JB/T 7237-1994 Test methods for three-wheeled agricultural transport vehicles
Some standard content:
Machinery Industry Standard of the People's Republic of China
JB/T7237-1994
Three-wheeled agricultural transport vehiclebzxz.net
Published on July 18, 1994
Test method
Implemented on July 1, 1995
Ministry of Machinery Industry of the People's Republic of China
JB/T72371994
Subject content and scope of application
Cited standards
Three-wheeled vehicle test
Front wheel shock absorber
Clutch
Gearbox||t t||Compilation of test report for chain drive and gearbox connected rear axle (semi-floating) with brake assembly
Appendix A Test record form for three-wheeled agricultural transport vehicle (supplement) 11
Machinery Industry Standard of the People's Republic of China
Three-wheeled agricultural transport vehicle
1 Subject content and scope of application
Test method
JB/T7237-1994
This standard specifies the vehicle parameters, performance and reliability of three-wheeled agricultural transport vehicles (hereinafter referred to as three-wheeled vehicles) and the quality, performance and reliability test methods of main components.
This standard applies to three-wheeled vehicles and main components. Reference standards
GB1496
GB5373
GB6231
JB3803
JB3901
JB3987
JB/T5673
JB/T7236
ZB T63 003
3 Three-wheeled vehicle test
3.1 Tested three-wheeled vehicle
Cold-rolled cylindrical helical compression spring
Technical conditions
Methods for measuring noise of motor vehicles
Methods for determining the size and mass parameters of motorcyclesMethods for determining the cleanliness of tractors
Bench test methods for automobile drive axles
Bench test methods for automobile simple shock absorbers
Bench test methods for automobile mechanical transmissionsGeneral technical conditions for painting of agricultural and forestry tractors and implementsTechnical conditions for three-wheeled agricultural transport vehicles
Technical conditions for cylindrical helical compression springs for tractor clutch
Bench test methods for tractor clutch
Tractor clutch cover and pressure plate assembly
Test methods
3.1.1 The tested three-wheeled vehicle must be accompanied by an instruction manual and relevant technical documents. 3.1.2 The structure and accessories of each assembly of the three-wheeled vehicle must be consistent with the accompanying documents. 3.1.3 Adjust and maintain the tricycle according to the items specified in the instruction manual to ensure that the tricycle has a normal technical condition. 3.1.4
The loading state of the tricycle shall comply with the provisions of each test item. The cargo mass and the number of passengers when fully loaded shall comply with the provisions of the instruction manual. The load shall not change its mass due to the environment, shall be evenly distributed in the car and its movement shall be restricted, and the loading height shall not exceed the car board. The test personnel and instruments riding on the vehicle shall be included in the cargo mass. 3.1.5 Except for the starting performance test, the tricycle shall be preheated before other performance tests so that all parts reach the normal working temperature. During the performance test, no adjustment of the tricycle is allowed. If necessary, it shall be approved by the responsible unit and carried out under its supervision, and then the relevant items shall be tested again, and the details shall be recorded in the report. 3.2 The test line
must be a test line designated by the local public security traffic management department and can be used for tricycles. Approved by the Ministry of Machinery Industry on July 18, 1994
Implemented on July 1, 1995
3.3 Road Test Conditions
3.3.1 Test Road and Climate
JB/T7237-1994
a. Except for special provisions, the test shall be carried out on a clean, dry, flat asphalt or cement road, with the longitudinal slope of the test section not exceeding 0.3% and the length adapted to the test item requirements; b. Except for the reliability test which is not restricted by climatic conditions, all other tests shall be carried out in a rainless and air-tight environment with a temperature of 20℃±15℃ and a wind speed of no more than 3m/s at a height of 1.2m above the ground. According to the test requirements, the temperature, wind speed and air pressure shall be measured and recorded at the beginning and end of the test. 3.3.2 Test instruments
a. Five-wheel tester: distance correction coefficient should be adjusted to less than ±0.5%; b. Steering angle meter: steering wheel diameter 400m, digital display value 1N; c. Sound level meter: precision grade, its error does not exceed +0.5dB (A); d. Multi-function dynamometer: range 980N, display value IN; e. Floor scale: weighing less than 10t, sensitivity less than 5kg; f. Electric dynamometer (selected according to the test method): range 5000N, display value 5N; g. Slope meter: scale Value 0.5%;
