Like most other basic mechanisms, metal springs existed for a long time in the Bronze Age. Even metal and wood are used as structural parts of flexible bows and arrows and military catapults. During the Renaissance, accurate clocks and watches made accurate clockwork inevitable for the first time. 14th century witnessed the development of revolutionary astronomical navigation and accurate clocks. The exploration of the world and the conquest of European colonial powers have continuously provided impetus for the watchmaker's "science and art". Another field of firearms has promoted the development of springs. /kloc-during the industrial revolution in the 0/8th century, large, accurate and cheap springs were put forward. In view of the clockmaker's clockwork is mostly made by hand, the mass production material of clockwork is piano steel wire or similar material. Advanced manufacturing methods make springs everywhere. Computer control line and sheet bending machine allow customized spring processing, which is obviously a special machine. The spring is just an accumulator. It has the function of storing energy, but it cannot be released slowly? [ 1]?

Spring compression spring tension spring torsion spring tower spring (14 sheets)

When releasing, the function of slow release should be realized by "spring+large transmission ratio mechanism", which is more common in mechanical watches. Springs have been used for a long time, and ancient bow and crossbow is two kinds of springs in a broad sense. Strictly speaking, the inventor of the spring should be British scientist robert hooke. Although the helical compression spring had appeared and been widely used at that time, Hooke put forward Hooke's law-the elongation of the spring is proportional to the force. According to this principle, a spring scale using spiral compression spring appeared in 1776. Soon, the clockwork made for clocks and watches according to this principle was also invented by Hooke himself. The spring that conforms to Hooke's law is the real spring. The belleville spring was invented by belleville, a Frenchman. It is a washer spring with truncated cone section, which is made of metal sheet or forging blank. After the emergence of modern industry, in addition to disc springs, new types of springs have appeared, such as gas springs, rubber springs, scroll springs, die springs, stainless steel springs, air springs and memory alloy springs. ? [ 1]?

Industry model

For the spring industry, the supply of low-grade ordinary springs exceeds demand for a long time, and the supply of high-grade products (high strength, high stress, different parts and special materials) exceeds demand. The output of China spring industry is saturated. According to experts' statistics, the annual output of springs in China has reached 4 billion pieces, and there are more than 2 1 category and 1 600 varieties of various spring products, mainly including valve springs, suspension springs, diaphragm springs, damping springs, hydraulic springs, oil pump springs, disc springs, high-temperature springs, clamp springs, tension springs and torsion springs. The spring industry developed rapidly during the Eighth Five-Year Plan and the Ninth Five-Year Plan, especially in Shanghai, Tianjin, Guangzhou, Shandong, Changchun and Chongqing, which was better than other industries in general. Cars, motorcycles, mopeds, internal combustion engines, electric power, instruments, etc. It will also develop, and the development of these industries will drive the development of the spring industry. Faced with the macroeconomic situation, the long-term accumulated contradictions in the industry, such as low product quality, loose organizational structure and weak development ability, are further highlighted. From a deep-seated perspective, it is mainly the market, system and mechanism. Industry insight researchers believe that with the transformation of the national economy from the seller's market to the buyer's market, some deep-seated contradictions, especially the structural contradictions accumulated over the years, have become increasingly prominent. At present, the unreasonable industrial structure is as follows: overcapacity in some industries and unreasonable product structure; The technical structure is unreasonable, and the equipment level of major industries is low; The enterprise organization is small and scattered, lacking competitive strength and advantages, and the regional structure is similar, which fails to reflect comparative advantages and cooperation benefits. ? [ 1]?

develop

Although the spring industry is a small industry in the whole manufacturing industry, its role cannot be underestimated. The country's industrial manufacturing industry and automobile industry should be accelerated, and the spring industry, as one of the basic parts, needs an ultra-early development to adapt to the rapid development of the whole country's industry. In addition, the expansion of the scale and variety of spring products and the improvement of the quality level are also the needs of upgrading mechanical equipment and improving the performance of supporting hosts. Therefore, spring products play an important role in the industrial development of the whole country. Daily necessities industry and hardware industry, including lighters, toys, locks, door hinges, fitness equipment, mattresses, sofas, etc. The demand for springs is the largest in quantity, tens of billions, with low technical requirements and very low price. Generally, they are produced by small spring factories scattered all over the country, which have unique advantages in cost and it is difficult for large spring factories to compete with them. Therefore, new spring enterprises are born from time to time. In the future, the market demand will increase by 7%~ 10% every year. After China's entry into WTO, the export volume of daily-use hardware products increased significantly, which led to the demand for springs. However, due to the influence of international market demand and trade barriers, the international market has its uncertain side. ? [ 1]?

