JB 9976-1999 This standard is a revision of ZB J62 006.10-88 "Noise Limits for Forging Machinery Noise Limits for Sheet Metal Bending Machines and Folding Machines". This standard specifies the noise limits for sound power levels and sound pressure levels of sheet metal bending machines and edge folding machines. This standard applies to sheet metal bending machines and edge folding machines. This standard was first published in April 1988. JB 9976-1999 Noise Limits for Sheet Metal Bending Machines and Folding Machines JB9976-1999 Standard download and decompression password: www.bzxz.net

ICS25.120.01
J62
JB
Machinery Industry Standard of the People's Republic of China
JB9976-1999
Sheet Metal Bending Machine, Folding Machine
1999-05-14 Issued
State Machinery Industry Bureau
Noise Limits
2000-01-01 Implementation
Issued
JB99761999
Foreword
This standard is a revision of ZBJ62006.1088 "Forging Machinery Noise Limits Sheet Metal Bending Machine, Folding Machine Noise Limits". The technical content of this standard is basically consistent with ZBJ62006.10-88, and it has only been re-edited according to relevant regulations. This standard shall be implemented from January 1, 2000. This standard replaces ZBJ62006.10-88 from the date of implementation. Appendix A of this standard is the appendix of the standard.
This standard is proposed and managed by the National Technical Committee for Standardization of Forging Machinery. The responsible drafting unit of this standard: Shanghai Punching and Shearing Machine Factory. This standard was first issued in April 1988.
Scope
Standards of the Machinery Industry of the People's Republic of China
Noise Limits of Sheet Metal Bending Machines and Folding Machines
This standard specifies the noise limits of sound power and sound pressure level of sheet metal bending machines and folding machines. This standard applies to sheet metal bending machines and folding machines. 2 Referenced Standards
JB9976-1999
Replacement of Police ZBJ62006.10-88
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are all valid. All standards will be revised, and parties using this standard should explore the possibility of using the latest version of the following standards. JB/T3623--1984 Forging Machinery Noise Measurement Method 3 Noise Limits for Sheet Metal Bending Machines
The noise A-weighted sound power level L of sheet metal bending machines during continuous idling operation must not be greater than that specified in Table 1. 3.1
Table 1
Male
Transmission form
Mechanical transmission
Hydraulic transmission
≤630
100
95
Sound
Force
KkN
>630~2500
Power level Lwa
Work
dB(A)
110
100
>2500
105
3.2 The A-weighted sound pressure level L of the noise at the specified position when the sheet metal bending machine is running continuously at no load shall not be greater than that specified in Table 2. Table 2
Male
Transmission form
Mechanical transmission
Hydraulic transmission
≤630
85
82
Nominal
kN
Force
>630~2500
Sound pressure level Lm
dB(A)
90
85
>2500
88
3.3 The A-weighted sound pressure level L of the impulse noise at the specified position during a single stroke of the sheet metal bending machine without load should not be greater than that specified in Table 3. Approved by the State Machinery Industry Bureau on May 14, 1999, and implemented on January 1, 2000
Transmission form
Mechanical transmission
4 Noise limits for folding machines
1
630
95
JB9976-1999
Table 3
Nominal
kN
Force
>630-2500
Pulse sound pressure level Engineering
Lpa
dB(A)
100
The A-weighted sound power level Lw of the noise when the folding machine is running continuously at no load should not be greater than that specified in Table 4. Table 4
Foldable plate friction
mm
Number of swings of folding machine
times/min
Sound power level LwA
dB(A)
2
#4
95
≤2.5
>4wwW.bzxz.Net
98
≤4
102
>2.5
The A-weighted sound pressure level L of noise at the specified position when the folding machine is running continuously at no load should not be greater than that specified in Table 5. Table 5
Thickness of foldable plate
mm
Number of gripping of folding frame
times/min
Sound pressure level Lg
dB(A)
4
82
≤2.5
>4
84
$4
86
>2.5
>2500
>4
105
>4
88
The A-weighted sound pressure level Ll of impulse noise at the specified position during no-load single stroke of the folding machine should not be greater than that specified in Table 6. 4.3
Table 6
Thickness of foldable plate
mm
Number of swings recorded at folding edge
times/min
Impulse sound pressure level La!
dB(A)
2
54
92
≤2.5
>4
94
≤4
96
>2.5
>4
98
Measurement method
JB99761999
The measurement method of this standard shall comply with the provisions of JB/T3623. 6 Instructions for use
The instructions for use of this standard are shown in Appendix A (Appendix to the standard). JB9976-1999
Appendix A
(Appendix to the standard)
Instructions for the use of this standard
A1 For all trial prototypes of new or improved designs, new products produced in small batches, or the first batch of sheet metal bending machines and folding machines produced after process or material changes, as well as sheet metal bending machines and folding machines undergoing quality grade assessment and performance tests, the noise sound pressure level should be measured, and it is recommended to measure the noise sound power level. A2 For sheet metal bending machines and folding machines produced in normal batches, only the noise sound pressure level can be measured during factory inspection.
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