This standard specifies the laboratory measurement method and limit values ​​of the vertical transmission vibration of the driver's seat of agricultural wheeled tractors. This standard applies to the driver's seat of agricultural wheeled tractors with rigid rear axle suspension. This standard does not apply to the driver's seat installed on special-purpose tractors. GB/T 8421-2000 Laboratory measurement and limit values ​​of transmission vibration of the driver's seat of agricultural wheeled tractors GB/T8421-2000 Standard download decompression password: www.bzxz.net

1Cs 65. 060. 10
National Standard of the People's Republic of China
GB/T84212000
NEQIS5007:1990
Laboratory measurement and limits of operator's seatlransmitted yibratiun for agricultural wheeled tractors
Laboratory measurement and limits of operator's seatlransmitted yibratiun for agricultural wheeled tractors 2000-03-16 release || tt || 2000-09-01 implementation || tt || National Quality and Technical Bureau release || tt || GB/TB4212500 || tt || This standard adopts 1506007:1V90 agricultural wheeled machine standard driver seat transmission vibration evaluation index 3, and merges GF/F8421-1587 agricultural wheeled machine driving vibration evaluation index> and (:3T6972--198 agricultural wheeled tractor driver seat selection and selection. This standard is different from the international standards in terms of the test results: considering the domestically produced tractor The existing technical level of machinery products is half, and changes and formulation are made to meet the national conditions of the vibration classification and transmission vibration limit values. This standard is issued and replaces GB/T8431-1987 and GRT6972-1986. This standard is proposed by the National Machinery Industry Bureau.
This standard is under the jurisdiction of the National Machinery Standardization Technical Committee. The main drafting units of this standard are: Lunan Machinery Research Institute, Luosuo Fourth Design Institute: The main drafters of this standard are: Li Guoying, Wan Qing, Fang Qin. 1 National Standard of the People's Republic of China
Laboratory test and limit values ​​of vibration transmitted by the driver's seat of agricultural wheeled tractors
Laboratory test and limit values ​​of vibration transmitted by the driver's seat
mrusurenieni end linits nf operator'r seatIrunsmitesl vibratinn far agricultural wbeeled tractor5GB/I84212000
neqIs05007:1990
代4/ 8421*18
RT 6372-15
This standard specifies the laboratory test method and limit values ​​for the vertical transmission of the operator's seat of industrial wheeled tractors. This standard is applicable to the operator's seat of empty wheeled tractors with a test frame. This standard is not applicable to the operator's seat installed on special purpose tractors: 2 Reference standards
The points contained in the following standards constitute the text of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards will be revised. Parties using this standard should explore the possibility of using the new version of the following reference standards. B/235-137 Anye traction machine driver's seat modification main net ratio device position measurement GB/1M34-1988 vibration and shock numerical method and expression method GR/T13A231 dynamic and sensor control force method GB12-1995 machine key dynamic and shock after strengthening the machine root installation 3 terms, definitions and requirements
This standard uses the following terms (abbreviated), definitions. 3.1 vehicle frequency
The measurement signal is analyzed at the frequency city. 3.2 Sample time aalyninlirueduralinm The vibration number used for analysis is the time interval, 5:33oerectraldensit
The average speed per unit bandwidth, /Hz
3.4 Acceleration value density function (PlFrrhahlinyesiyFuneiiornfacreeralionamplitndeg The ratio of the probability of occurrence of the instantaneous value of the acceleration value to the gain. 3.5 The unique point (Sll\)aesticcexpoiar is roughly equivalent to a conventional point in the consideration of the personnel and the relevant information. 4 Tractor vibration classification and limit value
4.1 Standard grouping of tractors
According to the standard machine without ear quality and the dynamic properties of the carbon pool at the connection point, it is divided according to Table 1. National Quality and Technical Supervision Bureau 2000-3-16 Approved 2000 09-01 implementation
machine pulling machine dynamic sub-topic
GB/T8421-2000
tractor infinite maximum repair g
6J7R 50D
>6 5ng
foreign: the drag machine is not equipped with rats. If the amount is small, the quality of the cloud salt and the quality and the time period can be known. 4.2 When the test and evaluation methods are in accordance with the provisions of this standard, the vibration of the vibration sensor on the driving seat of each machine shall not exceed the limit value given in Table 2, or the machine shall be disassembled. Test method
5.1 Test and data analysis
5.1.1 Spherical sensor and release device
Empty seat transmission is also completed, m
The original power on the driving seat base and the transmission to the driving distance on the female body are measured by the speed change sensor, and its installation method is in accordance with the provisions of 5.1.2.
