Some standard content:
ICS 65. 060. 10
National Standard of the People's Republic of China
GB/T4331—2003
Replaces (B/r4331-1984
Test methods for agricultural trailers
Test nethods for agricultural trailer2003-11-28Promulgated
General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China
Implementation on 2004-06-01
GB/T 4331—2003
This standard is a revision of GB/T4331—1984 Test Method for Agricultural Trailers. This standard replaces GB/T4331-1984 Test Method for Agricultural Trailers. Compared with GB/T4331-1984, the main technical content changes of this standard are as follows: - Added reference standards, test preparation and conditions; Deleted some performance test contents in the original standard: - Added reliability assessment content:
- Adjusted the performance record form, and deleted the reliability assessment record form. Appendix A of this standard is an informative appendix.
This standard was proposed by the China Machinery Industry Federation. This standard is under the jurisdiction of the National Agricultural Machinery Standardization Technical Committee. The drafting units of the standard are: China Agricultural Mechanization Science Research Institute, National Agricultural Machinery Quality Supervision and Inspection Center, Jiangnan Transport Machinery Co., Ltd.
The main drafters of this standard are Li Zhiqing, Wu Sihang, and Qian Luming. The previous versions of the standards replaced by this standard were released as follows: -CB 4331—1977, GB/1 4331—1984. Scope
Test methods for agricultural trailers
This standard specifies the test conditions and test methods for agricultural trailers. GB/T 4331—2003
This standard applies to the performance test of agricultural trailers and tractors (hereinafter referred to as vehicle groups) and the reliability test of agricultural trailers (hereinafter referred to as trailers).
2 Normative referenced documents
The clauses in the following documents also become clauses of this standard through reference in this standard. For any referenced document with a date, all subsequent amendments (excluding errors) or revisions are not applicable to this standard. However, the parties who reach an agreement based on this standard are encouraged to study whether to use the latest versions of these documents. For any referenced document without a date, the latest version shall apply. This standard shall apply. GB/T3187-1994 Reliability and maintainability terms (eqvIEC:191-1) GB/T4330-2003 Agricultural trailers
3 Test preparation and conditions
3.1 Test preparation and requirements
3.1.1 Select the matching tractor according to the trailer model and specifications. The power and type of the tractor shall be consistent with the provisions of the trailer manual, and the tractor shall be in good and normal technical condition. 3.1.2 The test trailer shall be consistent with the manual and adjusted and maintained in accordance with the manual to ensure the good technical condition of the trailer.
3.1.3 The instruments and meters used in the test shall meet the measurement accuracy requirements, shall be qualified by verification and within the validity period. The main instruments and meters used in the test are shown in Appendix A (informative appendix).
3.1.4 During the entire test period, except for the use and technical maintenance in accordance with the provisions of the manual, the technical condition of the sample vehicle shall not be adjusted or changed arbitrarily (replacement, repair, etc.). If necessary, it must be approved by the test organization and carried out under its supervision. Then re-test the relevant items and make detailed records.
3.1.5 Any abnormal phenomenon that occurs during the test should be recorded in detail. 3.1.6 Test measurement accuracy requirements
Unless otherwise specified, the measurement accuracy of various parameters should meet the requirements of Table 1 (take the larger value of the absolute error and the relative error).
3.2 Test conditions
3.2.1 During the full-load test, the items used should be able to fully ensure that they are evenly distributed in the car. Empty mass: The mass of the trailer without load, mud and complete accessories. Fully loaded mass: The total mass of the trailer after being evenly loaded in the car according to the rated load. 3.2.2 The trailer size parameters, the hydraulic parameters of the dump trailer when dumping and the tangential tension test of the towing ring of the full trailer should be measured on a solid and flat surface. The results of the main parameters of the trailer should be recorded in the record table. 3.2.3 The driving brake performance and parking brake performance of the vehicle should be tested on a flat, hard, clean, dry, water-filtered or asphalt road surface with an adhesion coefficient between the tire and the ground of not less than 0.7. At the same time, the road slope of the driving brake performance test should not exceed 1%. 3.2.4 During driving braking, the brake mark of the trailer should be larger than the brake mark of the tractor. 3.2.5 The reliability test mileage and various road conditions should meet the requirements specified in 5.2. GB/T 4331--2003
Name of measured parameter
Linear dimension
4 Vehicle performance test
4.1 Purpose
Measurement accuracy requirements
Indication error
=0, 1 8
2:0.1 ktn/h
±c. 31 m
-1.0 N-m
Measurement accuracy requirements
Relative error/is
±2, 0
To assess whether the relevant technical indicators of the trailer's operating performance meet the requirements of GB/ 4330 and relevant technical specifications. 4.2 Braking performance test
4.2.1 Driving brake performance test
The driving brake performance test can be carried out when the trailer is empty or fully loaded. The braking distance test and stable deceleration test can be carried out by using the braking distance test and stable deceleration test methods.
