Contact spring has various shapes and structures for different purposes.
According to the shape can be divided into straight spring and curved spring, according to the shape of the plate can be divided to rectangle, trapezoid, triangle and stage shape, etc.
Material
Contact spring can be used as the flat steel strip ,The material can be phosphor bronze, tin bronze, 65mn, 55Si2Mn, 60Si2MnA, 55SiMnVB, 55SiMnMoV, 60CrMn, 60CrMnB, 302, 316, etc.
Characteristics
The feature it is easy to bend in only one direction - the minimum stiffness plane, while in the other direction it has a large tensile stiffness and flexural rigidity.
Therefore, the spring is suitable for detecting the sensitive elements, elastic support, positioning device and flexible connection in the instrument or automatic device.
Application
According to the characteristics of materials, it is widely used in various kinds of contact devices, and the most used is the simplest straight cantilever spring.
The resistance of the contact sheet must be small, so it is made of bronze.
The measure of a spring is the change of force or displacement.
If the fixed structure and spring load mode can guarantee working length is constant, the leaf spring stiffness is constant, the scope of small deformation, when necessary, can also get nonlinear characteristics, such as the spring pressure on limit board or on the adjusting screw, change its working length.
Technical requirement
1. The radius of the bending part.
If the curvature radius of the bending part is relatively small, then these parts should produce great stress.
if the bending part should be avoided to produce greater stress, the bending radius should be at least five times the thickness of the plate.
2. Stress concentration at the gap or hole.
The spring plate usually has a ladder part and a hole, which will produce stress concentration at the step where the size changes sharply.
The larger the diameter of the hole, the greater the stress concentration factor.
3. The shape and dimension tolerance of spring plates.
Leaf spring multi-purpose stamping processing, when the design should consider to choose suitable stamping processing of shapes and sizes and at the same time, also give full consideration to the spring piece when bending springback, produced by the heat treatment deformation size tolerance, etc.
The requirements for heat treatment of spring plates should be put forward according to the performance requirements. The hardness of the heat treatment can be determined between 36 and 52HRC.