h, tire pressure gauge: range 10MPa, indicated value 50kPa;i. tachometer: 30~10000r/min, accuracy ±0.5%;j. anemometer: 0~30m/s, indicated value 0.1m/s;k. atmospheric pressure gauge: error ±70Pa;1. thermometer: scale value 0.5℃;
m. stopwatch: indicated value 0.01s;
n, measuring cylinder: capacity 250 or 500mL, scale value 5mL. 3.4 Test method selection
When there are more than two test methods for the same test item in this standard, one can be selected according to the requirements of the competent department or the conditions of the test equipment. 3.5 Acceptance and running-in of the tested tricycle
3.5.1 One vehicle is used for performance test and two vehicles are used for reliability driving test. 3.5.2 The test vehicle shall be inspected and accepted by the test responsible unit according to the acceptance rules for tricycles and relevant documents. The inspection items are listed in Table A1 of Appendix A (Supplement), and the inspection results are recorded in the table. 3.5.3 Before the test, the test tricycle shall be maintained and run-in according to the provisions of the instruction manual, and the running-in conditions shall be recorded in Table A1. 3.6 Determination of dimensions and mass parameters
The dimensions and mass parameters of the tricycle shall be carried out in accordance with the provisions of the three-wheeled motorcycle in GB5373. The dimensions of the driver's operating position of the handlebar tricycle are shown in the figure in JB/T7236, and the measurement results are recorded in Table A2 and Table A3 respectively. 3.7 Normal temperature starting performance test
3.7.1 The starting test is carried out at a normal temperature and pressure greater than or equal to 5℃, and the diesel engine and cooling water are not preheated. 3.7.2 Starting time is the time from the start of starting (hand cranking or pressing the button) to the time when the engine starts to run automatically. The start is successful if the electric start time is less than or equal to 30 seconds and the hand crank start time is less than or equal to 15 seconds. After the start is successful, turn off the engine immediately. Stop for 2 minutes and then start and stop again. Repeat twice. 3.7.3 Starting failure occurs if the engine fails to run automatically or the starting time exceeds the specified time from the start of starting to the stop of cranking or pressing the button. 3.7.4 The tricycle is started successfully if two out of three starts are successful. The starting performance test results are recorded in Table A4. 2
3.8 Maneuverability test
JB/T 7237 - 1994
3.8.1 Measurement of the minimum turning circle diameter and the maximum turning angle of the steering axis3.8.1.1 Replace the steering handle of the handlebar tricycle to be tested with a steering force angle meter with a diameter of 400mm. For steering wheel tricycles, a force angle meter is installed on the steering wheel.
3.8.1.2 The tricycle is unloaded and put in the lowest gear, and driven at a stable low speed. The steering wheel or the steering handle is turned to the extreme position in one direction, and the turning angle of the steering angle meter is recorded. At the same time, the track of the contact point between the symmetrical center plane of the front wheel and the ground is marked on the ground. After driving a full circle, exit the test site, and then use a tape measure to measure the diameter of the track circle in three evenly distributed directions and take the average value. The measurement should be carried out in the left turn and right turn directions, and each measurement should be carried out twice, and the average value should be taken. The maximum value of the two average values of left and right turns is the minimum turning circle diameter of the vehicle. The test results are recorded in Table A5.
a. The turning angle θ recorded by the force angle meter of the steering handlebar tricycle shall be taken as the maximum turning angle θzb. The maximum turning angle θ of the steering axis of the steering wheel tricycle shall be calculated according to formula (1): (1)
Radius of the steering axis rocker arm, mm;
Where:
Radius of the steering gear rocker arm (or gear pitch circle), mm. 3.8.2 Straight-line driving control force test
3.8.2.1 A straight section of 200m in length is marked in the middle of the test road as the test area. There should be an appropriate distance between the two ends of the test area so that the test tricycle can reach a speed of 25km/h before arriving at the test area. 3.8.2.2 The test tricycle is unloaded, and is replaced with (or equipped with) a steering force angle meter with a diameter of 400mm. It is monitored by a five-wheel instrument and drives straight through the test area at a stable speed of 25±0.5km/h. The maximum control force in the test area is recorded. Test twice each way and take the average value. The test results are recorded in Table A5.
3.8.3 Steering control force test
3.8.3.1 Draw a semicircle with a radius of 3.5m and a straight-line section on the test site as shown in Figure 1. Figure 1
3.8.3.2 The three-wheeled vehicle to be tested is unloaded, and is replaced with (or equipped with) a steering force angle meter with a diameter of 400mm. It is monitored by a five-wheel instrument and driven at a stable speed of 10±0.5km/h. The center plane of the front wheel is along the route shown in Figure 1. It turns from a straight driving state to a U-turn of 180° and then returns in a straight line. The steering control force in the A and B test areas is recorded. The test is carried out in the left turn and right turn directions respectively, and each is measured twice. The average value is taken. The steering control force test results are recorded in Table A5. 3.9 Inspection line inspection of three-wheeled vehicles
3.9.1 Inspection line inspection items
JB/T 7237-1994
a. Front and rear axle load mass (including driver's weight); b. Braking force of left and right rear wheels;
C. Maximum stable speed;
d. Luminous intensity of the high beam of the headlight;
e. Smoke emission.
3.9.2 The inspection method shall be in accordance with the provisions of the public security traffic management department. 3.10 Power performance test
3.10.1 Test conditions
Two straight sections of 100m and 200m are marked on the test road as the test area. There should be enough auxiliary working sections at both ends of the 200m test area so that the test vehicle can reach the maximum speed before arriving at the test area. The tricycle is fully loaded and the speed is measured with a five-wheel instrument. 3.10.2 Minimum stable speed test
3.10.2.1 Minimum stable speed in the lowest gear
The tricycle is driven in the lowest gear with the smallest possible throttle, and enters the 100m test area at the minimum speed that can be driven stably, and the stable speed passing through the test area is measured. After passing the test area, immediately step on the accelerator pedal to accelerate. During this period, the engine should not be turned off and the transmission system should not be moved. If these situations occur, increase the vehicle speed appropriately and retest to find the lowest stable vehicle speed that can accelerate smoothly. Repeat the test twice in this state. Take the average of the speeds of passing the test area four times as the lowest stable vehicle speed in the lowest gear. The test results are recorded in Table A6.
3.10.2.2 Lowest stable vehicle speed in the highest gear
Measure in the same way as measuring the lowest gear. The test results are recorded in Table A6. 3.10.3 Highest speed test
The tricycle starts from a place far enough away from the 200m test area, shifts gears to accelerate to the highest gear, and steps on the accelerator to the bottom, so that the test vehicle reaches the highest speed before arriving at the test area, and maintains a stable speed through the 200m test area. Measure the speed through the test area. The test should be carried out twice in each direction and the average value is taken. The measurement results are recorded in Table A6. 3.10.4 Highest gear acceleration performance test
3.10.4.1 The test road is a 200m long test area with 50m long speed test areas at both ends of the test area. There should be an appropriate distance outside the speed test area so that the test vehicle can accelerate to 15km/h before reaching the test area. 3.10.4.2 The test vehicle is in the highest gear and passes through the speed test area at a steady speed of 15km/h. When it reaches the starting point of the test area, the accelerator is immediately pushed to the bottom to accelerate until the speed reaches 30km/h. The time and distance from the initial speed of 15km/h to the speed of 30km/h are recorded with a five-wheel instrument. The test is carried out twice each way and the average value is taken. The results of the highest gear acceleration performance test are recorded in Table A7. 3.10.5 Maximum climbing ability test
3.10.5.1 Measured maximum climbing ability
Select a straight section with a slope close to the maximum climbing grade (design value) of the tested tricycle on a hard road surface and a uniform slope of 20m as the test area. Measure the slopes at the beginning, middle and end of the test area, and take the average value as the slope of the test area. The slope above the test area should not be greater than the test area, and there should be a gentle slope or flat road below the test area. After the tested tricycle starts with the lowest gear, immediately step on the accelerator to the bottom and drive up the ramp and pass the test area. If it passes the test area smoothly, the load should be added; if it cannot climb the ramp, the vehicle should stop, reduce the load, and retest. If the test road slope is not suitable (large or small), the load or gear can be changed 4
JB/T7237-1994
times, and the test can be repeated until it can or cannot pass after reducing or increasing 25kg. Special attention should be paid to safety protection during the test. When increasing the load, the strength of the component should not be exceeded. The load that can pass the test area and the test slope are recorded, and converted into the maximum slope that can be climbed when climbing the slope with the lowest gear at the rated load mass according to formula (2). The test results are recorded in Table A8. αmax=arc sin（
sinα'）.
