Basic knowledge of mechanical operation safety

1. What are the main causes and types of mechanical accidents?
Mechanical accidents cause mainly the following kinds of injuries:
1. Mechanical equipment parts and components for rotating motion into injury. For example, in machinery, equipment gear, support pulley, pulley, chuck, shaft, light screw, lead screw, shaft joint and other parts are rotating motion. The main forms of injuries caused by rotating motion are strangulation and object strike.
2. Injury caused by linear motion of parts and components of mechanical equipment. Such as forging hammer, punch, cutting plate. Several pressure parts, the head of the bed of the planer, the bed surface of the gantry magazine bed and the bridge crane, the trolley and the lifting - several structures, are made of linear motion. The injuries caused by the zero parts of linear transport capacity mainly include crush injury, smash injury and crush injury.
3. Injuries caused by knives. For example, the turning tool on the lathe, the milling cutter on the milling machine, the drill bit on the drilling machine, the grinding wheel on the grinding machine, the saw blade on the saw machine and so on are the tools used for processing parts. The main injuries caused by cutting tools in processing parts are scald, stab wound and cut.
4. Injuries caused by parts being processed. Mechanical equipment may cause personal injury in the process of processing parts. This kind of injury accidents are mainly: (1) the processing parts are not fixed is thrown out hurt, such as lathe chuck clamp is not strong, in rotation will be thrown out of the workpiece hurt. ② The processed parts may be damaged in the process of lifting and loading.
5. Injuries caused by electrical systems. Most of the machinery used in factories is powered by electricity, so each machine has its own electrical system. It mainly includes motor, distribution box, switch, button, local lighting and zero (ground) and feed wire. Electrical systems harm people mainly by electric shocks.
6. Injuries caused by hand tools.
7. Other injuries. Mechanical equipment may cause other injuries in addition to those mentioned above. For example, some mechanical equipment is accompanied by strong light, high temperature, and the release of chemical energy, radiation energy, and dust toxic substances and so on, which may cause harm to the human body.

2. What are the basic safety requirements of mechanical equipment?
Basic safety requirements for mechanical equipment, mainly:
1. The layout of mechanical equipment should be reasonable, and it should be easy for the operator to load and unload the workpiece, process observation and remove debris; At the same time should also facilitate maintenance personnel inspection and maintenance.
2. The strength and stiffness of the zero parts and parts of the mechanical equipment should meet the safety requirements, and the installation should be firm, and failure should not occur frequently.
3. Mechanical equipment shall, in accordance with relevant safety requirements, be equipped with reasonable and reliable safety devices that do not affect operation.
For example:
(1) For rotating parts and components should be equipped with protective cover or protective baffle, protective railings and other safety protective devices, to prevent the occurrence of hinge injury.
(2) For over pressure, overload, over temperature, over time, over stroke and other dangerous accidents can occur zero, components, should be installed with insurance devices, such as overload limiter, travel limiter, safety valve, temperature relay, time breaker and so on, so that when dangerous situations occur, due to the role of the insurance device and eliminate dangerous situations, to prevent the occurrence of accidents.
(3) For some actions need to warn people or remind attention, should be installed signal device or warning plate. Such as electric bell, horn, buzzer and other sound signals, as well as a variety of light signals, a variety of warning signs are such safety devices.
(4) Interlocking device should be installed for some parts and parts whose action sequence cannot be reversed. That is, an action must be performed after the completion of the previous action, otherwise it is impossible to act. This ensures that no accidents will occur due to the wrong sequence of actions.

4. Electrical devices of mechanical equipment must meet the requirements of electrical safety, mainly include the following points:
(1) The power supply wire must be correctly installed, and there must be no damage or copper exposed place.
(2) Motor insulation should be good, and its terminal board should be protected by cover plate to prevent direct contact.
(3) Switches, buttons, etc. should be intact, and the live parts should not be exposed.
(4) There should be a good grounding or zero device, the connecting wire should be firm, there should be no disconnect place.
(5) Local lighting should use 36V voltage, forbid the use of 1lOV or 220V voltage.

