This standard specifies the noise limits for the sound power level and sound pressure level of closed presses. This standard applies to closed presses, closed double-action stretching presses, closed multi-station presses (hereinafter referred to as closed presses). Type press). JB 9974-1999 Noise limit for closed press JB9974-1999 Standard download and decompression password: www.bzxz.net

ICS25.120.01
J62
JB
Machinery Industry Standard of the People's Republic of China
JB9974-1999
Closed press
1999- Released on 05-14
Noise limits
Implemented on 2000-01-01
National Machinery Industry Bureau
Released
JB9974-1999||tt| |Foreword
This standard is a revision of ZBJ62006.8-88 "Noise Limits for Forging Machinery Noise Limits for Closed Presses". The technical content of this standard is basically consistent with ZBJ62006.8-88, and has only been re-edited in accordance with relevant regulations. This standard will be implemented from January 1, 2000. This standard replaces ZBJ62006.8-88 from the date of implementation. Appendix A of this standard is an appendix to the standard.
This standard is proposed and centralized by the National Forging Machinery Standardization Technical Committee. The unit responsible for drafting this standard: Jinan Second Machine Tool Factory. This standard was first published in April 1988.
1 Scope
Machinery Industry Standard of the People's Republic of China
Closed Presses
Noise Limits
This standard specifies the sound of closed presses Noise limits for power level and sound pressure level. JB9974-1999
replaces ZBJ62006.8-88wwW.bzxz.Net
This standard applies to closed presses, closed double-action stretching presses, closed multi-station presses (hereinafter referred to as closed presses) Machine 2 Referenced Standards
The following standards contain provisions that, by reference in this standard, constitute provisions of this standard. The edition indicated is valid at the time of publication of this standard and all standards shall be revised. Standard parties should explore the possibility of using the latest version of the following standards JB/T3623-1984 Forging machinery noise measurement method 3
Noise limits
3.1 Noise during continuous dry operation of closed presses. A-weighted sound power level Lw should not be greater than the provisions of Table 1, Table 1
nominal force
kN
sound power level Lw
dB(A)|| tt||3.2
3. 3
2500
110
>2500~6300
115
>6300~25000|| tt | ||kN
Pulse sound pressure level La1
dB(A)
≤2500
95
>2500-6300
100
>630025000
105
The noise A-weighted sound pressure level L at the specified position when the closed press is continuously running idling should not be greater than the requirements in Table 3. Table 3|| tt||Nominal force
kN
Sound pressure level Lg
dB(A)
Approved by the National Machinery Industry Bureau on 1999-05-14≤2500||tt| |86
>2500-6300
88
>630025000
88
2000-01-01 implementation
JB99741999||tt ||3.4 ??The noise A-weighted sound pressure level L at the operating position of the closed press during a single stroke without load should not be greater than 90dB(A). Measurement method
4
Measurement of this standard. The method should be as specified in JB/T3623 5
Instructions for use
The instructions for use of this standard are shown in Appendix A of JB9974-1999
Appendix A||tt| |(Appendix of the standard)
Instructions for use of this standard
A1 Any new or improved design trial prototype, small batch trial production of new products, or the first batch of production after process or material changes Closed press products, as well as closed press products subject to quality grade assessment and performance testing, should have their noise sound pressure levels measured, and it is recommended to measure their noise sound power levels.
A2 For normal batch-produced closed press products, only the noise sound pressure level can be measured during factory inspection.
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