ISO 7635:2006
(Main)Road vehicles — Air and air/hydraulic braking systems of motor vehicles, including those with electronic control functions — Test procedures
Road vehicles — Air and air/hydraulic braking systems of motor vehicles, including those with electronic control functions — Test procedures
ISO 7635:2006 specifies the method of testing the air or air over hydraulic braking systems of vehicles of categories M and N (excluding M1 and N1) as defined in Annex 7 to the UN-ECE Consolidated Resolution on the Construction of Vehicles (R.E.3.), which are built to comply with UN-ECE Regulation 13/09, including supplements 1-6. Test methods covering lock actuators or the electrical regenerative braking systems of electric and hybrid vehicles are not included in this edition.
Véhicules routiers — Systèmes de freinage à air comprimé ou hydropneumatiques pour les véhicules à moteur, y compris les systèmes à fonctions de commande électroniques — Méthodes d'essai
General Information
Relations
Standards Content (Sample)
INTERNATIONAL ISO
STANDARD 7635
Third edition
2006-06-01
Road vehicles — Air and air/hydraulic
braking systems of motor vehicles,
including those with electronic control
functions — Test procedures
Véhicules routiers — Systèmes de freinage à air comprimé ou
hydropneumatiques pour les véhicules à moteur, y compris les
systèmes à fonctions de commande électroniques — Méthodes d'essai
Reference number
ISO 7635:2006(E)
©
ISO 2006
---------------------- Page: 1 ----------------------
ISO 7635:2006(E)
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.
© ISO 2006
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2006 – All rights reserved
---------------------- Page: 2 ----------------------
ISO 7635:2006(E)
Contents Page
Foreword. v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions. 2
4 Symbols . 4
5 Test site conditions . 6
5.1 Test site . 6
5.2 Road surface condition. 6
5.3 Ambient conditions . 7
6 General requirements. 7
7 Recommended sequence of the tests . 8
7.1 Preparation and static checks and tests. 8
7.2 Basic performance tests — Unladen . 9
7.3 Failure tests – Unladen. 9
7.4 ABS tests — Unladen . 9
7.5 ABS tests — Laden. 10
7.6 Failure tests — Laden. 10
7.7 Basic performance tests — Laden. 10
8 Vehicle preparation. 11
8.1 Documents and basic data . 11
8.2 Braking system condition and bedding . 11
8.3 Adjustment of braking equipment . 11
8.4 Tyre conditions . 11
8.5 Devices and instruments needed for the testing . 11
9 Static tests and checks . 13
9.1 Static braking force and control force vs. line pressure . 13
9.2 Capacity of energy sources. 13
9.3 Service braking system — Response time measurement. 14
9.4 Automatic braking . 15
9.5 Brake failure and defect warning signals. 15
9.6 Tests on vehicles equipped with spring brake actuators. 17
9.7 Additional tests on vehicles equipped with EBS . 18
10 Basic performance tests — Unladen . 18
10.1 Type 0 test (service braking system cold brake effectiveness, engine disconnected). 18
10.2 Type 0 test (service braking system cold brake, engine connected). 19
10.3 Parking braking system — Hill holding test . 19
10.4 Secondary braking system test. 19
10.5 Wheel locking sequence . 20
11 Failure tests — Unladen. 20
11.1 Service braking system partial failure test (type 0 test, cold brake effectiveness, engine
disconnected). 20
11.2 Failed load sensing device test/function test . 21
11.3 Failure of the energy source on vehicles equipped with EBS . 21
12 ABS tests — Unladen . 22
12.1 ABS failure. 22
12.2 Determination of the peak coefficient of adhesion on the high adhesion surface. 23
© ISO 2006 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO 7635:2006(E)
12.3 Determination of adhesion utilization on high adhesion surface. 24
12.4 Determination of adhesion utilization on low adhesion surface. 26
12.5 Additional checks . 26
13 ABS tests — Laden . 27
13.1 Additional split adhesion test. 27
13.2 Energy consumption on low adhesion surface . 27
14 Failure tests — Laden. 30
14.1 Service braking system partial failure test (type 0 test, cold brake effectiveness, engine
disconnected). 30
14.2 Failed load sensing device test . 30
14.3 Energy source failure test. 30
15 Basic performance tests — Laden . 30
15.1 Parking braking system — Hill holding test. 30
15.2 Parking braking system — Dynamic test . 32
15.3 Wheel locking sequence . 32
15.4 Type 0 test (service braking system cold brake effectiveness, engine disconnected). 32
15.5 Type 0 test (service braking system cold brake, engine connected) . 32
15.6 Warning device test . 33
15.7 Energy storage capacity test . 33
15.8 Type II or type IIA tests (downhill, endurance braking test). 33
15.9 Type I test (fade test) . 36
Annex A (normative) Typical braking equipment. 38
Bibliography . 40
iv © ISO 2006 – All rights reserved
---------------------- Page: 4 ----------------------
ISO 7635:2006(E)
Foreword
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 interested 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 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 technical 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. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 7635 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 7635:2003), which has been technically
revised.
