hole, causing concentrated force and fracture. The better diameter of the countersunk hole is the outer diameter of the spring + 1.5mm. For free-length springs, use the countersunk hole shape.
(8) If the guide pin length and counterbore depth are short, the guide pin is too short, which will cause wear and breakage of the guide pin head and spring. The ideal length of the guide pin is set to more than 1/2 of the spring length, please reverse the C3 chamfer.
(9) When replacing the square head or using a spring, the spring is distorted by force, causing the inner ring spring to insert into the outer ring (or the outer ring into the inner ring), resulting in breakage.
(10) When double torsion springs are used in series, it will cause the spring to bend and exceed the length of the guide pin or countersunk hole, causing breakage for the same reason, and due to the slight difference in the load of the spring itself, it will cause surface breakage with weak loads.
(11) Debris and foreign matter inclusions When in use, the foreign matter inclusion part will cause the effective coil to have no effect. Only by compressing other parts, the actual number of effective coils will become smaller, resulting in high stress and fracture near the surface. Do not allow foreign matter to enter the spring.