Mechanical safety technology knowledge of the whole
The safety function of machinery refers to the machinery and its components of certain functions are designed specifically to ensure safety, it is mainly divided into two categories of the main safety functions and auxiliary safety functions. The following is a complete list of mechanical safety technology knowledge that I have organized for you, welcome to read and browse.
The first section of the machinery industry safety summary
Knowledge of the first, the main categories of machinery products
1, the main products of the machinery industry, including 12 categories:
2, focusing on the understanding of the (2) Heavy Mining Machinery; (4) Petrochemical General Machinery.
3, non-mechanical industries including railway machinery, construction machinery, textile machinery, light industrial machinery, shipping machinery, etc..
Knowledge point two, the dangerous parts of machinery and equipment and protection measures
(a) the dangerous parts of machinery and equipment
1, machinery and equipment can cause collision, entrapment, shear, rolled into a variety of injuries.
2, between rotating parts, connectors, moving parts; close type; through the type; one-way sliding.
(ii) mechanical transmission mechanism safety protection countermeasures
1, the common transmission mechanism on the machine tool has a gear meshing mechanism, belt drive mechanism, couplings, etc., it is necessary to protect the dangerous parts of the transmission mechanism.
2, the safety technology measures taken are generally divided into direct (design), indirect (protective devices) and instructive (safety regulations, set signs) three categories.
3, focus: gear drive safety protection: gear drive mechanism must be equipped with a fully enclosed type of protective device, there is no protective cover shall not be used; belt drive device can be used to protect the cover of the metal skeleton of the protective net, and the distance from the belt should not be less than 50mm, do not affect the operation of the machine. General transmission mechanism from the ground below 2 m, to set up a protective cover. 3 cases to protect: the distance between the pulleys in more than 3 m; belt width of more than 15 cm; belt rotation speed of more than 9 m/min; couplings and other protection of the most common is? Type shield.
Knowledge Points III, types of mechanical injuries and preventive countermeasures
(a) types of mechanical injuries
1, the mechanical state: the normal working state, abnormal working state, non-working state.
2, the mechanical industry including mechanical injuries, non-mechanical hazards.
3, the main dangers and hazards: object strikes, vehicle injuries, mechanical injuries, lifting injuries, electrocution, burns, fire, fall from height, and other 14 kinds.
(B) machinery injury prevention countermeasures: sequential order
1, to achieve the intrinsic safety of machinery: ① Eliminate the causes of danger. ② reduce or eliminate the number of contacts with the dangerous parts of the machine; ③ make it difficult for people to approach the dangerous parts of the machine (or provide safety devices so that approaching these parts will not lead to injury); ④ provide protective devices or protective clothing.
2, the protection of operators and related personnel safety: ① through training to improve people's ability to identify hazards; ② through the redesign of the machine, so that the danger is more visible (or the use of warning signs); ③ through training, to improve the ability to avoid injury; ④ to take the necessary action to avoid the injury of the self-consciousness.
(C) the technical requirements of general mechanical safety facilities
1, the general requirements of mechanical safety guards. Safety guards are reliable and chained with the operation of the equipment.
2, focus: emergency stop switch. Emergency stop switch should ensure that instantaneous action can terminate all movements of the equipment. For equipment with inertial movement, emergency stop switch should be chained with the brake or clutch to ensure rapid termination of operation. Emergency stop switch shape should be different from the general switch, the color is red; emergency stop switch should be arranged to ensure that the operator is easy to reach, and no danger; equipment from the emergency stop switch to stop running, must be restarted according to the start-up sequence in order to re-open.
3. When the shield is used as a platform or ladder, it should be able to withstand a vertical force of 1500n.
Knowledge Point 4, machinery safety design and machine safety devices
(a) Intrinsic safety: a method of machinery safety through the designer of the machinery, to take measures at the design stage to eliminate hidden dangers.
(ii) Fail-safe: the designer should ensure that there is no danger when the machine fails.
(iii) Positional safety: The safety is achieved by positioning the parts of the machine in such a way that they cannot be reached.