© ISO 2006 – All rights reserved v
---------------------- Page: 5 ----------------------
INTERNATIONAL STANDARD ISO 7635:2006(E)
Road vehicles — Air and air/hydraulic braking systems of motor
vehicles, including those with electronic control functions —
Test procedures
1 Scope
This International Standard specifies the method of testing the air or air over hydraulic braking systems of
vehicles of categories M and N (excluding M1 and N1) as defined in Annex 7 to the UN-ECE Consolidated
Resolution on the Construction of Vehicles (R.E.3.) which are built to comply with UN-ECE Regulation 13/09
including supplements 1-6. Test methods covering lock actuators or the electrical regenerative braking
systems of electric and hybrid vehicles are not included in this edition.
NOTE Requirements of UN-ECE Regulation 13 related purely to the design of braking systems and braking system
components are not part of this International Standard.
The values in square brackets [ ] and the values in tables are taken from UN-ECE Regulation No. 13.
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 latest edition of the referenced
document (including any amendments) applies.
ISO 611:2003, Road vehicles — Braking of automotive vehicles and their trailers — Vocabulary
ISO 1176:1990, Road vehicles — Masses — Vocabulary and codes
ISO 3833:1977, Road vehicles — Types — Terms and definitions
ISO 7638-1, Road vehicles — Connectors for the electrical connection of towing and towed vehicles — Part 1:
Connectors for braking systems and running gear of vehicles with 24 V nominal supply voltage
ISO 7638-2, Road vehicles — Connectors for the electrical connection of towing and towed vehicles — Part 2:
Connectors for braking systems and running gear of vehicles with 12 V nominal supply voltage
ISO 11992 (all parts), Road vehicles — Interchange of digital information on electrical connections between
towing and towed vehicles
ISO 12161, Road vehicles — Endurance braking systems of motor vehicles and towed vehicles — Test
procedures
ISO 21069-1:2004, Road vehicles — Test of braking systems on vehicles with a maximum authorized total
mass of over 3,5 t using a roller brake tester — Part 1: Pneumatic braking systems
© ISO 2006 – All rights reserved 1
---------------------- Page: 6 ----------------------
ISO 7635:2006(E)
1)
ISO 21069-2 , Road vehicles — Test of braking systems on vehicles with a maximum authorized total mass
of over 3,5 t using a roller brake tester — Part 2: Air over hydraulic braking systems
UN-ECE Regulation N° 13, Uniform provisions concerning the approval of vehicles with regard to braking
NOTE UN-ECE Regulation 13 is periodically updated through amendments and supplements, with this International
Standard having been prepared in accordance with the 09 series of amendments including supplements 1 to 6. When
using this International Standard, care should be taken to ensure that changes have not subsequently occurred that affect
the test methods or values given.
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 611, ISO 1176, and ISO 3833 and
the following apply.
3.1
braking systems
3.1.1
air-over hydraulic braking system
braking system having stored pneumatic energy, hydraulically actuated brakes and transmission means
incorporating a pneumatic to hydraulic converter
NOTE For a typical system diagram, see Figure A.1.
