The manufacturing process of springs mainly includes the following important links:
I. Design
The design of springs is the key starting step. Designers need to fully consider factors such as the use environment, load-bearing capacity, working frequency, and installation space of the spring. For different application scenarios such as automotive suspension systems, mechanical industries, and electronic equipment, the design parameters of springs will be very different. For example, in the design of automotive suspension springs, factors such as vehicle weight, driving road conditions, and requirements for comfort and handling need to be considered to determine parameters such as the stiffness, diameter, and number of turns of the spring. At the same time, advanced computer-aided design software should be used for simulation analysis to ensure that the spring can work safely and reliably under various working conditions.
II. Material selection
Appropriate materials are the basis for the performance of springs. Common spring materials include spring steel (such as 65Mn, 55Si2Mn, etc.), stainless steel (such as 304, 316, etc.), copper alloys, etc. Spring steel has high strength and elastic limit and is suitable for occasions with large loads; stainless steel springs have good corrosion resistance and are suitable for humid and corrosive environments; copper alloy springs have good electrical conductivity and thermal conductivity and are suitable for some special electronic and electrical application occasions. When selecting materials, comprehensive considerations should be made based on factors such as the use requirements and cost of the spring. For example, for springs working in high-temperature environments, special spring steel materials with high temperature resistance may need to be selected.
III. Processing
- Cold coiling: For springs with a small diameter, the cold coiling process is usually used. The spring material is coiled into the required shape by a spring coiling machine at room temperature. The cold coiling process has the advantages of high production efficiency, low cost, and good spring surface quality. During the cold coiling process, the parameters of the spring coiling machine, such as winding speed and tension, should be controlled to ensure the dimensional accuracy and shape accuracy of the spring.
- Hot coiling: For springs with a large diameter and high strength, the hot coiling process is generally used. First, the spring material is heated to a certain temperature to make it soften, and then it is coiled into shape by a spring coiling machine. After hot coiling, the spring needs to undergo heat treatment processes such as quenching and tempering to improve the strength and elasticity of the spring.
- Stamping: For some springs with special shapes, such as disc springs and ring springs, the stamping process can be used. The sheet or strip is stamped into the required shape by a stamping die. The stamping process has the advantages of high production efficiency, low cost, and high dimensional accuracy.
- Welding: For some large springs or springs with special structures, the welding process may be required. The various parts of the spring are welded together to form a whole. The welding process needs to select an appropriate welding method and welding material to ensure the welding quality.
IV. Heat treatment
Heat treatment is an important link in determining the performance of springs. The main heat treatment processes include quenching, tempering, annealing, etc.
- Quenching: The spring is heated to a certain temperature and then rapidly cooled to make the spring material obtain high hardness and high strength. Quenching can improve the elastic limit and fatigue strength of the spring. However, there is a large internal stress in the spring after quenching, and tempering treatment is required.
- Tempering: The quenched spring is heated to a certain temperature, held for a period of time, and then cooled. Tempering can eliminate the internal stress in the spring and improve the toughness and elasticity of the spring. The selection of tempering temperature and time should be adjusted reasonably according to the material and performance requirements of the spring.
- Annealing: For some springs that need cold working, such as cold coiled springs, annealing treatment may be required before processing. Annealing can reduce the hardness of the spring material and improve its plasticity, making it easier to process. The spring after annealing may also undergo recrystallization during use, thereby improving the toughness and elasticity of the spring.
V. Surface treatment
- Galvanizing: Galvanizing is a common spring surface treatment method. The spring is immersed in galvanizing solution to form a zinc layer on the spring surface. Galvanizing can improve the corrosion resistance of the spring and prolong the service life of the spring. The surface of the galvanized spring is smooth and has a high aesthetic degree.
- Chromium plating: Chromium plating can make the spring surface obtain higher hardness and corrosion resistance. The surface of the chromium-plated spring is bright and has good decorative properties. However, the chromium plating process has a high cost and causes certain pollution to the environment.
- Painting: For some springs with high appearance requirements, painting treatment can be used. Painting can make the spring surface obtain different colors and glosses and improve the aesthetic degree of the spring. At the same time, painting can also play a certain role in corrosion prevention.
- Blackening: Blackening is a chemical treatment method. The spring is immersed in a blackening solution to form a black oxide film on the spring surface. Blackening can improve the corrosion resistance and wear resistance of the spring, and at the same time, it can also make the spring surface have a certain decorative property.
VI. Inspection
- Dimensional inspection: Use measuring tools such as calipers and micrometers to inspect the dimensional parameters of the spring, such as diameter, length, number of turns, and pitch, to ensure that the dimensions of the spring meet the design requirements.
- Mechanical property inspection: Use equipment such as tensile testing machines and torsion testing machines to inspect the mechanical properties of the spring, such as elastic coefficient, yield strength, and fatigue strength. Mechanical property inspection is an important link in ensuring spring quality. Only springs that meet the requirements can be put into use.
- Surface quality inspection: Check whether there are defects such as cracks, scratches, and rust on the spring surface. Surface quality inspection can be carried out by methods such as visual inspection, magnifying glass inspection, and flaw detector inspection.
VII. Packaging
Package the inspected qualified springs to facilitate transportation and storage. Common packaging methods include plastic bag packaging, carton packaging, and wooden box packaging. When packaging, pay attention to protecting the spring to avoid damage to the spring during transportation and storage. At the same time, mark information such as the specification, model, and quantity of the spring on the packaging for easy management and use.