(d) Machine layout: space, lighting, piping layout, maintenance access safety.
(v) Machine safety guards
Key understanding: interlocking, control, two-hand control safety devices.
Knowledge Point V, machine manufacturing site safety technology
(a) lighting: plant span greater than 12 m, single-span plant on both sides should be light side windows, the width of the window should be not less than 1/2 of the length of the openings; more than one span of the plant is connected to the connected span should have a skylight, between the span and the span shall not be sealed with a wall. Workshop channel lighting to cover all channels, the length of coverage should be greater than 90% of the length of the workshop safety channel.
(ii) channel: including the main road and workshop safety channel.
1, the factory trunk road road surface requirements: vehicles traveling in both directions of the trunk road width of not less than 5m, there is a one-way sign of the trunk road width of not less than 3m; into the factory entrance, the dangerous sections need to be set up to limit the speed of the plate, signage and warning signs.
2, workshop safety channel requirements. Passage of cars, width >3m; passage of battery car width >1.8 m; passage of carts, tricycles, width >1.5 m; general pedestrian access width >l m.
(c) equipment layout: length >12 m for large equipment, 6 to 12 m for medium-sized equipment, <6 m for small equipment; equipment spacing: Large? 2 m, medium-sized? lm, small? 0.7 m; equipment and walls, columns distance: large? 0.9 m, medium-sized? 0.8 m, small? 0.7 m; higher than 2 m of the transport line should be a solid cover (net), for less than 2 m of the transport line should be added to both sides of the landing section of the guardrail, the height of the bar 1.05 m.
(d) material stacking
1, including the work station apparatus
2, the amount of product blanks stored: product blanks and other should be limited to deposit, day shift storage for each shift 1.5 times the amount of processing, night shift storage for the amount of processing 2.5 times, but not more than the large pieces of the shift quota.
3, the workpiece, material placement shall not be super-high, in the bottom of the stack and stack height ratio of 1:2 under the premise of the stack height does not exceed 2 m (except the unit super-high), sand box stacking does not exceed 3.5 m.
(e) ground state: the requirements of the production site is flat, clean. Deeper than 0.2 m, wider than 0.1 m pits, trenches, pools should have a reliable guardrail or cover.
Section II metal cutting machine tools and grinding machine safety technology
Knowledge point I. Hazardous factors of metal cutting machine tools
stationary parts, rotating parts, internal rotation bite, reciprocating motion and sliding hazards, flying objects.
Knowledge point two, metal cutting machine tools, safety and technical measures
1, machine tool operation abnormal state: 1) temperature rise abnormal 2) abnormal speed 3) vibration and excessive noise 4) the emergence of impact sound 5) input and output parameters abnormal 6) internal defects in the machine tool
vibration failure rate is the largest: machine tools due to vibration faults accounted for the entire failure of `60% ~ 70%.
2, the fault detection of wear parts in the motion machinery.
Focus: wear parts are drive shafts, bearings, gears, impellers, which rolling bearings and gear damage is more common.
3, metal cutting machine tools common risk factors control measures: 1) equipment reliable grounding, lighting using safe voltage. 2) wedges, pins can not be protruding from the surface. 3) with special tools, with goggles. 4) tail security bending device and set up the material frame. 5) parts mounted firmly. 6) timely maintenance of safety guards, protective devices. 7) the selection of qualified grinding wheels, mounted on the card is reasonable.
(8) to strengthen the inspection, to put an end to the phenomenon of violation of the rules, wear good labor protection products.
Knowledge point three, the safety requirements of the grinding machine
Sanding machine installation: location selection. The front of the sanding machine is equipped with a protective baffle of not less than 1.8m in height.
The balance of the grinding wheel. Grinding wheels with a diameter greater than or equal to 200mm should be static balanced after mounting the flange.
Wheel and chuck matching. The diameter of the wheel flange shall not be less than 1/3 of the diameter of the wheel being installed, and it is stipulated that the grinding wheel shall be replaced with a new one when it wears down to a diameter 10mm larger than the diameter of the flange.
