Design of lifting gear

Contents

INTRODUCTION

1 OVERVIEW OF EXISTING STRUCTURES

2 DEVELOPMENT OF LIFTING DEVICE DESIGN AND ANALYSIS OF ITS EFFICIENCY

2.1 Patent Search

2.2 Terms of Reference

2.3 Substantiation of geometric dimensions

2.4 Structural analysis of lever mechanism

2.5 Kinematic analysis of lever mechanism

2.5.1 Constructing Mechanism Plans

2.5.2 Diagram of mechanism support heel movement

2.5.3 Construction of mechanism speed plans

2.5.4 Construction of speed diagram of mechanism support heel

2.5.5 Construction of acceleration plans of the mechanism

2.5.6 Building the slide acceleration diagram

2.5.7 Construction of link speed hodograph

2.6 Power analysis of the mechanism

2.6.1 Determination of reactions in kinematic pairs and links

2.6.2 Determining the balancing moment

by kinetostatic method

2.6.3 Determination of balancing moment by Zhukovsky method

3 CALCULATION OF ECONOMIC INDICATORS

3.1 Work planning at the product development stage

3.2 Calculation of costs for product development

3.3 Calculation of costs at the stage of mock-up

3.4 Calculation of production cost

4 OCCUPATIONAL AND ENVIRONMENTAL PROTECTION

4.1 Analysis of working conditions, hazardous and reliable production factors

4.2 Occupational Safety Measures

4.3 Safety requirements for tools and equipment

4.4 Industrial sanitation and occupational health

4.5 Fire Safety

4.6 Environmental Protection

4.7 Drawing up a network accident model

4.8 Calculation of accident probability

CONCLUSION

LIST OF SOURCES USED

APPLICATION

Introduction

Jack (from goll. dommekracht) - a device for lifting and briefly holding the load. When replacing a regular or buying an additional car jack, you need to take into account the design features on which not only the convenience of work, but also its capabilities depend.

General Information

The configuration of cars of old releases included screw and rack jacks with a carrying capacity of 500 kg. Under such jacks with a folding catch on the body of the car, special sockets should be provided, which are often clogged with dirt and ice or deformed, which makes their use difficult. Incorrect installation causes damage to the side surfaces of the wings, doors, or thresholds. In addition, if the thresholds and sockets are weakened by corrosion, there is a risk of falling of the car, moreover, not all jacks supplied with the car have acceptable stability and adaptability to various situations.

Today, from a huge variety of modern jacks, you can choose devices that meet the requirements of both a motorist who intends to carry it with him and use it only for his car, and a large car service in which cars of different classes are constantly serviced.

2.5 Kinematic analysis of lever mechanism

Kinematic analysis of mechanisms generally involves three main tasks:

- determination of link positions and construction of trajectories of individual points;

- determination of speeds of points and angular speeds of links;

- determination of accelerations of points and angular accelerations of links;

For mechanisms with one degree of mobility, the law of movement of one of the links, usually the main shaft of the machine, is set. This link is called the host. Determination of the listed kinematic characteristics is carried out within one period (cycle) of steady-state movement of the mechanism for several positions, which makes it possible to solve the given task with sufficient approximation. Without knowledge of the above kinematic parameters, it is impossible to solve the further problem of rational sizing. For example, the trajectories of some points of the mechanism are needed to determine the travel of the links, the outline of the contour of the machines, as well as to establish the correspondence of the movement of the working links of the machine with the correct sequence of the process.

In some machines (in long and strict machines), large changes in the speed of the working link are not allowed, since the durability of the structure depends on this. From what is said, it is necessary to know the speeds of the points of some links and, for clarity, it is convenient to present them in the form of graphs.

Using speed plans, the reduced mass is determined (without knowledge of which

the moment of inertia of the flywheel cannot be determined), the law of movement of the machine, etc.; acceleration plans are needed to find the inertia forces of the links. Kinematic investigation of the mechanisms is carried out on the assumption that the driving links rotate at a constant angular speed, despite the fact that in reality the angular speed of rotation of the crank is not constant. This assumption is made due to the small difference between the average and actual angular velocity of the crank, and also technically facilitates the construction of acceleration plans.

Kinematic study of mechanism schemes is performed by graphical and analytical methods. The former are distinguished by clarity and relative simplicity, but do not give accurate results. Analytical methods allow you to obtain the required accuracy of the results, but are characterized by great complexity and labor-intensive calculations.