Jmax =tg am× 100%
Where: Jmx——converted maximum climbing grade, %; amax—converted maximum slope angle of ramp, (°); a”——slope angle of test ramp, (); m——rated total mass of the tested tricycle, kg; m——maximum total mass of the tested tricycle when passing through the test area, kg; —lowest total transmission ratio of the tested tricycle; —total transmission ratio of the gears actually used during the test. 3.10.5.2 Maximum climbing gradeability measured by traction method (2)
The tested tricycle is fully loaded, and the test traction frame is installed on the rear of the frame to hang the electric tensile instrument. The load vehicle (or other motor vehicle) is horizontally towed in the lowest gear and the accelerator is pressed to the bottom. The load vehicle is loaded (braked) and towed for not less than 20m until the engine of the tested tricycle fails to work normally. Record the test results and convert the maximum slope according to formula (3). (Ff)× 100..
Jmax=tg[arc sin (
Where: F is the traction force of the tricycle, N; g is the acceleration due to gravity, 9.8 m/s2;
f is the rolling resistance coefficient, which is 0.02 for hard road surfaces; the rest are the same as in (2)
The maximum gradeability test results are recorded in Table A8. 3.11 Sliding test
(3)
A 300 m straight section is marked in the middle of the test road as the test area. There are appropriate preparation areas at both ends of the test area so that the test tricycle can reach a speed of 30 km/h before reaching the test area. The test tricycle is fully loaded and travels at a steady speed of 30 km/h. When it reaches the end of the test area, the clutch pedal is quickly pressed and the gear is shifted to neutral, so that the tricycle slides straight to a stop. The initial sliding speed and sliding distance are recorded with a five-wheel instrument. The test is repeated twice and the average value is taken. The test results are recorded in Table A9.
3.12 Braking performance test| |tt||3.12.1 Driving Braking Performance Test
A 20m long straight section is marked in the middle of the test road as the test area. The two ends of the test area are appropriately long so that the tricycle can reach a speed of 20km/h before arriving at the test area.
The brake drum of the tested tricycle is in a cold state (below 100℃). After the tricycle arrives at the test area with a full load and a steady speed of 20km/h, the clutch and brake pedals are quickly pressed to emergency brake until it stops completely, and then the gear lever is put into neutral. The initial braking speed and braking distance are recorded with a five-wheel instrument, and the deviation distance is measured with a tape measure. The test should be carried out twice each way and the average value is taken. The test results are recorded in Table A9. The deviation distance refers to the vertical distance from the center point of the rear wheel braking end to the extension line of the center of the straight pressure and drag mark at the beginning of braking. 5
3.12.2 Parking Braking Performance Test
JB/T 7237 -1994
The three-wheeled vehicle under test is fully loaded and driven on a smooth, clean, dry cement or asphalt road with a slope of 20%, braked and stopped, the parking control handle is moved to the maximum working position, then the vehicle is put in neutral, the foot brake is released, and the diesel engine is running rapidly. The parking mark line is drawn on the rear tire and the contact point with the ground. After 5 minutes, the rotation line displacement of the outer diameter of the rear tire and the relative displacement with the ground are measured. Then the test vehicle turns 180° and repeats the above test. The test results are recorded in Table A9. 3.13 Road driving fuel consumption rate test
The test road is a highway of level 3 or above (including level 3), with little traffic, small slope, accurate road signs, and a length of more than 25km. The three-wheeled vehicle under test is fully loaded and driven at an average speed of about 25km/h according to the normal use method, and drives back and forth once on the 25km test section. If it is necessary to stop during driving, the engine should be turned off, and the engine is not allowed to run rapidly for a long time. According to the test equipment conditions, the fuel consumption can be measured by one of the following methods:
a. Use a fuel flow meter, and the reading value is mL;
b. Before the test, fill the fuel tank with fuel on flat ground, and after driving, use a measuring cylinder to measure the fuel in the tank, and the scale value of the measuring cylinder is 5mL; C.Use an auxiliary fuel tank, weigh the difference in the total mass of the auxiliary fuel tank (including fuel) before and after the test (pound scale sensitivity 5g), and then convert it into volume L according to the actual specific gravity.