Grinding wheel guard. The opening angle above the spindle level is not allowed to exceed 65 ゜, the opening is greater than or equal to 30 ゜ must be set up to block the chip screen plate, the clearance between the circumference surface of the grinding wheel and the plate should be less than 6mm.
Workpiece bracket of the sanding machine. The diameter of 150m or more must be set adjustable bracket, the distance between the grinding wheel and the bracket should be less than 1/2 of the minimum external dimension of the workpiece to be ground, but the maximum should not be more than 3mm.
Safety requirements for the use of sanding machine: prohibit side grinding; not allowed to operate in the front; not allowed to **** with the operation.
Section III stamping (shear) machinery safety technology
Knowledge Points I. Hazardous factors of stamping operations
The structure of the equipment has the danger; action out of control; switch malfunction; the risk of molds and dies (the injury part is mainly hand).
Knowledge point two, stamping operation safety technology measures
Including the improvement of stamping mode of operation, reform of the die structure, mechanization and automation, set up mold and equipment protection devices. Mechanization and automation of stamping operations is to reduce the labor intensity of workers, to ensure personal safety fundamental measures.
Focus: stamping equipment safety devices. According to the structure is divided into mechanical, push-button, photoelectric, inductive and so on. Mechanical guards. Mainly: push hand type, pendulum (toggle), pull hand safety devices.
Knowledge point three, shearer safety technical measures
Precautions when operating the shearer (focus 2, 4, 5). Should not be alone 1 person to operate the shearing machine; moving parts must be installed protective cover; the operator's fingers to maintain a safe distance, fingers from the mouth of the scissors should be kept at least 200mm away from the distance, and leave the compression device.
Section IV woodworking machinery safety technology
Knowledge Points I, woodworking machinery hazardous and harmful factors
Knife axis high speed, multiple knives and multiple edges, manual feeding and so on. Mechanical injury: high risk, high probability of occurrence; fire and explosion: serious consequences; biological and chemical hazards of wood; wood dust hazards; noise and vibration hazards.
Knowledge Points II, woodworking machinery safety technology measures
1, in the design of woodworking machinery should be made to have perfect safety devices, including safety guards, safety control devices and safety alarm signaling devices. Unarmed manipulation of the author must have safety measures, muffling, dust absorption or ventilation devices, the knife axis and electrical should be a safe joint control device, the use of safe feeding devices or set up a separate knife, anti-bounce safety screen protection devices, set up in case of emergency shutdown of the safety control device.
2, hand press flat planer hurt hand for multiple accidents, hand press flat planer cutter shaft design and installation requirements: 1) must use cylindrical cutter shaft, absolutely prohibit the use of square cutter shaft. 2) The outer edge of the pressure blade should be matched with the outer circle of the cutter shaft, when the hand touches the cutter shaft, it will only bruise the skin of the fingers, and won't be cut off. 3) Planer blade outreach can't be more than the cutter shaft OD 1.1mm. 4) Planer mouth opening amount should be comply with the regulations.
Section V casting safety technology
Knowledge points, casting operation hazardous and harmful factors
fire and explosion, burning, mechanical injury, fall from height, dust and toxic hazards, noise and vibration, high temperature and heat radiation
Knowledge Points, casting operations, safety and technical measures
(I) Process requirements
Under the conditions of the process possible, it is appropriate to use the wet operation, the poor operating conditions of the occasion is appropriate to use the robot remote-controlled isolated operation. Less polluting modeling, core-making section in the centralized heating area should be arranged in the non-heating season minimum frequency of wind downwind side, in the non-centralized heating area should be located in the full minimum frequency of wind downwind side.
(ii) building requirements: casting workshop should be arranged in the high-temperature workshop, power plant complex, built in the plant other production buildings do not release harmful substances on the downwind side; the main direction of the plant should be north-south direction; green belt.
(c) dust: electric arc furnace smoke purification equipment should be used dry high-efficiency dust collector; cupola smoke purification should be used mechanical exhaust smoke purification equipment.
Section VI forging safety technology
Knowledge of a forging characteristics
in the state of burning metal, the equipment used, such as air hammer, steam hammer, friction press, etc., the work issued by the impact, the force is very large,
Knowledge of a forging hazardous harmful Factors
Hazardous accidents: mechanical injuries, fire and explosion, burning (800~1200).
Occupational hazards: noise and vibration, dust and poison hazards, heat radiation.
Knowledge Points III, forging safety and technical measures
12 points (mastery of key starters 3, 4, 5 and 11). Exposed drive (gear drive, friction drive, crank drive or belt drive, etc.) must have a protective cover; starting device must be able to ensure that the equipment for rapid switching, and to ensure that the equipment running and stopping the state of continuous and reliable; electric starter button box, its buttons need to be labeled with ? Start? Start? Stop? and other words. Parking button is red, its position is higher than the start button 10?12 mm; newly installed and after major repairs to the forging equipment, should be based on equipment drawings and technical specifications for acceptance and testing.
Section VII basic knowledge of safety ergonomics
Knowledge Points I. Definitions and research content
(a)? People? Machine? environment? Systems
The fundamental need to address safety issues is to mechanize and automate the production process.
(ii) types of man-machine systems: there are two main categories, one for mechanized, semi-mechanized control of man-machine systems; the other for fully automated control of man-machine systems.
1) mechanized, semi-mechanized control of man-machine system: people mainly act as operators and controllers of the production process. The safety of the system depends mainly on the rationality of the distribution of human-machine functions, the intrinsic safety of the machine and human error.
2) fully automated control of man-machine system: people are monitoring and management. The safety of the system depends mainly on the intrinsic safety of the machine, the machine's redundancy system failure, and the person in the low load emergency response deterioration.
Section VIII Human Characteristics
Knowledge Points I. Anthropometric Measurements
(a) Static Measurements.
Measurement methods: can be taken in different positions, mainly standing, sitting, kneeling and lying down, and so on.
Anthropometric measurements are the dimensions of different parts of the human body, which are involved in the design of different devices or products.
Factors affecting anthropometric data: ethnicity, gender, age, and occupation.
(ii) Dynamic measurement
(iii) Guidelines for the use of anthropometric data
Maximum-minimum criterion, adjustability criterion, averaging criterion, criterion for the use of up-to-date anthropometric data, locality criterion, criterion for the combination of functional corrections and minimum psychological space (dress code correction, functional correction to get the minimum functional dimensions, and additional psychological corrections to get the optimal functional dimensions).
Knowledge
Knowledge point two, human physiological characteristics
1, vision
Dark adaptation and bright adaptation ability: dark adaptation transition time is longer, about 30min; bright adaptation about 1min;
Glare harmful effects: the destruction of the dark adaptation, the visual afterimage; reduce the illuminance of the retina; weaken the contrast between the object of observation and the background; the blurred feeling when observing objects. Objects produce a fuzzy feeling, etc., these will affect the normal operation of the operator.
Visual illusion: shape illusion, color illusion, object movement illusion. One of the common shape illusion is the length illusion, direction illusion, contrast illusion, size illusion, near and far illusion and perspective illusion. Color illusions are contrast illusion, size illusion, temperature illusion, distance illusion and fatigue illusion.
Visual damage and visual fatigue: the maximum brightness of visible light that the eye can withstand is about 106cd/m2. 300m of short-wave ultraviolet light can cause ultraviolet ophthalmia. UV radiation 4 ~ 5h after the eyes will be congested, l0 ~ 12h after the eyes will make the eyes severe pain and can not open the eyes. Frequent exposure to infrared radiation can cause cataract. Looking directly at high brightness light sources such as lasers and sunlight can cause macular burns, which may result in irrecoverable vision loss. Low illumination or low-quality light environments can cause refractive defects in various eyes or early formation of presbyopia. Glare or light with dramatic and frequent changes in illumination can cause a reduction in visual function.
Visual movement law: the human eye to look at a target to get a visual impression, the shortest gaze time of 0.07 ~ 0.3s, here with the brightness of the illumination. The pause time of human eye vision takes 0.17s on average.
2. Hearing. The function of hearing is to distinguish the height and strength of the sound, but also to determine the direction and proximity of the sound source in the environment.
Hearing absolute thresholds: frequency threshold, sound pressure threshold and sound intensity threshold.
Auditory discrimination threshold: the ability of the human ear to distinguish between sounds of different frequencies and different intensities.
The ability to recognize the direction and distance of sound.
3, human sensation and reaction
Reaction time: is the sum of the time used from including the sensory reaction time to the start of the action. Under general conditions, the reaction time is about 0.1-0.5S, for complex selective reaction time up to 1-3S, to carry out complex judgment and awareness of the reaction time of an average of 3-5S.
Ways to reduce the reaction time: 1) reasonable selection of the type of perception (auditory reaction time is the shortest 0.1-0.2S); 2) according to the principles of ergonomics to design machines; 3) through the training to improve human reaction time. training to improve human reaction speed.
(B) the characteristics of the human body parameters
and product design and operation of the machine related parameters: static parameters, dynamic parameters, physiological parameters, biomechanical parameters.
Human labor intensity parameters: oxygen consumption, heart rate, human labor intensity. Physical labor intensity according to the size of the labor intensity index i is divided into 4 levels: light labor, medium intensity labor, heavy intensity labor, very heavy physical labor.
(C) fatigue
Definition of fatigue: fatigue is divided into muscle fatigue (or physical fatigue) and mental fatigue (or mental fatigue) two.
Elimination of fatigue: the design should take into account the human physiological and psychological factors; improve the working environment; reasonable arrangement of rest and leisure time.
3, fatigue determination methods: subjective feeling questionnaire method, analyze the electroencephalogram, determine the strobe value, intelligence test, mental test, continuous shooting changes in human movement.
4, monotonous work and shift work
Measures to avoid monotonous work: cultivate multi-faceted hands, work extension, operation redesign, show the ultimate goal of the work, dynamic information report, the implementation of recreational work, improve the operating environment.
Shift work: single-shift system, two-shift system, three-shift system or four-shift system. Many enterprises are practicing the "four-shift, three-run system". Four shifts, three running system?
Knowledge.
Knowledge point three, human psychological characteristics
Ability: refers to a person's ability to complete a certain task. There are mainly sensation, perception, observation, attention, memory, thinking and imagination, and the ability to operate.
The sum of the various abilities constitutes human intelligence, which includes human cognitive ability and activity ability.
Moods and emotions. The insecure emotions are impatience and irritability.
Section IX Characteristics of Machinery
Knowledge Point I. Definition and Characteristics of Machinery Safety
Characteristics of Machinery Safety. Modern machinery safety has: systematic, protective, friendly, holistic.
Knowledge point two, mechanical fault diagnosis technology
The basic process of fault diagnosis includes the establishment of diagnostic documents and diagnostic implementation of two major parts. Diagnosis of the basic steps of the implementation process: signal detection, feature extraction (or signal processing), state identification, diagnostic decision-making.
(C) fault diagnostic techniques
1, the detection and analysis of vibration signals
Vibration signals are generally measured by displacement, velocity or acceleration sensors. Sensors should be installed as far as possible in the diagnosis of the object sensitive points or from the core part of the nearest key points.
2, oil analysis technology: the application of more spectral oil analysis and iron spectrum oil analysis .
3, temperature detection and infrared monitoring technology.
4, ultrasonic flaw detection technology: can be all solid materials for flaw detection and testing.
5, surface defect detection technology: magnetic particle flaw detection, penetration detection, eddy current detection.
Knowledge Points III, mechanical reliability design and maintenance design
Reliability definition: refers to the system or product in the specified conditions and specified time, the ability to complete the specified function.
Reliability metrics: reliability, failure rate (or failure rate), average life (or average trouble-free working time), maintenance, effectiveness.
Effectiveness: narrow reliability r (t) and maintenance degree m (?) of the combination of the degree of effectiveness, also known as the degree of effectiveness. The synthesis is called the degree of effectiveness, also known as the generalized reliability.
