This standard specifies the design and calculation of plane scroll springs for general machinery. This standard applies to plane scroll springs with rectangular cross-section materials, thickness of 0.5~4mm and width of 5~80mm. This standard does not apply to springs with special properties. JB/T 7366-1994 Design and calculation of plane scroll springs JB/T7366-1994 Standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
Design and Calculation of Plane Scroll Springs
1 Subject Content and Scope of Application
This standard specifies the design and calculation of plane scroll springs for general machinery JB/T 7366--- 94
This standard applies to plane scroll springs (hereinafter referred to as springs) with rectangular cross-section materials, thickness of 0.5-4mm and width of 5-80mm.
This standard does not apply to springs with special properties. 2 Reference standards
(GB3525 Spring steel, tool steel cold rolled steel strip GB3530 Heat treated spring steel strip
GB8708 Special-shaped steel wire for automobile body accessories 3 Spring forms
3.1 Plane scroll springs are divided into non-contact plane scroll springs (type A) and contact plane scroll springs (type B) according to whether the spring coils are in contact or non-contact, as shown in Figure 1.
Figure 1 Plane scroll spring types
3.2 Non-contact plane scroll springs are often used to produce reverse Torque, such as the compression spring of the motor brush. Contact type plane scroll spring, often used as a storage energy base, such as various prime movers. 4 Parameter name and code of spring
Parameter name and code of spring are shown in Table 1.
Approved by the Ministry of Machinery Industry of the People's Republic of China on July 26, 1994 710
Implementation on July 1, 1995
Material width
Parameter name
Contact type spring wound on the mandrel Outer diameter of the spring coil Mandrel diameter||tt ||Inner diameter of the fusion spring box
Inner diameter of the spring coil of the contact spring when it is not subjected to external rotationMaterial elastic modulus
Material thickness
Material section moment of inertia
Material working circle expansion length
Material fixed length on the mandrel
Material fixed length on the spring box
Material expansion total length
Working revolutions of the spring
Number of coils of the spring in the free state
Number of coils of the contact spring when it is not subjected to torque
fusion spring Number of turns of the contact spring when it is wound tightly on the core shaft Maximum radius of the non-contact spring
Minimum radius of the non-contact spring
Spring torque
Minimum output torque of the spring
Maximum output torque of the spring
Limiting torque of the spring
Bending section modulus
Bending stress on the material section
Ultimate tensile strength of the material
Sustainability limit of the material
Deformation angle
5Material
JB/T 7366—94
5.1 Springs are generally made of the materials listed in Table 2, and can also be made of other materials agreed upon by both parties. 5.2
The thickness dimension series of the materials is shown in Table 3.
The width dimension series of the materials is shown in Table 4.
5.4The hardness and strength of the materials. Table 5 lists the hardness and strength of the heat-treated spring steel strip. Single
rad(\)
GB3525
GB 3530
GB8708
Strength level of steel strip
JB/T7366
Material name
Spring steel, tool steel cold-rolled steel strip
Heat-treated spring steel strip「,!, Grade Ⅱ
Special-shaped steel wire for automobile body accessories
375~485
486-600
Note: ①The thickness of grade 1 strength steel strip is not more than 1.0mm. ②) And the thickness of grade 1 strength steel strip is not more than 0.8mm. 6
Basic calculation formula of springbZxz.net
The deformation angle under the action of torque T is calculated according to formula (1):The working speed under the action of torque T is calculated according to formula (2):The strength under the action of torque T is calculated according to formula (3):Wherein; 1-material section inertia moment, 1=bh\/12; material bending section modulus, Z=bh2/6.
7 Non-contact plane scroll spring (Type A) 7.1 Structure and characteristics of non-contact spring
65Mn.50CrVA.60Si2MnA.60Si2Mn65Mn.T7A.T8A.T9A.60Si2MnA.70Si2Cr65Mn.50CrVA
Tensile strength
12751600
1579~1863
eeatnaoooanantbsiciononcasniaonoicaoincinnot (l)T
2元E转
7.1.1 Non-contact springs are divided into two types: one with fixed outer end (Figure 2a) and one with rotating outer end (Figure 2b). 712
e+++-+eee++++
·（2）
αExternal end fixation
JB/T7366—94
bExternal end rotation
Figure 2 External end fixation form of non-contact spring 7.1.2 The characteristics of non-contact spring are linear, see Figure 3. Characteristic line of non-contact spring
7.2 Design calculation of non-contact spring
The design of non-contact spring generally gives the corresponding deformation angle of the torque T. After selecting the more suitable material according to the working conditions, the relevant parameters are calculated. The strength and deformation calculation formulas listed and their derived formulas are mostly approximate formulas. The calculation results have a certain error with the actual situation, especially when the number of spring coils is less than 3, the error is even greater. For springs with higher precision requirements, experimental corrections should be carried out. 7.2.1 The deformation angle of the spring is calculated according to formula (4): 12K,T_2Ko
Where: K,
coefficient, when the outer end is fixed K,-1; when the outer end rotates K,=1.25. 7.2.2 The stiffness of the spring T\ is calculated according to formula (5): T
The stiffness of non-contact springs is relatively stable.
