GB/T 19844-2018Leaf springs -- Technical specifications (English PDF)

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.

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 delta mm The amount of bending of the side of the spring reed (see Figure 11)

25 design stress sigmad 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 sigma MPa/mm The stress of the unit deformation of the clamped state, ie sigmad/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

7 Test methods

See Appendix C for spring test methods.

8 Acceptance rules

9 Identification, packaging and storage

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 sigmad, specific stress sigma

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

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=(...