1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 6312:2010Road vehicles Brake linings Shear test procedure fordisc brake pad and drum brakeshoe assembliesBS ISO 6312:2010 BRITISH STANDARDNational forewordThis British Sta
2、ndard is the UK implementation of ISO 6312:2010.The UK participation in its preparation was entrusted to TechnicalCommittee AUE/11, Braking systems.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the ne
3、cessaryprovisions of a contract. Users are responsible for its correctapplication. BSI 2010ISBN 978 0 580 64387 3ICS 43.040.40Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Co
4、mmittee on 30 September 2010.Amendments issued since publicationDate Text affectedBS ISO 6312:2010Reference numberISO 6312:2010(E)ISO 2010INTERNATIONAL STANDARD ISO6312Third edition2010-08-15Road vehicles Brake linings Shear test procedure for disc brake pad and drum brake shoe assemblies Vhicules r
5、outiers Garnitures de freins Mthode dessai de cisaillement des ensembles de plaquettes de freins disque et segments de freins tambour BS ISO 6312:2010ISO 6312:2010(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this file may be printed or
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10、 + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2010 All rights reservedBS ISO 6312:2010ISO 6312:2010(E) ISO 2010 All rights reserved iiiContents Page Foreword iv Introduction.v 1 Scope1 2 Normative references1 3 Terms and definitions .1 4 Symbols and units
11、.2 5 Sampling and conditioning 2 6 Test rig and fixtures 2 6.1 Test rig2 6.2 Fixtures.3 7 Test procedure.5 8 Calculation of shear strength.6 9 Presentation of results6 Annex A (normative) Test procedure flowchart.8 Annex B (informative) Test report .10 Bibliography11 BS ISO 6312:2010ISO 6312:2010(E)
12、 iv ISO 2010 All rights reservedForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body inter
13、ested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical
14、 Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the te
15、chnical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. IS
16、O shall not be held responsible for identifying any or all such patent rights. ISO 6312 was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 2, Braking systems and equipment. This third edition cancels and replaces the second edition (ISO 6312:2001), which has been technical
17、ly revised. BS ISO 6312:2010ISO 6312:2010(E) ISO 2010 All rights reserved vIntroduction The shear property relates to stresses at the area of contact between lining and carrier in disc brake pad and drum brake shoe assemblies. The specification for the average rate of load and the recommendation for
18、 variations in the instantaneous rate of load given in this International Standard take into account current practice, based upon an examination of equipment in use. This third edition of this International Standard incorporates technical updates generated in the course of harmonization efforts duri
19、ng the development of ISO 15484. BS ISO 6312:2010BS ISO 6312:2010INTERNATIONAL STANDARD ISO 6312:2010(E) ISO 2010 All rights reserved 1Road vehicles Brake linings Shear test procedure for disc brake pad and drum brake shoe assemblies 1 Scope This International Standard specifies a method for measuri
20、ng the strength of the bond connection between the lining material and the carrier in disc brake pad and drum brake shoe assemblies (shear strength). This International Standard is applicable to assemblies that are integrally moulded, bonded or that use mechanical retention systems (MRS) of both typ
21、es used for brakes on road vehicles. This International Standard does not apply to riveted assemblies. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the l
22、atest edition of the referenced document (including any amendments) applies. ISO 611, Road vehicles Braking of automotive vehicles and their trailers Vocabulary 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 611 and the following apply. 3.1 lining f
23、riction material component of a brake lining assembly 3.2 carrier component of a brake lining assembly to which the friction material is attached 3.3 bond area A contact area between lining and carrier 3.4 mechanical retention system MRS attachment method where mechanical protrusions on the backing
24、plate aid the retention of the friction material or the underlayer 3.5 shear force at failure F total load applied at the time of shear failure BS ISO 6312:2010ISO 6312:2010(E) 2 ISO 2010 All rights reserved3.6 shear strength at failure ratio of the load at failure divided by the bond area 4 Symbols
25、 and units The symbols and preferred units used in this International Standard are given in Table 1. See Clause 8. Table 1 Symbols and units Quantity Symbol Unit Shear force at failure F N Bond area A mm2Shear strength at failure MPa 5 Sampling and conditioning This procedure can also apply for samp
26、les during product development, on finished products, or after special treatment (such as that covered by ISO 6314) or usage (inertia-dynamometer testing or field use) with the appropriate preparation. Perform the testing on a complete assembly or a section (coupon) of the assembly. When testing a s
27、ection or coupon, apply the load in the radial or tangential direction relative to the vehicle mounting position. Indicate the test orientation on the test report. If needed, prepare the sample edges to ensure good contact with the loading and fixed tools. Remove noise insulating shims before the te
28、st. When testing a lined shoe, the test area may cover the full assembly or segments of an assembly confined by saw cutting down to the carrier (see Figure 1). Use five samples for standard testing. NOTE The test procedure applies a load in a direction that might not be in accordance with the loadin
29、g direction of the product in service. A high aspect ratio, chamfered, or slotted pads might influence the shear behaviour of the pad assembly. 6 Test rig and fixtures 6.1 Test rig The test rig shall be a compression or tensile testing machine or similar (shear testing) machine of sufficient capacit
