GB/T 42611-2023 PDF in English
GB/T 42611-2023 (GB/T42611-2023, GBT 42611-2023, GBT42611-2023)
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Test method for sightseeing vehicle brake performance
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GB/T 42611-2023: PDF in English (GBT 42611-2023) GB/T 42611-2023
GB
NATIONAL STANDARD OF THE
PEOPLE'S REPUBLIC OF CHINA
ICS 97.200.40
CCS Y 57
Test method for sightseeing vehicle brake performance
ISSUED ON: MAY 23, 2023
IMPLEMENTED ON: SEPTEMBER 1, 2023
Issued by: State Administration for Market Regulation;
Standardization Administration of PRC.
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Normative references ... 4
3 Terms and definitions ... 4
4 Technical requirements ... 5
4.1 General requirements for sightseeing vehicles ... 5
4.2 Special requirements for sightseeing combination buses ... 7
5 Test methods ... 8
5.1 Preparation before the test ... 8
5.2 Visual inspection ... 8
5.3 Service braking test ... 9
5.4 Strength test for the service braking system ... 9
5.5 Parking braking test on ramps ... 10
5.6 Braking heat fade test for garden patrol minibuses ... 10
5.7 Braking heat fade test for sightseeing combination buses ... 10
5.8 Braking heat fade recovery test ... 10
5.9 Speed limiting braking test for garden patrol minibuses ... 10
5.10 Air pressure test for sightseeing combination bus braking system ... 11
5.11 Braking test after the carriage of the sightseeing combination bus is
disconnected ... 11
References ... 13
Test method for sightseeing vehicle brake performance
1 Scope
This document specifies the technical requirements and test methods for the braking
performance of sightseeing vehicles.
This document is applicable to the braking performance test of sightseeing vehicles
(including garden patrol minibuses and sightseeing combination buses, hereinafter
referred to as "sightseeing vehicles").
2 Normative references
The following documents contain the provisions which, through normative reference in
this document, constitute the essential provisions of this document. For the dated
referenced documents, only the versions with the indicated dates are applicable to this
document; for the undated referenced documents, only the latest version (including all
the amendments) is applicable to this document.
GB/T 21268 General technical conditions for garden patrol minibus
GB/T 38433 General technical specifications for sightseeing combination bus
3 Terms and definitions
The terms and definitions defined in GB/T 21268 and GB/T 38433 and the following
apply to this document.
3.1 braking distance
The distance traveled from the moment the driver starts to activate the brake control
device to the moment the sightseeing vehicle stops, when the sightseeing vehicle travels
at a specific initial speed.
3.2 service braking system
The braking system by which the driver can directly or indirectly control the sightseeing
vehicle to slow down or stop the sightseeing vehicle.
3.3 parking braking system
On permitted ramps or level roads, the braking system that uses a mechanical
mechanism to keep the sightseeing vehicle stationary, while the driver does not need to
continuously operate the control device.
3.4 braking device
A mechanism or device that slows, stops a vehicle's wheels, or holds a vehicle's wheels
in a stopped state.
NOTE: Generally it refers to the actuating components of the braking system and its ancillary devices.
3.5 braking heat fade
Multiple braking operations or driving with the braking device in an incompletely
combined state cause the braking device temperature to rise, resulting in a decline in
the braking performance of the sightseeing vehicle.
3.6 braking stability
During the braking process, the ability of the sightseeing vehicle to maintain straight
driving without adjusting the steering wheel, which is reflected in the fact that any part
of the vehicle (except for parts not included in the width of the vehicle) during the
braking process does not exceed the specified test channel width.
3.7 electronic parking device
The device in which the holding mechanism is activated by an electronic switch button,
and the electronic control unit and actuator work together to realize the parking braking.
NOTE: This device is a parking brake device controlled by an electronic system.
