Some standard content:
ICS43.160
Machinery Industry Standard of the People's Republic of China
JB/T8582.5—2001
Agricultural vehicles
Shock absorbers
Agricultural vehicles Shock absorbers2001-06-04 Issued
China Machinery Industry Federation
2001-10-01 Implementation
JB/T85825-2001
This standard is formulated to improve the quality of agricultural vehicles, standardize the matching shock absorber components, and protect the interests of users and enterprises. Appendix A of this standard is a prompt appendix.
Appendix B of this standard is a standard appendix.
This standard is proposed and managed by the National Agricultural Vehicle Standardization Technical Committee. Drafting units of this standard: Jiangsu University of Science and Technology, Agricultural Vehicle Development Research Center of Machinery Industry, Zhejiang Anji Weitai Shock Absorber Co., Ltd.
The main drafters of this standard are Chen Kunshan, Xue Nianwen, Wang Guolin, Jiang Haobin, Hu Xiaoan and Han Keyi. This standard was first issued in June 2001.
1 Scope
Machinery Industry Standard of the People's Republic of China
Agricultural vehicles shock absorbers
Agricultural vehicles shock absorbers JB/T8582.5—2001
This standard specifies the structural dimensions, technical requirements, test methods, inspection rules, marking, packaging, transportation and storage of shock absorbers for agricultural vehicles.
This standard applies to shock absorbers for three-wheeled agricultural vehicles and four-wheeled agricultural vehicles (hereinafter referred to as shock absorbers). 2 Referenced standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard was published, the versions shown were all valid. All standards are subject to revision. Parties using this standard should explore the possibility of using the latest versions of the following standards GB/T1239.2—1989
GB/T28281987
GB/T 169471997
JB/T5673—1991
QC/T6251999
3 Definitions
Technical conditions for cold-circuited cylindrical helical compression springsBatch inspection counting sampling procedures and sampling tables (applicable to continuous batch inspection)Fatigue test specifications for helical springs
General technical conditions for painting of agricultural and forestry tractors and implementsElectroplating and chemical treatment layers for automobiles
This standard adopts the following definitions.
3.1 Indicator card
Relationship curve between shock absorber resistance P and piston displacement s. Speed characteristic dampspeedaurve
The relationship between the shock absorber resistance P and the piston speed V. 3.3 Durability
The relationship between the shock absorber resistance P and the number of operations n. 3.4 Three-wheeled agricultural transport vehicle front shock absorber assembly (referred to as tricycle shock absorber assembly)threewheelagriculturalvehicleshodabsorber
A device (component) located between the frame and the wheel of a three-wheeled agricultural transport vehicle, which mitigates and attenuates the impact and vibration caused by the ground, and at the same time bears and transmits various forces and torques acting between the wheel and the frame. Three-wheeled agricultural transport vehicle front shock absorber (referred to as tricycle shock absorber)3.5
The part of the tricycle shock absorber assembly after the buffer spring is removed. 3.6 Simple shock absorbertdescopicshodkabsorbarA circular simple shock absorber.
Three wheel agricultural vehicle damper approved by China Machinery Industry Federation on June 4, 2001, implemented on October 1, 2001
Structural dimensions
JB/T8582.5—2001
The main structural dimensions of the shock absorber shall comply with the provisions of Table 1. Table 1
Diameter of working cylinder of shock absorber for three wheel vehicles
Diameter of working cylinder of simple shock absorber
Technical requirements
The shock absorber shall comply with the requirements of this standard and be manufactured according to the drawings and technical documents approved by the prescribed procedures. The appearance of the shock absorber shall be smooth and free of obvious defects such as bruises, scratches and rust. The weld of the shock absorber shall be uniform and flat, and there shall be no welding defects such as cracks, leakage and slag inclusion. The thickness and hardness of the chrome plating layer of the shock absorber shall not be lower than the provisions of Fe/Ep·Cr10 in QCT625. The coating quality of the paint parts of the shock absorber shall not be lower than the provisions of TQ-1-2-DM in JB/T5673. 53
The shock absorber shall be filled with oil of the specified brand and volume. On the tension and compression test bench, after 10 tension and compression cycles at a frequency of 5Hz±2Hz and a stroke of 30mm±1mm, there shall be no abnormal noise or other phenomena. After the tension and compression test, there shall be no oil leakage when placed horizontally for more than 8 hours. 5.7
The cleanliness of the shock absorber shall comply with the provisions of the enterprise standards or relevant technical documents. There shall be no abnormal friction between the buffer spring of the tricycle shock absorber assembly and the tricycle shock absorber. The buffer spring of the tricycle shock absorber assembly shall comply with the provisions of Level 2 in GB/T1239.2. 5.10
The ratio of the recovery resistance to the compression resistance of the shock absorber shall be greater than or equal to 12. The load-bearing mass, spring stiffness and damping force (the sum of restoring resistance and compression resistance) of the shock absorber assembly of the tricycle shall comply with the specifications in Table 2. The range of rated restoring resistance and rated compression resistance of the cylinder shock absorber shall comply with the provisions in Table 3.
