1、 Collection of SANS standards in electronic format (PDF) 1. Copyright This standard is available to staff members of companies that have subscribed to the complete collection of SANS standards in accordance with a formal copyright agreement. This document may reside on a CENTRAL FILE SERVER or INTRA
2、NET SYSTEM only. Unless specific permission has been granted, this document MAY NOT be sent or given to staff members from other companies or organizations. Doing so would constitute a VIOLATION of SABS copyright rules. 2. Indemnity The South African Bureau of Standards accepts no liability for any
3、damage whatsoever than may result from the use of this material or the information contain therein, irrespective of the cause and quantum thereof. ISBN 978-0-626-22572-8 SANS 1622:2009Edition 1.1Any reference to SABS 1622 is deemedto be a reference to this standard(Government Notice No. 1373 of 8 No
4、vember 2002)SOUTH AFRICAN NATIONAL STANDARD Road vehicle safety standard New replacement brake drums for motor vehicles Published by SABS Standards Division 1 Dr Lategan Road Groenkloof Private Bag X191 Pretoria 0001Tel: +27 12 428 7911 Fax: +27 12 344 1568 www.sabs.co.za SABS SANS 1622:2009 Edition
5、 1.1 Table of changes Change No. Date Scope Amdt 1 2009 Amended to change the designation of SABS standards to SANS standards, with no technical changes. Foreword This South African standard was approved by National Committee SABS SC 22F, Steering committee for construction of motor vehicles Braking
6、, in accordance with procedures of the SABS Standards Division, in compliance with annex 3 of the WTO/TBT agreement. This document was published in March 2009. This document supersedes SABS 1622:1995 (edition 1). Annexes A and B form an integral part of this document. SANS 1622:2009 Edition 1.1 1 Co
7、ntents Page Foreword 1 Scope 3 2 Normative references 3 3 Definitions 3 4 General requirements 5 Annex A (normative) Light vehicle brake drum performance tests 8 Annex B (normative) Heavy vehicle brake drum performance tests 10 SANS 1622:2009 Edition 1.1 2 This page is intentionally left blank SANS
8、1622:2009 Edition 1.1 3 New replacement brake drums for motor vehicles 1 Scope This standard specifies the composition and the performance requirements of new replacement cast-iron brake drums for motor vehicles. 2 Normative references The following standard contains provisions which, through refere
9、nce in this text, constitute provisions of this standard. All standards are subject to revision and, since any reference to a standard is deemed to be a reference to the latest edition of that standard, parties to agreements based on this standard are encouraged to take steps to ensure the use of th
10、e most recent edition of the standard indicated below. Information on currently valid national and international standards may be obtained from the SABS Standards Division. SANS 1034, Grey iron castings. 3 Definitions For the purposes of this standard, the following definitions apply: 3.1 brake lini
11、ng component that comprises the friction material and that makes contact with the brake drum when the brakes are applied 3.2 contact surface (see figure 1) inner surface of the drum, which is contacted by the brake lining 3.3 crazing pattern of small hairline cracks 3.4 dynamometer machine that simu
12、lates the inertia effect when a motor vehicle is being braked 3.5 heat (thermal) spots hard spots that are caused by changes in the structure of the drum material and that result from the temperature gradient within those spots SANS 1622:2009 Edition 1.1 4 3.6 heavy vehicle vehicle of category M2, M
13、3, N2, N3, O3or O43.6.1 M2vehicle vehicle that is used for the carriage of passengers, that comprises more than eight seats in addition to the drivers seat, and that has a maximum mass not exceeding 5 t 3.6.2 M3vehicle vehicle that is used for the carriage of passengers, that comprises more than eig
14、ht seats in addition to the drivers seat, and that has a maximum mass exceeding 5 t 3.6.3 N2vehicle vehicle that is used for the carriage of goods and that has a maximum mass exceeding 3,5 t but not exceeding 12 t 3.6.4 N3vehicle vehicle that is used for the carriage of goods and that has a maximum
15、mass exceeding 12 t 3.6.5 O3vehicle trailer that has a maximum mass exceeding 3,5 t but not exceeding 10 t 3.6.6 O4vehicle trailer that has a maximum mass exceeding 10 t 3.7 light vehicle vehicle of category M1, N1, O1or O23.7.1 M1vehicle vehicle that is used for the carriage of passengers and that
16、comprises not more than eight seats in addition to the drivers seat 3.7.2 N1vehicle vehicle that is used for the carriage of goods and that has a maximum mass not exceeding 3,5 t 3.7.3 O1vehicle single-axle trailer, other than a semi-trailer, that has a maximum mass not exceeding 0,75 t 3.7.4 O2vehi
17、cle trailer, other than a trailer of category O1, that has a maximum mass not exceeding 3,5 t 3.8 reference brake lining brake lining that is selected for the purpose of testing the performance of brake drums, being the original equipment (OE) lining for the drum, which the drum under test is intend
