Application of force spring

1. Definition

As the name implies, a fixed force spring is a spring that can maintain a constant elastic force within the corresponding stroke, also called a constant force spring. Its use is linear motion, and its resilience is generally used. English name: constant spring. Its common graphics are as follows:

Advantages: Compared with ordinary compression or tension springs, its elastic force is very constant, and it can output elastic force close to a straight line to ensure that the product will not change due to changes in elastic force during use. In a long and narrow space, the space can be reduced as much as possible., Improve the possibility of beautiful design of products. The graph is as follows:

Disadvantages: Because it is used in a straight line, its space must need a certain length to play its role. Compared with the scroll spring, its life is obviously shorter, generally only about 2000 to 5000 times.

2.  Application of force spring

1. Lifting fan

Compared with the old design of fixing the fan head by screws, the fixed force spring can be easily lifted and lowered, and can be easily fixed in the midway position, making the fan more beautiful and convenient. At present, this kind of design has been sold abroad for many years, and the design is quite mature.

2. Liquid crystal display

In the process of increasing the size of the display and increasing the requirements, the old display that can only adjust the angle back and forth obviously cannot meet the requirements. The current display can rotate 360 degrees, tilt forward and backward, slide up and down, and can do almost anything. The function of sliding up and down and stopping at any fixed point is realized by using a fixed force spring. Through its balanced elastic force, it can stably hold the monitor head at any position to prevent sliding down. At present, all the world's PC predators adopt this new design, making it more and more perfect in function.

3. Up and down sliding doors and windows

In the European and American markets, up and down sliding doors and windows have been selling well, and the upward sliding force comes from the fixed force spring. Through the resilience of a set of fixed force springs on each side, the glass doors and windows can easily slide upward, reducing Its heavy resistance.

4, supermarket automatic sales shelves

In order to enable guests to see that the goods on the shelves are neat and beautiful, salesmen are often required to sort out the shelves. Now in some high-end shopping malls, automatic push shelves are used. As long as the goods in front are taken out, the goods in the back are automatically pushed before they live, which ensures the appearance and cleanliness and saves time. It is the automatic sales shelves that use the force spring to realize this function.

5. Motor carbon brush pressing device

Because the ordinary carbon brush device uses a compression spring, the elastic force of the compression spring gradually attenuates when it is used to the tail end, so that the carbon brush cannot press the shaft with a constant force, which reduces the performance of the motor, and adopts a double-coil design The fixed force spring can always give the carbon brush a constant elastic force from beginning to end, so that the performance of the motor is always stable.

6、 ……

Material Selection of 3. Force Spring

SUS301 series of spring material, this material has high hardness, high tensile strength, smooth surface, good rust resistance, easy side processing... making this material almost become the force spring of choice. Its hardness can reach about Hv600 (after low temperature heat treatment), the tensile strength can reach more than 1665Mpa, and the nickel content is between 6.0 and 8.0 to ensure its good anti-rust performance.

Of course, if the use environment is more harsh, in the ultra-high temperature or ultra-low temperature environment, you can also choose SJ101 series of wide temperature and high strength constant elastic alloy, at high temperatures can still maintain high strength, constant elasticity, low expansion coefficient. But its material unit price is expensive, under normal circumstances do not use.

4. Design of force spring

The design of the torsion spring is generally considered from two aspects:

1. Performance

The two most important properties, one for the elastic value, two for life. Generally, the thicker the elastic material, the wider the width, the higher the elastic force. In the same size of the material, the smaller the inner diameter of the crimp, the higher the elastic force, and vice versa. The life is the opposite, in the same production conditions, the thinner the material, the better the life, in the same size of the material, the smaller the inner diameter of the curl, the shorter the life, and vice versa.

2. Installation space

Generally, the outer diameter value of the fixed force spring is set according to the installation space. Sometimes when the center shaft is used, the inner diameter value must be taken into account at the same time. The general outer diameter of the fixed force spring cannot be larger than the installation space, otherwise friction will occur. Affect use.