The braking distance is tested with a fifth wheel instrument or a non-contact photoelectric speedometer, and the stable deceleration is tested with a car tractor deceleration instrument: the instrument must be calibrated before the test.
Test with a fifth wheel instrument or a non-contact photoelectric speedometer: the vehicle group is tested in a cold brake state (below 100°C), the tractor is accelerated to make the vehicle group speed higher than 20 km/h (wheeled tractor group) or 15km/h (walking tractor group), and then the gear is disengaged and the vehicle group is decelerated by sliding. When the wheeled tractor group drops to 20kph/h and the walk-behind tractor group drops to 15kph/h, the brake is pressed sharply to make the vehicle group stop at the maximum deceleration. Test twice on the simple road section and take the average value. Test with a car tractor deceleration meter: the vehicle group drives with the tractor in the highest gear and appropriate throttle: the vehicle group passes the 30-50 m speed measurement area at a stable speed: ensure that the wheeled tractor group is at 20 km/h after the measurement area, and the auxiliary tractor group is at 15 km/h The vehicle is traveling at a speed of about 100 km/h. At this time, the clutch and brake are abruptly engaged. The trailer vehicle group is braked to a stop at the maximum deceleration. The stable deceleration is calculated according to the braking deceleration curve. On the same road section 1, the test is repeated twice in each round trip. The average value is taken. The initial speed V of the vehicle is calculated according to formula (1):
Wu:
V The initial speed at the beginning of braking, in meters per second (m/s) L = the length of the road section, in meters (m),
The time of the measurement section, in seconds. When the error between the measured initial speed at the beginning of braking and the required initial speed is greater than 3 ktn/h, the test data is invalid. Use a wheel gauge or a non-contact photoelectric speedometer to test the braking distance. When the braking initial speed is different from the specified initial speed, the braking distance is corrected according to formula (2). However, when the error between the measured initial speed and the required initial speed is greater than 1 km/h, the test data is invalid. Where:
S.- 400: 5
SBraking distance correction value. Unit is meter (n).
Actual initial braking speed, unit is kilometer per hour (km/h)V
S——Actual braking distance of the vehicle group (from pressing the brake pedal to stopping), unit is meter (n)The measurement results shall be recorded in record table 4.
During the driving brake performance test, the vehicle group shall not exceed the specified test track width. Speed.
Total deceleration
Braking coordination
Figure 1 Braking deceleration curve
4.2.2 Parking brake performance test
Time?
GB/T43 31--2003
Under no-load condition, after the trailer or vehicle group stops on a 20% slope by braking in both the forward and reverse directions (without driver control, the tractor is in neutral gear), it remains stationary for a period of not less than 30 minutes for pneumatic and hydraulic braking and not less than 5 minutes for mechanical braking. An equivalent method can be used to test, where the trailer or vehicle group stops on a flat road for 3)nmin (5 minutes for mechanical braking), and then the trailer or vehicle group is towed by another vehicle. When the wheels begin to roll or slide, the traction resistance is not less than 20% of the total weight of the towed vehicle, and the measurement results are recorded in the record sheet 5.
4.3 Braking stability measurement
Draw the test track sideline on the test road surface (wheeled tractor group: line width 3.0m; hand-held tractor group: line width 2.5m). The test group accelerates along the center line of the test track to make the group speed higher than 20km/h (wheeled tractor group) or 15km/h (hand-held tractor group). Then shift gears and coast to slow down. When the wheeled tractor group drops to 20km/h and the hand-held tractor group drops to 15km/h, brake suddenly to stop the trailer and check whether any part of the group exceeds the test track. Record the measurement results in the record sheet 4
4.4 Other items are inspected by visual inspection or conventional methods. 5 Trailer reliability test
5. January
In order to assess the reliability of the trailer under normal use, the convenience of maintenance, and the durability of the main parts and wearing parts. 5.2 Test mileage and road surface requirements
5.2.1 Test mileage
The one-way travel of a walking tractor-trailer combination shall not be less than 5000km; the one-way travel of a wheeled tractor-trailer combination shall not be less than 10000kmGB/T 4331—2003
5.2.2 Test road surface and proportion requirements
Farmland, dirt roads and uneven bad roads (damaged road surface, exposed roadbed gravel roads, seriously damaged road surface asphalt and cement roads should not be less than 30%;
General gravel roads and third and fourth-level highways should not be less than 40%! The rest should be asphalt and cement roads,
5.3 Driving speed requirements
Under the premise of ensuring safety, the vehicle should be driven at a higher speed as much as possible. During the entire test period, the average speed should not be less than 60% of the maximum speed of the tractor. The night waiting single trip of each test sample vehicle is not less than 5 times the single trip of the test sample vehicle: the average speed on the bad road should not be less than the tractor 40% of the maximum speed of the engine
5.4 Test equipment requirements
The test trailer should be overloaded and operated according to the following proportions: rated load of 0.5~2t trailer, overloaded by 40%; rated load of 3-~7t trailer, overloaded by 30%; rated load of 8-~9t trailer, overloaded by 25%. 5.5 Test sample vehicle acceptance
Before the test, the selected test sample vehicle should be accepted according to the instruction manual and relevant technical documents, and the problems found should be recorded in detail.
5.6 Test methods and requirements
5.6.1 Before and after the reliability driving test, the performance of the trailer or vehicle group shall be tested in the following items according to the provisions of 4.2 under the same conditions. Test:
… Braking distance or stable deceleration
- Parking brake.
5.6.2 Each test vehicle should be recorded by a dedicated person, and the record content includes: mileage, road conditions, driving time, fuel consumption and fault conditions, etc.
5.6.3 During the test, if a fatal fault occurs in the vehicle, the test can be suspended; if a general or serious fault occurs, the test can be continued after the fault is eliminated.
5.6.4 Final inspection
After the test, the test vehicle should be fully inspected and all newly discovered faults should be recorded. 5.7 Fault classification and judgment principles
5.7.1 Fault classification
5.7.1. 1 Faults are divided into essential faults, secondary faults and misuse faults. Their definitions are shown in GB/T3187. 5.7.1.2 According to the degree of harm caused by the trailer fault and the difficulty of troubleshooting, the faults are divided into four categories: fatal faults, serious faults, general faults and minor faults (see Table 2). 2 Fault classification
Fatal faults
Serious faults
General faults
Minor faults
Classification principles
Faults that endanger the safety of trailer driving, cause personal injury or death, or cause the failure of major assemblies, resulting in major economic losses, affect the driving safety of the trailer, or cause damage to major components or the specified importance index is obviously beyond the specified range and cannot be repaired in a short time (about 3 days). min) with wearing parts and tools on board. Faults that must be stopped for repair obviously affect normal use or performance indicators exceed the specified range, and do not cause damage to major components. Faults that can be eliminated in a short time with wearing parts and tools on board. Faults that are severely peeled off from the exterior decorative protective layer do not cause the trailer to stop or performance indicators exceed the limit. Faults that can be eliminated in about 5 minutes with tools on board without replacement parts. Faults that are slightly peeled off from the exterior decorative protective layer.
5,7.2 Fault judgment rules
GB/T4331--2003
5.7.2.1 When calculating reliability indicators, only the number and type of essential faults are counted. If the essential fault causes subordinate faults, the fault type should be determined according to the fault that causes the most serious consequences, and only one fault is counted. Misuse faults and subordinate faults caused by them are not counted in the number of faults, and should be recorded in detail and truthfully.
5.7.2.2 When a component fails after adjustment and maintenance according to the instruction manual or when the component reaches the specified life limit, no fault treatment shall be performed, but a detailed record shall be made truthfully
5.7.2.3 For faults such as "three leaks" and loose fasteners, when counting the number of faults, each joint surface shall be counted as one fault. 5.7.2.4 After the fault is eliminated, the repeated occurrence of the same fault shall be counted according to the actual number of faults, but if the fault is repeated due to improper handling and repair, it shall be counted as one fault.
