Recommendations for the metal spring industry

At present, the widely used metal spring stress and deformation calculation formula is derived from material mechanics. Without a certain amount of practical experience, it is difficult to design and manufacture high-precision springs, along with the progress of design stress, the past experience is no longer used.

In recent years, the design method of the finite element of spring has entered the practical stage, and a lot of practical speeches have been made, such as the effect of the spiral angle on spring stress, the relationship between stress and fatigue life calculated by finite element method, etc. The comparison of stress is calculated using the current design method and the finite element method is analyzed. For the same structure of the spring, under the same load, it can be seen from the figure, the effective ring less or the helix angle of the high stress spring stress pressure, the results of the two methods are relatively large difference. This is due to the increase of the spiral angle, increase the load eccentricity, so that the outer diameter of the spring or lateral deformation is larger, so the stress is relatively large. The current design calculation method can not be reflected locally, and the law of finite element can be more local reaction.

For example, as the design stress of the metal spring progresses, the helical angle increases, which shifts the exhaustion source of the spring from the inside of the reed ring to the outside. To this end, it is necessary to use spring precision analysis technology, the current application of a wide range of methods is finite element method. The characteristic of the vehicle suspension spring is that in addition to sufficient fatigue life, its permanent deformation should be small, that is, anti-relaxation function to be in the defined range, otherwise because of the different deformation of the spring, the body center of gravity will occur. At the same time, consider the effects of environmental erosion on their fatigue dye life.

With the increase of vehicle maintenance period, the permanent deformation and fatigue life are put forward more stringent requirements, for which it is necessary to use high-precision design methods. The finite element method can guess the effect of spring stress fatigue life and permanent deformation, and can correctly reflect the relationship between spring fatigue life and permanent deformation of the material.

Spring design has made some progress in the use of reliability technology, but to further improve, data development and accumulation is required. With the development of computer technology, at home and abroad to compile a variety of versions of the spring design program, for the metal spring technical staff to provide a convenient premise for the development of different. The design program is used to complete the development of the curved clutch spring and drum suspension spring, which are more difficult to design. With the development of spring application technology, but also to the designers put forward a lot of need to pay attention to and solve the new topic.

Such as materials, pressure and shot treatment on the effects of fatigue and relaxation function, design is difficult to cut when calculating, rely on experimental data to determine. Also, according to the current design formula to find the number of laps, the spring stiffness made than the design stiffness value is smaller, need to reduce the effective number of laps, in order to meet the design requirements. The current design trend of high-volume production products, taking the maximum working stress and fatigue life requirements as an example.

Spring finite element analysis method, although the high level of spring technology in the country has entered practical, although China has the technical development of this aspect, but has not yet formed a practical model. In addition, an optimized design has been introduced in the design process of the spring. The structure of the spring is simple, the function is simple, the influence structure and function of the parameter variables are less, so the designer early use of the analysis method, the illustration method or the illustration analysis method to find the best design, and achieved some results.

With the development of computing technology, the optimization design of non-linear planning by computer has achieved effective reliability design is a series of analysis and design techniques used to ensure the reliability of the products designed, and its function is to make the design edited on the basis of the possible failure of the products, so that the designed products reach the defined reliability target value, which is a supplement and perfection of the traditional design methods.

6 advantages of computer spring machines in China

First, the innovation ability of the strongest in the country.
Cam-free spring machine in China, the computer is the first, broke the traditional cam drive molding spring model, boldly introduced the first generation, the second generation, the third generation, is now the sixth generation of products cm-10-235 machine, from the original 3 axes, 4 axes, 6 axes, optimized to the current 10 or 12 axes, from the original non-turning line to the current turning line, from a single seat to the current double slide, from the original 2 mm, 4 mm Let customers more satisfied, so, there will also be a small number of voices, said that the computer is not good, such as the strength of the accuracy of stability and so on, it is because 4 years ago, indeed, the technology is not mature, but now, the computer spring machine has been exported to Japan, Korea, has become an internationally competitive spring machine brand, are the result of continuous innovation, at the same time, the industry also has some imitators, they always walk behind the computer, because the core competitiveness of the computer is in technology innovation, is the This is currently difficult for other manufacturers to do.