3 calculation of economic indicators

When designing any device, it is necessary to evaluate the feasibility from an economic point of view. The equipment to be created should have a low production cost along with improved technical characteristics in relation to analogues. This original lifting device is in demand in the industrial equipment market, as this is a relatively new type of equipment. It allows you to smoothly change the climbing height parameters at a sufficiently high lifting speed. It is in these qualities of this type of equipment that consumer enterprises are interested. In this situation, competition between the main producers is growing rapidly. Equipment becomes cheaper, but at the same time it does not lose its technical characteristics.

The proposed lift model is characterized by its functional simplicity, and therefore easy to control. However, this does not make it not competitive with respect to analogues. The analogues are reviewed in Chapter 1.

We will make calculations to determine the cost of a unit of development.

The main absolute indicators include the cost of fixed assets, the production area, the enterprise program (in conditional repairs and in monetary terms), the number of personnel, the cost of repair of the product, the volume of gross production, profit and annual savings of the enterprise.

The main objective of the feasibility study of the production of the product is to determine the size of the economic effect and use in the production of the main and related results obtained in solving the given technical task.

To calculate depreciation charges, RUB will choose a linear accrual method, which consists in a uniform (year-by-year) accrual of depreciation. In this method, depreciation is accrued based on the annual depreciation rate selected for different groups of fixed assets.

The cost of a unit of production is the monetary amount of costs for its production and sale. We take one product as the costing unit.

4 Occupational and Environmental Protection

The project provides for measures on labor protection, industrial sanitation, environmental protection and fire safety according to

GOST 12.1.003 - 83, GOST 12.1.004 - 91, GOST 12.1.009 - 76, GOST 12.1.04685, GOST 12.1.012 - 2004, GOST 12.1.016 - 79, which regulate fire safety, noise, lighting, vibration and air standards at workplaces.

When developing measures for nature protection and ventilation, we use

GOST 17.2.3.0278, GOST 17.4.3.03 - 85, for soil pollution control and protection ,

GOST 17.13.13 - 86 for protection of water surface from contamination.

Occupational safety at the design stage is a crucial condition for ensuring safe and healthy working conditions.

4.1 Analysis of working conditions, hazardous and harmful industrial factors

One of the principles of labor law in Russia is ensuring safe working conditions. Dangerous and harmful conditions and production factors create a human environment. The territory of the enterprise should be landscaped, not contaminated with garbage and materials.

Location of filling stations shall provide safe area from parking of vehicles

Occupational injuries are caused by lack of organization of work, neglect of safety regulations and industrial sanitation.

The most characteristic causes of accidents are: violation of the technological process, failure of equipment and tools or its non-compliance with the conditions of the performed work, lack of fences, inappropriate working clothes, insufficient lighting, low level of technical culture of production.

Dangerous and harmful production factors characteristic of repair shops can be distinguished: physical, chemical and psychophysical. The reasons for the latter are mental overvoltage, monotonous labor, emotional overload.

Physical harmful and hazardous production factors broken down into components: unprotected movable elements of equipment and parts of machines (motors, shafts, belt gears, etc.), increased dust and gas content of the air of the working zone (electro and gas welding equipment, exhaust gases of cars, acid evaporation in the storage room, etc.), increased and decreased air temperature of the work area, increased noise and vibration level at the work place (the main source is production equipment, working transport), a dangerous level of voltage in the electric network, the closure of which can pass through the human body (equipment operates at 220 V, 380 V), lack of natural light moving through the territory of the machine.

These factors do not exhaust all the hazards that can arise in real production. The challenge is to identify all hazards and hazards with the necessary completeness. In this regard, it is necessary to be guided by the requirements set forth in regulatory documents.

4.3 Safety requirements for tools and equipment

The equipment and tools shall meet the following safety requirements throughout their life cycle:

the tool must always be clean, dry and serviceable;

control of equipment shall be convenient, easy;

rotating parts of the equipment shall be protected, if this is not possible, it shall be installed with a guard in the form of a warning inscription, and the moving parts shall be painted in bright colour;

equipment control shall be as far as possible with designation of operations, functions, all fences shall have electrical and other interlocks;

rotary stands shall have fixation devices;

stationary equipment shall be installed on foundations and securely fixed;

persons who have been trained in their operation are allowed to work on stands and equipment;

a plate with the inscription prohibiting operation on it is displayed on the faulty equipment;

All lifting mechanisms shall be partially and fully inspected within the prescribed time frame, in accordance with the documentation and tests carried out by engineering and technical personnel.