30、y to apply the shearing load by activating a ram. The test rig shall provide equipment to register the exact load applied at the instant of shear failure. The load application rate shall be controlled in such a way that the load increases at an average rate of (4 500 1 000) N/s (as determined from t
31、ypical vehicle-based evaluation). If a constant crosshead speed machine is being used, the load rate shall be set to (10 1) mm/min. Indicate on the test report the type of machine control (load rate or crosshead speed) used for the test, so that it allows comparisons of results between different tes
32、t rigs. Avoid any shock loading during the test. BS ISO 6312:2010ISO 6312:2010(E) ISO 2010 All rights reserved 3Dimensions in millimetres Figure 1 Lined shoe in segmental test condition 6.2 Fixtures 6.2.1 General The shearing test fixture shall have the means to hold a test sample such that it is pa
33、rallel to the loading tool. To avoid sharp edges, this tool shall have a radius of 2 mm or less at the part in contact with the test sample. If a specific radius is used, note it on the test report as a deviation from the test procedure. If the surface area of the loading tool includes the draft ang
34、le of the friction material, note it on the test report. 6.2.2 Drum brake shoe assembly The fixture (see Figure 2) shall be designed so that the loading tool is in contact with the edge of the lining for the full sample length and thickness within (1 0,2) mm of the shoe platform. The load applicatio
35、n on the loading tool shall be in a direction parallel to the plane of the shoe platform. Support the shoe to maintain uniform loading along the length of the lining sample. The width of the loading tool shall be greater than the width, W, of the lining. 6.2.3 Disc brake pad Design the test fixture
36、(see Figure 3) such that: the location of the plane of the backplate is parallel to the plane of the loading tool; the loading tool is in contact with the edge of the lining within (1 0,2) mm of the backing plate (carrier) and conforms to the sample lining profile, including as optional draft angles
37、 from the moulding process; the loading tool is self-aligning; the loading tool is in contact with the full sample length of the lining edge parallel to the backplate support; the load-bearing edge of the backing plate rests against a rigid support with a thickness no greater than that of the backin
38、g plate; in order to prevent assembly movement under testing, a pressure fixture applies a face load of (0,5 0,15) N/mm2of the lining area at a right angle to the shear load; the face load is applied in such a way that friction force is minimized and does not significantly influence the shear load m
39、easurement. BS ISO 6312:2010ISO 6312:2010(E) 4 ISO 2010 All rights reservedDimensions in millimetres Key 1 loading tool 2 loading punch profile, (1 0,2) mm clear off shoe platform 3 lining face support 4 fixed bottom tool 5 shoe platform supported by tool (support u platform thickness) aCentre of th
40、rust of top ram to be positioned thus. bLoading direction, parallel to shoe platform. cThrough test tool. Figure 2 Drum brake shoe test fixture BS ISO 6312:2010ISO 6312:2010(E) ISO 2010 All rights reserved 5Dimensions in millimetres Key 1 loading tool (parallel to backing plate support) 2 backing pl
41、ate support 3 face load fixture C u backplate thickness aDirection of shear force. bPivot. cFace load. dMinimized friction at interface. Figure 3 Disc brake pad test fixture 7 Test procedure Carry out the test procedure as described below (Figure A.1 provides a flowchart of the test procedure). a) C
42、onduct the test at ambient temperature (23 5) C. Agree with customer prior to testing for other ambient conditions. b) When conducting a shear tests at elevated temperatures, heat the sample uniformly to the bond line temperature within 30 min and test 60 s after removal from the heating unit. Recom
43、mended temperatures are (200 10) C for drum brake linings and (300 10) C for disc pads. BS ISO 6312:2010ISO 6312:2010(E) 6 ISO 2010 All rights reservedc) Place the brake shoe or disc brake pad in the appropriate shear-test fixture in the orientation indicated for the test (radial or tangential). d)
44、Apply the load at the rate specified in 6.1, continuing until complete failure occurs. e) (Optional) Record the failure load together with the shear pattern expressed as a percentage as specified in Clause 9. Assess the fracture surface of uncut edges (2 mm from the friction pad or brake shoe outlin
45、e) and core zones separately. If a visual assessment is doubtful, perform (optional to the test requestor) an analysis with a reference solution as described below. 1) Prepare 1,0 l of reference solution by mixing: 80 g of CuSO4; 30 g of NaCl; 100 ml of 0,01 N hydrochloric acid (0,364 6 g HCl in a 1
46、,0 l solution); add distilled water or de-ionized water to obtain a total solution volume of 1,0 l. 2) Immerse the backplate in the reference solution for 5 s. 3) Assess the fracture condition and record as follows: a material has fractured when the fracture surface is not coloured brown by the refe
47、rence solution; if there is a bonding fault between the glue and the backplate, there will be a regular and homogeneous brown colouring at the surface of fracture. 8 Calculation of shear strength Calculate the shear strength, , using Equation (1), as follows: FA = (1) Calculate A from the friction m
48、aterial profile at the bond line and not at the pad face, as chamfers or slots are pad surface effects. Report the shear strength as the minimum and the average of the results of the number of samples tested. 9 Presentation of results The test report (see Annex B) shall include the following informa
49、tion: a) type and supplier of the brake shoe assembly or disc brake pad friction material, and batch identification; b) sample type and load orientation when testing using a section or coupon; c) number of samples tested (five recommended); d) minimum and average shear force, or minimum and average shear strength, values, or both; e) loading tool with/without taper angle from moulding process; BS ISO 6312:2010ISO 6312:2010(E) ISO 2010 All rights reserved