Calculate the fuel consumption per 100 kilometers according to formula (4), and calculate the fuel consumption per ton of 100 kilometers according to formula (5). The test results are recorded in Table A10. Gts
Grs×100
Where: Grs——fuel consumption per 100 kilometers, L/100km; V——fuel consumption passing through the test area, L;
S—length of the test area, km;
gmp——fuel consumption per ton of 100 kilometers, L/(t100km); ms——mass of the tested tricycle, calculated according to the total mass and cargo mass, kg. The maximum noise level outside the vehicle during acceleration is measured 3.14
According to GB1496.
5 The performance test results of tricycles are summarized and recorded in Table A11. 3.15
3.16 Reliability driving test
Two test vehicles are required for each vehicle type.
3.16.2 Except for the driving road and climate conditions, the other test conditions shall comply with the provisions of 3.1 to 3.5. 3.16.3 Main performance test of the whole vehicle
Each test vehicle shall be subjected to the following performance tests in accordance with the relevant provisions of this standard after running-in and before the driving test: a. Power performance test (except maximum gradeability); b. Braking performance test;
c, road driving fuel consumption test;
d. Measurement of the maximum noise level outside the vehicle during acceleration. The test results are recorded in Table A15.
3.16.4 Driving test
...（4）
..（5）
JB/T 7237 -1994
The total mileage of each three-wheeled vehicle for the finalization test of new products is: 15,000 km for vehicles with a maximum speed of less than or equal to 30 km/h; 20,000 km for vehicles with a maximum speed of more than 30 km and less than or equal to 40 km/h. The test mileage of a modified vehicle is 5,000 km. 3.16.4.1 Driving roads and climatic conditions
Three test sections are selected, including plain roads of level 3 and below, rough roads and mountain roads, and the more accurate mileage of the test sections is measured, and a driving route map is drawn. The test should be carried out on the above sections, and the mileage on plain roads of level 3 and below shall not exceed 50% of the total mileage, the rough roads shall not be less than 30%, and the mountain roads shall not be less than 20%. The climatic conditions are in accordance with the normal use of local motor vehicles.
3.16.4.2 Driving rules and records
a. During driving, the vehicle should be driven as fast as possible while ensuring safety, so that the average speed during the entire test period is not less than 60% of the maximum speed. The night mileage of each test vehicle should not be less than 5% of the total mileage; b. Each shift (or day) should be driven, operated, and maintained according to the instructions for use. The technical status of the test vehicle shall not be adjusted or changed arbitrarily, and the driving record form A12 shall be filled in as required. Carefully observe and record all abnormal phenomena of the test vehicle; c. The driving conditions on the three types of roads should be photographed; d. Summarize the mileage and fault conditions on various roads and fill in the summary forms A13 and A14. 3.16.4.3 Fault classification and handling
According to the cause of the fault and the severity of the consequences of the fault that affects the normal driving of the tricycle and the correlation of the fault, the tricycle faults are divided into the following four categories:
a. Fatal fault: endangering the driving safety of the tricycle, causing personal injury or death or major assembly a, serious fault: the main parts and assemblies are damaged, or driving safety is affected, and the fault cannot be eliminated in a short time with wearing parts and on-board tools;
c, general fault: the tricycle stops running or performance declines, but generally does not cause serious damage to the main parts and assemblies, and can be eliminated in a short time by replacing wearing parts and on-board tools: d, minor fault: generally does not cause the tricycle to stop running or performance decline, does not need to replace parts, and can be easily eliminated with on-board tools.
For specific classification and judgment rules, refer to the relevant standards for three-wheeled motorcycles. If a fatal fault occurs during the driving test, it is considered that its reliability does not meet the requirements, and the design of the relevant parts or mechanisms should be improved and the reliability test should be repeated. If other types of faults or mechanical damage occur, in addition to detailed records according to Table A12, the cause should be analyzed and determined, and then the fault should be eliminated or spare parts should be replaced to continue the driving test. 3.16.5 Retest of the main performance of the whole vehicle
After the three-wheeled vehicle under test completes the driving test, the passenger part can be adjusted, and then the main performance retest is carried out. The test content and method are the same as 3.16.3. After the test, analyze and compare the performance changes and record them in Table A15. 3.16.6 Analysis of the convenience of operation and maintenance
Based on the driving test, analyze the driver's operating position size and operation performance, safety protection devices and maintenance convenience of the three-wheeled vehicle.
