Torsion springs are helical springs. The torsion spring can store and release angular energy or by rotating the arm around the axis of the spring to statically fix a device. The ends of the torsion springs are fixed to other components that pull them back to their original position when other components rotate about the center of the spring, creating a torque or rotational force.
The turn spring is a helical spring which can store and release angular energy or by rotating the arm around the axis of the spring to statically fix a device. This type of spring is usually tight, but there is a pitch between the coils to reduce friction. They create resistance to rotating or rotating external forces. According to the application requirements, the torsion spring is designed to rotate (clockwise or counterclockwise) to determine the rotation of the spring.
Main parameter editing
d (spring wire diameter): This parameter describes the diameter of the spring wire.
Dd (mandrel maximum diameter): This parameter describes the maximum diameter of the spring shaft in industrial applications with a tolerance of ±2%.
Di (inner diameter): The inner diameter of the spring is equal to the outer diameter minus twice the wire diameter. In the working process of the torsion spring, the inner diameter can be reduced to the diameter of the spindle.
Inner diameter tolerance ± 2%.
De (outer diameter): equal to the inner diameter plus twice the wire diameter. During the working process of the torsion spring, the outer diameter will become smaller and the tolerance (±2%±0.1)mm.
L0 (natural length): Note: The natural length will be reduced during work, with a tolerance of ±2%.
Ls (support length): This is the length from the shaft of the spring ring to the spring support, tolerance ± 2%.
An (maximum torsional angle): The maximum torsion angle of the torsion spring, tolerance ± 15 degrees.
Fn (maximum load): The maximum force allowed on the torsion spring support, tolerance ± 15%.
Mn (maximum torque): Maximum allowable torque (Newtons*mm), tolerance ±15%.
R (spring stiffness): This parameter determines the resistance of the spring when it is working. Newton * mm/degree, tolerance ± 15%.
A1 & F1 & M1: (torsional angle, load and torque): The following formula can calculate the torsional angle A1 = M1/R. Knowing the load, the torque can be calculated using the formula M = F*Ls.
Supporting position: The torsion spring supports four positions: 0°, 90°, 180° and 270°
Spiral direction: The right-hand spring rotates counterclockwise and the left-hand spring rotates clockwise. All our springs can be produced in two directions.
Spring Part No. : Each spring has a corresponding number : Category . (De * 10) . (d * 100) . (N * 100) . For right-handed springs, the relevant symbol is D. For left-handed springs, the relevant notation is G. The N mark indicates the number of turns. For example: D.028.020.0350 The part number represents the right-handed torsion spring, the outer diameter is 2.8 mm, and the stainless steel wire diameter is 0.9 mm, with a total of 3.5 turns.
Performance factor editing
Performance factor: Spring stiffness, maximum deformation, maximum load and direction of rotation.
Spring stiffness refers to the angular return torque produced by angular displacement per unit.
The maximum deformation is the maximum deformation before the spring is damaged.
Torsion springs are right-handed, left-handed and double-handed.
Application editing
Torsion springs are mechanical parts that work with elasticity. Generally made of spring steel. Used to control the motion of parts, ease impact or vibration, energy storage, measurement of force, etc. Widely used in computers, electronics, home appliances, cameras, instruments, doors, motorcycles, harvesters, automobiles, and other industries!
The main equipments for production equipment are: digital control multi-functional computer coil spring machine, mechanical automatic coil spring machine, grinding spring machine, heat treatment equipment, large hot coil spring production line, and quality inspection equipment.
Breakage Analysis
Cause of fracture
The torsion spring locally generates abnormal microstructure martensite at the initial stage of electrogalvanizing. Due to the presence of martensite stress, the internal stress caused by hydrogen in the spring matrix during pickling and electroplating causes the torsion spring to crack and lag. fracture. The torsion spring produced by the spring wire found a small amount of spring break before assembly by the customer, as shown in Fig. 1, with the position of the fracture as indicated by the arrow.
fracture
fracture
Torsion spring production process: Spring wire → coiled spring → low temperature stress annealing → high temperature oil removal → water washing → diluted hydrochloric acid washing → water washing → electro-galvanizing (80 min) → water washing → blanking → dehydrogenation treatment (200 °C, 4 h) → Feeding → Washing → Color Passivation → Washing → Drying → Cutting → Inspection.
Through the analysis of the metallographic structure and microhardness, the metallographic structure of the spring at and near the crack is martensite. Due to the large stress in the martensite structure, stress concentration regions are easily formed, and the martensitic structure is more sensitive to hydrogen embrittlement than bainite and pearlite, and is prone to hydrogen-induced intergranular fracture [4 - 5]. The formation of martensite should be due to the arc generated between the spring and the electrode at the initial stage of electrogalvanization, which causes the local spring to generate electric burns. The instantaneous high temperature at the electric burn site exceeds the austenitizing temperature, and then it is quenched in the electroplating solution to make the twist. The spring produces an abnormal martensite structure. In addition, torsion springs in the pickling and electro-galvanizing process inevitably have a hydrogen evolution and hydrogen-permeation process [6]. Part of the evolved hydrogen escapes from the surface as hydrogen molecules, and the other part adsorbs on the surface of the spring and diffuses to the interior of the spring matrix. . Hydrogen atoms that enter the matrix gradually accumulate at dislocations, grain boundaries, inclusions, etc., and combine to generate hydrogen molecules. As the concentration of hydrogen molecules continues to increase, the lattice is distorted and a large internal stress is generated [7]. Due to the presence of higher concentrations of hydrogen in the spring matrix and martensite interactions that occur during the electrogalvanizing process, the torsion springs are cracked and cause delayed fractures. Cracks and fractures cause galvanized shedding between the coating and the substrate.
Production process improvement suggestions:
(1) When the torsion spring is pickled to prevent over-etching, the corrosion inhibitor added in the pickling solution must have a strong corrosion inhibition effect and a strong hydrogen permeability resistance.
(2) In the electrogalvanizing process, strict operating procedures are adopted to prevent the occurrence of martensite; under the premise of guaranteeing the quality of plating, the electrogalvanizing time should be shortened as much as possible.
(3) After electrogalvanizing, reduce the interval between plating and dehydrogenation as much as possible, and use an effective hydrogen removal process.
(4) Improve electrode protection measures to avoid arcing.