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

C. HYDRAULIC BRAKING SYSTEMS WITH STORED ENERGY

1. Capacity of energy storage devices

1.1. General

1.1.1. Vehicles on which the operation of the braking system requires the use of stored energy provided by hydraulic fluid under pressure shall be equipped with energy storage devices of a capacity meeting the requirements laid down in points 1.2 and 1.3.

1.1.2. However, the energy storage devices shall not be required to be of a prescribed capacity if the braking system is such that in the absence of any energy reserve it is possible with the service braking system control device to achieve a braking performance at least equal to that prescribed for the secondary braking system.

1.1.3. In verifying compliance with the requirements laid down in points 1.2.1, 1.2.2 and 2.1, the brakes shall be adjusted as closely as possible.

1.2. Vehicles of category T and C

1.2.1. Vehicles equipped with a hydraulic braking system with stored energy shall meet the following requirements:

1.2.1.1.

After eight full-stroke actuations of the service braking system control device, it shall still be possible to achieve, on the ninth application, the performance prescribed for the secondary braking system.

1.2.1.2.

Testing shall be performed in conformity with the following requirements:

1.2.1.2.1.

Testing shall commence at a pressure that may be specified by the manufacturer but is not higher than the cut-in pressure.

1.2.1.2.2.

The energy storage devices shall not be fed; in addition, any energy storage devices for auxiliary equipment shall be isolated.

1.2.2. Tractors equipped with a hydraulic braking system with stored energy which cannot meet the requirements of point 2.2.1.4.1 of Annex I shall be deemed to satisfy that point if the following requirements are met:

1.2.2.1.

After any single transmission failure it shall still be possible after eight full-stroke actuations of the service braking system control device, to achieve, at the ninth application, at least the performance prescribed for the secondary braking system or, or, where performance prescribed for the secondary braking system requiring the use of stored energy is achieved by a separate control device, it shall still be possible after eight full-stroke actuations to achieve, at the ninth application, the residual performance prescribed in paragraph 3.1.4 of Annex II of this Regulation.

1.2.2.2.

Testing shall be performed in conformity with the following requirements:

1.2.2.2.1.

With the energy source stationary or operating at a speed corresponding to the engine idling speed, any transmission failure may be induced. Before inducing such a failure the energy storage device(s) shall be at a pressure that may be specified by the manufacturer but not exceeding the cut-in pressure.

1.2.2.2.2.

The auxiliary equipment and its energy storage devices, if any, shall be isolated.

1.3. Vehicles of categories R and S

1.3.1. If towed vehicles are equipped with energy storage devices (energy reservoirs), they shall be such that, after eight full-stroke actuations of the tractor's service braking system, the energy level supplied to the operating members using the energy, does not fall below a level equivalent to one-half of the figure obtained at the first brake application and without actuating either the automatic or the parking braking system of the towed vehicle.

1.3.2. During the test, the following requirements shall be satisfied:

1.3.2.1.

The pressure in the energy storages at the beginning of the test shall be 15 000 kPa;

1.3.2.2.

The supplementary line shall be stopped; in addition, any energy storage device(s) for auxiliary equipment shall be isolated;

1.3.2.3.

The energy storage device(s) shall not be replenished during the test.

1.3.2.4.

At each brake application, the pressure in the hydraulic control line shall be 13 300 kPa.

2. Capacity of hydraulic fluid energy sources

The energy sources shall meet the requirements set out in the following points:

2.1. Vehicles of category T and C

2.1.1 Symbols

2.1.1.1.

‘p₁’ represents the maximum system operational pressure (cut-out pressure) in the energy storage devices specified by the manufacturer.

2.1.1.2.

‘p₂’ represents the pressure after four full-stroke actuations with the service braking system control device, starting at p₁, without having fed the energy storage devices.

2.1.1.3.

‘t’ represents the time required for the pressure to rise from p₂ to p₁ in the energy storage devices without application of the service braking system control device.

2.1.2. Conditions of measurement

2.1.2.1. During the test to determine the time t, the feed rate of the energy source shall be that obtained when the engine is running at the speed corresponding to its maximum power or at the speed allowed by the governor.

2.1.2.2. During the test to determine the time t, energy storage devices for auxiliary equipment shall not be isolated other than automatically.

2.1.3. Interpretation of results

The time t shall not exceed 30 s in the case of tractors.

2.2. Tractors equipped with a hydraulic control line for towed vehicles

2.2.1. To determine the feed rate of the energy source the supplementary line towed vehicle simulator as prescribed in paragraph 3.6.2.1 of Annex III to this Regulation shall be connected to the coupling head of the hydraulic supplementary line of the tractor.

2.2.2. The test shall be performed under the following conditions:

2.2.2.1.

The test shall be carried out at an ambient temperature between 15 °C and 30 °C.

2.2.2.2.

The supplementary line towed vehicle simulator shall be connected to the coupling head of the supplementary line before the test with engine not running.

2.2.2.3.

The engine speed of the tractor during the test shall be 25 % above idling speed.

2.2.2.4.

The parking brake control of the tractor shall be fully released during the test.

2.2.3. With the engine running and the bleeding device fully closed, the time elapsing when the pressure at the testing port close to the female ISO 16028:2006 coupling rises from 300 kPa to 1 500 kPa shall not exceed 2,5 seconds.

2.3. Vehicles of category R and S

If a towed vehicle using an energy storage device to assist the service braking system and such an energy storage device is recharged by the control line pressure during application of the service braking and/or by an energy source fitted on the towed vehicle, the following requirements shall be met:

2.3.1. The energy source shall be powered by the tractor simulator according to Appendix 2 of Annex III via the electrical connector conforming to ISO 7638:2003.

2.3.2. Symbols

2.3.2.1.

‘p_R1’ represents the maximum system operational pressure (cut-out pressure) in the energy storage device specified by the manufacturer.

2.3.2.2.

‘p_R2’ represents the pressure after four full-stroke actuations of the tractor's service braking system control device.

2.3.2.3.

‘t_R’ represents the time required for the pressure to rise from p_R2 to p_R1 in the energy storage device without application of the service braking system control device of the tractor.

2.3.3. Conditions of measurement

During the test to determine the time t_R the following requirements shall be satisfied:

2.3.3.1.

The pressure in the energy storage device at the beginning of the test shall be the pressure ‘p_R1’.

2.3.3.2.

The service braking system shall be operated four times by the control line of the tractor simulator.

2.3.3.3.

At each brake application, the pressure in the control line shall be 13 300 kPa.

2.3.3.4.

Energy storage devices for auxiliary equipment shall not be isolated other than automatically.

2.3.3.5.

The valve feeding the energy storage device by the pressure of the control line shall be closed during the test.

2.3.4. Interpretation of results

The time t_R shall not exceed 4 min.

3. Characteristics of alarm devices

With the engine stationary and commencing at a pressure that may be specified by the manufacturer but does not exceed the cut-in pressure, the alarm device shall not operate following two full-stroke actuations of the service braking system control device.