The acceleration sensor is sensitive and can measure the average square of the acceleration end at 0. 05--10 m/s*, the peak value is greater than 6: the accuracy of the acceleration sensor and the amplifier shall be within the range of 1.8~2.5% of the actual root mean square value. The response rate of the acceleration sensor shall be greater than 30DHz and it shall be able to withstand an instantaneous speed of 100m/s without damage. 5.1.2 Installation of the acceleration sensor
5.1.2.1 The acceleration sensor (accelerometer) shall be located in the vertical projection area of ​​the vehicle seat cushion at the test bench or the installation base. The deviation distance from the vertical half of the vertical direction through the center of the driver's seat shall not exceed 1m. The measurement direction shall be parallel to the measurement Z axis (see Figure 1).
If the dynamic test is carried out in the connection type shown in the figure, the acceleration sensor installed on the driver's seat base and the acceleration sensor installed in the central measuring disc should be at the same distance from the control point, and the error should not exceed ±20mm2. 2-axis - push bone to head 5.1.2.2 Vibration of the driver's seat GB/T8421-2000 sets a standard. The acceleration sensor is installed in a semi-measuring disc with a diameter of 250mm=50mm. The disc is made of semi-iron material and placed on the seat cushion of the driver. A thin metal disc with a diameter of 75.mm±5mm is used to carry the effective acceleration sensor. The disc type is shown in Figure 2. Place the heart rate sensor on the bed, with the heart rate sensor close to the heart rate sensor and parallel to the heart rate axis (see 1). Install the heart rate sensor as shown in the figure. 5.1.3 Recorder 675±5 5 250 5r
The semi-rigid circular
space
filter of the sensor is used for analysis only. The playback accuracy of the sensor recorder is ~3% of the total signal RMS value within the frequency range
5.1.4 Frequency weighting can be implemented by one of the following three methods: 5.1.4.1/3 bandwidth method
The alarm signal recorded by the sensor recorder is input into the data analyzer. According to the frequency given in Table 3, analyze each 1/3 speed minute. The RMS value of each minute is represented by 2. The average value within the specified sampling time is Multiply the weighted component of the known velocity by 1/3 times the weighted factor W given in Table 2 to get the weighted velocity component of the end. Then, according to formula (1), we can get the weighted root mean square value of the velocity component:
GB/T8421-20QC
In order to obtain the 1/3 of the center frequency of the spherical velocity and the root square value, m/s, the two light intensity efficiency factors are:
And it should also satisfy the following formula;
Formula, B,--the end band of the frequency analysis, HT--the sampling time, not less than 3,
1/3 of the center period of the estimated frequency band/Hs
5.1.4.2 Kecheng Ken method
Add W
0. :0--6 dD
.ER--AJB
n. 63——4 d
n. 25--12 :1-
r. 20n -14 H
3.125= —18 d
0. =0 - 2
The method is to add a weighted network between the induction data and the time return integral, so as to obtain the weighted motion directly. The weighted network has a grid effect formed by the 2 oil grip provided by the 3. The error of the excitation curve: 2~-4Hz is not more than ±2.5LB, and the other frequency is not more than 2. The integrator should indicate the flat force of the weighted acceleration magic. For the integral of the test operation time, ta.
yuan city:
frequency blood weight such as inverse speed ms
shortest sampling time T is not ≥: 2J s:
14B/signal prediction process
15J0.81.2
5.1.4.3 equal bandwidth method
GR/T B421-2000
/Estimated strength
1821518
B/Time
Graph vertical direction (response
Equal bandwidth method should comply with the provisions of GB/110084, the range of the analysis should be from 1-201z, the sampling time T and the sampling bandwidth should meet the requirements of formula (4).