18、ed to replace SANS 1622:2009 Edition 1.1 5 4 General requirements 4.1 Equivalent requirements The requirements of clause 4 may be deemed to have been met if the component complies with alternative requirements that achieve the objectives of the requirements of this standard. 4.2 Metallurgical requir
19、ements 4.2.1 The material of the brake drum shall comply with the requirements for grade 250 cast iron as specified in SANS 1034. The Brinell hardness (HB 10/3000) measured on the flange of the drum shall be in the range 200 to 230. Test specimens that are representative of the applicable cross-sect
20、ional thickness of the casting shall comply with the minimum tensile strength requirements stated in SANS 1034. 4.2.2 A copy of the test certificates submitted by the foundry relevant to the sample submitted for testing shall be supplied with sample brake drums submitted for testing. 4.3 Physical re
21、quirements 4.3.1 Brake drums shall be free from visible hairline cracks, blowholes and other surface imperfections. 4.3.2 The spigot location hole (see figure 1) shall be concentric to within 0,2 mm with the diameter of the contact surface of the drum. 4.3.3 The pitch circle diameter (PCD) of the mo
22、unting stud holes shall be concentric to within 0,3 mm with the diameter of the contact surface of the drum. 4.3.4 The limits of ovality of the contact surface diameter shall not exceed 0,2 mm for a light vehicle drum and 0,3 mm for a heavy vehicle drum. 4.3.5 The inner and outer machined faces (see
23、 figure 1) shall be at 90 7 to the machined inner contact surface. 4.3.6 The contact surface shall be machined to a finish of 1,6 m to 3,2 m. 4.3.7 The portions of the inner and outer faces of the flange that are machined shall have a surface finish of 6,3 m to 12,5 m. 4.3.8 The thickness of the mat
24、erial that forms the drum cylinder wall (see figure 1) should be sufficient to allow for reconditioning cuts. The maximum oversize diameter allowed for this purpose shall be permanently marked or cast into the drum in a conspicuous position in such a manner as to preclude it from being removed when
25、the last reconditioning cut is made. 4.3.9 The shoulder (see figure 1) should be thick enough to allow for reconditioning cuts. 4.3.10 Drums shall be identified by the following: a) the batch number; b) the identification of the supplier; and c) the part number. SANS 1622:2009 Edition 1.1 6 Figure 1
26、 Brake drum 4.4 Performance requirements 4.4.1 Cold performance When tested in accordance with the procedure specified in annex A.2.1.2 or annex B.2.1.2, as relevant, the drum shall exhibit a torque output of at least 85 % of that of the equivalent OE drum. 4.4.2 Fade performance When tested in acco
27、rdance with the procedure specified in annex A.2.2.2 or annex B.2.1.3, as relevant, the drum shall exhibit a torque output of at least 85 % of that of the equivalent OE drum. SANS 1622:2009 Edition 1.1 7 4.5 Durability requirements 4.5.1 When tested in accordance with the procedure specified in anne
28、x A.2.2.3, a light vehicle drum shall comply with the requirements given in 4.5.1.1 to 4.5.1.5. 4.5.1.1 There shall be no, or only incipient, crazing of the contact surface. 4.5.1.2 There shall be no heat spotting of the contact surface. 4.5.1.3 There shall be no, or only incipient, scoring of the c
29、ontact surface. 4.5.1.4 The limits of ovality shall be as specified in 4.3.4. 4.5.1.5 The angle between the inner face and the contact surface shall be as specified in 4.3.5. 4.5.2 When tested in accordance with the procedure specified in annex B.2.2.3, a heavy vehicle drum shall comply with the req
30、uirements given in 4.5.2.1 to 4.5.2.5. 4.5.2.1 There shall be no, or only incipient, crazing of the contact surface. 4.5.2.2 There shall be no heat spotting of the contact surface. 4.5.2.3 There shall be no, or only incipient, scoring of the contact surface. 4.5.2.4 The limits of ovality shall be as
31、 specified in 4.3.4. 4.5.2.5 The angle between the inner face and the contact surface shall be as specified in 4.3.5. SANS 1622:2009 Edition 1.1 8 Annex A (normative) Light vehicle brake drum performance tests A.1 Apparatus Inertia dynamometer, that is fitted with a brake of a type and size suitable
32、 for the testing of brake drums of light commercial vehicles, and that has the following characteristics: a) rotary inertia, which shall be equivalent, within 5 %, to that portion of the mass of the vehicle that is braked by the relevant brake, and which is calculated by means of the following formu
33、la: I = M R2where I is the rotary inertia, in kilogram metre squared; M is the mass braked, equal to half the vehicle manufacturers axle rating (GA), in kilograms; R is the rolling radius of the tyre, in the stationary condition, in metres. b) instrumentation, to record the following: 1) a continuou
