ANNEX IX Requirements applying to vehicles with hydrostatic drive and their braking devices and braking systems
1. Definitions
For the purposes of this Annex:
1.1.
‘hydrostatic braking system’ means a braking system (either as a service and/or secondary braking system) that only uses the braking power of the hydrostatic drive;
1.2.
‘combination hydrostatic braking system’ means a braking system utilising both, the hydrostatic and friction braking effect, where, however, the braking forces are generated by a predominant braking proportion generated by the hydrostatic drive. The minimum prescribed proportion of the friction brake on the braking effect is specified in point 6.3.1.1;
1.3.
‘combination friction braking system’ means a braking system utilising both, the friction and hydrostatic braking effect, where, however, the braking forces are generated by a predominant braking proportion generated by the friction brakes. The minimum prescribed proportion of the friction brake on the braking effect is specified in point 6.3.1.2;
1.4.
‘friction braking system’ means a braking system where the braking forces are generated only by the friction brakes without taking into account of the braking effect of the hydrostatic braking system;
1.5.
‘graduated hydrostatic braking’ means the hydrostatic braking through which the driver is able to increase or decrease the vehicle speed at any time by a progressive action on its control device.
1.6.
‘hydrostatic drive control device’ which means a device, such as a lever or pedal, used to vary the vehicle speed.
1.7.
‘service brake control device’ means the control device by whose operation the prescribed service braking performance is attained;
1.8.
‘inch device’ means the device that affects the speed of the vehicle independently of the hydrostatic drive control.
2. Scope
This Annex applies to vehicles with maximum design speed up to 40 km/h, equipped with a hydrostatic drive which cannot be disengaged during travel and is declared by the vehicle manufacturer to act as a braking system or braking device which may be either:
2.1.
a service braking system and a secondary braking system or one of those two systems.
A service braking system may be one of the braking systems mentioned below under the condition that the service braking performance as specified in point 6.3.1 is fulfilled:
2.1.1.
‘Hydrostatic braking system’,
2.1.2.
‘Combination hydrostatic braking system’,
2.1.3.
‘Combination friction braking system’,
2.1.4.
‘Friction braking system’;
or
2.2.
a part of the braking systems mentioned under 2.1.
3. Special purpose vehicles
For special purpose works, some vehicles are equipped with a hydrostatic drive used both to retard and to propel the vehicle. This type of drive can therefore be recognised as a braking system, whether alone or in combination with a friction brake.
4. Classification of vehicles
4.1. Class I
:
vehicles with a maximum design speed ≤ 12 km/h.
4.2. Class II
:
vehicles with a maximum design speed > 12 km/h and ≤ 30 km/h.
4.3. Class III
:
vehicles with a maximum design speed > 30 km/h and ≤ 40 km/h.
5. Requirements
5.1.General
5.1.1.The drive control device shall be constructed in such a way that accidental reversing is prevented during a journey on the road.
5.1.2.To facilitate vehicle recovery, a device is required disengaging the connection between engine and drive wheels.
It shall be impossible to operate this device from the driving position during the journey on the road.
If a tool is needed to operate this device, it shall be carried on the vehicle.
5.2.Design requirements for the braking systems.
5.2.1.Service braking system
5.2.1.1.It shall be possible to apply graduated braking action of the service braking system. The driver shall be able to achieve this braking action from his driving seat and retain control of the steering device on the tractor with at least one hand.
5.2.1.2.The performance of the service braking system required under the Regulation shall be obtained by the actuation of a single control device.
5.2.1.2.1.This requirement is also deemed to be satisfied when the foot is moved from the drive pedal to the brake pedal or when at the start of the braking sequence, the drive control device is released or moved to neutral position by hand or foot.
5.2.1.2.2.The control device of the service braking system shall be designed to return to the initial position automatically when released.
This does not apply to the hydrostatic section of the braking system when the release of the hydrostatic drive control device creates the braking effect.
5.2.1.3.Contrary to point 5.2.1.1, with vehicles of Class I and Class II, when braking with the service brake system another brake system may also be used (secondary or parking braking system) to bring the vehicle to a stop on a gradient in the event of a residual creep speed.
