How to reduce the impact of noise and vibration of air tools

High levels of noise and vibration accompanying the operation of the equipment in all areas of manufacturing (engineering, construction, agriculture, etc.), Leading to lower productivity, poor product quality and well-being of workers. And when a large proportion of heavy and unskilled work, these factors (noise and vibration) may cause occupational diseases. Of the 800 thousand. Units of obsolete equipment, which currently operates in Ukraine, a certain portion of the pneumatic hand tools. Noise and vibration emitted by these tools (hammers, chisels, etc.) In size second only to such powerful emitters of noise and vibration as aircraft engines, powerful compressors, internal combustion engines, large pumps, etc.

Large pneumatic tools include pneumatic wrenches, hammers, chisels, drills and grinders, stamping hammers and others. They are now used in virtually all sectors of the Ukrainian economy. Noise measurements were made at a distance of 0.5 m from the instrument and 100 mm from the human ear. Local vibration directly investigated Hand pneumatic tool perpendicular to the palm of the right hand (7 ") and parallel to the right hand (X "), and also on the glass (in the field of support tools with the left hand).

The noise from the pneumatic tools

The level of the noise measured depending on the material and mode of operation is: pneumatic wrenches (depending on type) " from 103 to 118 dBA, pneumatic drilling machines " 92-99 dBA (such as a PC and " Bee "), pneumatic sanders " 88 " 110 dB (type SR 06-2 and SR-2), a pneumatic hammer type KM 25 - 108 dBA, pneumatic hammer Embossing SP 4209 - 113 dBA, pneumatic chisel EK19 " 115 " 118 dBA. As indicated above the noise spectrogram tools, the overall noise level is mainly determined by the spectral components situated in the area of ​​high frequency (1000 " 11 to 200 Hz), the intensity of which is within a 92 " 106 dB. Larger values ​​of the spectral components observed in the most noisy instruments " pneumatic chisels, hammers and wrenches, smaller values ​​" pneumatic drills and grinders. As you can see, the noise level of all of these instruments exceeds acceptable health standards in the workplace in the 1,2 " 1.5.

Vibration from pneumatic tools
 

But a special danger when working with pneumatic hand tools is a local vibration, which acts on the working hands and has a very serious impact on human health, causing diseases such as neuritis, vibration disease, and others. For example, in Poland, according to statistics, deafness and vibration disease ranks first among occupational diseases (only workers of working with pneumatic hand tools, there are more than 90 thousand. People). In Ukraine, according to the data for 2000 and the deafness vibrozabolevaniya are in second and third places. Studies conducted by doctors to workers handling Percussive, it was found that within 90 minutes when working with such a tool been severely impaired vibration sense, muscular endurance, increased blood pressure and skin temperature. Therefore it is necessary to know the levels of local vibration and timely to take measures to reduce it to prevent any signs of occupational disease.

Analysis of local vibration values ​​showed that the greatest amount of vibration is observed on the glass (chisel, hammer, drill machine type " Bee "), t. E. In place to support the tool with your left hand. And this figure is much higher than the allowable vibration values ​​Vibration in accordance with GOST 12.1.012 " 90 at almost all frequencies (except 1,000 Hz) in 2,7 " 7,5 times. 1000 Hz vibration in all studied instruments is less than the permissible values ​​in the 1.3-4.2 times.

Hand pnevmoinstrumen-ing, where he worked puts quite a considerable effort, the magnitude of vibration in both directions are approximately equal, except for the frequencies 500 and 1000 Hz, where the level of vibration in the direction of X " (parallel to the right hand) in 1,25 " 4 times the vibration in the direction of 7 " (perpendicular to the right hand). A characteristic feature of all test tools is that the magnitude of vibrations at the handle in both directions (7 ", X ") in comparison with the permissible values ​​of local vibration GOST 12.1.012 " 90 is reduced with increasing frequency, and at a frequency of 1000 Hz vibration on All instruments in the 1,1 " 4,25 times below acceptable standards, for example, if the value of the pneumatic hammer vibration at a frequency of 31.5 Hz (in either direction) exceeds the limit of local vibration in 5,5 " 6,5 times, 1000 Hz vibration levels below the permissible values ​​in 1,3-3,7 times.

It should be noted that of all the studied instruments least vibroaktivnosti proved pneumatic drilling machine type " Bee ", where the magnitude of vibrations at the handle slightly exceeded the allowable values ​​at low frequencies and was far below the levels of vibration at medium and high frequencies (in 1,7 " 3.3 times).

How to reduce the impact of   noise and vibration from   pneumatic tools.

Due to the wide distribution in the economy of Ukraine pneumatic hand tools and the impossibility of their complete replacement is now more modern tool (with a lower level of noise and vibration) can recommend a number of measures that would improve working conditions and to increase the levels of noise and vibration to the required permissible values.

These activities can be:

1. Application of damping coating on the surface of the instrument in contact with the hand operated (handle and a glass). As such coatings can be used mastic HP-17 (manufactured by " Lyubertsy carpet factory, Lyubertsy, Moscow region) or mastic VPM-2 (such as " ADEM "), developed on the production and technical enterprise (PTP) " Kievaviapromnaladka " . The thickness of the applied mastic should be equal to two or three thicknesses of metal to which it is applied.

2. To protect the left hand working tools should be put in place to support it (the glass) anti-vibration coupling, made of foam rubber or soft foam rubber.

3. To protect the left hand, if you can not wear a sleeve on the arm need to wear a special glove with padding of foam thickness of 30 " 40 mm or layered rubber coating such as " Buffalo " (development of PTP " Kievaviapromnaladka)

4. To protect the right hand need to paste over the handle-type coating " Buffalo " thickness of 6 " 10 mm.

5. Carry out the modernization of pneumatic tools, using the development of the plant " Pneumatic " (St. Petersburg).

6. To reduce the level of vibration can be replaced by local drummers more lightweight.

7. Application pnevmoshlifo typewriters, rotary shaft microturbine produced at a pilot plant in the Samara Aviation Institute, to reduce noise and local vibration far below the standards.

8. Carry out regular checks of vibration pneumatic tools at least once in 6 months with fixing it for a specific employee.

9. Carry out regular maintenance tool, followed by evaluation of its vibration characteristics.

10. Provide gidroprotsedury and self-massage for those exposed to local vibration.

11. From time to time one or two times a year a course of UV exposure (duration of the course with daily irradiation " one month) and vitaminopro-prevention, including a running twice a year, ascorbic acid, thiamine chloride, and nicotinic acid.

12. To reduce the high noise levels, acting on working, you need to use modern means of individual protection in accordance with GOST 12.4.051 " 78 and GOST 12.1.029-80 (insert hearing protector-WIDE headphones, disposable and reusable earplugs, helmets in combination with other headphones funds).