Effective number of turns refers to the number of turns that the spring can keep the same pitch. Effective number of coils of spring = total number of coils-number of supporting coils, calculated according to the structure.

1, for tension spring, the effective number of turns n = the total number of turns n 1, when n >: 20 is rounded to an integer circle, when n

2. For the compression spring, the effective number of turns n= the total number of turns n 1- the number of support turns n2, which can be obtained by looking up the table. The mantissa should be 1/4, 1/2, 3/4, or an entire circle.

Our popular algorithm is to subtract the total number of turns of the compression spring from the number of turns that will not deform when the upper and lower parts are in contact, generally reducing 2 turns; The effective turns of torsion spring and tension spring are the total turns.

Springs are mechanical parts that work by elasticity. Parts made of elastic materials deform under the action of external force, and then return to their original state after the external force is removed. Also called "spring". Usually made of spring steel. The types of springs are complex and diverse. According to the shape, there are mainly spiral springs, scroll springs, leaf springs and irregular springs.

Attention problem

Due to the limitation of product structure, multi-strand springs generally have the characteristics of high strength and good performance. Its material needs to ensure the final performance of spring strength and toughness. In the process of processing multi-strand springs, attention should be paid to:

1. According to product requirements, bearing rings can be cold bonded and hot bonded. It is not allowed to heat the spring until it sparks or turns white by thermal bonding, and the temperature of silicon manganese steel shall not be higher than 850℃. The support ring and the effective ring should be in effective contact, and the gap should not exceed 10% of the nominal gap between rings.

2. The characteristics of multi-strand springs can be determined by adjusting the lead, and the cable distance can be adjusted when winding. Lay length can be 3~ 14 times the diameter of steel wire, but it is generally appropriate to be 8~ 13 times. Its spring force is also closely related to free height, parallel end coil, outer diameter and steel wire performance, which can be changed by adjusting one or more of them.

3. Springs without supporting rings and springs with too thin steel wire diameter should not be welded with the spring head, but the terminal cable should not be obviously loose and should be deburred. Where the multi-strand spring needs to be welded at the head, the length of the welded part shall be less than 3 times the cable diameter (the longest shall not exceed 10 mm). The heating length should be less than one circle, and it should be polished smooth after welding. During gas welding, the welding parts should be locally annealed at low temperature.

4. The surface treatment of the spring can generally be phosphating or other treatments. If zinc and cadmium are to be galvanized, hydrogen should be removed after electroplating. After hydrogen removal, 3% (not less than 3 pieces) should be taken for a second interview, and there should be no fracture during the second interview. Dirt, salt marks and scale on the spring surface should be removed. The method can be sandblasting or gasoline cleaning, but not pickling.

5. The important spring pressing time is 24 hours, and the ordinary spring pressing time is 6 hours or 3~5 consecutive times, and each time it is held for 3~5 seconds. When pressing, the clearance between the spring and the spindle should be 10% of the spindle diameter. The gap is too small, the operation is difficult, and the gap is too large, which is easy to cause the spring to bend and deform. If one of the springs breaks during pressing, the rest should be reworked.

References:

Baidu Encyclopedia: Spring