Prevention and Countermeasures of the hottest mech

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Prevention and Countermeasures of mechanical injury

safety production work should focus on the word "prevention", that is, to prevent accidents. Analyze the accidents occurred during the operation of mechanical equipment, eliminate the unsafe factors of equipment, facilities and operation environment and human unsafe behaviors, take effective measures to prevent, avoid or reduce the occurrence of mechanical injury accidents, greatly improve the safety of mechanical equipment operation, and strengthen the personal protection of employees, Promoting the healthy development of enterprises

the concept and types of mechanical injury accidents

mechanical injury is one of the common accidents in the operation of mechanical equipment. Mechanical injury refers to the injury caused by mechanical equipment and tools, such as twisting, grinding, touching, cutting, stabbing, cutting, etc., that is, the injury caused by the knife flying out, the hand or other parts of the body being involved, the hand or other parts being touched by the knife, and being entangled by the rotating mechanism of the equipment. Except for mechanical injury caused by mechanical equipment that has been listed in other accident categories, such as vehicles, lifting equipment, boilers, pressure vessels and other equipment

moving machinery can cause damage. Gears, belt pulleys, chucks, couplings, etc. are all rotating. The main forms of injuries caused by rotating motion are winding, twisting, crushing and object strike. Operators' gloves, clothes, ties and long braids and long hair are easy to be rolled into or brought into the machine if they are in contact with rotating parts

linear motion of mechanical equipment parts can also cause * * injury. Punching machines, plate shears and planing machines used for metal forming in enterprises are all in linear motion. The injury accidents caused by them mainly include impact, stabbing, smashing and pressing, etc

II cause analysis of mechanical injury accidents

from the perspective of safety system engineering, the causes of mechanical injury can be analyzed from three aspects: human, machine and environment. Any defect in human, machine and environment may cause mechanical injury accidents

(I) unsafe behavior of people

1. touch the switch by mistake or start the machine against rules. The operator is inattentive or nervous during operation, resulting in misoperation or misoperation, or the operator has low professional and technical quality, unskilled operation, lack of formal professional training and insufficient supervision and inspection

2. operators do not operate in accordance with the regulations. Illegal operation is generally caused by operators' lack of safety knowledge and taking chances. It is considered that a violation may not necessarily cause an accident. Ignore safety measures when overhauling and inspecting machinery. During maintenance, necessary preventive measures were not taken, such as no power off operation, no warning signs hung at the power supply, etc. Enter the dangerous parts of the machinery accidentally or contact the dangerous parts of the machinery blindly without contacting the operator

3. Weak awareness of safety production, imperfect safety management mechanism

(II) unsafe factors of objects

1. improper design causes machinery not meeting safety requirements, mechanical failure, protection and safety device failure, etc

2. the safety protection facilities are not perfect or exist in name only. There are mainly the following situations: first, there are no safety protection facilities; Industry insiders predict that the second is the damage of safety protection facilities of mechanical equipment; Third, the safety protection facilities for mechanical equipment were removed; Fourth, the operators did not use safety protection facilities as required

(III) unsafe environmental factors

noise interference, poor lighting, no ventilation, improper temperature and humidity, narrow site, unreasonable layout, etc

III. measures and Countermeasures to prevent mechanical injury accidents

the magnitude of mechanical hazard risk depends not only on the type, purpose, use method of the machine and personnel's knowledge, skills, work attitude and other factors, but also on people's understanding of the danger and the measures taken to avoid the danger. Prevention of mechanical injury includes two aspects. First, improve the safety quality of operators or personnel, conduct safety training, improve the ability to identify hazards and avoid injuries, enhance the consciousness of avoiding injuries, and warn and mark dangerous parts; Second, eliminate the causes of danger, reduce or eliminate the times of contacting the dangerous parts of the machine, take safety protection devices to avoid approaching the dangerous parts, pay attention to personal protection, and realize the intrinsic safety of safety machinery

(I) strengthen the safety management of operators

1, establish and improve safety operation rules and regulations

2. Do a good job in three-level safety education, business and technical training and assessment. Improve safety awareness and safety protection skills. Achieve "four understandings" and "Three Abilities" (understand the principle, structure, performance, process flow, operation, maintenance and troubleshooting)

3. Wear personal protective equipment correctly

Although PVC is still very common in the Asian medical device market

4, safety inspection or patrol inspection shall be carried out according to regulations

5. Strictly abide by labor discipline and put an end to illegal operation or habitual violation

(II) pay attention to the basic safety requirements of mechanical equipment

1. The key is to make the equipment structure design reasonable, strictly implement the standards and control the design. During the design process, the rotatable parts that are easy to reach by the operator shall be closed as far as possible, and the parts that cannot be closed must be equipped with necessary safety protection devices: for the production equipment or parts in operation that exceed the limit position, reliable limit and speed limiting devices, anti falling and anti reversing devices shall be configured; Electric shock proof and fire alarm devices shall be provided for electrical circuits; For equipment that may produce dust, harmful gas or harmful steam during the process, automatic feeding and unloading devices shall be adopted, and suction, purification and discharge devices shall be provided; For the closed system of hazardous substances, it shall avoid running, emitting, dripping and leaking, and it shall be equipped with detection and alarm devices when necessary; For equipment producing highly toxic substances, emergency rescue measures for leakage shall be taken

