The type and function of the butterfly spring

The butterfly spring, also known as belleville spring washer, was invented by the Frenchman Belleville and is a conical cross-sectional washer spring made of metal plates or forged blanks. Disc springs can be divided into three categories according to the shape of the cross-section: including ordinary disc spring (its cross-section already shape is rectangular), disc spring with radial groove, and trapezoidal cross-sectional disc spring. Ordinary disc spring is divided into support surface and no support surface two categories, butterfly spring with radial groove is on the basis of ordinary disc spring, along the radial out of a number of evenly distributed grooves, grooves can be opened from the inner hole outward circle direction, can also be opened from the outer circle to the inner direction;

Butterfly spring function.

A spring is an elastic element that works by producing a large elastic deformation on its own. It is widely used in all kinds of machines. Its main functions are:

1) Control the movement of machinery, such as the spring in the internal combustion engine to control the opening and closing of the cylinder valve, the control spring in the clutch.

2) absorb vibration and shock energy, such as vibration-absorbing springs in various vehicles and springs of various buffers;

3) Store and release energy, such as clock springs, gun bolt springs, etc.

4) Measure the size of force, such as spring scales and springs in force gauges, etc.

Classification of butterfly springs.

According to the force nature, the spring can be divided into stretch spring, compression spring, twisting spring and bending spring, according to the shape can be divided into disc spring, ring spring, plate spring, coil spring, cone vortex spring and twisting rod spring, according to the production process can be divided into cold spring and hot roll spring. Ordinary cylindrical 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. Spring manufacturing materials should generally have high elastic limit, fatigue limit, impact toughness and good heat treatment performance, commonly used carbon spring steel, alloy spring steel, rust-free spring steel and copper alloy, nickel alloy and rubber. The manufacturing methods of butterfly spring are cold roll and hot roll method. Spring wire diameter is less than 8 mm of the general use of cold roll method, larger than 8 mm with hot roll method. Some springs are also subjected to strong pressure or shot treatment after being made to improve the carrying capacity of the springs.

Butterfly spring – spring classification.

There are many kinds of springs, if according to the load nature of their bear, the spring is mainly divided into stretch ingest editing spring, compression spring, twisting spring and bending spring and so on. If in accordance with the shape of the spring can be divided into coil spring, disc spring, ring spring, plate spring, reed and so on. The basic types of various springs are listed in the table.

The butterfly spring spiral twist inge spring is one of the most commonly used torsion springs. The coil has more laps, largedeformation, and larger storage energy characteristics, more used for compression and instruments, watches and clock strains. Plate springs can withstand large bending, often used in the load direction size is limited and the amount of deformation and larger occasions. Due to the good vibration cancellation ability of plate springs, this spring is commonly used in the suspension devices of automobiles, tractors and railway vehicles. The physical diagram of various types of springs is given below.

What does the battery spring have?

What are the effects of battery springs?

The battery spring changes under the action of external force, and after removing the external force, the spring can recover. Many tools and equipment are reset by the nature of springs. For example, many building doors are mounted on the close pages of the front slots with a reset spring when people come in and out, and the doors are automatically reset. People also use this function to make automatic umbrella, automatic pencil and other supplies, very convenient. In addition, a variety of buttons and buttons are also indispensable to the return spring.

Battery spring spring function:

A spring is an elastic element that works by producing a large elastic deformation on its own. It is widely used in all kinds of machines. Its main functions are:

1) Control the movement of machinery, such as the spring in the internal combustion engine to control the opening and closing of the cylinder valve, the control spring in the clutch.

2) absorb vibration and shock energy, such as vibration-absorbing springs in various vehicles and springs of various buffers;

3) Store and release energy, such as clock springs, gun bolt springs, etc.

4) Measure the size of force, such as spring scales and springs in force gauges, etc.

Identification of the spring machine clutch press coil spring

Identification and quality requirements for spring machine clutch press coil springs:

The role of the pressure disc spring is to use its tension to press the clutch disc and clutch plate tightly on the split wheel so that the engine’s power is reliably transferred to the drive train.

The quality requirements of the pressure plate spring are as follows:

First, materials: pressure disc spring material for 65Mn wire or I, II group carbon spring wire.

Second, hardness: quenched, tempered cold coil spring, hardness value should be in the range of 44-52HRC, under special circumstances its hardness value can be expanded to 55HRC.

Third, the appearance of quality requirements: the surface quality of the finished spring products should be smooth, no cracks, oxidizing skin, rust and other defects. Cold roll springs do not allow individual indentations, pits and scratches that extend beyond half of the material diameter tolerance.

Fourth, processing density.