5.2.2.Secondary braking system
5.2.2.1.With regard to the secondary braking system the relevant requirements of point 2.1.2.2 of Annex I shall be fulfilled.
5.2.2.2.If, in the case of a hydrostatic drive, the vehicle cannot be stopped on a gradient, then it is permissible to operate the parking braking system to stop the vehicle from residual creep speed to standstill. For this purpose the parking braking system has to be designed such that it is possible for it to be actuated during driving.
5.2.3.Parking braking system
With regard to the parking braking system the requirements of point 2.1.2.3 of Annex I shall be fulfilled.
5.3.Characteristics of the braking systems
5.3.1.The set of braking systems with which a vehicle is equipped shall satisfy the requirements laid down for service, secondary and parking braking systems.
5.3.2.In the event of breakage of any component other than the brakes or the components referred to in point 2.2.1.2.7 of Annex I, or of any other failure of the service braking system the secondary braking system or that part of the service braking system which is not affected by the failure, shall be able to bring the vehicle to a halt in the conditions prescribed for secondary braking, in particular, when the secondary braking system and the service braking system have a common control device and a common transmission; for example, when the braking effect is dependent on the operation of the proper operation of the power transmission i.e. converter, hydraulic pumps, pressure pipes, hydraulic motors or comparable components.
5.3.3.The systems providing service, secondary and parking braking may have common components as long as they fulfil the conditions as specified in point 2.2.1.2 of Annex I.
5.3.4.The braking force distribution of the service brake system must be designed in such a way that during braking there is no significant moment around the vertical axis of the vehicle if the limit of adhesion between tyres and road on homogeneous road surfaces is not attained.
5.3.5.The braking force distribution of the service braking system shall be by design such that during braking with the service brake system on surfaces with different coefficients of friction of split-μ 0,2/0,8 a minimum deceleration can be achieved that is at least 55 % of the mean fully deceleration dm of the service braking system prescribed for the respective vehicle class (see point 6.3). This can be proven by calculations; in this case the rolling resistance shall not be taken into consideration.
5.3.6.By way of derogation from point 5.3.2, in the event of a failure in the pump control device of the hydrostatic drive, it shall be possible to stop the vehicle with the performance prescribed for the secondary braking system. However, under this failure condition an additional device may be actuated that can always be easily operated from the driving position (for example a device acting on the engine speed, including the engine shut off control).
5.3.7.In the case of an inch device, or other comparable device, which can be operated during driving, provisions shall be taken to ensure that all prescribed requirements of this Annex (especially the braking performance) are still complied with when this type of device is actuated.
5.3.8.Warning signals and warning devices
The relevant requirements of point 2.2.1.29 and point 2.2.1.12 of Annex I shall be fulfilled.
5.3.9.The energy storage devices (energy reservoirs) of power-driven vehicles shall be such that after eight full-stroke actuations of the service braking system control device the pressure remaining in the energy storage device(s) shall be not less than the pressure required to obtain the specified secondary braking performance.
5.3.10.The pneumatic/hydraulic auxiliary equipment shall be supplied with energy in such a way that during its operation, the prescribed deceleration values can be reached and that even in the event of damage to the source of energy the operation of the auxiliary equipment cannot cause the reserves of energy feeding the braking systems to fall below the level indicated in point 2.2.1.12 of Annex I.
5.3.11.Wear of the brakes
The relevant requirements of point 2.2.1.10 of Annex I shall be fulfilled.
5.3.12.In the case of a tractor equipped with a complex electronic vehicle control systems according to Annex X, the requirements of that Annex shall be applied and the operation of the system shall not be adversely affected by magnetic or electrical fields. This shall be demonstrated by compliance with the technical requirements laid down in accordance with the relevant provisions of Article 17(2)(g) and (5) of Regulation (EU) No 167/2013.