4 Front wheel shock absorber
4.1 The spring performance test method shall comply with the relevant provisions of GB1239.2, and the test results shall be recorded in Table A16. 7
JB/T 7237 -1994
4.2 The quality inspection of paint shall comply with the relevant provisions of JB/T5673. 4.3 On the tension and compression test bench, the tension and compression cycles shall be repeated 10 times at a frequency of 5±2Hz and a stroke of 30±1mm. During the test, there shall be no abnormal phenomenon such as oil leakage or abnormal noise. After the test, there shall be no oil leakage after the test is placed horizontally for 10 minutes. 4.5 The damping force dynamometer test and reliability (durability) test method shall comply with the relevant provisions of JB3901, including: specimen stroke S: 80±1mm; test frequency: 75±2 cycles per minute. The test results are recorded in Table A17. 4.6 Bending static strength reserve coefficient
4.6.1 Test equipment and accuracy
a. Test equipment: hydraulic or mechanical loading equipment, dial indicator or displacement measuring instrument; b. Accuracy: the error of the force measurement system shall not exceed 8% of the full scale, and the error of the displacement measurement system shall not exceed 1% of the full scale. 4.6.2 Test conditions
a. Remove the shock absorber cover and buffer spring, and drain the damping lubricant when necessary: b. The shock absorber is fixed on the test bench at the maximum length as shown in Figure 2. The position of the support point in the figure should be the same as the position of the upper and lower connecting plates when the shock absorber is installed on the vehicle; Support
Dial gauge
c. The support or loading method must ensure that the shock absorber is basically not subjected to axial force; d. The support device should have sufficient rigidity;
e. Loading position and direction: The load P acts on the axis position C of the front wheel axle hole at the lower end of the shock absorber, and the direction is perpendicular to the axis of the shock absorber:
f. The dial gauge or displacement sensor is arranged at point C. 4.6.3 Test method
a. Determine the initial test load P2=3.5P according to Table 1. Table 1
Working cylinder diameter
Rated axial load m
Note: The actual vertical bending load can be calculated according to the actual vehicle load of the shock absorber. 8
Rated vertical bending load P.
P=mg sin25o
JB/T7237-1994
b. Preload P,=0.5Pe, and use it as the measurement reference point (zero point) of point C; c. Slowly load to Pz, hold for 1min, unload to P,, and record the permanent deformation △c (or damage) of point C; d. When △c<0.005L, the load of P, increases by 0.5P. Repeat loading and unloading to P, until △c≥0.005L (or damage), stop the test, record the failure (plastic deformation or damage) load P, (including P,), and calculate the vertical bending strength backup coefficient K, according to formula (6):
e. The test results are recorded in Table A18.
4.7 System resonance frequency, damping ratio and vibration acceleration transmissibility 4.7.1 Test equipment
4.7.1.1 Excitation table
a. Mechanical or electro-hydraulic servo excitation;
b. Excitation mode: sine sweep or single-frequency sine excitation; P.
c. Excitation frequency: the lower limit frequency is not greater than 1Hz, and the upper limit frequency is not less than 30Hz. Step-by-step or stepless adjustable: d. Maximum vibration amplitude: when the frequency is less than or equal to 5Hz, the amplitude is not less than 30mm; in the range of greater than 5Hz to less than or equal to 10Hz, the amplitude is not less than 2mm; in the range above 10Hz, the amplitude is not less than 0.5mm; e. Amplitude adjustment: step-by-step or stepless.
4.7.1.2 Measuring instruments
a. Instrument name: accelerometer, charge amplifier, recorder, signal processing equipment; b. Frequency range: 0.5~100Hz;
c. Signal-to-noise ratio: better than 40dB.
4.7.2 Test conditions
a.Fix the lower end of the shock absorber on the vibration table (see Figure 3); acceleration sensor B
mass block
additional sleeve
limit block
damper
acceleration sensor A
vibration table
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