1. The roughness of the spring end face should be not less than 12.5 m.

2. The compression spring support inglions that are tightly grinded at both ends should not be less than 3/4 of the circumference length, the end thickness is generally not less than 1/8 of the diameter of the wire. The end head thickness should be not greater than 1/3 of the diameter of the wire, and the width should be not less than 70% of the diameter of the wire.

3. According to the use requirements, can check the spring pitch unevenness. The tolerance is 10% of the spacing, the minimum tolerance value is generally 0.3mm. When the compression spring is compressed to 80% of the total deformation, the spring ring of the normal pitch is not allowed to touch. Wuhan spring.

4. The vertical tolerance between the two ends of the compression spring and the shaft of the spring is 2.5% of the free height, and the minimum tolerance value is 1mm. Wuhan spring.

5. The straight tolerance of the shaft of the compression spring is half the vertical tolerance.

How to choose spring material

The selection of spring material should be determined according to the load nature, stress state, stress size, working temperature, environmental medium, service life, requirements for conductive and magnetic conductivity, process performance, material source and price

In determining the cross-section shape and size of materials, the series sizes specified in national standards and ministerial standards should be preferred, and materials with non-standard series specifications should be avoided as far as possible. For medium and small springs, especially spiral tension springs, steel wires with strengthened treatment, isothermal cold drawn steel wire in lead bath and oil quenched tempered steel wire should be preferred, which have high strength and good surface quality, After cold drawing, carbon spring steel wire and Piano steel wire produce large residual stress. After processing spring, there is larger residual stress. After tempering, the size changes greatly, so it is difficult to control the size accuracy. Oil quenching and tempering steel wire is modulated and strengthened after steel wire is drawn to the specified size, There is basically no residual stress. After low temperature tempering, the size of the formed spring changes little, and the heat resistance stability is better than that of the cold drawn reinforced steel wire

For large and medium-sized springs, cold drawn material or polished steel after cold drawing shall be selected. For springs with low load accuracy and stress, hot-rolled steel can be selected. Flat steel of 55si2mn, 60Si2MnA, 55SiMnVB, 55simnmov, 60crmn, 60crmnb and other flat steels shall be selected for leaf spring, The materials with circular section, square section and rectangular section should be preferentially selected. They have strong bearing capacity, good impact resistance, and can make the spring miniaturized. However, the material sources are few and the price is high. Except for special needs, this kind of material is not selected as far as possible. In recent years, the development of using round steel wire to flatten instead of trapezoidal steel wire has achieved good results

The spring material working at high temperature requires good thermal stability, relaxation or creep resistance, oxidation resistance and corrosion resistance. With the increase of working temperature, the elastic modulus of spring material decreases, resulting in the decrease of stiffness and bearing capacity. Therefore, the change rate (value) of elastic modulus must be known for the spring working at high temperature, According to the provisions of GB 1239, when the working temperature of ordinary spiral spring exceeds 60 ℃, the shear modulus should be modified. The formula is: GT = KTG, in which G is the elastic modulus at normal temperature; GT is the shear modulus under working temperature T; KT — the temperature correction coefficient is selected according to table 2-98

The spring materials used at low temperature should have good low temperature toughness. Carbon spring steel wire, piano steel wire and 1Cr18Ni9 austenitic stainless steel spring steel wire, copper alloy and nickel alloy have good low temperature toughness and strength

At low temperature, the brittleness of materials is very sensitive to surface defects
At low temperature, the corrosion degree of environmental medium is much less than that in greenhouse
At low temperature, the elastic modulus and expansion coefficient of the material change little, so they can not be considered in the design

What are the specifications of the tension spring

Introduction: specifications of tension spring
Tolerance: O.D. (English) O.D. (Metric)
0.063 – 0.119 inch ± 0.003 inch 1.60 – 3.02 mm ± 0.08 mm
0.120 – 0.240 inch ± 0.005 inch 3.05 – 6.10 mm ± 0.13 mm
0.241 – 0.500 inch ± 0.008 inch 6.12 – 12.70 mm ± 0.20 mm
0.501 – 1.000 inch ± 0.015 inch 12.73 – 25.40 mm ± 0.38 mm
1.001 – 1.225 inch ± 0.020 inch 25.43 – 31.12 mm ± 0.51 mm
1.226 – 1.460 inch ± 0.030 inch 31.14 – 37.08 mm ± 0.76 mm
1.461 – 2.000 inch ± 0.040 inch 37.11 – 50.80 mm ± 1.02 mm
Load, P ± 10%
Elastic coefficient, R ± 10%
The position of the end, most parts are machined to ± 22 degrees
Tolerance: O.D. (English) O.D. (Metric)
0.063 – 0.119 inch ± 0.003 inch 1.60 – 3.02 mm ± 0.08 mm
0.120 – 0.240 inch ± 0.005 inch 3.05 – 6.10 mm ± 0.13 mm
0.241 – 0.500 inch ± 0.008 inch 6.12 – 12.70 mm ± 0.20 mm
0.501 – 1.000 inch ± 0.015 inch 12.73 – 25.40 mm ± 0.38 mm
1.001 – 1.225 inch ± 0.020 inch 25.43 – 31.12 mm ± 0.51 mm
1.226 – 1.460 inch ± 0.030 inch 31.14 – 37.08 mm ± 0.76 mm
1.461 – 2.000 inch ± 0.040 inch 37.11 – 50.80 mm ± 1.02 mm
P, 10% load
Elastic coefficient, R ± 10%
The position of the end, most parts are machined to ± 22 degrees

