Special Shape Springs

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The difference between the special-shaped spring and the conventional spring is that the spring itself is irregular, with bending and a large number of complicated angle designs, and the manufacturing and processing skills are relatively demanding, and the equipment is also relatively demanding. Generally, it is wound by a computer machine. There are many angles and bending, so the production speed is slow. Because of its complexity, the production and processing of special-shaped springs can often represent the technical level of a company.

Shaped spring is this kind of elastic element, which is widely used in mechanical equipment, electronics and other industries. The special-shaped spring will cause great elastic deformation when it is loaded, converting mechanical energy or kinetic energy into deformation energy. After the force is removed, the deformation of the special-shaped spring disappears and returns to the original state, and the deformation energy is converted into mechanical energy or kinetic energy.

1. Reducer coil spring: It is used in some special occasions. The material of the reducer spring is generally a circular section material, and most of them bear compressive loads.
2. Leaf spring: The material of this spring is spring strip (or plate), which is processed by corresponding molds on special equipment or general pressure processing machine tools. Leaf springs, wave springs, and light springs have thinner material thicknesses, while medium or large disc springs tend to be thicker, and these springs are also widely used.
3. When the installation space is limited, springs of rectangular cross-section materials are often used, because springs made of rectangular cross-section materials can obtain larger loads under the same space and the same deformation. Compared with the spring of circular section material, this type of spring has a large cross-sectional area in the same space, so it absorbs a large amount of energy, as shown in Figure 1. It can be used in heavy machinery, stamping dies or especially stiff springs
4. The disc spring is small in size and light in weight, and is widely used in buffering, vibration isolation and other occasions, and is widely used in stamping dies, valve clutch fasteners, and petroleum and geological engineering machinery.
5. The middle-convex helical compression spring can obtain a large amount of deformation because the smaller coils at both ends can be embedded in the middle coil. For example, some convex car brake springs are always in a tight state, open the car valve, the spring returns to deformation, and drives the brake to brake the car. The hair clipper also uses the feature of the convex coil spring to obtain greater deformation and stress in the effective space.
6. The volute coil spring is similar to the conical coil spring. It absorbs a large amount of energy under pressure. Due to the difficulty in manufacturing, it is only used in special cases limited by space. The flat scroll spring has a large number of coils, a large amount of deformation, and can store a large amount of energy. It is mostly used for compression springs and energy storage elements in instruments.
7. The leaf spring can be made of single-leaf spring steel plate or multiple pieces superimposed, and its buffering and damping performance is good, especially the damping performance of multi-leaf spring, which is mainly used for the suspension devices of automobiles, tractors and railway vehicles.
8. Unequal pitch coil springs are mainly used for suspension springs of motorcycles and small passenger cars and valve springs of high-speed engines. On the same spring, it can not only meet the requirements of small stiffness when the deformation is small, but also meet the requirements of high stiffness when the deformation is large. Unequal pitch springs just meet these special requirements. The schematic diagram of the unequal pitch coil spring is shown in Figure 2.
9. The torsion bar spring is actually a straight rod made of elastic material under the action of torque. It has a large deformation energy per unit volume and is mainly used for the suspension devices of various vehicles.
10. The ring spring is composed of an outer ring with an inner conical surface and an inner ring with an outer conical surface. The logarithm of the inner and outer rings is determined according to the size of the load and the requirements of deformation. Ring springs have high vibration damping capacity and are mainly used in heavy equipment and buffer devices.
11. Wire springs are all kinds of linear springs made of spring wire, generally made of cold-drawn spring steel wire. Wire springs are mostly used in situations where the load is small and the load characteristics are not strictly required. The cross-section of the wire spring is usually circular, so the load has no direction restriction and has the same bending stiffness in all directions.
12. There are two types of spring clips: circular section material and rectangular section material. Sometimes, for the convenience of assembly, the end of the clip ring is also bent for a section. When manufacturing the collar, the densely wound spring coil can be flattened by itself after being cut, and it must have a large initial stress during winding.
13. The serpentine spring is named for its zigzag shape like a snake. It is also called “Z” shape and “S” shape spring according to its shape. It is widely used in car seat cushions, so it is also called seat spring.
14. Multi-strand helical springs are generally made by twisting 0.5mm~3mm steel wire into a wire rope, and then coiling it into a spring. The most commonly used is a 3-strand~4-strand wire rope without a center strand. When the wire rope exceeds 4 strands, there should be a central strand. In order to prevent the wire rope from loosening after being stressed, the wire direction of the wire rope should be opposite to that of the spring.
15. Clamp springs such as (see Figure 3 below) are often used for fastening of automobile fluid tanks, and belong to the category of double torsion springs. This kind of spring can be rolled by CNC spring coiling machine in qualified enterprises. Generally, enterprises are rolled by hand, and some special auxiliary tools can be made during rolling. First cut and straighten the coil material, then make it into a “U” shape, and roll it into a curved shape on a special auxiliary device. When the auxiliary tool “b” is installed at the position of the feeding guide wheel, the semi-automatic production of the clamp spring can be realized, which improves the production efficiency by about 10 times compared with manual operation.

Shaped Spring Forming Machine

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The special-shaped spring forming machine usually refers to the special forming equipment for producing all kinds of tension springs, torsion springs and various snap rings and other elastic elements. The complexity of this type of special machine is higher than that of the coiling machine that coils the compression spring, also known as the multi-station machine. The common special machine for winding the tail hook torsion spring in China is the straight tail coil spring machine. Its action adopts a rack and pinion mechanism, the feeding method is a reciprocating one-way feeding mechanism, the coil spring is a core winding, and its pitch control is realized by a sliding rod that moves in a vertical direction through a cam. The cutting mechanism is also controlled by a cam. This type of machine can only make a simple torsion spring. The domestic model is Z56-25. Only torsion springs with a wire diameter of 2.5mm or less can be produced.

The machine used to make the snap ring is called a press brake and is in the form of a multi-station. The wire is fed into the die and then bent into the desired shape through a series of clamp actions. The key to this type of machine tool is the design and manufacture of molds. When changing varieties, molds and tools must be replaced. Adjustment takes a long time.

Due to the ever-changing varieties and shapes of springs, the mechanical energy of springs is required to meet the requirements of easy adjustment and suitable for many varieties. The new special-shaped spring forming machine has been able to complete a series of complex actions from wire feeding to coil spring, bending, etc., and finally complete the hook and loop processing of the spring tail. It can not only roll compression springs, but also can be applied freely to tension springs, torsion springs, double-ended torsion springs, double-layer springs, and various circlips. There are many types of foreign special-shaped spring forming machines, the main models are ZO type and FTU type of West German WAFIOS company, MS type and AT type of French TC and HP company, MCF type of Japan Okuno Co., Ltd., and Japan Xinxing Co., Ltd. The VF-800, etc.

Common Materials For Special-Shaped Springs