Accident Appraisal of Mechanical Injury

Mechanical injuries refer to injuries caused by extrusion, collision, impact, shearing, entanglement, twisting, throwing out, cutting, severing, stabbing, etc. when mechanical equipment is in motion (stationary) and when components, tools, and workpieces are in direct contact with the human body. It does not include injuries caused by vehicles and lifting machinery.
Mechanical injuries are mainly injuries caused by mechanical failures or unsafe behaviors of operators during the operation or use of machinery.
Zhongke Testing and Appraisal Institute can provide identification services for mechanical injury accidents, and make accurate identifications on trace evidence analysis, accident cause analysis, etc. in various mechanical injury accidents.

1. Ignore safety measures during maintenance and inspection of machinery. For example, if people enter the equipment (ball mill, etc.) for maintenance and inspection operations, do not cut off the power supply, do not put up a warning sign that no closing is allowed, and do not set up dedicated supervision and other measures, this will cause serious consequences. There are also accidents caused by misjudgment due to factors such as the timed power switch or temporary power outage. There are also cases where although the equipment is powered off, they start working before the equipment coasts to a complete stop, which also causes serious consequences;
2, lack of safety devices. For example, some mechanical transmission belts, gear machines, couplings close to the ground, pulleys, flywheels and other parts that are easy to harm the human body do not have intact protective devices; some manholes, feed port winch wells and other parts lack guardrails and covers, and there are no warning signs. If a person accidentally touches these parts accidentally, an accident will occur;
3, the layout of the power switch is unreasonable, one is not to stop immediately in an emergency; the other is that several mechanical switches are installed together, which can easily cause the mechanical trigger to be accidentally opened.
4, operating machinery and equipment in a sick condition and not meeting safety requirements;
5, cleaning, jamming, applying belt wax, etc. while the machinery is in operation;
6, arbitrarily entering dangerous operating areas of machinery (sampling, working, borrowing, picking items, etc.);
7, using personnel without the qualifications to operate machinery or operating errors by operators.

The person involved was operating the equipment of the three-roller composite rolling mill in the aluminum workshop of an industrial company. When performing a routine thickness check on the rolled steel strip, the roll surface of the back-up roller peeled off, and the peeling fragments were squeezed between the back-up roller and the intermediate roller, and broke into pieces. The thin pieces were ejected in the direction of the finished product, and one of them hit the vital part of the body of the person involved in front of the three rollers. The person involved pressed his waist and stepped back a few steps before falling to the ground. A large amount of blood flowed out from his waist. The workshop employees called 120 and died after treatment failed.
Our company was entrusted by the court to conduct technical appraisal and inspection on a general mechanical injury and death accident that occurred in an industrial company to find out the cause of the accident.
identification analysis results:
Our company's identification personnel went to the site to conduct an inspection. The analysis of the causes of this "mechanical injury accident" is as follows:
The support roller had defects such as pits on the roller surface before the incident. The relevant personnel directly used surface grinding to deal with it, and did not perform grinding treatment to eliminate surface defects on the working surface of the support roller. This is the greatest possibility of surface cracks. The relevant management departments did not take timely and correct measures to eliminate the defects that appeared before the peeling of
and another more conspicuous pit that still existed below the peeling position. Failure to take timely and effective measures for defects on the back-up roller surface allowed the back-up roller to run with disease, which eventually led to the roll surface peeling. In addition, the equipment inspection system was not implemented in place, indicating that the back-up roller management was not in place.