 

Second, servo motor shaft stake in the number of.
Computer spring machine is 10 axis or 12 axis, according to customer requirements, 10 axes can also be added to 11 axes, and other models in the country, generally 2 axes, 3 axes, 4 axes, 6 axes, 8 axes vary, the number of machines, his intelligence is quite enhanced, to do spring debugging more convenient, multi-axis is the development trend of spring machinery.

 

Third, debugging is the most convenient to use.
Convenience is also a kind of value, computer spring machine does not use the row cam, each servo motor is independently controlled by the computer system, each arm can adjust the position at will, basically no possibility of hitting the knife, transfer technician easy to learn to use, this is one of the core selling points of the computer, his arm stroke can be set freely according to product needs, no invalid action, so speed will also be improved, especially suitable for spring varieties of manufacturers.

 

Fourth, the production of special spring capacity is the strongest.
Computer spring machine because of the characteristics of multi-axis with free hand and translposuction function, decided that he produces special spring and wire productadvantage, because at present many angle more than extra long or spin ratio is very small products, cam spring machine is no way to form at once, computer spring machine can play its robot left and right movement, translline 320 degrees molding, the characteristics of the arm free arrangement, plus appropriate auxiliary tools, you can do the traditional cam machine can not be molded once, he can not be a single form. This is the core advantage of a computer spring machine.

 

Fifth, the highest frequency of participation in the exhibition.
Computer spring machine belongs to the high technical content of spring equipment, the first time to see people feel very magical, in the exhibition is very attractive to the audience, the computer every year in The domestic Guangzhou, Chongqing, Ningbo, Wuxi, Qingdao, Wenzhou, Shanghai and other places have exhibitions, convenient for friends in the industry to visit to negotiate. Basically, the number of times a year to participate in well-known industry exhibitions reached more than 6 times.

 

Exports abroad the most.
So far, the export of computer spring machines are: the United States, Japan, South Korea, Brazil, Turkey, Lebanon, India, Venezuela, Poland, and Vietnam, and really become china’s largest exporter of spring machines.

The principle of a computer spring machine

A computer spring machine is a special equipment used to produce springs. The key board, as an interactive interface of a human machine, plays the function of input operation command, editing spring processing program and modifying data, and plays an important role in the operation and control of the computer spring machine. In practical application, in order to facilitate operation, it is necessary to make the key plate chinese character and direct, which makes it unlikely to use the standard PC keyboard, so the development of a cheap and universal keyboard is very realistic.

In the PC, keyboard and host communication is ps/2 protocol, because the computer spring machine controller is a standard industrial PC controller, with a standard keyboard interface, in order to make the design simple and universal, here to use this standard keyboard interface, and the use of PS/2 protocol for keyboard and spring machine communication, design when using the microcontroller AT89S51 as a key plate processing key ingrate key recognition and data reception and transmission.

Spring machine key plate using the film panel switch form, film panel switch design is simple, easy to operate, easy to place, directly attached to a surface can be used, coupled with its water-proof and dust-proof performance, very suitable for industrial control applications. For a spring machine’s keyboard, the keys consist of three types: number keys, function keys and edit keys. The digital key of the spring machine is the input of the number, the function key corresponds to the operation command of the spring machine, and the edit key is used for editing the spring processing program, such as clear, save, etc.

A reasonable design of the key layout, universal spring machine and operation of convenience and reliability directly related, for the layout of specific keys, should consider the ease of operation and layout of the beautiful, the film panel under the row array circuit using a single-sided flexible circuit board (FPC) production, universal spring machine circuit protrusion form to ensure the feel of the keys.

What are the categories of metal springs by force nature

According to the force nature, the metal spring can be divided into stretch inglisal spring, compression metal spring, twisting metal spring and curved metal spring;

Ordinary cylindrical metal spring because of the simple manufacture, and according to the load conditions to make a variety of types, simple structure, so the application is the most widely.

Metal spring manufacturing data should generally have high elastic limit, fatigue limit, impact toughness and good heat treatment performance, commonly used with carbon metal spring steel, alloy metal spring steel, rust-free metal spring steel and copper alloy, nickel alloy and rubber.

The manufacturing methods of metal springs are cold roll and hot roll. Metal spring wire diameter is less than 8 mm of the general cold roll method, greater than 8 mm with hot roll method. Some metal springs are also subjected to strong pressure or shot treatment after being made, which can improve the carrying capacity of the metal spring.

