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GB/T 19844-2018: Leaf springs -- Technical specifications
Status: Valid GB/T 19844: Evolution and historical versions
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Leaf springs -- Technical specifications
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PDF similar to GB/T 19844-2018
Basic data | Standard ID | GB/T 19844-2018 (GB/T19844-2018) | | Description (Translated English) | Leaf springs -- Technical specifications | | Sector / Industry | National Standard (Recommended) | | Classification of Chinese Standard | J26 | | Classification of International Standard | 21.160 | | Word Count Estimation | 22,260 | | Date of Issue | 2018-09-17 | | Date of Implementation | 2019-04-01 | | Older Standard (superseded by this standard) | GB/T 19844-2005 | | Issuing agency(ies) | State Administration for Market Regulation, China National Standardization Administration | GB/T 19844-2018: Leaf springs -- Technical specifications---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order.
Leaf springs - Technical specifications
ICS 21.160
J26
National Standards of People's Republic of China
Replace GB/T 19844-2005
Leaf spring technical conditions
(ISO 18137.2015, MOD)
Published on.2018-09-17
Implementation of.2019-04-01
State market supervision and administration
China National Standardization Administration issued
Foreword
This standard was drafted in accordance with the rules given in GB/T 1.1-2009.
This standard replaces GB/T 19844-2005 "Sheet Spring". Compared with GB/T 19844-2005, the main technical changes are as follows.
--- Revised scope (see Chapter 1, Chapter 1 of the.2005 edition);
--- Revised the normative reference document (see Chapter 2, Chapter 2 of the.2005 edition);
--- Added parameter names, symbols and units (see Chapter 4);
--- Increased spring type (see Chapter 5);
--- Modified the material and increased the selection of GB/T 33164.1 (see 6.1, version 4.1 of.2005);
--- Modified length, assembly width, ear aperture and bushing inner diameter, side bend, curl verticality and parallelism (see 6.2,.2005)
Version 4.2);
---Modified spring stiffness (see 6.3.2; 4.3.2 of the.2005 edition);
---Modified fatigue life (see 6.3.4; 4.6 of the.2005 edition);
--- Modified hardness, decarburization, shot peening, lubrication and surface preservation, surface quality (see 6.4;.2005 editions 4.4, 4.5 and 4.7);
--- Increased design arc height (see 6.3.3);
--- Increased preload (see 6.4.4);
---Modified test methods (see Chapter 7);
--- Revised the acceptance rules (see Chapter 8);
--- Added Appendix A (see Appendix A);
--- Added Appendix B (see Appendix B);
--- Revised the normative appendix "Test methods for leaf springs" (see Appendix C, Appendix A of the.2005 edition).
This standard uses the redrafting method to modify the use of ISO 18137.2015 "plate spring technical conditions."
This standard has more structural adjustments than ISO 18137.2015. This standard and ISO 18137.2015 are listed in Appendix A.
The chapter number is compared to the list.
There are technical differences between this standard and ISO 18137.2015, and the terms involved in these differences have been passed through the margins on the outer side of the page.
The vertical single line (|) is marked, and a list of the corresponding technical differences and their causes is given in Appendix B.
This standard is proposed and managed by the National Spring Standardization Technical Committee (SAC/TC235).
This standard is drafted by. Dongfeng Motor Suspension Spring Co., Ltd., Jiangxi Dachangli Auto Parts Co., Ltd., Fuao Liaoning
Automotive Springs Co., Ltd., China Machine Productivity Promotion Center.
Participated in the drafting of this standard. Chongqing Hongyan Fangda Automobile Suspension Co., Ltd., Nanjing Automotive Group Co., Ltd. Automotive Engineering Research Institute,
China First Automobile Co., Ltd. Technology Center, Jiangxi Yuancheng Automotive Technology Co., Ltd., Shandong Leipad Automotive Technology Co., Ltd.
Company, Zhejiang Funiu Leaf Spring Co., Ltd., Fangda Special Steel Technology Co., Ltd., Qingdao Special Steel Co., Ltd.