3.1.2
pneumatic (full air) braking system
braking system in which the control and energy are transmitted from the point of application to the brakes by
pneumatic transmission devices
NOTE For a typical system diagram, see Figure A 2.
3.1.3
electronic braking system
EBS
braking system in which control is generated and processed as an electrical signal in the control transmission
NOTE Electrical output signals control devices, which produce actuation forces from stored pneumatic energy.
3.1.4
antilock braking systems
ABS
3.1.4.1
categories of ABS
⎯ Category 1: ABS which meets all the requirements of ECE R 13 Annex 13;
⎯ Category 2: ABS which meets the requirements of ECE R 13 Annex 13, except paragraph 5.3.5 of ECE
R 13 Annex 13 (no braking rate on split-adhesion surfaces is prescribed);
⎯ Category 3: ABS which meets the requirements of ECE R 13 Annex 13, except paragraphs 5.3.4 and
5.3.5 of ECE R 13 Annex 13 (all split adhesion tests are omitted).
1) To be published.
2 © ISO 2006 – All rights reserved
---------------------- Page: 7 ----------------------
ISO 7635:2006(E)
3.1.4.2
wheel control
3.1.4.2.1
directly controlled wheel
wheel whose braking force is modulated according to data provided at least by its own sensor
3.1.4.2.2
indirectly controlled wheel
wheel whose braking force is modulated according to data provided by sensor(s) of other wheel(s)
NOTE ABS with select-high control are deemed to include both directly and indirectly controlled wheels. In systems
with select-low control, all sensed wheels are deemed to be directly controlled wheels.
3.1.4.3
full cycling ABS
ABS which is repeatedly modulating the brake force to prevent the directly controlled wheels from locking
NOTE Brake applications where modulation only occurs once during the stop shall not be considered to meet this
definition.
3.2
vehicle loading
3.2.1
laden vehicle
vehicle laden so as to reach its maximum mass
3.2.1.1
laden motor vehicle other than semi-trailer tractor
vehicle laden to technically feasible maximum design total mass specified by the vehicle manufacturer and
acknowledged by the Technical Services
NOTE This mass may exceed the “maximum authorized total mass” permitted by national regulations. Mass
distribution on the axles is stated by the vehicle manufacturer. In the event of several load distribution patterns being
planned, the distribution of the maximum design total mass among the axles is such that the load on each axle is
proportional to the maximum load for each axle defined by the manufacturer.
3.2.1.2
laden semi-trailer tractor
vehicle laden as in 3.2.1.1, except that the load defined by the manufacturer may be repositioned halfway
between the fifth wheel coupling pin position and the centre-line of the rear axle(s), so as to compensate for
the dynamic load transfer from the semi-trailer
NOTE This additional load, representing the semi-trailer loading may be carried in a specially designed load frame.
3.2.2
unladen vehicle
3.2.2.1
unladen motor vehicle other than semi-trailer tractor
vehicle laden to complete vehicle kerb mass without load or occupant but with the fuel tank filled to at least
90 % of the capacity specified by the vehicle manufacturer at the start of test and complete with cooling fluid
and lubricants, and tools and spare wheel, if provided
NOTE During the tests, the fuel quantity in the fuel tank is maintained at least to 50 % of its capacity. An increase up
to 200 kg mass over this mass is allowed. This corresponds, for instance, to the driver, one observer and instrumentation.
If necessary, the appropriate vehicle mass may be removed. For a vehicle without body, the manufacturer declares the
minimum axle loads for a bodied vehicle.
© ISO 2006 – All rights reserved 3
---------------------- Page: 8 ----------------------
ISO 7635:2006(E)
3.2.2.2
unladen semi-trailer tractor
vehicle laden as in 3.2.2.1 including the fifth wheel coupling or an equivalent load (in value and in position)
3.3
Air system pressures
3.3.1
pressure indicated by manufacturer
reservoir pressure specified by the manufacturer from which it is possible to achieve the required efficiency for
service braking and which is the basis for the tests prescribed in 15.7.