Compression metal spring is to accept the pressure of the spiral metal spring, the data section used is mostly circular, but also with a rectangular and multi-stranded steel roll of the metal spring is generally equivalent to the distance of the compressed metal spring shape is: cylindrical, conical, medium convex and medium concave and a small number of non-circular.

There is a certain gap between the circle and the ring of the compressed metal spring, and when the outer load is carried out, the metal spring shrinks and deforms, and stores the deformation energy. What is a torque metal spring? The torque spring uses the lever principle to twist or rotate the elastic data of the soft and toughness of the material, so that it has great mechanical energy.

Stretching metal spring is a spiral metal spring that accepts axial pull, and stretch editing metal spring is generally made of circular cross- material. When not under load, the ring and the ring of the stretch ingon spring are generally tight without a gap.

The modification theory of the metal spring

Generally speaking, soft springs provide better comfort and maintain better track record when traveling through more rugged roads. But in the general road surface, but will cause the suspension system large up and down swing, affecting the control. In cars equipped with good aerodynamic components, soft springs can cause high changes in speed, resulting in different handling characteristics at low speedand and high speed. Tell us about the theory of spring modification.

The spring of the metal spring suspension system is most commonly used in circle springs because of its ease of production, high performance efficiency and low price. The physical definition of a spring is to store energy, when we apply a fixed force to the spring, it will produce deformation, when we remove the force then the spring will have a tendency to restore the original shape, but the spring in the rebound of the magnitude of the soup will often exceed its original length, until there is friction resistance to slow the spring rebound after the cause of the free shock soup, which slows the work of free spring shock soup is usually the task of the shock absorber.

The general spring is called a “linear spring”, that is, when the spring is forced, its compression deformation is to follow the physics of the “Huke’s law”: F – KX, where in which F is force, K is the elastic coefficient, X is the amount of deformation. For example, a linear spring is subjected to a force of 40Kg will cause 1cm compression, after each increase of 40Kg force 1 cm will certainly increase the amount of compression. In fact, there are other pressures present in the suspended spring, even when the spring is fully extended, the spring will still be subjected to pressure so that the spring itself is fixed to the car.

In the traditional spring, shock cylinder type suspension design, the spring plays to support the body and absorb uneven road surface and other forces on the impact of the tire, and the so-called other forces here include acceleration, deceleration, braking, turning and other forces caused by the spring. What is more important is to maintain the continuous contact between the tire and the road surface during the elimination of vibration and maintain the track of the car. Improving the tyre’s contact with the road surface is our primary consideration in improving handling.

The main function of the spring is to maintain the comfort of the car and keep the tire in complete contact with the ground, using the wrong spring will cause a negative impact on the quality of the car and handling. Imagine if the spring is completely stiff, the suspension system will not work. When the car jumps on uneven road surfaces, the tires will leave the ground completely, and if this happens at acceleration, braking or turning, the car will lose track. If the spring is soft, it is very comfortable with the “sitting bottom” situation, that is, the hanging trip exhausted. If the sitting bottom condition occurs at the bend can be regarded as the spring’s elastic coefficient becomes infinite (no compressed space), the body will produce an immediate weight shift, resulting in the loss of trace.

If the car has a long shock-absorbing journey, then it may be possible to avoid the “sitting bottom” situation, but the relative body will also become very high, and a high body means a high body center of gravity, the body center of gravity of the body of the high and low on the handling performance has a decisive impact, so too soft shock absorbent will lead to handling obstacles.

If the road surface is absolutely flat, then we don’t need springs and suspension systems. If the road surface is more rugged then a soft spring is required to ensure that the tire is in contact with the road surface, while the spring travel must also increase. The hardness of the spring is determined by the degree of ruggedness of the road, the more rugged the softer the spring, but the softer is a key issue, usually this requires the accumulation of experience, but also the factory and the team of important issues.