The main drafters of this standard. Liu Fuqiang, Wu Xiaotao, Zhang Yuehui, Cheng Peng, Wu Huiming, Chen Weifeng, Yu Fang, Li Yong, Qi Zhengming, Wang Jun,
Hao Jixiang, Wang Shaoju, Meng Xianyu, Ji Zhengxing, Li Ze, Chen Ming, Wu Jianming, Wang Yufeng, Lu Wei, Xiao Chunjun, Zhang Wei, Qin Lifu.
The previous versions of the standards replaced by this standard are.
---GB/T 19844-2005.
Leaf spring technical conditions
1 Scope
This standard specifies the technical requirements and test methods for leaf springs.
This standard applies to leaf springs used in road vehicles (hereinafter referred to as "springs"). Other vehicle springs can be used as reference.
2 Normative references
The following documents are indispensable for the application of this document. For dated references, only dated versions apply to this article.
Pieces. For undated references, the latest edition (including all amendments) applies to this document.
Detachment layer depth determination method for GB/T 224 steel (GB/T 224-2008, ISO 3887.2003, MOD)
GB/T 230.1 Rockwell hardness test for metallic materials - Part 1. Test methods (A, B, C, D, E, F, G, H, K, N, T
Ruler) (GB/T 230.1-2009, ISO 6508-1.2005, MOD)
GB/T 231.1 Brinell hardness test for metallic materials - Part 1. Test methods (GB/T 231.1-2009, ISO 6506-1.
2005, MOD)
GB/T 1805 spring terminology
GB/T 2828.1. Sampling and sampling procedures - Part 1 . Batch-to-batch sampling plan searched by the acceptance quality limit (AQL)
(GB/T 2828.1-2012, ISO 2859-1..1999, IDT)
GB/T 31214.1 Spring shot peening Part 1. General (GB/T 31214.1-2014, ISO 26910-1.2009, IDT)
GB/T 33164.1 Spring steel for automotive suspension systems - Part 1. Hot rolled flat steel
JB/T 10802 spring shot peening technical specification
ISO 683-14 heat-treated steel, alloy steel and free-cut steel - Part 14. Hot-rolled steel for quenching and tempering springs (Heat-treatable
Steels,aloysteelsandfree-cuttingsteels-Part 14.Hot-roledsteelsforquenchedandtempered
Springs)
3 Terms and definitions
The terms and definitions defined in GB/T 1805 apply to this document.
4 parameter names, symbols and units
The parameter names, symbols, and units in Table 1 apply to this document. For ease of use, a working diagram of the leaf spring is given, as shown in Figure 1.
Table 1 Parameter names, symbols, and units
No. Parameter Name Symbol Unit Description
1 End width bA mm Width of spring roll or slide
2 Assembly width bE mm Width of spring assembly within U-bolt clamping range
3 arc height C mm
The spring mounting center (center bolt or center pin) is the first piece to be pulled to two negative
Vertical distance of the connection point
4 Free arc height C0 mm Arc height of the spring in free state or no load
5 Design arc height Cd mm spring arc height when subjected to design (nominal) load
6-volume aperture dA mm inner diameter of spring-loaded ear hole
7 bushing inner diameter di mm inner diameter of spring bushing
8 Load FN springs bear the total force
9 Design load Fd N The nominal load given by the spring design
10 Maximum test load Fmax, t N Maximum load given by the spring during performance test
11 height H mm overall height of the spring
12 Free height H0 mm Spring free or height without load
13 Design height Hd mm The height at which the spring is subjected to the design load
14 chord length l mm distance between spring two load points
15 free chord length l0 mm chord length of spring in free state or no load
16 Fixed end length lA mm Distance from spring fixed end to mounting center
17 Straightening length lST mm The distance between the two load points when the first piece of spring is fully extended
18 Fixed end straightening length lST, A mm Fixed length of the first piece of spring when the first piece is fully extended
19 Spring Stiffness RN/mm Spring produces load when unit is deformed
20 deformation s mm spring changes in arc height under load
21 Design deformation sd mm Spring deformation under design load
22 Clamping deformation sd, j mm Design deformation of the spring under clamping
23 Maximum test deformation smax, t mm Deformation of the spring under maximum test load
Table 1 (continued)
No. Parameter Name Symbol Unit Description
24 Side bending δ mm The amount of bending of the side of the spring reed (see Figure 11)
25 design stress σd MPa
(clamped state) under design load.