5.7.2.5 When judging the type of fault, it shall be judged by the final consequences, and it can only be judged as one of the four types of faults. 5.8 Calculation of reliability assessment criteria
The reliability assessment test of trailers adopts on-site reliability driving test, with fixed-distance truncation. 5.8.1 Average mileage to first failure
MTTFF ES.nS
In the formula,
MTTFF--mean mileage before failure (point estimate), in kilometers (km): number of test vehicles:
S,--prescribed cut-off mileage for fixed-distance test, in kilometers (kin): \…The number of test vehicles that had their first failure (excluding minor failures) during the test; S,.-the sum of the mileage of the test vehicles that had their first failure (excluding minor failures), in kilometers (km). · (3)
If all test vehicles have failures (excluding minor failures) after reaching the specified test mileage, it is stipulated that: MTTFF>nS, 5. 8. 2 Mean mileage between failures
MTBF=nS
Wu Zhong:
Mean mileage between failures (point estimate), in kilometers (km): Number of test vehicles:
S, a specified cut-off mileage for the fixed-range truncation test, in kilometers (km); the total number of failures (excluding minor failures) that occurred on each test vehicle during the test. If all test vehicles do not experience any failure (excluding minor failures) after reaching the specified test range, it is stipulated that MTBF>nS. 5.8.3 Mean time to repair
MTTR - 2e.
Where:
MTTR---mean time to repair, in hours (h):--the total number of failures of the test sample vehicles during the test period; t.-the sum of the failure repair times of the test sample vehicles, in hours (h). .4
（5）
5.9 The total number of self-unloading of the unloading trailer shall not be less than 000 times. The actual number of self-unloading shall not be less than 100 times, and the rest may not open the vehicle board, and the load capacity shall be in accordance with the requirements of 5 and 4. , so that the hydraulic cylinder pre-lifts the car body and tilts it 2:°～30°, then it drops. The number of left and right and rear unloading tests is basically the same,
GB/T4331—-2003
6 Test report
6.1 After the test, the test data should be sorted, counted and analyzed, and a test report should be submitted. 6.2 The content of the performance test report should include:
a) Test conclusion,
b) Test overview;
Performance data summary table.
6.3 The content of the reliability test report should include: Test conclusion;
Test overview (including the test, number of units, sample vehicle provider, participating test units, test mileage, time and location, participants, etc.);
Trailer introduction (including trailer structure and technical characteristics, etc.): test conditions.
In addition, the report also includes the structure of the trailer,Charts and photos. Table 3 Record of the measurement of main parameters of trailers
Trailer number:
Compliance date;
Main parameters
External dimensions
Inner corridor of the car
Length
Length x width
Diameter of car sideboard
Traction frame
Diameter of traction ring
Gross vehicle mass
Rear end height
Axle mass G)
Rear axle mass G
Minimum ground clearance
Measurer:
Measurement results||tt| |Wheel static force
Manufacturing unit:
Factory number:
Main parameters
Center of gravity level
Bearing surface height
Distance from front axle4bzxz.net
Distance from rear axle
Distance between wheel and frame
Distance between wheel and bottom
When the first section is extended
Cylinder pressure
Dumping time
When the second section is extended
When the third section is extended
When the fourth section is extended
The maximum overturning angle of the vehicle
Record Person:
Impact test results
Tractor model:
Trailer type:
Name of loaded goods:
Road conditions:
Table 4 Braking performance test record
Initial braking speed/
Testing method
Sample vehicle number Test number Driving direction
Braking distance
Testing method
Average
Testing method Sample vehicle number, Test number Driving direction 2
Predetermined speed
Speed test||tt ||Tester
Average value
(km/h)
: Initial braking speed/
(km/h)
Braking distance
Actual value
Test date:
Test location:
Loading mass (kg):
Environmental pollution:
Test result/cut
Braking distance
Corrected value
Test result
Stable braking deceleration?
(m/s*)
GB/T 4331—2003
Modulation stability
Braking stability
Recording person:
GB/T43312003
Trailer type:
Ramp conditions:
Sample garage number
Staircase car 1
LoujunⅡ
Sample car serial number
Sample car 1
Tester:||t t||Parking direction
Upward direction ()
Downhill direction (reverse)
Upward direction ()
Downhill direction (reverse)
Traction direction
Forward direction
Rearward direction
Forward direction
Rear direction
Table 5 Parking performance test record
Parking time/min
Factory number:
Test date:
Parking slope/(megawatt)
Parking time/minTotal traction mass/kg
Parking brake condition
Traction resistance N
Recorder
Equivalent slope (%)
Photoelectric speedometer
Fifth wheel instrument
Automobile tractor deceleration tester
Semiconductor or digital point thermometer
Flowmeter or measuring cylinder
Mechanical or digital dynamometer
Spring dynamometer
Tape measure, tape measure
Torque wrench
Angle meter
Appendix A
(Informative Appendix)
Main instruments and meters for testing
GB/T4331—2003
Each】
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