Design and production steps of compression spring

1. According to the actual product demand, select spring material according to the standard
2. According to the product force value, compression stroke, fatigue and other requirements, determine the internal and external diameter, effective number of turns, and wire diameter range of compression spring
3. Put relevant parameters into design parameter formula
4. It is reasonable and feasible for spring manufacturer to design and produce spring

Necessary information of compression spring:
(1) Control diameter (a) outer diameter, (b) inner diameter, installation guarantee dimension (c) inner diameter of sleeve, (d) outer diameter of round rod
(2) Wire or bar size
(3) Material (type and grade)
(4) Number of turns: (a) total number of turns and (b) right or left rotation
(5) Style of ends
(6) Load at a certain deflection length
(7) Load ratio of one inch to several inches in length
(8) Maximum solid height
(9) Minimum compression height in use

The metal spring is under pressure and torsion

Compression spring is a pressure of the coil spring, it uses a material cross-section is round, but also with a rectangle and multi-stranded steel roll, precision spring is generally equivalent pitch, the shape of the compression spring is: cylindrical, conical, mid-convex and medium concave and a small number of non-circular, compression spring between the ring and the ring a certain gap, when subject to external load spring deformation, storage deformation energy.

A coil-shaped spring made of spring wire wrap. There are more types of coil springs, according to the appearance can be divided into ordinary cylindrical coil spring and variable diameter coil spring, according to the direction of the spiral line can be divided into metal spring and right-spin spring. The cylindrical coil spring is simple in structure, easy to manufacture and most widely used, and its characteristic line is straight, which can be used as a compression spring, stretch spring and torsion alt-spring.

When the load is large and the radial size is limited, two compression springs of different diameters can be used together to form a combined spring. The variable diameter coil spring has a conical coil spring, a snail coil spring, and a mid-concave coil spring. The buffering performance of the cone coil spring is good and can withstand a larger load. The worm coil spring can store more energy and withstand larger loads, but the manufacturing process is more complex. The mid-concave coil spring has a similar performance to a conical coil spring and is used for cushions and mattresses. The carrier surface of the spring wire has a circular and rectangular, etc., with a circular cross-section most commonly used.

A coil spring, a torsional spring, is a spring that withstands a torsional deformation, and its working part is also tightly wound into a spiral. The end structure of the torsion al-spring is a twisting arm that is machined into various shapes, not a hook ring. Twisting springs are often used in the balance mechanism in machinery and are widely used in industrial production such as automobiles, machine tools and electrical appliances.

The plating problem of the metal spring

1, spring plating after the diameter difference.

Reason: The spring line to be plated by the super-difference, when plating the spring surface zinc volume is not uniform.

Solution: Treat the pre-plating inspection of the plating spring, find that the super-difference line is processed in a timely manner;

2, the surface of the zinc layer in the rope, strands when there is a phenomenon of peeling;

Reason: The spring is not clean before plating, resulting in poor binding force between zinc and steel-based surface, zinc-plated spring in plating, the deposition speed is too fast, the surface of the zinc layer is rough, not dense, the use of the pre-deformation is unreasonable, resulting in scraping.

Methods to solve the zinc layer shedding method: increase the concentration of electrolytic acid wash, electrolytic alkali washing solution or increase electrolytic acid washing, electrolytic alkali washing current;

3, the surface coating is not uniform thickness;

Reason: the surface of the cathode gun head is not clean, affecting the conductivity of the spring and cathode gun, resulting in the current instability of the spring to be plated;

The method of solving the zinc layer unevenness: often clean the surface of the cathode gun head to ensure normal contact with the cathode, often adjust the zinc block with the spring to be plated, zinc block reduced to a certain extent, to be replaced often.

4, the surface coating has black imprint;

Reason: The spring surface after chemical acid wash is not rinsed cleanly, the cathode gun head is in poor contact with the spring surface, the head of the gun has black oxide stuck to the metal spring, in galvanizing when covered with zinc atoms.

The solution to the zinc layer has a black stamp: chemical acid wash to wash the spring surface clean;

Anti-corrosion treatment of metal springs

A dense protective film is created on the surface of the spring by means of a chemical reaction to prevent spring corrosion. Oxidation and phosphating are usually used.

Oxidation treatment and phosphating treatment, low cost, high production efficiency, general spring manufacturing plants are using oxidation treatment, as anti-corrosive treatment.

(1) Oxidation treatment steel oxidation treatment is also known as blue, black, boiled black. After oxidation treatment, the spring surface produces a protective magnetic iron oxide, this oxide film is generally blue or black, and sometimes black-brown. Its color is determined by the surface state of the spring, the chemical composition of the spring material, and the oxidation process.