Average stress at the root of multiple leaf springs;
Less stress at the maximum stress point of the leaf spring
26 Specific stress σ MPa/mm The stress of the unit deformation of the clamped state, ie σd/sd,j
5 spring type
The common types of springs are shown in Figures 1 through 10.
Figure 1 Equal-section springs at both ends
a)
Figure 2 Variable section springs at both ends
b)
Figure 2 (continued)
Figure 3 isometric spring with one end of the roller at one end
Figure 4 Variable section spring with one end of the roller at one end
Figure 5 Equal-section springs of the skateboards at both ends
Figure 6 Variable section springs at both ends of the slide
Figure 7 Two-stage stiffness equal-section spring on the auxiliary spring
Figure 8 Two-stage stiffness variable section spring on the auxiliary spring
Figure 9 Two-stage stiffness variable section spring under the auxiliary spring
Figure 10 gradient stiffness spring
6 Technical requirements
6.1 Materials
Spring materials should generally be made of hot-rolled flat steel in accordance with GB/T 33164.1 and ISO 683-14. If there are special requirements, both the supply and demand sides
Negotiation.
6.2 Dimensions and shape tolerances
6.2.1 Length
See Table 2 for the allowable deviation of the length of the spring and the length of the fixed end.
Table 2 length tolerance unit is mm
Straightening length lST Fixed end straightening length lST, A
Range allowable deviation range allowable deviation
lST≤2000 ±3.0 lST, A≤1000 ±1.5
lST >2000 ±4.0 lST, A >1000 ±2.0
6.2.2 Assembly width
The allowable deviation of the width of the spring assembly shall be in accordance with Table 3. The allowable deviation of the width of the machined part shall be negotiated between the supplier and the purchaser.
Table 3 Assembly width tolerance unit is mm
Assembly width bE allowable deviation
bE≤100 2.5-0.8
bE >100 3.0-0.8
6.2.3 End width
The allowable deviation of the spring coil width should meet the requirements of Table 4. If there are special requirements, the supplier and the buyer will negotiate.
Table 4 End tolerance is in millimeters
Roll width bA allowable deviation
Machining 0-0.5
Unmachined 1.5-1.5
The allowable deviation of the spring slide end width is negotiated by both the supplier and the buyer.
6.2.4 Ear hole diameter and bushing inner diameter
The tolerance of the unprocessed ear aperture should be no more than ±0.5mm, and the allowable deviation of the processed ear diameter is negotiated by both the supplier and the buyer.
The allowable deviation of the inner diameter of the bushing is negotiated between the supplier and the buyer.
6.2.5 Side bending
The side of each piece of spring loaded into the bracket is not more than 1.5 mm per meter, and the remaining pieces are not more than 3 mm per meter (Figure 11
Shown).
Description.
b---The width of the reed.
Figure 11 side curved view
6.2.6 Roller verticality and parallelism
After the spring coil is installed in the bushing, the allowable deviation of the perpendicularity and parallelism of the axis of the inner diameter di of the ear bushing should be no more than 1 (as shown in the figure).
12)).
Figure 12 Schematic diagram of the parallelism and perpendicularity of the ears
6.3 Spring characteristics
6.3.1 Permanent deformation
The spring permanent deformation should be no more than 0.5mm.
6.3.2 Spring stiffness
The spring stiffness tolerance shall comply with the requirements of Table 5. If there are special requirements, the supplier and the buyer will negotiate.