5.3.13.If a tractor with a hydrostatic drive is authorised to tow a category R2, R3, R4 or S2 vehicle shall satisfy the relevant requirements of point 2.1.4, 2.1.5, 2.2.1.16, 2.2.1.17 and 2.2.1.18 of Annex I.
5.3.14.Response time
Where a tractor is fitted with a service braking system which is totally or partially dependent on a source of energy other than the muscular effort of the driver, the requirements of point 3.3 of Annex II shall be satisfied for the non-hydrostatic part of the service braking system.
6. Braking tests
6.1.General
6.1.1.The relevant requirements of point 2.1 of Annex II shall be fulfilled.
6.1.2.During the brake test the drivability shall be assessed (e.g. tendency for lifting the rear axle due to the braking action of the service brakes).
6.1.2.1.Lift-off is not permitted for Class III vehicles.
6.1.2.2.Lifting-off of an axle is permissible for vehicles of Class I and Class II at a deceleration exceeding 4,5 m/s2; however, the driving stability shall be preserved.
Here, the braking effect of the hydrostatic drive has also to be taken into account.
6.2.Type-0 test
6.2.1.General
6.2.1.1.The brake shall be cold. A brake is deemed to be cold when the conditions as specified in point 2.2.1.1 of Annex II are met.
6.2.1.2.The test shall be conducted under the conditions as specified in point 2.2.1.3 of Annex II.
6.2.1.3.The road shall be level.
6.2.2.In the case of manually operated drive control device (Class I and Class II vehicles), the performance of the service brake shall be assessed by moving the drive lever to neutral just before operating the service brake in order to ensure not to brake against the hydrostatic system. In the case of Class III vehicles this sequence shall be automatic, using only the service brake control.
6.2.3.Service braking system
The limits prescribed for minimum performance, both for tests with the vehicle unladen and for tests with the vehicle laden, are those laid down in point 6.3 for each class of vehicle.
The service braking system has to meet the requirements in point 6.3.1.
When used as a service braking system,
6.2.3.1.a combination hydrostatic braking system shall also meet the requirements with regard to the minimum braking portion of friction brake(s) as specified in point 6.3.1.
6.2.3.2.a combination friction braking system shall also meet the requirements with regard to the minimum braking portion of friction brake(s) as specified in point 6.3.1.
The performance of the friction brake shall also be determined. In this type of test, the effect of the hydrostatic transmission shall be neutralised to assess the friction brake and rolling resistance.
If the hydrostatic brake cannot be disconnected for technical reasons, the proportion of the friction brake may be determined by another method, e.g.:
6.2.3.3.Successive brake tests are performed
6.2.3.3.1with the combination hydrostatic braking system with the friction brake(s) connected
6.2.3.3.2with the combination hydrostatic braking system with the friction brake(s) rendered inoperative (only 'hydrostatic braking')
Then this formula is used:
zF = zHy+F – zHy + R
zF
:
Mean fully developed deceleration of the friction braking system including rolling resistance
zHy
:
Mean fully developed deceleration related only to the braking effect of the hydrostatic braking system including rolling resistance
zHy+F
:
Mean fully developed deceleration of the combination hydrostatic braking system.
R
:
Rolling resistance = 0,02
6.2.4.Secondary braking system
6.2.4.1.The secondary braking effectiveness test shall be conducted by either simulating the actual failure conditions in the service braking system or by carrying out this test with a secondary braking system which is independent from the service braking system.
6.2.4.2.The system shall be tested with the appropriate control device.
The prescribed performance shall be obtained by applying to the control device a force not exceeding 600 N on a foot or 400 N on a hand operated control device. The control device shall be so placed that it can be easily and quickly applied by the driver.
6.2.4.3.The limits prescribed for minimum performance, both for tests with the vehicle unladen and for tests with the vehicle laden, are those laid down in point 6.3.2 for each class of vehicle.