(ii) maintenance design
Maintainability refers to the ease of repair of faulty products. That is, in the specified conditions and specified time, the degree of difficulty in completing the task of repairing a certain product.
The main issues to be considered: accessibility, standardization and interchangeability of parts and components, safety of maintenance personnel.
Section X man-machine operating environment
Knowledge points, light environment
(a) light metrics
Concepts: luminous flux, luminous intensity (light intensity), brightness, illumination. Insufficient illumination is an important cause.
(ii) Impact of lighting on operations
Lighting and fatigue, lighting and accidents. Visual fatigue is a major cause of accidents and affects work efficiency.
Knowledge Points II, Color Environment
Characteristics of Colors Colors have three basic characteristics: hue, lightness, and chroma.
The physiological impact of color, visual fatigue.
Knowledge point 3, microclimate environment
Elements that make up a microclimate: air temperature, air humidity, air velocity, thermal radiation.
Air temperature, divided into comfortable temperature (21?3 ℃) and permissible temperature (comfortable temperature?3~5 ℃).
Air humidity, there are absolute humidity and relative humidity, relative humidity above 80% for high air humidity, less than 30% for low air humidity, comfortable humidity is generally 40% to 60%.
Airflow rate, outdoor generally 0.15m/s when the air is fresh.
(B) the human body's feeling and evaluation of the microclimate environment
1, the comprehensive evaluation of the microclimate environment. 1) Effective temperature (sensory temperature): dry bulb temperature, wet bulb temperature and air velocity; 2) discomfort index: dry bulb temperature, wet bulb temperature; 3) the three-ball temperature index wbgt: dry bulb, wet bulb, black bulb; 4) the degree of katak: air temperature, humidity and wind speed.
2, the impact of high-temperature operating environment on the human body: high-temperature environment to make people's heart rate and respiration accelerated, hot and humid environment on the central nervous system has an inhibitory effect, high-temperature environment, a large number of people's loss of water and salt.
3, low-temperature environment on the human body: hand touch sensitivity critical skin temperature is about 10 ℃.
Section 11: Human-Machine Systems
Knowledge Point 1: Human-Machine Information and Energy Exchange System Model
Any activity of the human-machine system is essentially the transfer and exchange of information and energy.
Knowledge point 2, human-computer function allocation
1, the main function of human in the human-computer system: sensing function, information processing function, manipulation function.
2, the human-machine function allocation principles: bulky, fast, durable, high reliability, high precision, regularity, monotonous, high-value arithmetic, operational complexity, poor environmental conditions, suitable for the machine; and research, creativity, decision-making, instructions and procedures for scheduling, checking, maintenance, troubleshooting, and to cope with the unpredictability of work, suitable for the people.
Knowledge Points III, man-machine system reliability calculations
(a) the reliability of man-machine system calculations
1, man-machine tandem system. Man-machine parallel system: parallel work redundancy method, backup redundancy method.
2, two people to monitor the reliability of the man-machine system: abnormal when the equivalent of two people in parallel; normal equivalent to two people in series.
Abnormal conditions, Rsr?=RHb?RM=[1-(1-R1)(1-R2)]RM
Normal conditions, Rsr?=RHc?RM=Rl?R2?RM
(B) man-machine system reliability design of the basic principles
1, the overall reliability of the system principle of high reliability of the constituent unit element Principles, design principles with a safety factor, the principle of high reliability approach, the principle of standardization, the principle of high maintenance (standardization of parts, component generalization, equipment serialization), the principle of prior testing and evaluation, the principle of prediction and prevention, ergonomics, technology and economy, the principle of review, collation of preparatory information and the principle of exchanging information, the principle of information feedback, and the establishment of the appropriate organizational structure.
2, the principle of high-reliability approach: redundant design, fail-safe devices, automatic insurance devices.
3, fail-safe structure has the following types:
① Negative passive. When the component unit fails, the machine becomes stopped.
② Active. When the component unit fails, the machine is alarmed on one side, and on the other side, it can still run for a short period of time.
③ Running operation type. Even if a component unit fails, the machine can run until the next periodic inspection.
Usually in industrial systems, most of the negative passive structure.
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