The methods of oxidation treatment are: salty oxidation method, alkali-free oxidation method and electrolytic oxidation method. To use alkaline oxidation method as many.

Alkaline oxidation is the spring is put into the temperature of about 140 degrees C, containing oxidant sodium hydroxide solution soaked for a certain time, oxidant and sodium hydroxide and iron action, the generation of sodium iron atwhichmate acid and sodium ferrite, and then react to each other, the formation of magnetic iron oxide.

The thickness of the oxide film layer is about 0.6 to 2 m. Although the oxide film can improve the corrosion resistance of the spring, but because of the thin film, and also have pores, so its protection is poor, can only be used in the corrosive medium to work in the spring. The antiseptic properties depend on the degree of density of the oxide film and its thickness, so it is determined by the concentration of sodium hydroxide, oxidant concentration, the temperature of the solution and other factors.

In order to improve the corrosion resistance and lubrication capacity of the oxide film, the treatment before and after oxidation treatment should be strengthened. The rust, oxide skin, oil, heat-treated salt residue, surface contact layer, etc. of the spring surface shall be thoroughly removed before oxidation treatment. After oxidation treatment, usually the spring in soap solution or heavy chromite filled treatment, and then washed, blow-dry or dry with flowing warm water, and finally on the water film to replace rust-proof oil or a certain temperature of mechanical oil for oil immersion treatment.

The oxidation treatment is subject to erosion of the surface crystal boundary of some hot-rolled spring materials, which will reduce fatigue strength to a certain extent, so it should be treated with caution when picking oxidation treatment.

Traditional oxidation treatments need to be warmed. In recent years, some domestic manufacturing units also use room temperature blackening agent, it overcomes the shortcomings of the traditional blacking process, saving a lot of energy.

Blackened agent for blue-green concentrate liquefaction, no impurities, no odor, non-combustion, non-explosion, non-corrosive, transport safety.

The dilution ratio commonly used when the spring is blacked out is about 1.5.

The operation process of the black agent is relatively simple, its route is: de-oiling, rinsing, acid line, rinsing, blacking (at room temperature 2 to 5min) rinsing, water film replacement rust-proof oil. Note: be sure to put the spring workpiece on the oil to go, clean, in order to put in the room temperature agent for oxidation treatment.

The oxidation treatment is low cost, the process formula is simple, the production efficiency is high, the oxidizing film has a certain elasticity, basically does not affect the characteristic curve of the spring, so the oxidation treatment is more widely used as the form of the coil spring, spring washer and chip spring, such as anti-corrosion and decoration measures.

The quality inspection of the spring after oxidation includes appearance inspection and corrosion resistance inspection.

Knowledge of metal springs – compression springs

The reed, due to its spiral geometry, is more difficult to strengthen with its reinforcement work than the reed on the flat surface. In addition, the reinforcement effect of the transletion of the reed must be strictly evaluated to fully understand the resistance of the reed against fatigue fracture.

The reed scored in a separate delivery chain system into the blast chamber, which is equipped with a set of parallel rollers, which are reinforced while the rollers roll non-stop, driving the reeds to rotate the edge. This way of rotating allows the high-speed pellet flow through the rings of the reed seine to hit the metal surface of the ring, where the reed stress is most concentrated.

For applications with high capacity requirements, an enhanced device that can spray two reeds at the same time can be selected. The latest results are based on the original shot-reinforced equipment, combined with multiple nozzles, for more targeted, fire-focused shot treatment for specific areas of the reed (stress concentration pleasing).

The reed reinforcement can be used by a continuous pass-through shot reinforcement device for one by one reinforcement treatment, allowing the reed geometric recesse to be exposed to high-speed pellet flow. Typical models are a toss for the top of the ejection reed, with a toss on the side and a left and right side of the spray reed.

This standard reed reinforcement equipment has a pass speed of 10 ft/min and, if higher production speed is required, the number of toss can be increased and the motor frequency is adjusted. Under operating conditions, the reedist is repeatedly affected by one-way bending stress and is therefore sometimes stress-reinforced. In the process of reinforcement, the simulation reed will be “stress-reinforced” in the later use process, so that it is subjected to the direction of the load with a “static stress” at the same time, to its shot reinforcement. After the reinforcement is complete, release the additional static stress. Experiments show that stress reinforcement can further extend the service life of the reed sedifes than conventional reinforcement.