3.3.2
maximum pressure
pressure available for normal operation:
⎯ cut-out pressure, in the case of an installation with a pressure regulating device; and
⎯ [90] % of the asymptotic pressure, in the case of an installation with a pressure-limited compressor.
3.3.3
minimum pressure
pressure available for normal operation:
⎯ cut-in pressure, in the case of an installation with a pressure regulating device; and
⎯ [90] % of the pressure indicated by the manufacturer, in the case of an installation with a pressure-limited
compressor.
3.4
vehicle types
vehicles subject to the European Agreement Concerning the International Carriage of Dangerous Goods,
e.g. ADR vehicles
4 Symbols
For the purposes of this International Standard the symbols given in Table 1 apply.
Table 1 — Symbols
Symbol Meaning Unit
2
a mean deceleration m/s
m
2
d mean fully developed deceleration m/s
m
E wheelbase m
ε the adhesion utilised by the vehicle: quotient of the maximum braking rate with the ABS
operative (z ) and the coefficient of adhesion (k)
AL
ε the ε value measured on axle i (in case of a power-driven vehicle with a category 3 ABS)
i
ε the ε value on the high adhesion surface
H
ε the ε value on the low adhesion surface
L
F actuating force N
F Normal reaction of road surface under dynamic conditions with the ABS operative N
dyn
F F on axle i N
idyn dyn
F normal reaction of road surface on axle i under static conditions N
i
F total normal static reaction of road surface on all wheels of power-driven (towing vehicles) N
M
4 © ISO 2006 – All rights reserved
---------------------- Page: 9 ----------------------
ISO 7635:2006(E)
Table 1 (continued)
Symbol Meaning Unit
a
F total normal static reaction of road surface on the unbraked and non-driven axles of the N
Mnd
power-driven vehicle
a
F total normal static reaction of road surface on the unbraked and driven axles of the power- N
Md
driven vehicle
a
F 0,01 F + 0,015 F (rolling resistance) N
Wm Mnd Md
2 2
g acceleration due to gravity (9,81 m/s) m/s
h height of centre of gravity specified by the manufacturer and agreed by the Technical m
Service conducting the approval test
h height of fifth wheel coupling (king pin) m
k
k coefficient of adhesion between tyre and road
k k -factor of one front axle
f
k k -value determined on the high adhesion surface
H
k k -value determined on axle i for a vehicle with a category 3 ABS
i
k k -value determined on the low adhesion surface
L
k value of adhesion for 100 % slip
lock
k k -factor of the power driven vehicle
M
k maximum value of the curve “adhesion versus slip”
peak
k k -factor of one rear axle
r
n number of brake applications
p maximum pressure supplied by the towing vehicle in the supply circuit for the trailer bar
max
p 65 % of p bar
1 2
p pressure level specified by the manufacturer enabling the prescribed performance of the bar
2
service braking system to be achieved
P mass of motor vehicle kg
M
P maximum permissible mass of the trailer allowed to be towed by the power-driven vehicle t
T
R ratio of k to k
peak lock
S stopping distance m
t, t , ∆t time interval s
i
t , t , t pump up times (ref. 9.2.1) min
1 2 3
t mean value of t s
m
t minimum value of t s
min
v vehicle speed km/h
v maximum speed of the vehicle km/h
max
v lower speed limit for the antilock energy consumption test km/h
u
V reservoir volume l
z braking rate
z braking rate of the vehicle with the ABS operative
AL
z mean braking rate
m
z maximum value of z
max
z mean braking rate of front axle
mf
z mean braking rate of rear axle
mr
z z of the power-driven vehicle on a “split-surface”
MALS AL
a
F and F : In case of two-axle power-driven vehicles these symbols may be simplified to corresponding F symbol.
Mnd Md i
© ISO 2006 – All rights reserved 5
---------------------- Page: 10 ----------------------
ISO 7635:2006(E)
5 Test site conditions
5.1 Test site
The test site should be of sufficient size, without obstacles, to provide a safe testing environment.