2BT140
Where: 0.3Hz
Assume that the mean square value of the equal bandwidth should be filled with the corresponding center frequency axis dynamic factor (see Figure 3) weighted sum or root, and the square root of the sum of the squares of the weighted dynamic levels of each equal bandwidth within the 1Hz beat rate range. 5.1.5 Calibration
5.1.5. 1. The accelerometer sensor shall be calibrated by the method specified in GB/T13823. The calibration procedure shall ensure that the accelerometer sensor has a daily sensitivity change of: less than ±2.5% of the average value within the range of 0-10Hz; less than ±6.0% of the half-mean value within the range of 2-80Hz. The sensor shall be fast at 15-30Hz. 5.1.5.2 Calibration method The accelerometer with a stable response shall be calibrated by the static calibration method. The static calibration method of the accelerometer can be used to obtain the sensitivity of the entire system. The sensor axis is then rotated by 1°, and the error from vertical to 1° is not greater than 1.1°. The position generated by the earth is converted to 19.1m/s (equal to 2g=9.80665m). The error of the screened electric value is not greater than 0.5%. Before and after the test, the pressure sensor should be calibrated and recorded. Each calibration should be compared with the internal electronic calibration of the whole system: the automatic position sensor is not easy to be adjusted or the state is difficult. After each test, the internal electronic calibration of the measurement system should be checked and adjusted immediately. Calibration should be performed to maintain the full range of the test. The speedometer installed on the driver's seat on the test bench should be of the same speed. The whole system should be recorded in writing before and after the test. 5.2 Test bench
5.2.1 Physical characteristics
GR/T 8421—2000
There shall be at least one 2-axis radio wave countermeasure. If the tester's requirements for PSD and PIF can be met, any suitable mathematical or simulation method may be used to generate the command signal. The moving part of the test bench is a platform for mounting the bed base, steering wheel and support plate for the driver's feet. The bench is limited to vertical movement and should avoid nonlinear vibrations that may cause false alarms or exceed the signal compensation capability. If the platform is used as a support (as shown in Figure 1), the distance from the support point to the double seat mark point (STP) shall not be less than 2cc0mm, and the height between the single seat mark point (S11) and the XX axis of the test bench shall be less than 200mm. 2001:
Product: This is for the purpose of not limiting the test bench structure. 4 Vibration test bench
5.2.2 Safety
When the acceleration of the seat is generated by 15/*, the thermal test bench shall have a safety device to ensure that the vibration is stopped. It is better to use a pressure device, such as an exciter or a reading. If an acceleration sensor is used as a safety protection signal acquisition component, its signal shall pass through a wave section with a rate of 100% to prevent the high-frequency component from exceeding the system's limit. If the test bench is not full pressure, it needs to be equipped with appropriate safety equipment. The hydraulic pressure or service can limit the speed of the test bench to within 1.3m5. The minimum size of the required equipment should meet the requirements of the system. Safety machine and switch: The tester and the operator of the control device on the system should be able to operate at the same time. The shutdown switch should be able to interrupt the interaction and control a door to release the system oil. During the test, the speed of the vehicle should be increased slowly and the test may be terminated at the request of the tester. 5.3 Test conditions
5.3.1 Type test
Test two independent seats,
Before the test, the driver's seat suspension should be adjusted according to the design specified by the manufacturer. If the manufacturer does not specify this condition, the seat should be run-in. During the run-in, the driver's seat should be under pressure (such as pressure) and adjusted according to the manufacturer's instructions. The driver should send a positive signal to the driver. The driver should be close to the room and the position sensor should reach 75% of the full stroke. During the running-in period, pay attention to prevent the overheating of the reducer. 5.3.2 Test Personnel
Test Person (single person) Two people should bear the weight, 6
GB.T84212000
The lighter total weight should be 5!kg ± 1kg. The waist weight should not exceed 5kg. The heavier total weight should be 9kg ± 5kg. The waist weight should not exceed 8kg. The test person sits on the driver's seat, with his feet on the bottom plate, and his hands standing on the turntable like a single driver. The driver's seat is adjusted according to the manufacturer's instructions. The distance between the turntable and the pedals and the driver's seat should be in accordance with the provisions of GB/T6235.