2. The layout of mechanical equipment shall be reasonable.

according to relevant regulations, the equipment layout shall meet the following requirements:

(1) the same distance between mechanical equipment: not less than 0.7m for small equipment; Medium sized equipment shall not be less than LM; Large equipment shall not be less than 2m

(2) before the equipment, the latest product delivery inspection of relevant enterprises shall be sent to Shanghai and Jiangsu for inspection. The distance between wall and column: small equipment shall not be less than 0.7m; Medium sized equipment shall not be less than 0.8m; Large equipment shall not be less than 0.9m

(3) operating space: not less than 0.6m for small equipment; Medium sized equipment shall not be less than 0.7m; Large equipment shall not be less than 1.1m

(4) transport lines higher than 2m shall be provided with solid protective covers

3. Improve the safety and reliability of mechanical equipment parts and components

(1) reasonably select the structure, material, process and safety factor

(2) the operator must adopt interlocking device or protective measures

(3) anti skid, fall prevention and personal injury prevention devices must be set, such as limit device, speed limit device, anti reverse device, protection, etc

(4) there must be a safety control system, such as automatic monitoring system, audible and visual alarm device, etc

(5) set a sufficient number of emergency switches whose shape is different from that of general emergency switches

4. Strengthen the safety protection of dangerous parts

fundamentally speaking, the protection against mechanical injury should be fully considered in the design and installation, including safety requirements, material requirements and installation requirements. The second is to pay attention when using. For example, belt transmission usually relies on the friction between the tension belt and the pulley to transmit motion. It not only has the commonness of general transmission devices, but also has the individuality of being easy to break the belt. Therefore, the protection of such devices should adopt the shield or protective fence to prevent the consumption of flame retardant in China from increasing to about 840000 tons in 2019, except for the belt transmission with a height of less than 2m, Belt drives with a center distance of more than 3m, a belt width of more than 15cm, or a belt speed of more than 9m/s, even with a height of more than 2m, should be protected. For chain transmission, a completely closed chain protective cover can be used according to its transmission characteristics, which can not only prevent dust, reduce wear, maintain good lubrication, but also prevent injury accidents

Article 32 of the regulations on safety and health in factories issued by the State Council in 1956 stipulates that "protective devices shall be installed for dangerous parts such as transmission belts, open gears, grinding wheels, electric saws, couplings close to the ground, rotating shafts, pulleys and flywheels." Therefore, the principle of practicality, firmness, durability and aesthetics should be adhered to when designing the safety protective cover of the transmission device. It is ideal if an automatic protective device is designed to push or pull any part of the human body out of the dangerous area

(1) the transmission belt, exposed gear, coupling close to the ground, belt pulley, flywheel and other parts of various machinery that are easy to hurt the human body must be provided with complete protective facilities. The mechanical equipment put into operation must be maintained as required, and the unqualified mechanical equipment shall be resolutely rejected. The self-made equipment must have scientific basis, meet the safety requirements, and can only be put into operation after passing the appraisal of the professional department. In order to avoid personal accidents, there should be devices that can stop quickly. Operators shall wear protective equipment according to relevant requirements

① pulley: pay attention to the tightness when installing the pulley. If the pulley is too tight, the belt will be broken. If the pulley is too loose, the normal rotation of the machine will be affected. There are two ways to protect the belt drive: one is to use a protective cover to cover the belt safely, and the other is to use a grid to protect the belt from human contact with the dangerous parts of the pulley during rotation

② gear: the most dangerous place in gear transmission is the gear meshing part and the gap between the gear spokes. In order to avoid the danger of gear transmission, the protective cover must be installed, and the gears must be completely covered and closed. For the protection of gear transmission and friction wheel transmission, protective devices should be installed in the meshing area respectively according to their characteristics. If possible, the gears should be installed in the fully closed base. The surface of the friction wheel is smooth, so the integral protection is not required, and only the contact part can be partially protected

③ chain drive: the dangerous part of chain drive is the chain drive system which is exposed outside the machine base within 2tn from the ground at the place where the chain enters the sprocket

④ shaft: all attachments protruding from the shaft surface or not smooth, such as keys, fixing screws, etc. exposed fixing screws are particularly harmful. In production, it is possible to roll up people's clothes and cause injury. Therefore, protective shaft sleeves must be installed. All exposed parts of the rotating shaft within 2rn above the ground must be covered and protected except those placed inside the machine

⑤ coupling: the risk of rotating shaft coupling is basically similar to that of shaft, but its severity is greater than that of shaft, because the surface finish is worse than that of shaft. The safe coupling must be free of protruding uneven parts. The bolt head and nut shall be buried in the coupling, or the outer diameter edge of the coupling shall be larger than the bolt fastening size in the design. In short, during the rotation of the coupling, the parts that may be dangerous must be provided with baffle cover and other protective measures

the transmission system of mechanical equipment is summed up as a "wheel" and a "shaft". The safety devices of the wheel and shaft must meet the standards to achieve the purpose of safety and reliability. For the protection of gear transmission and friction wheel transmission, protective devices shall be installed in the meshing area according to their characteristics. If possible, the gears shall be installed in the fully enclosed base. The surface of the friction wheel is smooth, so the integral type can not be used

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