6.3.Performance tests of service and secondary braking system (Type-0)
| Laden & Unladen | | Class I | Class II | Class III |
|---|
| (v in km/h; s in m; dm in m/s2) | v | ≤ 12 | ≤ 30 | ≤ 40 |
|---|
| 6.3.1. | Service braking system | s | ≤ 0,15v + v2/78 | ≤ 0,15v + v2/92 | ≤ 0,15v + v2/130 |
| dm | ≥ 3,0 | ≥ 3,55 | ≥ 5,0 |
| 6.3.1.1. | Minimum braking portion of friction brake(s) in a combination hydrostatic braking system | s | ≤ 0,15v + v2/26 | ≤ 0,15v + v2/40 | ≤ 0,15v + v2/40 |
| dm | ≥ 1,0 | ≥ 1,5 | ≥ 1,5 |
| 6.3.1.2. | Minimum braking portion of friction brake(s) within a combination friction braking system | s | ≤ 0,15v + v2/52 | ≤ 0,15v + v2/52 | ≤ 0,15v + v2/78 |
| dm | ≥ 2,0 | ≥ 2,0 | ≥ 3,0 |
| 6.3.2. | Secondary braking system | s | ≤ 0,15v + v2/40 | ≤ 0,15v + v2/40 | ≤ 0,15v + v2/57 |
| dm | ≥ 1,5 | ≥ 1,5 | ≥ 2,2 |
6.4.Brake test Type-I (fade)
6.4.1.The service brakes shall be tested in such a manner that, the vehicle being laden, the energy input to the brakes is equivalent to that recorded in the same period of time with a laden vehicle driven at a steady speed of 40 km/h on a 7 per cent down-gradient for a distance of 1,7 km.
6.4.2.Alternately, the test may be carried out on a level road, the tractor being drawn by a tractor; during the test, the force applied to the control device shall be adjusted so as to keep the resistance of the towed vehicle constant (7 per cent of the maximum total stationary axle load of the tested tractor). If the power available for hauling is insufficient, the test can be conducted at a lower speed but over a greater distance as shown in the table below:
| Speed [km/h] | Distance [metres] |
|---|
| 40 | 1 700 |
| 30 | 1 950 |
| 20 | 2 500 |
| 15 | 3 100 |
6.4.3.As an alternative to the procedure with continuous braking described in points 6.4.1 and 6.4.2., the test procedure described in point 2.3.1 of Annex II with repeated braking may also be used.
6.4.4.Hot performance
At the end of the Type-I test the hot performance of the service braking system shall be measured in the same conditions (and in particular at a constant control force no greater than the mean force actually used) as for the Type-0 test (the temperature conditions may be different).
6.4.4.1.The hot braking performance of the service braking system shall not be below the limits given in the table of following point 6.4.4.2.
6.4.4.2.Minimum prescribed hot performance (Type-I test)
| Service braking system | Hot performance as % of the prescribed value | Hot performance as % of the value recorded during Type-0 test |
|---|
| Hydrostatic braking system | 90 | 90 |
| Combination hydrostatic braking system | 90 | 80 |
| Combination friction braking system | 80 | 60 |
| Friction braking system | 75 | 60 |
6.4.5.The type-I Test can be omitted provided that the following two conditions are met:
6.4.5.1.
At least 60 % of the total braking forces during the Type-0 test of the service braking system (see point 6.2.3) is produced by the braking with the hydrostatic drive.
6.4.5.2.
The manufacturer can prove that overheating of the brakes in case of permanent operation is prevented.
6.5.Parking braking system
6.5.1.With regard to the parking braking system the requirements of point 3.1.3 of Annex II shall be fulfilled.
6.5.2.To check compliance with the requirement specified in point 2.2.1.2.4 of Annex I, a Type-0 test shall be carried out with the laden vehicle at an initial test speed of v ≥ 0,8 vmax. The mean fully developed deceleration on application of the control device of the parking braking system and the deceleration immediately before the vehicle stops shall not be less than 1,5 m/s2. The force exerted on the braking control device shall not exceed the specified values.
In the case of a manually operated drive control (Class I and Class II vehicles), the performance of the parking brake system in motion shall be assessed by moving the drive control to neutral just before operating the parking braking system in order to ensure not to brake against the hydrostatic system. In the case of Class III vehicles this sequence shall be automatic, using only the service brake control.