4 Technical requirements
4.1 General requirements for sightseeing vehicles
4.1.1 The pedal, handle, or electronic parking devices that implement service braking
and parking braking shall be convenient for the driver to operate. Sightseeing vehicles
shall have a complete service braking system and parking braking system that are
sufficient to decelerate, stop, and park the vehicle. The service braking function shall
act on all wheels of the sightseeing vehicle. The control device of the service braking
and the control device of the parking braking system shall be independent of each other.
4.1.2 The service braking distance and braking stability shall meet the requirements of
Table 1, and the brake pedal force shall not be greater than 700 N.
4.1.8 The service braking pedal or handle shall be arranged according to the operating
habits of the right foot or right hand.
4.1.9 The service braking system shall not affect the function of the service braking due
to corrosion of the brake pipeline by the brake fluid or air resistance caused by the
action of the engine and other heat sources.
4.1.10 Garden patrol minibuses shall be equipped with brake lights at the rear of the
car; sightseeing combination buses shall be equipped with brake lights in the last
carriage. The brake lights are triggered when the driver steps on the brake pedal.
4.1.11 Garden patrol minibuses with a speed limit function, when the specified speed
limit is reached, will automatically decelerate the vehicle through the retarder, motor
speed limit, or automatic start of the service braking system. The deceleration speed is
adjustable and the vehicle speed can be limited to within 110% of the design parameter
value.
4.2 Special requirements for sightseeing combination buses
4.2.1 For sightseeing combination buses that use air pressure braking, when the air
pressure of the braking system is lower than the starting air pressure, the alarm device
shall be able to continuously send an audible or visible alarm signal to the driver.
4.2.2 The braking system of each carriage shall have an independent air reservoir. The
capacity of the air reservoir shall ensure that under the condition of rated working
pressure and no further inflation, after five consecutive maximum braking travels of the
sightseeing combination bus, the pressure in the air reservoir can still remain no lower
than the starting air pressure.
4.2.3 The air pressure braking system of sightseeing combination buses shall be
equipped with a pressure limiting device to ensure that the air pressure in the air
reservoir does not exceed the maximum allowable air pressure. The air pressure braking
system shall be equipped with a device to keep the compressed air dry and separate oil
and water. After the braking air pressure reaches the rated working pressure, turn off
the power of the vehicle and keep it stationary for 2 hours; there shall be no obvious air
loss. After starting the sightseeing combination bus, press the brake pedal for five
consecutive times full travel; during this period, the braking system shall not alarm, and
the brake charging pump shall not start.
4.2.4 When the carriage is suddenly decoupled and separated while the sightseeing
combination bus is running, causing the braking pipe or braking signal line to break,
the carriage braking system shall brake immediately and enable the decoupled carriage
to brake and stop within 8m. The braking process shall not cause harm to passengers.
After the carriage stops, the parking state shall be easily released. If special tools are
needed, they shall be equipped with the vehicle.
4.2.5 When the sightseeing combination bus is braked, the danger caused by the
collision of carriages and the discomfort to passengers shall be avoided.
5 Test methods
5.1 Preparation before the test
5.1.1 All assemblies, components, accessories, and ancillary devices of the prototype
are fully equipped and fully running as required, so that they are in normal technical
condition. The battery voltage is sufficient, the oil and fluids meet the ex-factory
conditions, all mechanical transmissions are well lubricated, the braking system
functions normally, and the tire pressure meets the specifications in the manual.
5.1.2 The environmental conditions during the test shall meet the following
requirements:
a) Temperature is at -5 ℃~40 ℃;
b) The wind speed does not exceed 3 m/s;
c) The relative humidity of the air is not greater than 90%;
d) The altitude is less than 2000 m.
5.1.3 The test site shall be a dry, flat concrete or asphalt pavement, and the length and
width shall meet the test requirements.
5.1.4 The instruments, equipment, and measuring tools used in the test shall be verified
or calibrated and used within the validity period.
5.1.5 The unloaded and fully loaded state of the sightseeing vehicle during the test shall
meet the requirements of GB/T 21268 and GB/T 38433.
