Commission Delegated Regulation (EU) 2015/68Show full title

ANNEX XIII Requirements applying to hydraulic connections of the single-line type and to vehicles fitted with them

1. General

1.1. In addition to at least one type of connection as defined in point 2.1.4 of Annex I or points 2.1.5.1.1 to 2.1.5.1.3 of that Annex, a hydraulic connection of the single line type may be installed on the tractor.

1.2 Hydraulic connections of the single-line type shall be so designed as to ensure that the braking systems covered by the provisions of Annexes I to XII are not to be adversely affected by any operation of this equipment or in the event of any failure of this equipment.

1.3. The service braking system of the tractor shall be fitted with a device so designed that if the towed vehicle braking system should fail, or the control line between the tractor and towed vehicle should break, it will still be possible to brake the tractor with the effectiveness prescribed for the secondary braking system in this Regulation.

2. Hydraulic connections of the single-line type between tractors and towed vehicles equipped with hydraulic braking systems shall fulfil the following requirements:

2.1. Type of connection: hydraulic control line with the male connector on the tractor and the female connector on the towed vehicle. The connectors shall comply with ISO 5676:1983.

2.2. With the engine running and the control device of the service braking system of the tractor fully applied a pressure between 10 000 kPa and 15 000 kPa shall be generated on the control line.

2.3. With the engine running and no brake control device on the tractor applied (driving or stand-by condition), the pressure supplied at the coupling head of the control line shall be 0⁺²⁰⁰ kPa.

2.4. The response time requirements of Annex III do not apply to this type of connection.

2.5. The compatibility requirements according to Appendix 1 to Annex II do not apply to this type of connection.

3. Alternative requirements

As an alternative to the requirements of points 1 and 2, hydraulic connection of the single line type installed on tractors shall fulfil all the requirements of the current point, in addition to the provisions of points 1.2 and 2.1.

3.1. The hydraulic circuit shall be provided with a relief valve to prevent hydraulic pressures exceeding 15 000 kPa.

3.2. With no brake control device (including parking brake) applied on the tractor, at any engine revolutions per minute (RPM) between low idle and rated speed, pressure at coupling head shall be between 1 000 and 1 500 kPa.

3.3. Applying tractor service brakes gradually, pressure at coupling head shall increase progressively and reach the maximum specified value, which shall be between 12 000 and 14 000 kPa. Requirement shall be fulfilled at any engine RPM, as described in point 3.2.

3.4. Permissible relationship between braking rate TM/FM and the coupling head pressure p_m shall be lower than line AAA of Figure 1. Requirement shall be fulfilled by the unladen vehicle.

3.5. The response time at the coupling head, measured connecting the towed vehicle simulator (as described in point 3.10) to the tractor, shall not be higher than 0,6 seconds. The response time shall be measured at the coupling head, starting from the moment of the pedal actuation until the moment when pressure reaches the value of 7 500 kPa. During the test, engine RPM shall be set to 2/3 of the rated speed. The ambient and vehicle temperature shall be stabilised between 10 °C and 30 °C. The pedal actuation time necessary to reach a pressure of 10 000 kPa at the coupling head, shall be not less than 0,2 seconds.

3.6. In case of failure of the towed vehicle braking system part, located on the tractor side, a pressure drop to 0 kPa (measured at the coupling head) shall be generated within 1 second, in order to apply the brakes of the towed vehicle. The same provision applies in case of shut off or low efficiency of the energy source.

3.7. In case of failure of the tractor service brakes, operator shall be able to drop the pressure at the coupling head to 0 kPa. This requirement may be achieved by an auxiliary manual control device.

3.8. The tractor shall be equipped with the warning signal specified in point 2.2.1.29.1.1 of Annex I; it shall be activated when the pressure in the towed vehicle braking system drops below 1 000^{(+0 – 200)} kPa.

3.9. Braking valve and energy source shall be marked in accordance with the requirements laid down on the basis of Article 17(2)(k) and (5) of Regulation (EU) No 167/2013.

3.10. Towed vehicle simulator: The device simulating the towed vehicle braking system shall include a hydraulic circuit provided with one female coupler as per ISO 5676-1983 and two identical hydraulic energy storage devices, fitted with spring elements and fulfilling the requirements reported in Figure 2. The simulator shall be manufactured according to the provisions of Figure 3.

Figure 1

Relationship between braking rate TM/FM and coupling head pressure pm

pm

=

stabilised hydraulic pressure at the coupling head (kPa).

TM

=

sum of braking forces at the periphery of all wheels of tractors

FM

=

total normal static reaction of road surface on wheels of tractors

Figure 2

Characteristic of the towed vehicle simulator, depending on its maximum permissible mass

• diagram A B C for maximum permissible mass up to 14 tons.

• diagram A D E for maximum permissible mass higher than 14 tons

Note: tolerance admitted ± 2 %

Figure 3

Towed vehicle simulator layout

1

=

hose of 2 000 mm length with one female coupler as per ISO 5676-1983;

2

=

tube of internal diameter 8 mm and length of 4 000 mm;

3

=

tube of internal diameter 8 mm and length of 1 000 mm;

4

=

tube of internal diameter 8 mm and length of 1 000 mm;

5

=

piston brake simulating elements;

6

=

spring adjusted elements acting on the total stroke of the piston;

7

=

spring adjusted elements acting only at the end of the pistons stroke.