5. Control handles and foot switches of mechanical equipment shall meet the following requirements:
(1) The important handle should have reliable positioning and locking device. Coaxial handles should have obvious length differences.
(2) The handwheel can be detached from the rotating shaft during maneuvering to prevent personnel from being injured by rotating with the shaft.
(3) the foot switch should have a protective cover or hidden into the concave part of the bed, so as to avoid the fall of the zero, parts fall on the switch, start the mechanical equipment and hurt people. (4) The operation site of mechanical equipment should have a good environment, that is, the illumination should be appropriate, the humidity and temperature should be moderate, the noise and vibration should be small, the parts and the jig should be placed neatly. Because this can encourage the operator to feel comfortable, concentrate on the work.
(5) Each mechanical equipment should be based on its performance, operation sequence and other safe operation procedures and inspection, lubrication, maintenance system, so that the operator to comply with.
3. What are the common protective devices in the machining workshop? What is the main function?
Common protective devices in machining workshops include protective cover, protective baffle, protective railings and protective nets. Protective devices shall be installed in dangerous parts such as the transmission belt of mechanical equipment, coupling of gear close to the ground, rotating shaft, belt wheel, flywheel, grinding wheel and electric saw. There should be safety devices for the spinning part of pressure machinery such as press, roller, calender, electric planer and plate shears. Protective cover is used to isolate exposed rotating parts, such as pulley, gear, sprocket, rotary shaft, etc. Protective baffle, protective net has two forms of fixed and active, play the role of isolation, block metal chip splash. Protective railings are used to prevent people working at high altitudes from falling or to delimit safe areas. Generally speaking, the forms of protective devices mainly include fixed protective devices, interlocking protective devices and automatic protective devices.

4. What are the safety management regulations for mechanical equipment operators?
To ensure that mechanical equipment does not occur industrial accidents, not only the mechanical equipment itself should meet the safety requirements, but more importantly, the operator is required to strictly abide by the safety operation procedures. Of course, the safe operation procedures of machinery and equipment vary in content depending on the type, but the basic safety rules are:
1. Wear personal protective equipment properly. What should be worn must be worn, and what should not be worn must not be worn. For example, in machining, women are required to wear protective hats, if not wearing hair may be twisted in. It is also required not to wear gloves. If they are worn, the rotating part of the machine may twist the gloves in and injure the hands.
2. Before the operation, the mechanical equipment should be checked for safety, and the empty car should be run, and the normal confirmation can be put into operation.
3. Mechanical equipment should also be checked for safety in operation according to regulations. Especially to tighten the object to see if it is loose due to vibration, in order to re-tighten.
4. The equipment is strictly forbidden to operate with faults, and must not be used together to prevent accidents.
5. Mechanical safety devices must be used correctly in accordance with regulations, and must not be removed without use.
6. The tool, fixture and processing parts used in mechanical equipment must be installed firmly, not loose.
7. When the mechanical equipment is running, it is strictly prohibited to adjust it by hand; Also do not use the hand to measure parts, or lubrication, cleaning debris, etc. If necessary, the machinery should be shut down first.
8. When the mechanical equipment is running, the operator shall not leave the work position, in case no one will deal with the problem.
9. After the end of the work, the switch should be turned off, the cutting tool and workpiece from the working position, and clean up the work site, the parts, the jig and so on neatly placed, clean up the health of the mechanical equipment.

5. How to prevent industrial accidents in metal cold working workshops?

There are many kinds of machine tools in metal cold working workshop. As long as the workplace is properly arranged, the necessary protective devices and insurance devices are set up, and the safety operation procedures are strictly observed, industrial accidents can be effectively prevented.
Machine tool layout requirements:
1. Do not make parts or chips hurtful.
2. The operator is dazzled from direct sunlight.
3. It is convenient for handling finished products, semi-finished products and cleaning metal chips.
4. Workshop should set up a safe passage, so that personnel and vehicles driving unimpeded.
Protective device requirements:
1. Shield: Isolation of exposed rotating parts.
2. Protective railings. The parts of the machine tool that are easy to injure people during operation and the machine tools that are not operated on the ground should be equipped with protective railings of no less than 1m in height.
3. Protective baffle: prevent debris, chips and coolant splash.
Safety device requirements:
1. Overload safety device: automatically disengage or stop when overloaded.
2. Travel safety device: The moving parts can automatically stop or return to the predetermined position.
3. Sequential action interlock device: Until one action is completed, the next action cannot be performed.
4. Accident interlock device: In the case of sudden power failure, the compensation mechanism can act immediately or stop the machine tool.
5. Braking device: avoid loading and unloading the workpiece when the machine rotates; In case of sudden accident, the machine can be stopped in time.

