Council Directive of 26 July 1971 on the approximation of the laws of the Member States relating to the braking devices of certain categories of motor vehicles and of their trailers (71/320/EEC) (repealed)

[F1 ANNEX VII U.K. Cases in which Type I and/or II (or IIA) or III tests do not have to be carried out on a vehicle submitted for type-approval

Textual Amendments

F1 Substituted by Commission Directive 98/12/EC of 27 January 1998 adapting to technical progress Council Directive 71/320/EEC on the approximation of the laws of the Member States relating to the braking devices of certain categories of motor vehicles and their trailers (Text with EEA relevance).

1. Type I and/or II (or IIA) or Type III tests shall not have to be carried out on a vehicle submitted for type-approval in the following cases: U.K.

1.1. Where the vehicle in question is a motor vehicle, a trailer or a semi-trailer which, in respect of tyres, braking energy absorbed by each axle and method of fitting of tyres and brakes, is identical, as far as braking is concerned, to a motor vehicle, or trailer, or semi-trailer which: U.K.

1.1.1. has passed a Type I and/or II (or IIA) or III test U.K.

1.1.2. has been type-approved, with regard to braking energy absorbed, for mass per axle not lower than that of the vehicle concerned. U.K.

1.2. Where the vehicle in question is a motor vehicle, a trailer or a semi-trailer of which the axle or axles, in respect of tyres, braking energy absorbed by each axle and method of fitting tyres and brakes, is or are identical, as far as braking is concerned, to an axle or axles which has or have individually passed a Type I and/or II (or IIA) or Type III test for mass per axle not lower than that of the vehicle concerned, provided that the braking energy absorbed by each axle does not exceed the energy absorbed by that axle during the reference test or tests carried out separately on that axle. U.K.

1.3. Where the vehicle submitted for type-approval is fitted with a retarder, other than an engine brake, identical to a retarder which has already been tested under the following conditions: U.K.

1.3.1. In a test carried out on a gradient of at least 6 % (Type II test) or of at least 7 % (Type IIA test), this retarder has, on its own, stabilised the speed of a vehicle with a maximum mass at the time of testing at least equal to the maximum mass of the vehicle submitted for type-approval. U.K.

1.3.2. During the above test it shall be verified that the speed of rotation of the revolving parts of the retarder is such that, when the vehicle is travelling at a speed of 30 km/h, the retarding torque is at least equal to the retarding torque in the test mentioned in point 1.3.1. U.K.

1.4. Where the vehicle concerned is a trailer equipped with ‘S’-cam air-operated brakes (1) which satisfies the verification requirements of Appendix I to this Annex relating to a report of a reference axle test as shown in Appendix 2 of this Annex. U.K.

2. The term ‘ identical ’ as used in points 1.1, 1.2 and 1.3 means identical as regards the geometrical and mechanical characteristics of the vehicle parts mentioned in those items, and also as regards the characteristics of the materials from which these parts are made. U.K.

3. When advantage is taken of the above provisions, the type-approval communication in respect of braking (Annex IX, Appendix 2) shall contain the following particulars: U.K.

3.1. Where point 1.1 is applicable, the type of the approval number of the vehicle on which the Type I and/or II (or IIA) or III test serving as a reference test has been carried out (point 2.7.1). U.K.

3.2. Where point 1.2 is applicable, the table in point 2.7.2 shall be completed. U.K.

3.3. Where point 1.3 is applicable, the table in point 2.7.3 shall be completed. U.K.

3.4. Where point 1.4 is applicable, the table in point 2.7.4 shall be completed. U.K.

4. When a person applying for type-approval in a Member State refers to a type-approval granted in another Member State, that person shall produce the documents relating to such approval. U.K.

Appendix 1 Alternative procedures for Type I and Type III tests for trailer brakes

1. GENERAL U.K.

1.1. In accordance with point 1.4 of this Annex, the Type I and Type III fade tests may be waived at the time of type-approval of the vehicle provided that the braking system components comply with the requirements of this Appendix and that the resulting predicted brake performance meets the prescriptions of this Directive for the appropriate vehicle category. U.K.

1.2. Tests carried out in accordance with the methods detailed in this Appendix shall be deemed to meet the above requirements. U.K.

2. SYMBOLS AND DEFINITIONS (the reference brake symbols shall have the ‘e’) U.K.

P

=

normal reaction of road surface on the axle under static conditions

C

=

camshaft input torque

C _max

=

maximum technically permissible camshaft input torque

C _o

=

threshold camshaft input torque, i.e. minimum camshaft torque necessary to produce a measurable brake torque

R

=

tyre rolling radius (dynamic)

T

=

brake force at tyre/road interface

M

=

brake torque = T × R

z

=

braking rate T/P = M/RP

s

=

actuator stroke (working stroke plus free stroke)

s _p

=

effective stroke — the stroke at which the output thrust is 90 % of the average thrust (Th _A )

Th _A

=

average thrust — the average thrust shall be determined by integrating the values between one-third and two-thirds of the total stroke (s _max ).

l

=

lever length

r

=

radius of brake drum

p

=

brake actuation pressure

3. TEST METHODS U.K.

3.1. Track tests U.K.

3.1.1. The brake performance tests should preferably be carried out on a single axle only. U.K.

3.1.2. The results of tests on a combination of axles may be used accordance with point 1.1 provided that each axle contributes equal braking energy input during the drag and hot brake tests. U.K.