The test site shall have a road of sufficient length prior to the test area to enable the test speeds to be attained.
The test area should be of;
a) sufficient length to allow for poor braking performance; and
b) sufficient width to allow for poor directional stability under braking.
5.2 Road surface condition
5.2.1 Surface
5.2.1.1 The test area shall be a dry, smooth, hard-surface free of loose material providing a peak
coefficient of adhesion of about [0,8].
5.2.1.2 Additionally, for the testing of vehicle(s) equipped with an ABS a surface providing a peak
coefficient of adhesion k of [0,3] or less is needed. It shall be preceded and followed by a surface
peak
according to 5.2.1.1 of sufficient length on the approach side to enable the test speeds to be attained.
The ratio R = k /k and the adhesion vs. slip curve have to be available for this surface in line with
peak lock
ECE R 13, Annex 13, Appendix 4.
Until such test surfaces become generally available, tyres at the limit of wear, and higher values up to [0,4]
may be used. The actual value obtained and the type of tyres and surface shall be recorded.
For testing vehicles fitted with ABS of category 1 or 2, it is also necessary for a low adhesion surface (k ) to
L
have a high adhesion surface (k ) on at least one side to enable the split-adhesion tests to be performed.
H
Both surfaces shall be sufficiently wide to be able to determine, using the vehicle under test, the peak
coefficients of adhesion separately.
The above described surfaces shall be such that k is equal to or greater than [0,5], and k /k is equal to or
H H L
greater than [2]. If any doubt arises that this requirement is met (e.g. the high adhesion surface is wet), the
peak coefficients of adhesion shall be ascertained by using the procedure detailed in subclauses 12.2
and 12.4. However, the peak coefficients of adhesion shall always be measured when testing a vehicle fitted
with antilock brakes of category 1 to check the braking rate on the split surface (reference 13.1).
5.2.2 Gradient
5.2.2.1 Road surface shall be level with a tolerance of ± 1 % of the average gradient, measured over a
minimum distance of 50 m.
5.2.2.2 Type II and type IIA test site conditions
Table 2 — Type II and type IIA test site conditions
Gradient Length of gradient
% km
Type II 6 6
Type IIA 7 6
NOTE In support of the tests specified in 15.8, additional information regarding practical test site conditions can be
taken from ISO 12161, including a test procedure using a vehicle dynamometer test bench.
6 © ISO 2006 – All rights reserved
---------------------- Page: 11 ----------------------
ISO 7635:2006(E)
5.2.2.3 The parking braking system hill holding test may be conducted on an appropriate gradient or on a
level road as specified in 10.3 and 15.1.
5.2.3 Camber
The camber or transverse gradient across the road surface shall not exceed 2 %.
5.3 Ambient conditions
5.3.1 Wind speed
The tests must be performed when there is no wind liable to affect the results. The wind speed shall not
exceed an average of 5 m/s.
5.3.2 Air temperature
The air temperature shall be recorded in the test report.
6 General requirements
6.1 General test conditions to be followed during the determination of braking performance
a) vehicle speed (reference 6.11);
b) without exceeding the maximum permissible control force;
c) engine disconnected or connected (as prescribed);
d) without wheel-locking, except immediately before stopping unless specifically allowed;
e) without deviation of the vehicle from its course (steering corrections of less than 90° allowed, if not
otherwise specified);
f) loading condition: unless otherwise specified, all tests should be carried out with the vehicle laden and
unladen.
6.2 During all phases of the following test procedures, any unusual braking performance characteristics
and/or vehicle behaviour e.g. course deviation or abnormal vibration, shall be observed and reported.
6.3 During the tests with the engine connected on vehicles with a manual gearbox, the clutch may be
disengaged just before the vehicle stops to avoid the engine stalling.
6.4 Deceleration measurements used in the following test procedures, unless otherwise stated, refer to the
“mean fully developed deceleration” as defined in UN-ECE Regulation 13 Annex 4 paragraph 1.1.2.
6.5 Tes
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.