34、s recording of the drum rotational speed; 2) the number of revolutions completed during a stop, accurate to within one-eighth of a revolution; 3) the time taken to stop; 4) a continuous recording of the temperature measured in the centre of the path swept by the lining; 5) a continuous recording of
35、the brake application control line pressure or force; and 6) a continuous recording of braking torque. A.2 Drum performance tests A.2.1 Tests with an equivalent OE drum A.2.1.1 Bedding-in sequence An OE drum, equivalent to the drum to be tested, shall initially be installed with the reference brake
36、linings to match. A.2.1.1.1 Run the dynamometer at a rotational speed equivalent to 80 km/h. A.2.1.1.2 Apply a pressure to the system to attain a torque equivalent to a deceleration of 5,8 m/s2to achieve a stop. SANS 1622:2009 Edition 1.1 9 A.2.1.1.3 Continue this procedure until the linings have at
37、 least 80 % contact, but ensure that the temperature does not exceed 180 C. (To shorten the time required, a bedding-in machine may be used.) A.2.1.2 Cold performance test sequence A.2.1.2.1 Run the dynamometer at a rotational speed equivalent to 80 km/h. A.2.1.2.2 Apply a pressure to the system to
38、attain a torque equivalent to a deceleration of 5,8 m/s2. A.2.1.2.3 Make three such brake applications, with the initial temperature not exceeding 100 C. A.2.1.2.4 Record the average of the pressure required. A.2.1.3 Fade test sequence A.2.1.3.1 Test the drum by successively applying and releasing t
39、he brake on the dynamometer 15 times. Apply a pressure sufficient to maintain a constant deceleration equivalent to 5 m/s2from an initial rotational speed equivalent to 100 km/h, until the speed drops to half this value. Ensure that the duration of each cycle is 50 s. A.2.1.3.2 Immediately after thi
40、s, apply a pressure equivalent to a deceleration of 5,8 m/s2, and record the time taken to stop the dynamometer. A.2.2 Tests with sample drum A.2.2.1 Cold performance test sequence Repeat the procedure given in A.2.1.1 to A.2.1.2.4 (inclusive). A.2.2.2 Fade test sequence Repeat the procedure given i
41、n A.2.1.3. A.2.2.3 Durability test sequence A.2.2.3.1 With the same reference brake linings fitted, run the dynamometer at a rotational speed equivalent to 90 km/h. A.2.2.3.2 With this speed as the initial speed, carry out a sequence of 100 stops, applying a constant torque equivalent to a mean brak
42、ing deceleration of 3 m/s2. Allow sufficient time between stops to ensure that the initial temperature does not exceed 100 C. A.2.2.3.3 Carry out a sequence of 100 further stops from the same initial speed and applying the same constant torque. The time given between stops should be such that the in
43、itial temperature does not exceed 200 C. A.2.2.3.4 Carry out a sequence of stops as in A.2.2.3.3, except that the time between stops should be such that the initial temperature does not exceed 300 C. A.2.2.3.5 Remove the drum and examine it for compliance with 4.5.1. SANS 1622:2009 Edition 1.1 10 An
44、nex B (normative) Heavy vehicle brake drum performance tests B.1 Apparatus Inertia dynamometer, that is fitted with a brake of a type and size suitable for the testing of brake drums of heavy commercial vehicles, and that has the following characteristics: a) rotary inertia, which shall be equivalen
45、t, within 5 %, to that portion of the mass of the vehicle that is braked by the relevant brake, and which is calculated by using the following formula: I = M R2where I is the rotary inertia, in kilogram metre squared; M is the mass braked, equal to half the vehicle manufacturers axle rating (GA), in
46、 kilograms; R is the rolling radius of the tyre, in stationary condition, in metres. b) instrumentation, to record the following: 1) a continuous recording of the drum rotational speed; 2) the number of revolutions completed during a stop, accurate to within one-eighth of a revolution; 3) the time t
47、aken to stop; 4) a continuous recording of the temperature measured in the centre of the path swept by the lining; 5) a continuous recording of the brake application control line pressure or force; and 6) a continuous recording of braking torque. B.2 Drum performance tests B.2.1 Tests with an equiva
48、lent OE drum B.2.1.1 Bedding-in sequence An OE drum, equivalent to the drum to be tested, shall initially be installed with the reference brake linings to match. B.2.1.1.1 Run the dynamometer at a rotational speed equivalent to 60 km/h. B.2.1.1.2 Apply a pressure to the system to attain a torque equ
49、ivalent to a deceleration of 4 m/s to achieve a stop. B.2.1.1.3 Continue this procedure until the linings have at least 80 % contact, but ensure that the temperature does not exceed 180 C. (To shorten the time required, a bedding-in machine may be used.) SANS 1622:2009 Edition 1.1 11 B.2.1.2 Cold performance test sequence B.2.1.2.1 Run the dynamometer at a rotational speed equivalent to 60 km/h. B.2.1.2.2 Apply a pressure to the system to attain a torque equivalent to a deceleration of 4,4 m/s2. B.2.1.2.3 Make three such brake applications, with the initial tempe