Elastic force formula

edit

F=kx, f is elastic force, k is stiffness coefficient (or obstinacy coefficient), and x is the length of spring extension (or compression). Example 1: If a spring with a stiffness coefficient of 100N/m is pulled with a force of 5N, the spring will be extended by 5cm. Example 2: When the spring is pulled by 10N, the total length is 7cm, and when it is pulled by 20N, the total length is 9cm. Stretch 3cm, what is the force? ? [ 1]?

Structural classification

edit

According to the mechanical properties, springs can be divided into tension springs, compression springs, torsion springs and bending springs, disc springs, ring springs, leaf springs, spiral springs, truncated cone scroll springs and torsion bar springs, and can be divided into cold spiral springs and hot spiral springs according to the manufacturing process. Ordinary cylindrical springs can be made into various types according to the load because of their simple manufacture, simple structure and wide application. Generally speaking, the spring manufacturing materials should have high elastic limit, fatigue limit, impact toughness and good heat treatment performance. Commonly used are carbon spring steel, alloy spring steel, stainless steel spring steel, copper alloy, nickel alloy, rubber and so on. The manufacturing methods of springs include cold coil method and hot coil method. Generally, the diameter of spring wire by cold rolling method is less than 8 mm, and that by hot rolling method is greater than 8 mm. Some springs must be punched or shot peened after being made, which can improve the bearing capacity of the springs. ? [ 1]?

Springs can be divided into the following six categories:

1, torsion spring, is a kind of spring that bears torsional deformation, and its working part is tightly wound into a spiral shape. The end structure of the torsion spring is a torsion arm processed into various shapes, not a hook. Torsion spring uses the lever principle to make the elastic material with soft and high toughness twist or rotate, which makes it have great mechanical energy. 2. Tension spring is a spiral spring that bears axial tension. When there is no load, the coil of the tension spring is usually tight and there is no gap. 3. The compression spring is a spiral spring that bears axial pressure. The cross section of the materials used is mostly round, but also rectangular and multi-strand steel. Springs are usually equally spaced. The shapes of compression springs are: cylindrical, conical, convex-concave and a small number of non-circular. There will be a certain gap between the coils of the compression spring. When subjected to an external load, the spring contracts and deforms to store deformation energy. 4. Progressive spring, which adopts the design with inconsistent thickness and density, has the advantage that when the pressure is not great, it can absorb the ups and downs of the road surface through the part with lower elastic coefficient to ensure the ride comfort. When the pressure increases to a certain extent, the thicker part of the spring plays the role of supporting the car body, but this kind of spring has the disadvantages of indirect control and poor accuracy. 5. Linear spring, the thickness and density of linear spring from top to bottom are unchanged, and the elastic coefficient is fixed. This kind of spring can make the vehicle obtain more stable and linear dynamic response, which is beneficial to the driver to control the vehicle better. Mostly used in performance-oriented modified cars and competing cars, the disadvantage is of course that comfort is affected. 6. Short springs The shorter the short springs, the more? [ 1]?

Leaf spring with air cushion

Short and thick, combined with short springs, can effectively reduce the center of gravity of the car body, reduce the roll when cornering, make cornering more stable and smooth, and improve the cornering maneuverability of the vehicle. However, the damping setting of the original shock absorber tends to be comfortable, so the matching between the short spring and the original shock absorber is not very stable, and the rebound and compression of the short spring can not be effectively suppressed. Driving on a bumpy road will give you an uncomfortable feeling of jumping. In the long run, the life of the shock absorber will be greatly shortened, and oil leakage may occur. Of course, these conditions are relative. If you drive everyday, the damage will not be so serious. Try not to drive violently. After all, the original shock absorber can't bear the pressure of high load. ? [ 1]?

torsion spring

Torsion spring utilizes the lever principle, through the elasticity of materials.