3.1.2.1. This is ensured if the following are identical for each axle: brake geometry (Figure 2), lining, wheel mounting, tyres, actuation and pressure distribution in the actuators. U.K.

3.1.2.2. The result recorded for a combination of axles will be the average value for these axles. U.K.

3.1.3. The axle(s) should preferably be loaded with the maximum static axle load, though this is not essential provided that due allowance is made during the tests for the difference in rolling resistance caused by a different load on the test axle(s). U.K.

3.1.4. Allowance shall be made for the effect of the increased rolling resistance resulting from a combination of vehicles being used to carry out the tests. U.K.

3.1.5. The initial speed of the test is prescribed. The final speed shall be calculated by the following formula: U.K.

where

v ₁

=

initial speed (km/h)

v ₂

=

final speed (km/h)

v ₀

=

mass of the towing vehicle (kg) under test conditions

P ₁

=

mass of the trailer borne by the non-braked axle(s) (kg)

P ₂

=

mass of the trailer borne by the braked axle(s) (kg).

3.2. Inertia dynamometer tests U.K.

3.2.1. The test machine shall have a rotary inertia simulating that part of the linear inertia of the vehicle mass acting upon one wheel, necessary for the cold performance and hot performance tests, and capable of being operated at constant speed for the purpose of the test described in points 3.5.2 and 3.5.3. U.K.

3.2.2. The test shall be carried out with a complete wheel, including the tyre, mounted on the moving part of the brake, as it would be on the vehicle. The inertia mass may be connected to the brake either directly or via the tyres and wheels. U.K.

3.2.3. Air cooling at a velocity and air flow direction simulating actual conditions may be used during the heating runs, the speed of air flow being not greater than 10 km/h. The temperature of the cooling air shall be the ambient temperature. U.K.

3.2.4. Where the tyre rolling resistance is not automatically compensated for in the test, the torque applied to the brake shall be modified by subtracting a torque equivalent to a rolling resistance coefficient of 0,01. U.K.

3.3. Rolling road dynamometer tests U.K.

3.3.1. The axle should preferably be loaded with the maximum static axle load, though this is not essential provided that due allowance is made during the tests for the difference in rolling resistance caused by a different mass on the test axle. U.K.

3.3.2. Air cooling at a velocity and air flow direction simulating actual conditions may be used during the heating runs, the speed of air flow being not greater than 10 km/h. The temperature of the cooling air shall be the ambient temperature. U.K.

3.3.3. The braking time has a duration of 1 second after a maximum build-up time of 0,6 seconds. U.K.

3.4. Test conditions U.K.

3.4.1. The test brake(s) shall be instrumented so that the following measurements can be taken: U.K.

3.4.1.1. A continuous recording to enable the brake torque or force at the periphery of the tyre to be determined. U.K.

3.4.1.2. A continuous recording of air pressure in the brake actuator. U.K.

3.4.1.3. Speed during the test. U.K.

3.4.1.4. Initial temperature on the outside of the brake drum. U.K.

3.4.1.5. Brake actuator stroke used during the Type 0 test and Type I or Type III tests as applicable. U.K.

3.5. Test procedures U.K.

3.5.1. Supplementary cold performance test U.K.

3.5.1.1. This test shall be carried out at an initial speed equivalent to 40 km/h in the case of Type I test and 60 km/h in the case of Type III test in order to evaluate the hot braking performance at the end of Type I and Type III tests. U.K.

3.5.1.2. Three brake aplications shall be made at the same pressure (p) and at an initial speed equivalent to 40 km/h (in the case of Type I test) or to 60 km/h (in the case of Type III test), with an approximately equal initial brake temperature not exceeding 100 °C, measured at the outside surface of the drum. The applications are at the brake actuator pressure required to give a brake torque or force equivalent to a braking rate (z) of at least 0,50. The brake actuator pressure shall not exceed 6,5 bar, and the camshaft input torque (C) shall not exceed the maximum technically permissible camshaft input torque (C _max ). The average of the three results shall be taken as the cold performance. U.K.

3.5.2. Type I test U.K.

3.5.2.1. This test shall be carried out at a speed equivalent to 40 km/h with an initial brake temperature not exceeding 100 °C, measured at the outside surface of the drum. U.K.

3.5.2.2. A braking rate shall be maintained at 0,07 including the rolling resistance (see point 3.2.4). U.K.

3.5.2.3 The duration of the test shall be two minutes and 33 seconds or 1,7 km at 40 km/h. If the test velocity cannot be achieved then the duration of the test can be lengthened according to point 1.3.2.2. of Annex II. U.K.

3.5.2.4. Not later than 60 seconds after the end of the Type I fade test, a hot performance test shall be carried out in accordance with point 1.3.3 of Annex II at an initial speed equivalent to 40 km/h. The brake actuator pressure shall be that used during the cold performance test. U.K.

3.5.3. Type III test (fade test) U.K.

3.5.3.1. Test methods for repeated braking. U.K.

3.5.3.1.1. Track tests (see Annex II, point 1.6). U.K.

3.5.3.1.2. Inertia dynamometer test. U.K.

For the bench test as in Annex VII, Appendix 1, point 3.2, the conditions may be as for the road test according to Annex II point 1.6.1 where

3.5.3.1.3. Rolling road dynamometer test U.K.

For the bench test as in Annex VII, Appendix 1, point 3.3, the conditions shall be as follows:

Number of brake applications	20
Duration of braking cycle (braking time 25 seconds and recovery time 35 seconds)	60 seconds
Test speed	30 km/h
Braking rate	0,06
Rolling resistance	0,01.

3.5.3.2. Not later than 60 seconds after the end of the Type III test a hot performance test shall be carried out in accordance with point 1.6.2 of Annex II to this Directive. The brake actuator pressure shall be that used during the Type 0 test. U.K.

3.6. Test report U.K.

3.6.1. The result of tests carried out in accordance with point 3.5 shall be reported on a form, a model of which is shown in Appendix 2 to this Annex. U.K.

3.6.2. The brake and the axle shall be identified. Particulars of the brakes, the axle, the technically permissible mass and the numer of the corresponding test report shall be marked on the axle. U.K.

4. VERIFICATION U.K.

4.1. Verification of components U.K.

The brake specification of the vehicle to be type-approved shall be verified by satisfying each of the following criteria:

	Item	Criteria
4.1.1.	(a) Brake drum cylindrical section	No change allowed
	(b) Brake drum material	No change allowed
	(c) Brake drum mass	May change between - 0 and + 20 % of the reference drum mass
4.1.2.	(a) Proximity of wheel to outside surface of brake drum (dimension E)	Tolerances to be determined by the technical service conducting the approval tests
	(b) Part of brake drum not covered by wheel (dimension F)
4.1.3.	(a) Brake lining material	No change allowed
	(b) Brake lining width
	(c) Brake lining thickness
	(d) Brake lining actual surface
	(e) Brake lining method of attachment
4.1.4.	Brake geometry (Figure 2)	No change allowed
4.1.5.	Tyre rolling radius (R)	May change subject to the requirements of point 4.3.1.4 of this Appendix
4.1.6.	(a) Average thrust (TH A )	May change provided that the predicted performance meets the requirements of point 4.3 of this Appendix
	(b) Actuator stroke (s)
	(c) Lever length
	(d) Brake actuation pressure (p)
4.1.7.	Static mass (P)	P shall not exceed P e (see point 2)

4.2. Verfication of brake forces developed U.K.

4.2.1. The brake forces (T) for each subject brake (for the same control line pressure p _m ) necessary to produce the drag force specified for both Type I and Type III test conditions shall not exceed the values T _e as stated in the Record of Test Results, Appendix 2, point 2 of this Annex, which were taken as a basis for the test of the reference brake. U.K.

4.3. Verification of hot performance U.K.

4.3.1. The brake force (T) for each subject brake for a specified pressure (p) in the actuators and control line pressure (p _m ) used during the Type 0 test if the subject trailer shall be determined by the methods described in items points 4.3.1.1 to 4.3.1.4. U.K.

4.3.1.1. The predicted actuator stroke (s) of the subject brake shall be determined from the following relationship: U.K.

s shall not exceed the effective stroke (s _p ).

4.3.1.2. The average thrust output (Th _A ) of the actuator fitted to the subject brake at the pressure specified in point 4.3.1 shall be determined. U.K.

4.3.1.3. The camshaft input torque (C) shall be then given by U.K.

C shall not exceed C _max .

4.3.1.4. The predicted brake performance for the subject brake shall be given by U.K.

R shall not be less than 0,8 R _e .

4.3.2. The predicted brake performance for the subject trailer shall be given by: U.K.

4.3.3. The hot performances following the Type I or Type III tests shall be determined in accordance with points 4.3.1.1, 4.3.1.2, 4.3.1.3 and 4.3.1.4. The resulting predictions given by point 4.3.2 shall satisfy the requirements of this Directive for the subject trailer. The value used for the ‘ figure recorded in the Type 0 test ’ , as prescribed in Annex II, point 1.3.3 of 1.6.2 shall be the figure recorded in the Type 0 test of the subject trailer. U.K.

Appendix 2 Model reference axle test report form as prescribed in Appendix 1, point 3.6

Figure 1

Section through axle assembly

Figure 2

Brake geometry]

(1)

[F1 Other brake designs may be approved upon presentation of equivalent information.]

Textual Amendments

F1 Substituted by Commission Directive 98/12/EC of 27 January 1998 adapting to technical progress Council Directive 71/320/EEC on the approximation of the laws of the Member States relating to the braking devices of certain categories of motor vehicles and their trailers (Text with EEA relevance).