JIS-A-8304-1987-ENG.pdf
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1、I - l JIS UDC 621.86/.87 : 624/628 : 629.1 1 .O14 : 534.63 JAPANESE INDUSTRIAL Testing Method of STANDARD. Operator Seat-transmitted Vibration for Construction Machinery JIS A 8 3 0 4 - 1 9 8 7 Translated and Published by Japanese Standards Association Printed in Japan 9s Copyright Japanese Standard
2、s Association Provided by IHS under license with JSALicensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 03/14/2007 20:48:22 MDTNo reproduction or networking permitted without license from IHS -,-,- J I S A*8304 87 m 4933608 0004524 L W In the event of any doubt arising, the original
3、 Standard in Japanese is to be final authority. Copyright Japanese Standards Association Provided by IHS under license with JSALicensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 03/14/2007 20:48:22 MDTNo reproduction or networking permitted without license from IHS -,-,- UDC 62 1.8
4、6/.87:624/628:629.11 .O 14:534.63 JAPANESE INDUSTRIAL STANDARD J I S Testing Method of Operator Seat- A 8304-1987 transmitted Vibration for Construction Machinery , Scope This Japanese Industrial Standard specifies the testing method in laboratory for the measurement and evaluation of the vibration
5、in vertical direction on the operator seat of tractor, tractor shovel and tractor-scraper of crawler type and wheel type out of construction machinery. 2. Definitions For the purposes of this Standard, following definitions apply: (i) operator seat That portion of the machine provided for the purpos
6、e of supporting the buttocks of the seated operator, including the seat suspension mechanism, (2) measurement axis The vertical axis az from buttocks to head of the o seated operator (refer to Fig, 1) Fig. 1. Measurement Axis Reference Standards: JIS B 0153-Glossary of Terms Used in Mechanical Vibra
7、tion and Shock IS0 7096 Earth-moving machinery-Operator seat Transmitted vibration Copyright Japanese Standards Association Provided by IHS under license with JSALicensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 03/14/2007 20:48:22 MDTNo reproduction or networking permitted withou
8、t license from IHS -,-,- J I S A88304 87 m 4933608 0004526 5 m 2 A 8304-1987 (3) frequency analysis The spectral analysis of vibration phenomena. (4) measuring period The time duration in which the vibration measurement for analysis is carried out continuously. 3. Symbols and Abbreviations a : , ins
9、tantaneous value of acceleration. a f : a w : awt : awfB : awfs : Be: f : T : Wf : 9: SIP : root mean square value of 1/3 octave acceleration having center frequency f. instantaneous value of vibration weighted acceleration vibration weighted rms acceleration calculated as described in 4.4.1, 4.4.2
10、and 4.4.3. awr at the seat mounting base (see 5.3.2). awr at the seat disc (see 5.3.1). resolution band width of a frequency analysis (Hz). frequency (Hz ) . measuring time duration (s). vibration weighting factor. acceleration of gravity (international standard: 9.80665 m/s2 at O sea level). Seat I
11、ndex Point 4. Test Apparatus and Measuring Instrument 4.1 Vibration Test Stand 4.1.1 Physical Characteristics The vibration test stand, hereinafter referred to as the “test stand“, shall have the following physical characteristics. (1) The test stand has an electro-hydraulic feedback control system
12、with freedom at least in measurement axis az or is the apparatus having equivalent or superior performance. The system shall have dynamic response capable of driving the mounting base of the loaded seat in accordance with the power spectra of input acceleration for random vibration test specified in
13、 6. (2) The transfer function characteristics of test apparatus may be compensated for during the synthesis of the command input signal in order that a, output of power spectral density, hereinafter referred to as the “PSD“, and probability density function, hereinafter referred to as the “PDF“ requ
14、irements are satisfied at the seat mounting base. Any appropriate digital or analog method may be used to generate the command signal providing that the output PSD and PDF requirements are satisfied at the seat mounting base. Copyright Japanese Standards Association Provided by IHS under license wit
15、h JSALicensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 03/14/2007 20:48:22 MDTNo reproduction or networking permitted without license from IHS -,-,- 3 A 8304-1987 (3) The moving portion of the test stand shall consist of a platform to provide for the seat mounting base and flat fl
16、oor space for operator foot support. The stand shall as a rule, be constrained to travel in a vertical direction and shall be free from resonances and nonlinearities, which would distort the output vibration beyond the correction capability of signal compensation. Fig. 2 Representative actual wheel
17、specification in the case of using handle If the platform is carried on an arm, as shown in Fig. 2 the distance from the arm pivot to the SIP shall be at least 2000 mm. 4.1.2 Safety Countermeasures The test stand shall have the following fety countermeasures: The test stand shall have Sail-safe prov
18、isions capable of automatic shut-down when the seat mounting base acceleration exceeds 15 m/s2 for any reason. It is preferred that this provision be a hydraulic means, such as supply pressure relief valve and/or a load limiting valve across the piston of the hydraulic cylinder, If an acceleration t
19、ransducer is used as the sensor for safety purposes, its signal shall be passed through a low pass filter with a 20 Hz cut-off frequency to avoid automatic shut-down from high frequency components beyond the hydraulic capability of the test stand. If the test stand is not of the hydraulic type, adeq
20、uate safety devices shall be used. The hydraulic pump and/or servo-valves shall be sized to limit the test stand velocity to 1.3 m/s, and the accumulator shall be of the minimum size required to provide the proper system response. Fail-safe shut-down switches shall be provided to both the person in
21、the test seat and the operator of the test apparatus. Copyright Japanese Standards Association Provided by IHS under license with JSALicensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 03/14/2007 20:48:22 MDTNo reproduction or networking permitted without license from IHS -,-,- JIS
22、A*A304 87 4933b08 0004528 9 4 A 8304-1987 The shut-down switches shall shut down hydraulic power supply and actuate a valve to release the system hydraulic pressure. In all tests, the excitation vibration shall be increased slowly to allow the test to be terminated at the request of the person in th
23、e seat. 4.2 Acceleration Transducers Vibration transmitted to the seat shall be measured by an acceleration transducer described in 5.3.1. transducer, together with its associated amplifier, shall be capable of measuring rms acceleration levels ranging from 0.1 to 10 m/s2 with a crest factor (ratio
24、of peak value of vibration wave form to rms value) as great as 6. The acceleration The acceleration transducer and amplifier with proper calibration for the test, shall be capable of an accuracy of at least k 2.5 % of the actual vibration levels in the frequency range from 0.8 to 40 Hz. Further, the
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