torsion spring

The torsion or rotation of soft and tough elastic materials gives them great mechanical energy. It is a spring subjected to torsional deformation, and its working part is also closely surrounded or separately surrounded by coils. The end structure of the torsion spring is processed into various shapes of torsion arms, from single torsion to double torsion, and even the deformation of various torsion bars can be modeled according to the design. Torsion springs are commonly used in mechanical balancing mechanisms and are widely used in industrial production such as automobiles, machine tools and electrical appliances. ? [ 1]?

compression spring

Compression spring (compression spring) is a spiral spring that bears axial pressure. Spring no.1

compression spring

Generally, it can be divided into equal pitch spring and variable pitch spring. The shapes of compression springs are cylindrical, conical, convex and concave, and a few are non-circular. There is a certain gap between the coils of the compression spring. When subjected to an external load, the spring contracts and deforms to store deformation energy. Variable pitch springs are becoming more and more common, not only constant pitch springs, but also variable pitch springs can play different roles in different environments. ? [ 1]?

Carbon nano-spring

The diameter of carbon nanotube spring can reach several hundred microns and the length can reach several centimeters. Its spin structure has a broad application prospect, which is expected to be used in the fields of retractable conductors, flexible electrodes, miniature strain sensors, supercapacitors, integrated circuits, solar cells, field emission sources, energy-consuming fibers and so on. It makes it possible to prepare carbon nanotube electronic devices visible to the naked eye, and it is also expected to be applied to medical devices, such as tension sensing bandages. This new structure can also be developed into multifunctional carbon nanotube fiber composites for utilization. ? [ 1]?

extension spring

Tension spring (tension spring) is a spiral spring that bears axial tension and is generally made of circular cross-section material. When there is no load, the coil of the tension spring is usually tight and there is no gap. It is widely used in machines and instruments to control the movement of parts, store energy and measure force. Its hook forms include side hook tension spring, long hook tension spring, English hook tension spring, German hook tension spring, semi-circular hook tension spring, duckbill hook tension spring, etc., and the materials are stainless steel, piano steel, high carbon steel, phosphor copper, beryllium copper, oil tempered alloy spring steel, etc. ? [ 1]?

Leaf spring with air cushion

Air spring is to add pressurized air into a flexible closed container to make use of the compressibility of air.

spring

At present, a nonmetallic spring with elastic function can be roughly divided into two types: bag type and membrane type. Air spring has excellent elastic characteristics, which can greatly improve the riding comfort of high-grade vehicles and thus greatly improve the running comfort of vehicles, so air spring has been widely used in automobiles and railway locomotives. In addition, compared with ordinary steel springs, air springs have many advantages, so they are also used in some mechanical equipment and precision instruments. [ 1]?

manufacturing process

manufacturing equipment

As an important part in the industrial system, springs are used in a large amount and in a wide variety, so the production of springs has been made by hand and gradually moved towards automation. In China 90 years ago, there were few mechanical equipment specialized in producing springs in the spring industry. With the increasing expansion of the spring market, professional spring equipment enterprises gradually entered China, such as Northeast Spring Machinery (Ding Qiao) and Hong Guang (KHM), and gradually occupied the mainstream spring production market. Northeast EN502 universal machine? [ 1]?

Spring manufacturing equipment

, is the use of proprietary mechanical mechanism, convenient and fast production of various springs, special-shaped elastic elements.

spring

Hong Guang's equipment is a high-speed equipment for producing compression springs and tension springs. There are also many professional spring equipment manufacturers abroad, such as Wafios and MEC (now ORII &; MEC) and so on. Domestic production of large-scale spring numerical control hot coil machine is still blank. Although the spring industry is a small industry in the whole manufacturing industry, its role cannot be underestimated. The expansion of production and sales scale, the increase of varieties and the improvement of spring quality level are also the needs of updating mechanical equipment and improving the performance of supporting main engine. Therefore, spring products have played an important role in the industrial development of the whole country. Since the reform and opening up, with the economic globalization and the establishment of China's manufacturing power status, the supporting demand for springs has surged. In addition, the investment in spring planting is not high, the technical threshold is low, and the investment recovery is fast. Since 1980s, the number of spring production enterprises has increased rapidly. As of? [1] At the end of 2010, there were 724 enterprises above designated size engaged in spring manufacturing in China, with 654.38+10,000 employees. In 20 10, the sales revenue exceeded 30 billion yuan, and the total profit exceeded 654.38+06 billion yuan. Spring is a very competitive product. In the market, domestic enterprises with low-end products have cost advantages and certain competitiveness in price, while foreign capital and joint venture technology with high-end products have advantages. Cutting-edge products, such as elastic stents for cardiovascular diseases, are almost monopolized by foreign medical giants, and domestic enterprises have nothing to do. Automobile spring is the most competitive field in domestic and foreign enterprises' market, and domestic and foreign enterprises have their own strengths, so it is difficult to compete. The spring industry has gradually entered the industrial chain competition from the past price war and service competition, and completed the industrial chain by standardized means. Although the standard system of this industry is relatively perfect, it is far behind the market demand because it was formulated earlier, especially compared with developed countries such as Japan, Europe and America, the current national standards and industry standards are still low, which leads to the weak competitiveness of domestic spring products in the international market. Therefore, the introduction of new industry standards in line with international standards as soon as possible is the primary problem that the industry needs to solve. During the "Twelfth Five-Year Plan" period, China's automobile, railway, instrumentation and other industries will maintain rapid and stable development thanks to relevant national policies and related industrial revitalization plans. In addition, some emerging industries, such as conventional weapons, nuclear power and aircraft manufacturing, all need the participation of springs. With the increasing national strength of China, the investment in national defense science and technology is increasingly abundant, which is also an important aspect of business opportunities in the spring industry. Under the background of good external environment and steady growth of downstream demand, China spring industry will maintain rapid and stable development. It is estimated that by the end of the 12th Five-Year Plan, that is, 20 15 years, the sales of China spring industry is expected to reach 60 billion yuan. ? [ 1]?

cold forming

1) One-time automation capability of cold forming process. The cold forming machine has been developed to 12 claw. The steel wire in the range of (0.3 ~ 14) mm can be formed at one time on the eight-claw forming machine. The development direction of molding process equipment: ① improving the molding speed, the main development trend is to improve the molding speed of equipment, that is, consumption efficiency; (2) by improving the fineness of equipment parts, strengthening the heat treatment effect and improving the durability of equipment; ③ Add a length sensor and a laser range finder to stop the automatic closed-loop control manufacturing process of the CNC molding machine. 2) Cold forming process range. The maximum specification of large wire diameter spring winding machine is 20mm =2000MPa, and the winding ratio is 5. The cold forming process of micro-spring and eccentric spring with variable diameter or equal diameter material still has limitations. ? [ 1]?

Heating forming

1) the speed of thermoforming process. Only CNC2 axis hot spring coiler is used to form (9~25)mm specifications in China, and the highest speed is 17 pieces/minute. Compared with rich countries, there is a big gap. 2) Control ability of large spring hot forming process. Because there is only CNC2 axis hot spring coiler, there are three directions missing in shape control, and the accuracy is poor. Moreover, there is no automatic bar rotation control and adjustment mechanism, so the forming process and ability of hot coil spring are low. Therefore, the accuracy of the spring and the degree of external oxidation decarbonization are also low. [ 1]?

Spring function

strong function

① Control the movement of machinery, such as valve spring in internal combustion engine and control spring in clutch. (2) Absorb vibration and impact energy, such as buffer springs under cars and trains, damping springs in couplings, etc. (3) storing and outputting energy as power, such as clock springs and springs in firearms. ④ Used as force measuring elements, such as dynamometers and springs in spring scales. The ratio of spring load to deformation is called spring stiffness. The greater the stiffness, the harder the spring. Spring is an elastic element widely used in mechanical and electronic industries. When it is loaded, it can produce large elastic deformation and convert mechanical work or kinetic energy into deformation energy. After unloading, the deformation of the spring disappears and returns to its original state, and the deformation energy is converted into mechanical work or kinetic energy. ? [ 1]?

Measurement function

We know that within the elastic limit, the extension (or contraction) of the spring is directly proportional to the external force. Make use of this characteristic of spring to make a spring scale. ? [ 1]?