Working cylinder diameter
Axial rated load
Note: The damping force in the table is the value when the piston speed is 0.52m/s. Working cylinder diameter
Note: The resistance in the table is the value when the piston speed is 0.52m/s2
Restoring resistance
200-1200
1000-2800
1600-4500
Spring stiffness
Damping force
≥154
≥185
≥228
≥307||tt ||≥337
≥383
Compression resistance
≤1000
400-1800
JB/T8582.5—2001
5.12 The permanent deformation of the buffer spring of the tricycle shock absorber assembly shall not exceed 0.5% of the total height, and the height difference of each pair of the buffer spring of the tricycle shock absorber assembly under the rated axial load shall not exceed 2% of the total height. 5.13 When the tricycle shock absorber assembly is tested with resonance frequency and acceleration transfer rate, its resonance frequency shall not exceed 1.7Hz, the minimum vibration excitation acceleration when it plays a vibration reduction role shall not exceed 0.6m/s2, the maximum acceleration transfer rate at the resonance frequency shall not exceed 2.8, the acceleration transfer rate within 3.5~10H shall not exceed 0.5, and the acceleration transfer rate shall not have a peak value greater than 1 in the frequency range above 10Hz. Note: The shock absorber assembly of a tricycle shall be tested according to the load-bearing mass, spring stiffness and damping force or according to the resonance frequency and acceleration transmission rate, and the two are equivalent. 5.14 During the durability bench test, the simple shock absorber shall not leak oil within 5×105 cycles, and the shock absorber of a tricycle shall not leak oil within 3×10 cycles. The resistance attenuation rate shall not exceed 35% of the rated value, the damping lubricant consumption shall not exceed 15% of the specified filling amount, the permanent deformation of the buffer spring of the tricycle shock absorber assembly shall not exceed 4% of the spring deformation under the limit working load, and all parts shall not be damaged. 5.15 The vertical bending stiffness K of the tricycle shock absorber shall meet the requirements of formula (1). The vertical bending strength reserve coefficient shall not be less than 5. ng (f + tana) ≤ 0.05K..
Where: Kw vertical bending stiffness, N/mm; m—rated axial load of tricycle shock absorber, kg; g gravity acceleration, g=10m/s2;
J. ——Rolling resistance coefficient, g=0.2
α—installation rear inclination angle of tricycle shock absorber assembly, (°). 6 Test method
6.1 Performance of buffer spring of tricycle shock absorber assembly (1)
The performance test of buffer spring of tricycle shock absorber assembly shall be carried out in accordance with the provisions of GB/T1239.2, and the test results shall be recorded in Table Al of Appendix A (Suggested Appendix).
6.2 Vertical bending stiffness and vertical bending strength reserve coefficient of tricycle shock absorber 6.2.1 Test equipment and accuracy
a) Test equipment: hydraulic or mechanical loading equipment, dial indicator or displacement measuring instrument, b) Accuracy: the error of force measurement system shall not exceed 8% of the full scale, and the error of displacement measurement system shall not exceed 1% of the full scale 6.2.2 Test conditions
a) Remove the outer cover and buffer spring of the tricycle shock absorber assembly, and drain the damping lubricant if necessary: b) The tricycle shock absorber is fixed on the test bench at the maximum length as shown in Figure 1. The position of the support point in the figure should be the same as the position of the connecting plate when the tricycle shock absorber assembly is installed on the whole vehicle:) The support or loading method must ensure that the tricycle shock absorber is basically not subjected to axial force: d) The support should have sufficient rigidity;
e) Loading position and direction, the load P acts on the front wheel axle hole axis position point C at the lower end of the tricycle shock absorber, and the direction is perpendicular to the axis of the tricycle shock absorber:
f The dial indicator or displacement sensor is arranged at point C. 3
6.2.3 Test method
a) Determine the initial test load P according to Table 4, = 3.5P: Working cylinder diameter
JB/T8582.5—2001
Rated axial load capacity
Reducing device
White distribution
Rated vertical bending load P. (Po=mgsn25°)N
Note: The actual vertical bending load can be calculated according to the actual loading mass of the tricycle shock absorber assembly. b) Preload P=0.5P, which is used as the measurement reference point (zero point) of point C. c) Slowly load to P, hold for 1 min, unload to P, and record the permanent deformation △C (or damage) of point C. d) When AC<0.005L, load P, increase the load by 0.5P, and repeat loading and unloading to P until AC≥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 (2): KP./Po
e) The test results are recorded in Table A2 of Appendix A. Resonance frequency, damping ratio and vibration acceleration transmission rate of shock absorber assembly of tricycle 6.3
6.3.1 Test equipment
1 Excitation table
a) Mechanical or electro-hydraulic servo excitation:
JB/T8582.5-2001
b) Excitation mode: excitation scanning or single-frequency sine excitation; 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: within the range of frequency less than or equal to 5Hz, the amplitude is not less than 30mm: within the range of frequency greater than 5Hz to less than or equal to 10H, the amplitude is not less than 2mm; within the range of frequency above 10Hz, the amplitude is not less than 0.5mm; e) Amplitude adjustment: step-by-step or stepless.