Table 5 Spring stiffness tolerance
Spring type allows deviation
Variable section spring ± 6%
Other types of spring ±8%
6.3.3 Design arc height
The allowable deviation of the arc height of the spring design shall be no more than ±7.0mm. If there are special requirements, the arc height shall be grouped according to the negotiation between the supplier and the buyer.
6.3.4 Fatigue life
Under the test conditions of stress amplitude 323.6MPa and maximum stress 833.5MPa, the spring fatigue life should be no less than 100,000 times. Such as
There are special requirements, which are negotiated between the supplier and the buyer.
6.4 Manufacturing requirements
6.4.1 Hardness
After the heat treatment of the reed, the hardness should be 388HBW~461HBW (41HRC~48HRC), as required by the supplier and the buyer.
Negotiation.
6.4.2 Decarbonization
The total decarburization depth of the reed tensile surface shall not exceed the requirements of Table 6.
Table 6 Decarburization depth requirements
Reed thickness/mm total decarburization depth
≤8 3.0% reed thickness
>8~15 2.5% reed thickness
>15 1% reed thickness 0.15mm
6.4.3 Shot peening
The reed tensile surface shall be shot blasted after heat treatment, and the shot peening shall be carried out according to GB/T 31214.1 and JB/T 10802.
Strength and coverage are negotiated between the supplier and the buyer.
6.4.4 Preloading
The spring shall be preloaded according to the load specified in the product drawing.
6.4.5 Lubrication and surface preservation
When lubrication is required, the contact surface of the spring reed should be coated with a lubricant.
The spring shall be surface treated in accordance with the requirements of the drawings.
6.4.6 Surface quality
On the tension surface of the spring, the indentation, hairline, flash, and bruise should be minimized.
The spring coils allow for traces during processing in the range of 120° from the ear gap.
7 Test methods
See Appendix C for spring test methods.
8 Acceptance rules
8.1 Overview
The spring inspection shall be delivered after passing the inspection by the inspection department of the manufacturer, and shall be accompanied by a product quality certificate.
8.2 Inspection classification
8.2.1 Factory inspection items
The factory inspection shall include the following items.
a) permanent deformation;
b) design arc height;
c) spring stiffness;
d) the diameter of the ear or the inner diameter of the bushing;
e) the verticality of the ears;
f) the parallelism of the ears;
g) assembly width;
h) end width;
i) surface quality;
j) Hardness.
8.2.2 Type inspection items
Includes factory inspection items and fatigue life. In one of the following cases, the spring should be type tested.
a) When trial production, finalization and commissioning of new products or old products are carried out in different places;
b) Old products have great changes in structure, materials and processes, which may affect product performance;
c) When requested by the user.
8.3 Sampling plan
The products produced by stereotypes are in accordance with GB/T 2828.1 once a normal sampling plan. The sample size and sampling base are specified in Table 7.
Table 7 Sampling plan units
Batch range sample number
2~50 2
50~500 3
>500 5
Note. The fatigue test sample does not exceed 3 pieces.
9 Identification, packaging and storage
9.1 Identification
The spring should be identified, and the identification method and identification content should be negotiated between the supplier and the buyer.
9.2 Packaging
Packaging spring product packaging should ensure that it should not be loose, scattered and damaged under normal transportation and handling conditions.
9.3 Storage
Storage spring products should be placed in a sheltered, ventilated, dry place.
Appendix A
(informative appendix)
Comparison of this standard with ISO 18137.2015 chapter number
Table A.1 gives a checklist of the numbering of this standard chapter number and the ISO 18137.2015 chapter number.
Table A.1 Comparison list of the standard chapter number and ISO 18137.2015 chapter number
This standard chapter number ISO 18137.2015 chapter number
4 3.2
6.2.1 5.2.1
6.2.2 5.2.2
6.2.3 5.2.3
6.2.4 5.2.4
6.2.5 5.2.5
6.2.6 5.2.6
6.3.1 -
6.3.2 5.3.1
6.3.3 5.3.2
6.3.4 5.3.3
6.4 5.4
6.4.1 5.4.1
6.4.2 5.4.2
6.4.3 5.4.3
6.4.4 5.4.4
6.4.5 5.4.5
6.4.6 5.4.6
7 Appendix A
8 -
9.1 6
9.2 -
9.3 -
Appendix A -
Appendix B -
Appendix C Appendix A
Appendix B
(informative appendix)
Technical differences between this standard and ISO 18137.2015 and their causes
Table B.1 gives the technical differences between this standard and ISO 18137.2015 and their causes.