Corrosion resistance of various stainless steel springs

The corrosion resistance of various stainless steel springs is introduced
304 is a kind of universal stainless steel, which is widely used to make equipment and parts with good comprehensive performance (corrosion resistance and formability)
301 stainless steel spring presents obvious work hardening phenomenon during deformation, which is used in various occasions requiring higher strength
302 stainless steel is essentially a variant of 304 stainless steel with higher carbon content
302B is a kind of stainless steel with high silicon content and high oxidation resistance
303se and 303se are free cutting stainless steels containing sulfur and selenium respectively
303se stainless steel is also used to make parts requiring hot upsetting because of its good hot workability under such conditions
304L is a variety of 304 stainless steel spring with low carbon content, which is used in the occasion where welding is required. The lower carbon content makes the carbide precipitated in the heat affected zone near the weld to the minimum, and the precipitation of carbide may cause intergranular corrosion (welding corrosion) of stainless steel spring in some environments

Design method of tension spring and compression spring

Design method of tension spring and compression spring:
The task of spring design is to determine the diameter of spring wire D, the number of working coils N and other geometric dimensions, so as to meet the strength constraints, stiffness constraints and stability constraints, and further require the corresponding design indicators (such as volume, weight, vibration stability, etc.) to achieve the best
The specific design steps are as follows: first, according to the working conditions and requirements, try to select the spring material and spring index C. Since sb is related to D, it is often necessary to assume the diameter D of the spring wire in advance. Next, calculate the values of D, N and other corresponding geometric dimensions. If the results obtained do not conform to the design conditions, The above process needs to be repeated until a solution satisfying all constraints is obtained. In practical problems, the feasible scheme is not unique, and it is often necessary to obtain the optimal solution from multiple feasible schemes
Example 12-1 a cylindrical spiral compression spring is designed. The spring wire section is circular. The minimum load Fmin = 200N, the maximum load Fmax = 500N, the working stroke H = 10mm. For class II operation of spring, the outer diameter of the spring shall not exceed 28mm, and the end shall be tightly ground
Solution:
Trial calculation (1)
(1) Select spring material and allowable stress. Select C grade carbon spring steel wire
According to the requirement of outer diameter, C = 7, d = 3.5mm from C = D2 / D = (D-D) / D, sb = 1570mpa from table 1, and from table 2: [t] = 0.41sb = 644mpa
(2) Calculate the diameter of spring wire D
From the equation, k = 1.21
From the formula, D ≥ 4.1 mm
Therefore, the initial value of D = 3.5mm does not meet the strength constraint condition and should be recalculated
Trial calculation (2)
(1) 3. D = C > 3
From C = (D-D) / D, d = 4.4mm
According to table 1, sb = 1520mpa, from table 2 we can know that [t] = 0.41sb = 623mpa
(2) Calculate the diameter of spring wire D
From the equation, k = 1.29
From the formula, D ≥ 3.7mm
It can be seen that I > d = 4.4mm meets the strength constraint condition
(3) Calculate the number of effective working cycles n
According to figure 1, the deformation is determined as λ Max: λ max = 16.7mm
According to table 2, g = 79000n / mm2,
From the formula, n = 9.75
Taking n = 10, considering that both ends of the spring are tightly connected, the total number of turns is N1 = n + 2 = 12. So far, a feasible scheme meeting the constraint conditions of strength and stiffness is obtained. However, considering further reducing the spring’s overall size and weight, the trial calculation is carried out again
Trial calculation (3)
(1) Still select the above spring material, take C = 6, get k = 1.253, d = 4mm, look up table 1, get sb = 1520mpa, [t] = 0.41sb = 623mpa
(2) The diameter of spring wire is calculated. D ≥ 3.91mm. It is known that d = 4mm meets the strength condition
(3) According to trial calculation (2), λ max = 16.7mm, g = 79000n / mm2
From the formula, n = 6.11
Take n = 6.5 turns, still refer to both ends and tighten one circle, N1 = n + 2 = 8.5
This result satisfies the constraint conditions of strength and stiffness, and is a better solution in terms of overall dimension and weight. This solution can be initially determined, and other dimensions can be calculated and checked for stability
(4) The deformation values λ max, λ min, λ Lim and the actual minimum load Fmin are determined
The ultimate load of the spring is as follows:
Because the number of working turns is changed from 6.11 to 6.5, the deformation and minimum load of the spring are also changed accordingly
According to the formula:
λmin=λmax-h=(17.77-10)mm=7.77mm
(5) Calculate the spring pitch P, free height H0, helix angle γ and spring wire development length L
Under the action of Fmax, if the distance between two adjacent coils is greater than or equal to 0.1D = 0.4mm, if δ = 0.5mm, the pitch of spring under no load is
p=d+λmax/n+δ1 =(4+17.77/6.5+0.5)mm=7.23mm
P is basically in the range of (1 / 2 ~ 1 / 3) d 2
The free height of the spring with the end face tightly ground is
Take the standard value H0 = 52mm
The helix angle of spring without load is
The range of γ = 5 ° to 9 ° is basically satisfied
Development length of spring wire
(6) Stability calculation
b=H0/D2=52/24=2.17
Using fixed support at both ends, B = 2.17 < 5.3, so it will not lose stability

Application and market of spec tension spring

Application and market of spec tension spring:
Tension spring is widely used in national defense, ocean, computer, electronics, automobile, mold, medicine, biochemistry, etc
It includes: aerospace, railway, nuclear power, wind power, thermal power, engineering machinery, mining machinery, construction machinery, elevator and other fields. In China, it has successfully matched or replaced the tension springs on domestic power plants and steel plants. The quality exceeds the requirements of customers, greatly reduces the production risk caused by the use of inferior tension springs, improves the production efficiency and saves the operation cost

Overview of torsion spring

In general, spec torsion spring (torsion spring) is usually used on a supported mandrel or shank. It is recommended that the spindle size should allow about 10% clearance in the listed deviation. If the deviation is large, the shank size should be reduced. In order to make the spring function in good condition, the space in the assembly (minimum axial space) must be sufficient. The minimum axial space cannot refer to the length of the coil

In general, spec torsion springs are used on a supported spindle or shank. It is recommended that the spindle size should allow about 10% clearance in the listed deviations. If the deviation is large, the shank size should be reduced. In order to make the spring function well, the clearance in the assembly (minimum axial space) must be sufficient. The minimum axial space cannot refer to the length of the coil

 

Spec torsion spring should be used in the direction of winding coil. Because of the residual stress, the maximum load is low in the direction of loosening. The torque values listed are the recommended maximum torques. These values can be increased by about 20% with only a little adjustment under static conditions
During the inspection, the load should be applied to 1 / 2 of the strut length (E). The use of other lengths will slightly change the current length of the wire and affect the test results

For example, when en = 0.187, P = m / en = 0.047/0.187 = 0.251b, what is the load of component t012-090-055 when en = 0.187, P = m / en = 0.047/0.187 = 0.251b? The torque value of intermediate deformation can be calculated by direct proportion. For example, component t030-180-250,90. The torque value of deformation is 0.312 in LB (35.3 N-mm).
The listed reference torque values should be achieved at the listed deviations. The torque values at the intermediate deviation can be calculated by direct proportion. For example, the torque value of component t030-180-250 with 90 ° deviation is 0.312 in IB

Material overview of compression spring

Material of compression spring:
Instrument wire for parts beginning with number C: in accordance with ASTM a228 or AMS 5112. When the temperature exceeds 121 degrees Celsius (250 degrees Fahrenheit), the use of musical instrument wire springs is not recommended
Stainless steel wire for parts beginning with number C: 302 stainless steel, conforming to ASTM a313 or AMS 5688, spring tempered (physical and chemical properties only). Springs made of stainless steel are not recommended when temperatures exceed 260 degrees Celsius (500 degrees Fahrenheit)
Musical instrument wire for parts with numbers beginning with D: in accordance with DIN 17223 or JIS g4314 swp-nb
Or AMS 5112, it is not recommended to use the spring made of metal string of musical instrument
Stainless steel wire for parts with numbers beginning with D: 301, 302 or 304 stainless steel, in accordance with DIN 17224 or JIS g4314, Sus 302 / 304 or AMS 5688, spring tempered (physical and chemical properties only). Springs made of stainless steel are not recommended when temperatures exceed 260 ° C (500 ° f)
Type 302 stainless steel is slightly magnetic. There may be a little residual nickel on the surface of stainless steel. This is a normal phenomenon and will not affect the function of the parts
Wire diameter refers to the diameter before forming
Unless stainless steel is specified, musical instrument wire shall be used in general. When inquiring and ordering, the letter “m” or “s” shall be used to indicate stainless steel and musical instrument wire respectively