—12—2K[]
7.2.3 The thickness of the spring material section is calculated according to formula (6): 6,T
Where. K,
coefficient, K21 when the outer end is fixed; K,=2N·mm/rad when the outer end rotates
（4）
·（5）
The selected h value should comply with the series values ​​in Table 3
JB/T7366—94
When designing, the width 6 value is generally selected from the series values ​​in Table 4 based on the requirements of the installation space, and then the five values ​​are calculated. 7.2.4 The second rotation of the spring is calculated according to formula (7): 业--6K,T
2元元Fbh3
7.2.5 The working length l of the spring material is calculated according to formula (8): Ebh_rEbh\
7.2.6 The unfolded length L of the spring material is calculated according to formula (9): 元Eh
L-1+length of the fixed part at both ends
7.2.7 The pitch l of the spring is calculated according to formula (10): (R-- R)
7.2.8 The inner radius R and the outer radius R of the spring are calculated according to formula (11) and formula (12): R,=(8~15)h mm
RR,+not
7.2.9 The strength check of the spring is calculated according to formula (13): 6K,T
7.3 The allowable stress of the spring material
n element EhK
e-++++*---..+-(7)
（8）
（11）
: (13)
The allowable stress of the spring material can be selected by referring to the allowable stress of the cylindrical helical torsion spring. For carbon steel strips and alloy steel bars, when the number of torque actions is less than 10″, take 0.80; when it is greater than 10\ times, take]=（0.60~0.80）g; when it is greater than 10° times, take F(0.50~0.60)amg
8 Contact type plane scroll spring (type B)
8.1 Structure and characteristics of contact type spring, see Figure 4. T.
Figure 4 Structure and characteristics of contact type spring
JB/T7366-94
The AJ line in the figure is the theoretical characteristic of the spring, which is linear, and BEF is the output torque characteristic, which is a curve. 8.2 Contact type Design and calculation of springs
The design and calculation of contact springs are generally based on the maximum output torque T2 and the corresponding working speed n, and the relevant parameters are selected and calculated. The relevant calculation formulas listed are mostly approximate formulas, and the results have a certain error from the actual situation. For springs with higher precision requirements, experimental corrections should be carried out.
8.2.1 Refer to Figure 4 for the torque of the spring.
Limiting torque T: Calculated according to formula (14):
Maximum output torque T2 is calculated according to formula (15): TK
Minimum output torque T, calculated according to formula (16): N
Ti = (0. 5~0. 7)T2= (0. 5~0.7) K Where: K
Fixed coefficient, related to the external end fixing form, according to Table 6. Table 6
Fixed form
Hinged fixing
0.65~0.70
8.2.2 The number of revolutions and turns of the spring refer to Figure 4. The theoretical working number of revolutions n is calculated according to formula (17):
Pin fixing
0. 72~0. 78
Yuan Ebh3
The number of turns of the spring n in the free state. According to formula (18), calculate: 11Ath +d—
The number of turns of the spring placed in the spring box without torque is calculated according to formula (19) m
The number of turns of the spring wound on the core shaft is calculated according to formula (20) n2=
The effective working turns of the spring are calculated according to formula (21): tds
V-type fixed
0.80~0.85
n=K(n2—)
In the formula; K,-
Effective coefficient, its value can be found in Figure 5 according to di/h
Liner fixed
0. 90~0. 95
..........
8.2.3 Thickness of spring material section
The thickness of the material section is calculated according to formula (22): JB/T 7366--94
Figure 5 Effective coefficient K.
100d/h
When designing, generally select the width 6 value according to the requirements of the installation space, and then calculate the five values. The final selected h and 5 values ​​should comply with the series values ​​in Table 3 and Table 4.
8.2.4 Spring mandrel and spring box diameter
The mandrel diameter is calculated according to formula (23):
d≥(15~25)h
The outer diameter of the spring wound on the mandrel is calculated according to formula (24): 14th
The inner diameter of the spring box is calculated according to formula (25):
D,= V2. 55th+d
The inner diameter of the spring coil when the spring is unwound is calculated according to formula (26): Di
8.2.5 The unfolded length of the spring material
The unfolded length of the working part material is calculated according to formula (27): Eh
The unfolded length of the material is calculated according to formula (28):
Ehn
L-i+ta+ip
In the formula: a-—The length fixed on the core shaft, generally taken as l=（1～1.5）dt; The length fixed on the spring box, generally taken as p=0.8 yuan d1. Ip
When designing, 1/h=3000～7000 can generally be taken, and the maximum shall not exceed 15000. 8.3 Spring material
The material can be selected according to Table 2, or other materials can be selected according to design requirements. 8.4 Spring end fixing type
The inner and outer end fixing types of springs are shown in Tables 8 and 9.716
(28)
JB/T 7366--94
This fixing type is suitable for springs with large mandrel diameters. This fixing type is suitable for springs made of thicker materials. This fixing type is to make the mandrel surface into a spiral shape and fix the spring ends with hooks. Suitable for springs in important and precision mechanisms
This fixing type is simple and suitable for springs in less important mechanisms. The pin end will cause a large stress concentration in the spring material. 717
JB/T 7366--94
This type of fixing has large friction between the circles, which greatly reduces the output torque and makes the monthly stiffness unstable. It is not suitable for springs in precision and particularly important mechanisms. The friction between the circles of this type of fixing is lower than that of the hinge type fixing, and is suitable for springs of larger sizes. This type of fixing has a simple structure and is suitable for springs of smaller sizes. It is easy to break at the bend. This type of fixing is to rivet
a lining at the end. The two
lugs on both sides of the Jiangcun lining are respectively inserted into the rectangular holes of the bottom and the cover of the box. Since the lining can move radially in the square hole, the friction between the circles is reduced when winding, and it has a relatively stable stiffness, which is a more reasonable type of fixing.
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