6.3.1.2 Measuring instruments
a) Name: acceleration sensor, charge amplifier, recorder, signal processing equipment: b) Frequency range: 0.5~100Hz:
c) Signal-to-noise ratio: better than 40dB.
6.3.2 Test conditions
a) Fix the lower end of the tricycle shock absorber assembly on the vibration table, as shown in Figure 2; Acceleration sensor
Limit block
Heat absorber
Speed sensor A
Vibration table
b) Fix the mass block on the vibration column, and the mass of the mass block is equal to the rated axial load of the tricycle shock absorber assembly: C) The gravity of the mass block should act on the buffer spring. When there is a distance between the mass block and the spring, a sleeve can be added (see Figure 2) or a limit block can be installed on the vibration column. The position of the lower end of the sleeve or the limit block should be the same as the position of the connecting plate or the lower connecting plate when the tricycle shock absorber assembly is installed on the whole vehicle:
d) Arrange the acceleration sensor A on the fork or on the vibration table near the fork, and arrange the acceleration sensor B on the vibration damping column or on the mass block near the vibration damping column.
6.3.3 Test method
JB/T8582.52001
a) Starting from the lower limit frequency less than 1H, perform sinusoidal excitation on the three-wheeled vehicle shock absorber assembly and measure the vibration acceleration at the upper and lower ends at the same time. b) Calculate the acceleration transfer rate at different frequencies according to formula (3): T)=1a)
Where: T(f)--acceleration transfer rate at frequency f; a, ()--excitation acceleration at the upper end of the shock absorber at frequency F, m/s; aa)
-excitation acceleration at the lower end of the shock absorber at frequency f, m/s?. (3)
c) Draw the acceleration transfer rate curve (see Figure 3). When measuring curve A, it should be measured under a larger excitation amplitude state, and the highest test frequency should not be less than four times its resonance peak value (but not less than 5H); d) When using sinusoidal scanning excitation, if the variation range of the amplitude of the measured signal exceeds the range of a certain gear of the instrument within the measured frequency range, segmented measurement can be performed;
e) When using single-frequency sinusoidal excitation, the excitation frequency can refer to the following values: 05, 0.6, 0.8, 1.0, 1.3, 1.6, 20, 2.5, 3.2, 4.0, 5.0, 6.3, 8.0, 10.0Hz; appropriately increase the measurement points near point a shown in the curve in Figure 3. Thank you letter 8.m
6.3.4 Data processing
a) Resonance peak value Tamax: the acceleration transmission rate value of the highest point a on the curve in Figure 3; b) Resonance frequency f: the frequency corresponding to point a on the curve: c) Damping ratio 5: Determine according to formula (4):
d) The test results are recorded in Table A3 of Appendix A. 6.4 Power test
6.4.1 Purpose
Measure the power diagram of the test piece.
6.4.2 Equipment
A shock absorber test bench that meets the requirements of Appendix B (Appendix to the standard). 6.4.3 Test conditions
Frequency Hz
a) Test temperature: 18~32℃:
b) Test specimen test stroke s: (100±1) mm; JB/T8582.52001
c) Test specimen test frequency n: (100±2) times/min; d) Speed v: According to a) and b) determined by formula (5) shock absorber piston speed: v=πsnx10*=0.52m/s
Where: shock absorber piston speed, m/s;
-test piece test stroke, mm;
-test piece test frequency, times/min;
Yuan——pi, take 3.14
When the shock absorber stroke is small and the test stroke of 100mm is not suitable, the test speed value should be selected according to the relevant technical documents; e) Direction: Plumb direction:
f Position: When installed, in the middle position of about half of the shock absorber stroke. The buffer spring should be removed from the shock absorber assembly of the tricycle. 6.4.4 Test method
a) Regularly obtain the calibration constant l of the force measuring element according to the test bench calibration method in Appendix B; b) When the test piece is not installed, draw the baseline: c) Vibrate according to 6.4.3 and record the dynamometer diagram within three to five reciprocating times of the test piece. 6.4.5 Resistance calculation
As shown in Figure 4, calculate the restoring resistance and compression resistance according to formula (6) and formula (7). Figure 4
Where: P restoring resistance, N:
Py—compression resistance, N;
a, b—the distance between the restoring part (f) and the compression part (y) of the dynamometer diagram and the reference line, mm; 1—the calibration constant of the test bench force measuring element, N/mm. 6.5 Speed characteristic test
JB/T8582.52001
Detect the resistance of the shock absorber at different piston speeds and obtain the speed characteristics of the test piece. 6.5.2 Equipment
A shock absorber test bench that complies with the provisions of Appendix B
6.5.3 Test conditions
6.5.3.1 Test temperature: 18~32℃.
6.5.3.2 Test piece test stroke s: 20~100mm. 6.5.3.3 Speed v
Calculate according to formula (8):
Where:
Shock absorber piston speed, m/s, the maximum test speed should not be less than 1.2m/sTest piece test stroke, mm;www.bzxz.net
n—test piece test frequency, times/min;
Pi, take 3.14.
4The buffer spring of the tricycle shock absorber assembly should be removed. 6.5.4 Installation of shock absorber
Same as e) and f in 6.4.3.
6.5.5 Test method
One of the following methods can be selected according to specific requirements. 6.5.5.1 Direct recording method
On the test bench specified in 6.5.2, use the corresponding electrical measuring device and the sensor element to obtain the piston speed and resistance signal of the test piece during the vibration process, and input the two signals into the recording device at the same time to directly obtain the speed characteristics of the test piece. The speed characteristic curve is shown in Figure 5.
6.5.5.2 Multi-condition synthesis method
According to 6.5.3.2, the stroke or frequency can be changed to obtain the changing speed v value and the resistance P under the corresponding working condition, forming the speed characteristic 8
JB/T8582.5—2001
Several points are connected smoothly to form the test curve of speed characteristic Pv. a) When the stroke is fixed and the frequency is changed
1) Determine the speed according to 6.5.3.3;
2) Measure the dynamometer diagram at different frequencies according to 6.4.4; 3) Measure the test speed characteristic Pv curve as shown in Figure 6. b) When the stroke is fixed and the frequency is changed
1) Test frequency: 100 times/min;
2) Measure the dynamometer diagram at different strokes according to 6.4.4: 3) Measure the test speed characteristic Pv diagram as shown in Figure 7. Figure 6
Durability test
6.6.1 Purpose
To determine the durability of the test piece.
6.6.2 Equipment
JB/T8582.52001
Mechanical or electro-hydraulic servo test bench, single-acting or double-acting, frequency not less than 180 times/min, stroke should meet the requirements of 6.4. 6.6.3 Single-acting test bench test method
6.6.3.1 Test conditions
a) Test temperature: After the test piece is heated up, the temperature of the upper end of the outer wall is kept below 70℃ by forced cooling, and monitored in time; b) The upper and lower mounting positions of the test piece should be well centered and installed in the plumb direction: c) Position: It should be roughly in the middle of the shock absorber: d) Number of working cycles: 5×10 times for cylinder shock absorber: 3×10 times for tricycle shock absorber: e) Test stroke of test piece: 100mm±1mm. 6.6.3.2 Test record
a) Record the dynamometer diagram according to 6.4 at the beginning and end of the test. b) According to the recorded dynamometer diagram, calculate the resistance change rate according to formula (9) and formula (10): 8.-Px100%
Pa-PL×100%
Where: S. Restoration resistance change rate, %; ey——Compression resistance change rate, %;
Po, P.——Restoration resistance at the beginning and end of the cycle, N; Pyo, Pyl——Compression resistance at the beginning and end of the cycle, N. (9)
) Record the abnormal conditions and oil leakage of the shock absorber during the test. Generally, damaged parts can be replaced and the test can be continued, but the damage of the parts, the cause of damage and the number of cycles must be recorded in detail, and the damaged parts must be kept. d) If any of the following situations occurs, it indicates that the durability of the specimen does not meet the requirements and the test should be terminated: 1) The shock absorber column of the tricycle shock absorber is broken or bent; 2) The shock absorber cylinder is cracked or deformed:
3) The weld between the connecting part and the shock absorber cylinder is cracked; 4) Other faults that may cause a major accident to the whole vehicle. e) After the test cycle is completed, check and record the wear of the key parts and key parts of the key parts of the specimen. f Check and compare the changes, differences and defects of the two dynamometer diagrams recorded at the beginning and end of the cycle. g) Record whether there are other abnormal situations. 6.6.4 Double-action test bench test method
6.6.4.1 Test equipment
Double-action fatigue test bench.
6.6.4.2 Test conditions
a) Test temperature: After the specimen is heated up, the temperature of the upper end of the outer wall is kept below 70°C by forced cooling and monitored in time; b) Movement mode: The upper and lower ends move in the vertical direction at the same time; Upper end vibration specification:
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