Disc spring din2093

Disc spring, referred to as disc spring (din2093), is also mistakenly written as butterfly spring. Disc springs was invented and used in the middle of the 19th century. At that time, Belleville, a Frenchman, applied for a design patent for the disc spring. Nowadays, some places still call it Belleville springs.

In the 21st century, disc spring is used in more fields, such as aerospace, defense system, medical equipment, automobile, electric power, construction, machine tool and other industries

The standard of disc spring in the world is the German din2093 standard. Earlier, the disc spring standard used in China was GB / t1972-1992. Now the national standard of disc spring in China is GB / t1972-2005.

Characteristics of disc spring

Features of disc spring:
1. It has high stiffness, strong shock absorption capacity, and can bear large load with small deformation, which is suitable for the occasions with small axial space requirements.
2. It has variable stiffness, and the spring has a wide range of nonlinear characteristics.
3. With the same disc spring and different combination methods, the spring characteristics can be changed in a wide range. It can be combined by means of lamination and lamination, and can also be combined with different thickness and different number of pieces.
The more the number of springs, the greater the load.
characteristic
Short travel and heavy load
Small space required
It is convenient to use in combination
It is easy to repair and replace
High economy and safety
Long service life

Spring winding technology

Winding method of spring
Using various spring winding machines will produce various quality problems. In addition to effective control and reasonable adjustment of the machine, there are many factors affecting the spring winding, such as the accuracy of material size, the uniformity of material strength (soft and hard), the state of material surface, the precision of the machine, especially the technical level of the operator, etc. In the process of production, inspection must be carried out frequently to find problems in time and correct them at any time.

One end of the mandrel is clamped on the chuck of the lathe, and the other end is pressed by the center. The lathe speed is lowered and the material to be wound is clamped at the core bar’s drilling position. The work efficiency is very high
Quality control of winding spring

The following is a list of common quality problems and troubleshooting methods of ordinary spring winding machine.
① The diameter of the supporting ring increases
This is mainly due to the fact that the helix angle of the supporting ring is smaller than that of the effective coil. On the premise that the feeding length remains unchanged (consistent) and the position of the coil spring ejector does not change, the diameter of the two adjacent coils must have a size, and the diameter of the supporting ring with small helix angle is larger than that of the effective coil with large helix angle.

Solutions: first, design a special variable diameter cam plate, similar to the method of winding the convex spring, so that the diameter of the intermediate ring is slightly larger. When the pitch plate just pushes the pitch, the diameter of the spring supporting ring and the effective ring is basically the same; second, the pitch plate with boss is used to hook the spring coil when winding the spring, which is more suitable for winding the spring with large diameter and large winding ratio.
For the CNC spring winding machine, the diameter of the supporting ring and the effective ring can be controlled by controlling the position of the spring pin sliding seat in sections.

Design and calculation of spring

Name and designation compression coil spring tension coil spring
The spring diameter D / mm is determined by the strength calculation formula
Spring pitch diameter D2 / mmd2 = CD
Spring inner diameter D1 / mmd1 = d2-d
Spring outer diameter D / MMD = D2 + D
Spring Index C C = D2 / D, generally 4 ≤ C ≤ 6
For compression spring, g = 5 ° to 9 ° is recommended
The effective number of turns n is determined by the calculation of deformation conditions, generally n > 2
The total number of turns N1 compression N1 = n + (2 ~ 2.5); stretching N1 = n
N1 = n + (1.5-2) (y I type hot coil); the mantissa of N1 is 1 / 4, 1 / 2, 3 / 4 or the whole circle, and 1 / 2 coil is recommended
When N1 = n + 1.5, H0 = NP + DLI type H0 = (n + 1) d + D1
When N1 = n + 2, H0 = NP + 1.5dl type Ⅱ H0 = (n + 1) d + 2D1
When N1 = n + 2.5, H0 = NP + 2DL Ⅶ H0 = (n + 1.5) d + 2D1
When N1 = n + 2, H0 = NP + 3D
When N1 = n + 2.5, H0 = NP + 3.5D
Working height or length HN / mmhn = H0 lnhn = H0 + LN, LN deformation
Pitch P / mm P = D
Spacing D / MMD = p-dd = 0
Compression spring height diameter ratio BB = H0 / D2