6. What safety matters should the Turner pay attention to?
The safety matters for turning workers are:
1. Wear tight protective clothing with the cuffs closed; Wear protective hats for long hair; Do not wear gloves during operation.
2. The loading and unloading chuck on the spindle of the machine tool should be carried out after the shutdown, and the power of the motor can not be taken from the chuck.
3. Clamping workpiece chuck, dial, chicken heart clip protruding part of the best use of protective cover, so as not to hang clothes or other parts of the body, such as no protective cover, the operation of attention to leave, do not get too close.
4. When clamping the workpiece with the center, it is necessary to pay attention to the center and the center hole should be completely consistent, not damaged or skewed center, the center hole should be cleaned before use, and the center seat should be fixed.
5. When turning slender workpiece, in order to ensure safety, the center frame or tool holder should be used, and the long lathe part should be marked.
6. When turning the irregular shape of the workpiece, should be installed balance block, and try to balance after cutting.
7. Tool clamping should be firm, the extension of the tool head should not exceed 1.5 times the height of the tool body, the shape and size of the gasket under the tool body should be consistent with the shape and size of the tool body, the gasket should be as little and flat as possible.
8. The ribbon chips and spiral chips cut down should be removed with hooks in time and should not be pulled by hand.
9. In order to prevent crushing chips from hurting people, transparent baffle should be installed in the appropriate position.
10. Except for the lathe equipped with automatic measuring tools in operation, the workpiece should be stopped to measure, and the tool rest to a safe position.
11. When sanding the surface of the workpiece with emery cloth, move the tool to a safe position, and be careful not to let hands and clothes touch the surface of the workpiece.
12. When grinding the inner hole, do not use fingers to support emery cloth, use a stick instead, and the speed should not be too fast.
13. Do not place tools, fixtures or workpieces on lathe body and spindle transmission.

7, milling workers should pay attention to safety matters are:
1. At the beginning of cutting, the milling cutter must slowly feed to the workpiece, must not have impact phenomenon, so as not to affect the accuracy of the machine tool or damage the cutting edge of the tool.
2. Machining workpiece to pad flat, clamping, so as not to loose in the process of work caused by accidents.
3. Speed adjustment and direction change, as well as the correction of the workpiece, tools should be stopped after.
4. You should not wear gloves while working.
5. Remove the cuttings from the surface of the bed with a brush at any time. Remove the cuttings from the milling cutter by stopping.
6. After the milling cutter with blunt, should stop grinding edge or change the knife, stop before the first back knife, when the tool is not all away from the workpiece, do not stop.

8, planer workers should pay attention to safety matters:
1. The planer should be clamped, there should be a certain gap between the blade and the workpiece before the work, and the first knife should not be too deep to prevent damage to the blade or injury.
2. Operation is not allowed to stand in front of the shaper, but not in front of the shaper to check the work.
3. Adjust the stroke of the machine tool and tighten the bolt that controls the stroke.
4. Around the planer table, an upright protective cylindrical baffle which can be turned up is provided.
5. Centralize the chip cleaning in the special chip cutter. So as not to cut the foot.

9, grinding machine workers should pay attention to safety matters:
1. Before starting, it is necessary to check whether the device of the workpiece is correct, whether the fastening is reliable, whether the magnetic sucker is normal, if not, it is not allowed to start.
2. When driving, the manual adjustment mode should be used to leave a proper gap between the grinding wheel and the workpiece, and the starting feed amount should be small to prevent the grinding wheel from cracking.
3. Measuring the workpiece or adjusting the machine tool and cleaning work should be stopped before.
4. In order to prevent debris injury when the grinding wheel is damaged, the grinding machine must be equipped with a protective cover. It is forbidden to use the grinding wheel without a protective cover for rubbing.

10, drill workers should pay attention to safety matters:
1. Do not wear gloves to operate, do not use hands to remove iron filings.
2. Head should not be too close to the drill press, must wear a hat when working.
3. Before drilling, the workbench should be tightened, and the radial drilling machine should also tighten the radial arm before drilling.
4. At the beginning of drilling and the workpiece to drill through, must not be too hard.

11. When operating on stamping equipment, the operator shall abide by the following safety operation procedures:
1. Before operation, it is necessary to carefully check whether the protection device is in good condition and whether the clutch brake device is flexible and safe. All unnecessary objects on the workbench should be cleaned to prevent the vibration falling on the foot switch during work, resulting in sudden start of the punch and accidents.
2. When punching small workpiece, do not use the hand, there should be special tools, it is best to install automatic feeding device.
3. The operator must be careful to control the foot switch, the foot should be removed from the foot switch when loading and unloading parts. It is strictly prohibited for outsiders to stay around the foot switch. 4. If the workpiece is stuck in the mold, the application of special tools to take out, not allowed to use the hand, and should be removed from the foot pedal.

12. Safety matters that fitters should pay attention to are: