[F1ANNEX 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
Appendix 1 Alternative procedures for Type I and Type III tests for trailer brakes
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. |