Development length L / MML = pd2n1 / cosgl = pd2n + unfolded length of hook
Calculation formula of spring force: the design data of pressure spring, in addition to the spring size, needs to calculate the maximum load and the load of displacement size; spring constant: expressed by K, when the spring is compressed, the load of every 1mm increase (kgf / mm); spring constant formula (single position: kgf / mm): k = (g × D4) / (8 × DM3 × NC) g = steel modulus of wire: Piano steel wire g = 8000; stainless steel wire g = 7300; Phosphor bronze wire g = 4500; brass wire g = 3500 d = wire diameter do = od = outer diameter Di = id = inner diameter DM = MD = medium diameter = do-d n = total number of coils NC = effective number of coils = n-2 spring constant calculation example: wire diameter = 2.0mm, outer diameter = 22mm, total number of coils = 5.5 coils, steel wire material = piano wire k = (g × D4) / (8 × DM3 × NC) = (8000 × 24) / (8 × 203 × 3.5) = 0.571kgf/mm. The K value of tension spring is the same as that of pressure spring.

The initial tension of tension spring: the initial tension is equal to the force required to pull apart the tightly attached spring and coil. The initial tension occurs after the spring is rolled and formed. When the tension spring is made, the initial tension of each tension spring is uneven due to the difference of steel wire material, wire diameter, spring index, static electricity, lubricating grease, heat treatment and electroplating.

Therefore, when installing the tension spring of various specifications, it should be pre pulled until the parallel coils are slightly separated. The force required is called the initial tension. The formula of spring constant (unit: kgf / mm): k = (E × D4) / (1167 × DM × P × n × R) e = steel modulus of wire: e = 21000 for Piano steel wire, e = 19400 for stainless steel wire, e = 11200 for phosphorus bronze wire, Brass wire e = 11200 d = wire diameter do = od = outer diameter Di = id = inner diameter DM = MD = medium diameter = do-d n = total number of turns r = arm of force under load p = 3.1416 Hooke’s law f = – KX K is spring coefficient X is tensile type variable f = kx, K is stiffness coefficient, X is elongation.

Heat treatment technology of spring steel

According to the forming method, the manufacturing of spring steel can be divided into cold forming and hot forming.
Due to its good impact toughness and surface compressive stress, the tendency of inner sleeve cracking during assembly, outer rib falling off and inner sleeve fragmentation during use is greatly reduced, and the edge stress concentration of roller can be reduced. Therefore, the average life and reliability of Austempering are higher than that of M quenching.
Heat treatment of thermoforming spring

The heating temperature is slightly higher than the quenching temperature. After heating, it is hot rolled, then quenched by waste heat, and finally tempered at 350 ~ 450 degrees to obtain tempered troostite structure. This is a thermomechanical treatment process, which can effectively improve the elastic limit and fatigue life. This method is generally used in large leaf springs of automobiles. For neutral coil spring, it can also be formed under cold condition, and then quenched and tempered.
Spring Factory suggests that in order to further develop the performance potential of spring steel, three points should be paid attention to in spring heat treatment: most spring steel is silicon manganese steel, silicon can promote decarburization, manganese can promote grain growth.

 

Therefore, the heating temperature, heating time and heating medium should be selected and controlled. If salt furnace is used for rapid heating and heating under protective atmosphere. Tempering should be carried out as soon as possible after quenching to prevent delayed fracture. Due to the high silicon content of spring steel, it is easy to produce graphitization in the process of annealing. The content of graphite is required to be inspected when the steel enters the factory. The tempering temperature is generally 350 ~ 450 ℃. If the steel surface is in good condition (e.g. after grinding), the low limit temperature tempering should be selected; otherwise, the upper limit temperature tempering can be used to improve the toughness of steel and reduce the sensitivity of surface defects.

Heat treatment of cold formed spring steel
Spring manufacturers remind you that for small springs, such as coil springs or spring steel strips with wire diameter less than 8 mm, they can be shaped after heat treatment or cold deformation, that is, cold drawing and cold rolling. The cold drawn steel wire has high strength, which is obtained by the work hardening of cold drawing deformed steel.
Quenching and tempering steel wire: this kind of steel wire is cold drawn to the final size, then hardened and tempered at medium temperature, and finally formed by cold rolling. The disadvantage of this kind of strengthening is that the process is more complicated and the strength is lower than that of lead quenched cold drawn steel wire.

In practice, it is found that the elastic limit of the steel wire which has been strengthened after cold rolling is not high, because the cold rolling forming will be easy to move into error, and the initial plastic deformation resistance will be reduced due to Bauschinger effect. Therefore, a low temperature tempering must be carried out after the cold roll forming, which has caused many changes and improved the elastic limit.

Application of disc spring in industry

Disc spring is a kind of spring that we usually use. The disc spring is usually used for deformation, buffering and other functions, or depending on the elastic force to maintain the components in a certain position, such as the reset of mechanism components. The common materials of disc spring are carbon spring steel, alloy spring steel, stainless steel, etc. some special materials such as superalloy will be used. There will be different standards in different countries. The disc spring materials specified in GB / T 1972-2005 are 60Si2MnA and 50CrVA. 60Si2MnA has high silicon content, good strength and elastic limit, good tempering stability, but low hardenability, easy decarburization and graphitization.

There are many kinds of stainless steel materials for disc spring, which are often used in places with high requirements for corrosion resistance. Some stainless steels have good high-temperature mechanical properties and can work at higher temperatures.

In addition, there are some other mechanisms, such as the clamping fixture mechanism of wx001 centralized transmission device and the worm gear over torque mechanism. 60Si2MnA has a wide range of applications, mainly used for shock absorption leaf spring, spiral spring, cylinder safety valve spring, check valve spring of automobile and tractor, and also used to make important spring and anti-wear spring which work under alternating load and high stress. Compared with 60Si2MnA, 50CrVA has higher strength, yield ratio, toughness and higher fatigue strength. Compared with 60Si2MnA, 50CrVA has better hardenability, lower overheat sensitivity and low decarburization tendency. It is commonly used for making all kinds of spring bearing high stress, especially suitable for spring with high stress amplitude and strict fatigue performance requirements, and temperature below 250 ° C Valve spring, injector spring, etc.

The star disc spring is a kind of fastening spring. Its main function is to fasten the shaft and gear together to form a rigid connecting body, which can transmit torque and bear axial force, which is of great value in engineering technology. In the case of key connection, there are many cases where the shaft is slender and has poor rigidity, and the allowable torque is small. After the keyway is opened, the rigidity and the ability to bear the torque are weakened. The gear connected with the shaft often forms a weak link between the keyway and the tooth groove. In this case, the effect of using the star disc spring is much better.

Application field of rubber spring

Rubber spring is a kind of high polymer elastic spring. It has the advantages of long service life, low cost, good cold resistance, good air tightness and so on. In addition, rubber spring also has water-proof and electrical insulation, which is the best choice of vibration damping products in various industrial fields.

With the rapid development of industry in modern society, the number of large-scale industrial machinery is also increasing. Rubber spring is commonly used in mechanical equipment, vehicle travel mechanism and suspension, which can reduce vibration and cushion. For example, industrial machinery such as vibration machinery, double deck passenger car and heavy truck will be used in rubber spring.

Rubber spring has obvious vibration reduction effect in mechanical industry. Because rubber spring can withstand shear deformation and compression deformation, the internal friction damping of rubber spring is much larger than that of metal spring. Therefore, the amplitude of rubber spring vibrating screen machine is much smaller than that of other spring vibrating screen machines when it starts and stops and passes through resonance area The amplitude is stable, but the energy consumption is larger than that of metal spring. The resistance of rubber spring to transmit sound is much greater than that of metal spring, so the sound insulation is better and the noise during working hours is small.

Rubber spring can be made into a variety of different shapes and sizes of products. The structure of rubber spring is very compact, which can effectively use space. Its elastic coefficient is much smaller than that of metal, and it changes in a large range with the change of hardness. Therefore, changing the hardness of rubber can make the spring obtain different stiffness, that is, the stiffness of rubber spring with the same shape can also be selected in a certain range.

State classification of spring operation

There are hundreds of springs. According to its running state, it can be divided into static spring and dynamic spring.
Static spring refers to the spring with limited vibration times in operation, such as safety valve spring, spring testing machine, spring pad, scale spring, constant load spring, mechanical spring, watch hairspring, etc.

Dynamic spring refers to the spring whose vibration times are more than 1 × 106, such as engine valve spring, vehicle suspension spring, shock proof spring, coupling spring, elevator buffer spring, etc.
Static spring material selection mainly considers tensile strength and stability, while dynamic spring material selection mainly considers fatigue, relaxation and resonance performance.

According to the load condition, the spring can be divided into three states: light load, general load and heavy load. Light load refers to the spring which bears static stress, low stress and small deformation, such as spring for safety device, spring for vibration absorption, etc. The designed service life is 103 ~ 104 times.

The general load refers to the common spring which has a design life of 105 ~ 106 times and is used under the condition of vibration frequency of 300 times / min. The lower the load stress, the longer the life.
Heavy load refers to the spring which works for a long time and vibrates frequently. Such as valve spring, air hammer, press, hydraulic controller spring, its load is high, often less than 10% of the allowable stress, service life is more than 1 × 106 times, usually 107 times.

Wrong cases of spring use

1. When used in series, the spring will bend and exceed the length of the guide pin or countersunk hole, resulting in the fracture of the same reason. Moreover, a slight difference in the load of the spring itself results in the fracture of the plane with the weaker load bearing greater compression.
2. If the gap between the spring inner diameter and the guide pin is too small, it will cause the collision wear of the inner diameter, and the abrasion part is the main reason for the spring fracture; on the contrary, if the gap is too large, the spring inner diameter is about – 1.0 mm. And long free length spring (free length / outer diameter greater than 4) please use segment step or guide pin to avoid collision with guide pin when spring body is twisted.
3. If the spring is used horizontally, the guide pin and spring will be worn and broken.
4. If there is no spring guide when using the spring, it is easy to cause the bottom of the spring and the spring body to twist. The high pressure of the twisted area is the main reason for the spring fracture. Therefore, when using the spring type, remember to use the inner diameter guide pin or the outer diameter guide device.
5. Use of more than the maximum compression
The pressure will cause damage. If it is used close to the seal length, the spring line will be gradually closed. In this way, the load curve will be raised with the increase of the spring number, and the high stress will cause the spring to break. Please do not use more than 300000 cycles.
6. If there is a gap, the spring will vibrate up and down, causing the spring to twist. If there is preloading, the spring will be more stable.
7. If the parallelism of the assembly surface is not good, the spring will be twisted, and local high pressure fracture will occur; and if the parallelism is not good, the spring will be twisted and the spring will be broken after more than 300000 cycles. Please improve the parallelism of assembly surface under the condition of no more than 300000 reuse.
8. When the spring is used, the spring is twisted by force, resulting in the inner ring spring inserted into the outer ring (or the outer ring inserted into the inner ring), resulting in fracture.
9. If the clearance head between the counterbore and the spring is too small, the force will be concentrated and broken due to the friction between the outer side of the countersunk hole and the spring compression. Please use the shape of countersunk hole when free long spring.
10. The length of guide pin and the depth of counterbore are short
If the guide pin is too short, the head of the guide pin and the spring will be worn and broken. The ideal length of the guide pin is set to be more than 1 / 2 of the spring length, and the chamfer of C3 should be inverted.

Technology and application of extension spring

Generally, the material of axial tension spring is a kind of tension spring. In the case of no load, the tension spring between the coils is generally tight and there is no gap.
Both ends of the tension spring can be fixed to other components. When these components are separated, the tension spring can connect all the components together again. The tension spring reverses when it is extended or pulled apart. When the ends of the stretch springs are pulled apart, the springs try to pull them back together. Like compression springs, tension springs also absorb and store energy. But unlike compression springs, most tension springs are usually under a certain degree of tension, even without any load. This initial tension determines the tightness of the tension spring coil without any load.

Tension spring can absorb and store energy, and it can also resist tension. The contact tightness of adjacent coils is determined by the initial tension. The initial tension of the spring can be controlled to meet the specific application requirements. The rings of the tension spring are closed together to resist tension. Under no-load condition, these coils are usually close together, and the retraction of the tension spring includes a hook, a small hole or other geometric shape interface for fixing to the connected components. They often provide resilience to components that are stretched in the starting position.

Applications of extension springs include the inside and outside of motor vehicles, garage door devices, vise clamps, vaporizers, medical breathing equipment, motion control, medical mobile equipment, hand tools, home care equipment, shock absorbers, pump springs, mechanical and electronic protection hardware, fluid control valves, mechanical aerospace components, actuators, and switchgear. There are many types of tension springs, from small medical and health equipment to mechanical brake springs in the field. For the application requirements of tension spring, you can specify various types of pull ring and hook. Close contact between adjacent coils produces an initial tension, which helps to control load and stiffness.