5.4 Test data or
5.4.1 The test data and the data collected on the standard test track of the tractor under normal working conditions and high speed are used as the basis. After statistical analysis, the test data of each tractor are selected to correspond to the representative value of the tractor standard or characteristic of the tractor of that level. The control input characteristics of each level of tractors during the data test are shown in Figures 5 to 3, and the acceleration power spectrum of each tractor is shown in Figure 5.4.2. The efficiency equation is determined by the corresponding standard value of the vibration generated at the base of the tractor in the random perturbation test in 5.5.2. 10
True: 2.7mg
Gu Zhang H2
(position -9. 5; sensor: low pass = 3. 2 1L2. Food suitable = 1, 9 1[z)3
Figure 5U-class Lakai's PSDH line
True average high rent value: 2m
Impact driver's alarm: 2.05m/
GB/T9421-2000
Frequency, 14
(vehicle value = 0.251 use: Ando-3.5Hz. Source -3.HFigure 6 [Light tractor's PSD front
ZHEAsn identification
True RMS value: 1-04/g
Through or 1g
(light value = 7.22 decision low -5.6H, Ketong = 2, 1H2) drop: 72-class tractor's PSE output
sensor RMS cabinet, 1. 74 u:/s*
Added RMS value: 1.Dank
GB/T 8421...2000
Amplitude -5.85Hz -2.11Hz:Hs, ... H'L
3-level PSD·5.85HI
H indicates that the low pass filter [T1] is consistent with the special frequency response of the product: and the low is determined by formula (5). H-RE/[C--13 137R*+25 6RIR*-11 37N+R8]*+(: 12Mr21 345R*+21 R16R6 126Ri ..(5] where R
is the frequency. Hz;
-HP+ is the frequency (Hz), and its value is shown in Table 4, 1 indicates that the low pass filter of the special frequency response of the product can be determined by the cabinet value of LP (6), 1=1/[:1- 13 13763 --25 6N*-13 137R--R')2-15 123R-21 845R$+2 456R*-5 126R')*[s .. . .. (6 )In the formula, R——/E.
F period rate, H
F. ——.P+ stop frequency (TIz), its value is shown in Table 4: The quotient filter of the Butters frequency response function is: FT,=S/(1+$126S-13137$*213465*+256685*12-E4651-1313755-265+S*) -- The low-pass filter of the Twoworth frequency response function is: LP=1/(115126813137$22184551256685+3866S131375—51268+55) In the two formulas: S-
(—1)
, the original in the table are the stop frequencies of HP and LP respectively, Hz..
Push-pull machine
Center running frequency Ht
GB/T 8421- 2000
The PSD at the indoor place is F, Hs
Design: 1. It represents the high and low pass response function of the product and the small pass wave device in decibels/times width. Table 5
Summer average gram value
Additional load and construction degree mean square estimate a-
Day standard position, mx
Manifest PS curved multi-stem
$.9--4.5 H
3--3.5 Hr
2.1~-2.RHx
I1. 9--2. 4 IIt
Additional purchase force root speed change position
Loss range within the true mean square root position minimum percentage
$.9r--4.5 Hs
$--3.5 Hz
2. 1.~2. 6 Hbzxz.net
1. 9~.2. 4 Table Hs
is divided into two sections according to the time T and the false conditions made in 5.1.4.2 and 5.1.4.3 in column 4.5. %
For all tests, the filter rate should meet the requirements of the most dense space of the four major points. The phase should not exceed the total mean square root value. The spring seat pass rate should be within the current high pass rate of three points. The total RMS value should be between 200% and at least 30%. The real RMS value should not exceed 4. The actual P5D value should be within the specified rate range. The rate in the frequency band must be protected from the boundary rate. 5.4.3 The actual or acceptance rate spectrum (PS\) of the test should be in accordance with the provisions of Table 5. 5.4.4 In order to generate the PSD and RMS value of the perturbation test required for the perturbation test, a double integrator can be used, a simulated signal generator can be used, and a digital signal generator with a digital-to-analog converter can be used: 5.4.5 During the test, the random data generated at the base should be in accordance with the provisions of Table 5.
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