Table B.1 Technical differences between this standard and ISO 18137.2015 and their causes
This standard chapter
Article number
Reason for technical differences
The technical differences between this standard and ISO 18137.2015(E) and their reasons are as follows.
Regarding the normative reference documents, this standard has made technical adjustments to suit
According to the technical conditions of our country, the adjustment situation is concentrated in Chapter 2, “Regulatory Citations.
In the "piece", the specific adjustment is as follows.
Replace the ISO 3887.2003 with GB/T 224 modified to adopt the national standard;
Replace GB 6T-1.2005 with GB/T 230.1 modified with international standards;
Replace ISO 6506-1.2005 with GB/T 231.1 modified to adopt international standards;
Replace ISO 26909.2009 with GB/T 1805, which is not equivalent to the international standard.
ISO 16249.2013;
Added references to GB/T 2828.1, GB/T 31214.1, GB/T 33164.1,
JB/T 10802
To meet domestic product requirements and standards
Coordination between
Parameter names, symbols, and units are added.
Clamping deformation sd,j, design stress σd, specific stress σ
Suitable for domestic design needs, universal use
Materials to increase domestic materials, changed to.
Springs should generally be made of hot-rolled flat steel in accordance with GB/T 33164.1 and ISO 683-14. Such as
Have special requirements, negotiated by both parties
Increase domestic materials, conducive to production, in line with
Domestic product requirements
6.2.1 The length tolerance of Table 2 is adjusted. lST≤2000 and lST >200
Length tolerance is adjusted by the European series
For domestic drawings
6.2.2
The international standard setting of the assembly width is based on the European series and is not suitable for domestic use. Assembly
The width is divided into. bE≤100 and bE >100
The international standard setting is in accordance with the European series.
Come, not suitable for domestic
6.2.6
The verticality and parallelism of the ears are changed to. the springs are placed in the bushings, and the ears are perpendicular to the ears.
The allowable deviation of the line should be no more than 1 (as shown in Figure 12). Will be in the international standard Figure 12
Benchmark made changes
The benchmark of the original international standard is wrong, plus
Correction
6.3.1
Increase the requirement for permanent deformation.
The permanent deformation of the spring should be no more than 0.5mm
Considering that the domestic OEM has permanently changed the spring
Shape requirements, still use GB/T 19844-
Permanent deformation requirements in the.2005 standard
6.3.2 The spring stiffness tolerance shall be in accordance with the requirements of Table 5 to remove the classification.
Domestic market products have clear rigidity
Claim
Table B.1 (continued)
This standard chapter
Article number
Reason for technical differences
6.3.3
According to the national conditions, change the design arc height to.
The allowable deviation of the arc height of the spring design shall not exceed ±7.0mm, and if required,
The two sides need to negotiate the arc height grouping
Combined with the current status of domestic spring industry technology, selected
Design the arc height type 2 in the international standard
As standard requirements; according to the actual installation of the OEM
Vehicle-to-design arc height tolerance requirements, the same
Consider the domestic spring industry production control
Level, using the design arc height grouping
Method, reaching the design arc height type 1 allows partial
Poor effect
6.3.4
The fatigue life is set at the lowest level according to the domestic level.
Under the test conditions of stress amplitude 323.6MPa and maximum stress 833.5MPa, the spring is fatigued.
Labor life should be no less than 100,000 times. If there are special requirements, the supplier and the buyer will negotiate
In line with domestic customs
6.4.1
Hardness, according to domestic requirements, gives clear regulations.