Reset function

The spring is deformed under the action of external force, and can be restored after the external force is removed. Many tools and equipment are reset by using the characteristics of springs. For example, the hinges of many building doors are equipped with return springs, which will automatically reset when people enter or leave the back door. People also use this function to make automatic umbrellas, mechanical pencil and other items, which is very convenient. In addition, all kinds of buttons and keys also need return springs. ? [ 1]?

Driving function

Mechanical clocks and wind-up toys are driven by winding. When the spring is tensioned, it will bend and deform, storing some elastic potential energy. After release, the elastic potential energy is converted into kinetic energy, which is driven by the transmission device to rotate. Toy guns, starting guns and military guns also work by using a property of springs. ? [ 1]?

Buffer function

A spring is installed between the locomotive frame and the wheel, and the elasticity of the spring is used to slow down the bump of the vehicle. ? [ 1]?

Vocal function

When air flows out of the spring holes of harmonica and accordion, it impacts the reed, which vibrates and makes a sound. ? [ 1]?

Compaction function

Observing various electrical switches, we will find that one of the two contacts of the switch must be equipped with a spring to ensure that the two contacts are in close contact and conduct well. If the contact is poor, the resistance at the contact will increase, and the heat generated when the current passes will increase, which will cause the metal at the contact to melt in severe cases. Springs are installed on the two metal posts of the bayonet cap, and the contact is good; As for the central metal piece of the screw cap and all the inserted metal pieces of the socket, they are reeds, and their function is to keep the two sides in close contact, thus maintaining a good state. In the cassette tape, there is a phosphor bronze reed, which makes the magnetic head in close contact with the tape by using the elastic force generated when the tape is bent and deformed. There is a long spiral spring in the stapler. On the one hand, it is used to push the staple tightly, and on the other hand, it sends the back staple to the front when the front staple is pushed out, so that the staple can be automatically pushed to the front until all the staples are pushed out. Many machines are automatically loaded, and the bullets in automatic rifles are automatically loaded by the function of springs. In addition, clips such as clothes pegs, ballpoint pens and pen covers are clamped on clothes by the pressing action of springs. ? [ 1]?

checkout equipment

There are various specifications of spring tension and compression testing machine, spring fatigue testing machine, physical and chemical metallographic analysis, different specifications of flaw detection equipment, material torsion and tension testing machine and so on. ? [ 1]?

Elastic force test

Attention problem

edit

Due to the limitation of product structure, multi-strand springs generally have the characteristics of high strength and good performance. Its material needs to ensure the final performance of spring strength and toughness. In the process of processing multi-strand springs, it should be noted that: 1, the support ring can be cold or hot according to product requirements. It is not allowed to heat the spring until it sparks or turns white by thermal bonding, and the temperature of silicon manganese steel shall not be higher than 850℃. The support ring and the effective ring should be in effective contact, and the gap should not exceed 10% of the nominal gap between rings. 2. The characteristics of multi-strand springs can be determined by adjusting the lead, and the cable distance can be adjusted when winding. Lay length can be 3~ 14 times the diameter of steel wire, but it is generally appropriate to be 8~ 13 times. Its spring force is also closely related to free height, parallel end coil, outer diameter and steel wire performance, which can be changed by adjusting one or more of them. 3. Springs without supporting rings and springs with too thin steel wire diameter should not be welded with the spring head, but the terminal cable should not be obviously loose and should be deburred. Where the multi-strand spring needs to be welded at the head, the length of the welded part shall be less than 3 times the cable diameter (the longest shall not exceed 10 mm). The heating length should be less than one circle, and it should be polished smooth after welding. During gas welding, the welding parts should be locally annealed at low temperature. 4. The surface treatment of the spring can generally be phosphating or other treatments. If zinc and cadmium are to be galvanized, hydrogen should be removed after electroplating. After hydrogen removal, 3% (not less than 3 pieces) should be taken for a second interview, and there should be no fracture during the second interview. Dirt, salt marks and scale on the spring surface should be removed. The method can be sandblasting or gasoline cleaning, but not pickling. 5. The important spring pressing time is 24 hours, and the ordinary spring pressing time is 6 hours or 3~5 consecutive times, and each time it is held for 3~5 seconds. When pressing, the clearance between the spring and the spindle should be 10% of the spindle diameter. The gap is too small, the operation is difficult, and the gap is too large, which is easy to cause the spring to bend and deform. If one of the springs breaks during pressing, the rest should be reworked.