Rock drilling machinery is widely used in underground and surface engineering in mining, tunnel, highway, railway, construction, quarrying, and other fields. It will make a loud noise during the operation, which is often uncomfortable. If it is not prevented, it will cause harm to the health of workers and cause pollution to the environment.

Hazards of rock drilling machinery noise

1. Damage to human hearing

People hear sound because the sound pressure transmitted in the atmosphere acts on the eardrum of the human ear and from neural receptors to the brain. If exposed to noise for a long time, it can cause hearing loss and hearing retardation.

2. Induce a variety of diseases

①Noise acts on the human central nervous system, causing symptoms such as dizziness, brain swelling, insomnia, dreaminess, palpitation, and general fatigue.

② It affects human organs, causes changes in gastrointestinal function, causes indigestion, loss of appetite, nausea, and vomiting, and leads to an increased incidence of gastric ulcers.

③ It makes the sympathetic nervous, causes tachycardia, arrhythmia, abnormal electrocardiogram, increased blood pressure, and even causes more serious heart disease.

④ It affects the metabolism of human nutrition, resulting in the lack of many vitamins.

⑤ Long-term exposure to noise can reduce people’s immunity, impair physiological function, and accelerate the aging process.

3. It affects the work efficiency of operators

In a high-noise environment, the operator’s attention is not easy to concentrate, which leads to a decrease in work efficiency and operation error, especially prone to accidents.

4. Damage to buildings and structures

Noise is formed by acoustic vibration. High power noise transmission in the air can cause strong air vibration, which has a destructive effect on surrounding buildings, structures, and even mechanical structures. It may also affect the operation of automatic control, remote control systems, or equipment.

There are so many hazards in the noise of rock drilling machinery, how to prevent and control the noise has become a research topic.

How to prevent and control rock drilling noise?

1. Basic control method of rock drilling noise

①Starting from the sound source, try to reduce the noise intensity.

Improve or change construction technology to replace high-noise equipment with low-noise equipment. Improve the mechanical design and reduce the original noise. Improve product processing accuracy and assembly quality. Take comprehensive measures to reduce mechanical vibration, etc.

② Take measures on the noise transmission, and try to cut off the connection between the noise source and the noise victim. For example, install mufflers in place for intake and exhaust noise.

③ Take protective measures for people exposed to noise to prevent them from noise hazards. Scientifically take individual protective measures, such as wearing anti-noise earmuffs and reducing the exposure time of operators to noise, etc.

2. Take measures according to different types of rock drilling machinery

①Noise control of pneumatic rock drill

Among the pneumatic rock drill noise sources, exhaust noise accounts for 87.4%, and other noise accounts for 12.6%. Aerodynamic noise control is the key to noise control of pneumatic rock drills.

②Noise control of hydraulic rock drill

The exhaust noise of the hydraulic rock drill is not as loud as that of the pneumatic rock drill, but it is still seriously harmful to human hearing. The noise of the hydraulic rock drill includes: “injection noise” caused by the airflow of the impact piston hitting the shank adapter, “pressure impulse noise” caused by the instantaneous deformation of the impact piston hitting the shank adapter collision piece, and “structure impact vibration noise” produced by body vibration caused by the impact system. For noise control of hydraulic rock drills, we should pay attention to the impact performance parameters of hydraulic rock drills. Try to make the shank adapter structure conducive to reducing injection noise. To explore the new material of impact piston and shank adapter, Improve the vibration resistance performance to reduce pressure impersonation noise. Focus on reducing structure impact vibration noise.

③ Noise control of hydraulic drilling rig

The noise sources of hydraulic drilling rigs include hydraulic rock drill noise and pump station noise.

Control the noise of the hydraulic drilling rig through 4 points:

A. Reasonably select the performance parameters of hydraulic rock drills.

B. Try to reduce the impact of hydraulic drill structure vibration noise.

C. Increase the rigidity and stability of the hydraulic drilling rig, and take shock absorption measures in many ways to avoid resonance of related components caused by impact vibration.

D. Rationally design supporting systems such as hydraulic pump stations,  as far as possible to reduce the noise of hydraulic drilling machines in a non-working state.

④ Noise control of pneumatic rotary drilling rig

The noise of the pneumatic rotary drilling rig is mainly composed of the exhaust noise of the pneumatic motor, the friction noise of the mechanical transmission, and the friction noise of the drilling. Its control can consider two aspects: reasonable selection of pneumatic motor type and performance parameters.

We are engaged in the rock drilling industry, and it is inevitable to encounter the noise of rock drilling machinery. Only by scientifically understanding the rock drilling machinery noise and taking corresponding measures to control it can we protect our health and promote the further development of rock drilling machinery.