After the heat treatment of the reed, the hardness should be 388 HBW~461 HBW (41 HRC~
48HRC), if required, negotiated by the supplier and the buyer
China's materials used in China are relatively concentrated, hard
Degree can clearly give the range
6.4.2 Decarbonization, according to domestic requirements, Table 6 is refined to give clear provisions. More reasonable
According to the domestic requirements, give clear regulations
For quality control
6.4.4
According to the domestic mature technology, to pre-press.
The spring should be preloaded according to the load specified in the product drawings.
Must be carried out in the domestic manufacturing process
Process
7 All in Appendix C, but in the form of a normative appendix
Make the standard a complete document, then
For use
8 In order to facilitate the use of both supply and demand as acceptance criteria, the provisions of the acceptance rules are more operational.
9 Regulation of product identification, packaging and storage is more operability
Appendix A adds the convenience of this standard chapter number and ISO 18137.2015 chapter number comparison query
Appendix B This standard and ISO 18137.2015 "Sheet Spring Technical Conditions" technical differences and reasons are more operable
Appendix C
The test method of the leaf spring is given in the form of a normative appendix, which is the same for the enterprise.
Method down measurement
More operability
Appendix C
(informative appendix)
Test method for leaf spring
C.1 Ear Aperture and Bushing Inner Diameter
The roll aperture and the inner diameter of the bushing are inspected using a smooth limit gauge or a special gauge.
C.2 Assembly width
The width of the assembly is checked with a special gauge.
C.3 end width
The end width is checked with a special gauge.
C.4 Roller verticality and parallelism
The verticality of the ears and the parallelism of the ears are checked by special inspection tools.
C.5 hardness
The Brinell hardness of the spring is tested according to the provisions of GB/T 231.1, and the Rockwell hardness should be tested according to the provisions of GB/T 230.1.
The test shall be carried out on the pressure side of each piece at a quarter of the length.
C.6 Decarburization
The spring decarburization layer shall be tested according to the provisions of GB/T 224, and the sampling part shall be negotiated by both parties.
C.7 Surface quality
The surface quality of the spring was examined by visual inspection.
C.8 permanent deformation test
C.8.1 Test device
The test device shall be capable of keeping the spring stable, capable of applying a static load to the spring slowly and continuously, and providing a test for detecting load and deformation.
Measuring mechanism, the load measurement accuracy is within ±1% of the maximum test load of the spring; the deformation measurement is not more than 0.2mm for the special value or
General gage inspection.
C.8.2 Support and clamping method
In order not to hinder the deformation of the spring, it should be supported by a small friction method as much as possible. The common support method is shown in Figure C.1. Middle part press
The clamping method and conditions specified in the product drawings are clamped.
a) Example of support method for the coil springs at both ends
b) Example of support method for a section spring such as a slide at one end of the coil end
Figure C.1 Example of a common support method
c) Example of support method for the slide springs at both ends
Description.
1---V-shaped loading block;
2---spring;
3---pin shaft;
4---sliding car;
5---fixed plate.
Figure C.1 (continued)
C.8.3 Test method
Measure the free arc height of the spring after loading and unloading the spring with the maximum test load specified by the product pattern.
The method then loads and unloads the spring 3 times, and measures the free arc height of the spring again after unloading. The difference between the two measurements is the permanent of the spring
Deformation.
C.9 Spring stiffness
C.9.1 Test device
Same as C.8.1.
C.9.2 Support and clamping method
Same as C.8.1.
C.9.3 Test method
The load is applied through a V-shaped loading block as shown in Figure C.2. First slowly load the spring to the maximum test load and unload it to zero negative
After the load, the spring is slowly loaded to the maximum test load and then unloaded. The load and corresponding deformation during the loading and unloading process are recorded, and the load and change are drawn.
The relationship curve (shown in Figure C.3).
The unit is mm
Figure C.2 V-shaped loading block detailed dimensions
Figure C.3 Spring load versus deformation curve
C.9.4 Calculation method for deformation under specified load
The deformation of the spring under the specified load is calculated according to equations (C.1), (C.2) and (C.3).
S1=(s11 s12)/2 (C.1)
S2=(...
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