5.2 Visual inspection
Check whether the braking system of the sightseeing vehicle complies with the
provisions of 4.1.1, 4.1.3, 4.1.6, 4.1.8, 4.1.9, 4.1.10, 4.2.1, and 4.2.3 through visual
inspection and functional verification.
5.5 Parking braking test on ramps
The sightseeing vehicle is fully loaded and parked on the ramp specified in 4.1.5. The
transmission is in neutral (if any), the engine is turned off or the running motor is turned
off, and the parking braking control device is operated to park the vehicle on the ramp.
Measure the braking force and the sliding distance of the vehicle within 10 minutes.
Carry out the upslope and downslope tests once each to check whether the test results
comply with the provisions of 4.1.5.
5.6 Braking heat fade test for garden patrol minibuses
When the ambient temperature is no less than 15°C and the garden patrol minibus is
fully loaded, after pressing the accelerator pedal to bring the vehicle to the maximum
speed, keep the accelerator pedal at the maximum stroke, and then slowly press the
brake pedal to bring the vehicle speed to 40%~50% of its maximum speed, continue
operating for 2 km, causing the braking device to heat up. Then perform the braking
distance test again according to the provisions of 5.3. Check whether the test results
comply with the provisions of 4.1.7.
NOTE: This item is not applicable to vehicles with active retarding protection functions.
5.7 Braking heat fade test for sightseeing combination buses
When the sightseeing combination bus is fully loaded, after five consecutive emergency
braking tests according to the test method specified in 5.3, immediately measure the
braking distance for one round travel, record the braking distance, and take the average
value. Check whether the test results comply with the provisions of 4.1.7.
5.8 Braking heat fade recovery test
After the sightseeing vehicle has been tested for braking heat fade, wait for the brake
temperature to return to the ambient temperature or wait for 1 hour, and then conduct
the braking distance test according to the provisions of 5.3. Check whether the test
results comply with the provisions of 4.1.2.
5.9 Speed limiting braking test for garden patrol minibuses
Place the garden patrol minibus on the chassis dynamometer in an unloaded state,
slowly press the accelerator pedal, and keep the accelerator pedal at the extreme
position. After the operation is stable, increase the torque of the rotating hub where the
drive wheel is located to give the garden patrol minibus a forward thrust until the
forward thrust reaches the value specified in formula (2). Run for 5 minutes, record the
vehicle speed within 5 minutes, and check whether the test results comply with the
provisions of 4.1.11.
where:
F -- the forward thrust given by the rotating hub to the garden patrol minibus, in
kilonewtons (kN);
G -- the unloaded weight of the garden patrol minibus, in kilonewtons (kN);
T -- the unloaded rolling resistance of the garden patrol minibus, in kilonewtons
(kN);
0.342 -- the downward component coefficient of the weight of the garden patrol
minibus on a 20° ramp.
NOTE 1: On a flat test road surface, when the garden patrol minibus under test is unloaded and the brake
is not activated, connect the test auxiliary vehicle to the garden patrol minibus, and connect the tension
sensor in series in the middle. Start the auxiliary vehicle and slowly pull the minibus under test. When
the minibus runs smoothly, record the traction data, which is the rolling resistance of the minibus.
NOTE 2: This test is not performed on sightseeing combination buses.
5.10 Air pressure test for sightseeing combination bus braking system
Start the sightseeing combination bus, make the braking air pressure reach the rated
working pressure, turn off the vehicle, and wait for 2 hours to observe whether there is
obvious air leakage; after starting the sightseeing combination bus, press the brake
pedal full travel for five consecutive times, during this period, observe whether the
braking system is giving an alarm, the brake charging pump is activated. Check whether
the test results comply with the provisions of 4.2.3.
5.11 Braking test after the carriage of the sightseeing combination bus is
disconnected
Before the test, it shall be checked to confirm whether the braking structure of the
carriage under test is normally closed and there are no abnormalities.
Use a forklift or other handling equipment to place or pull a carriage onto a ramp with
a specified design gradient; at this time, the carriage is in a braking state. Use a vehicle-
mounted or external air pump to pressurize the braking device (if it is an electric braking
...... Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.
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