4.4 Industrial sanitation and occupational health

Sanitary and hygienic requirements in the designed enterprise must comply with sanitary design standards of enterprises.

Ventilation of production premises serves to ensure proper sanitary and hygienic conditions at the workplace.

In all enclosed premises in automobile enterprises, where cars are located, engines work and harmful substances are released, forced tile ventilation is equipped. In addition, all rooms are equipped with windows and fragments for natural ventilation.

Due to mechanical ventilation in production rooms, regardless of the time of year and process modes, it is possible to maintain constantly set temperatures, humidity and cleanliness of air, which is called conditioning.

In the rooms for storage of spare parts, units, tools, tires located not in the basements of buildings, only natural ventilation is provided.

In addition to general, the premises provide for local plenum and local exhaust ventilation.

Compliance with the standards of temperature conditions in all premises of the enterprise is an important factor in preserving the health of workers.

To maintain normal temperature in cold season, rooms are equipped with heating according to GOST R 5099396.

Depending on the purpose of the room, the air is heated to the following temperatures:

1. Storage of + 6 С tyres;

2. For maintenance and repair of cars + 16 С;

3. For storage of spare parts, tools, oils, wiping materials

+ 10 C.

The heating scheme should take into account the uniform heating of the air in the rooms, be convenient in operation, accessible for repair.

To maintain heat in the cold season, exit and entrance gates must be insulated. All doors shall be interlocked with the system of air heat curtains in such a way that at the moment of opening of the gate warm air is simultaneously supplied to the production rooms.

By the time of winter, the window frames, window windows, framugs should be glazed and soaked, the heat curtains should be in good condition, and the entire heating system should be checked and repaired.

Rational lighting of production premises contributes to good visibility at workplaces and work facilities, directly on the car, reducing the visual stress of workers of the motor transport enterprise. Lighting should not give sharp shadows and highlights, should have the most correct rational direction of light flux to workplaces and facilities.

Hygienic requirements for rational artificial lighting are:

sufficient illumination and uniform illumination on working and surrounding surfaces in the absence of different shadows;

sufficient illumination for particular production processes is different and depends on the nature of the work performed and the reflection coefficient of the working surface. The smaller the detail and the further away it is from the eyes, the more illumination should be. With a large reflection coefficient, the illumination can be less.

In order to create healthy working conditions in the production premises, there must be sufficient natural lighting in the daytime and artificial lighting in the dark.

Natural lighting has a favorable physiological effect on human vision, so all production, storage, household, administrative and economic premises must have direct natural lighting according to SNiP 2-4-79.

Acting on the hearing organs, noise negatively affects the human nervous system. Noise is a messy combination of various different sounds.

As a unit of sound, 1B (white) is accepted - the smallest force of sound perceived by the human ear. The sound intensity level is expressed in decibels (DB) equal to 0.1B. the smallest level of sound intensity perceived by the human ear, equal to 1DB, is called the audible threshold. Noise level is measured according to GOST 121.003 - 86. Raising the sound intensity level to 130 DB causes hearing disease.

With prolonged exposure to noise, the attention and memory of workers is weakened, and industrial injuries increase.

At different types of works noise reaches the following values (DB):

engine run-in at the stand - 110-120;

straightening of metal body sheets - 105-110;

work of lathes - 80-90.

GOST 12.1.003 - 83 shall be observed in the production room.

To reduce noise effects on human hearing organs, it is necessary to:

improve the process;

use soundproofing barriers;

use noise-emitting linings and coatings;

attach the machines of units and mechanisms through elastic demiling connections;

bring particularly noisy processes to separate rooms;

Use personal protective equipment.

All applicants must undergo a full medical examination. For workers of harmful specialties (blacksmiths, welders, painters), check every three months, for the rest once a year.

Each production area shall be equipped with a medical first aid kit.

Workplaces shall be located at least 1 meter from the heating system.

4.5 Fire Safety

General requirements for fire safety are contained in GOST 12.1.004 - 91. The main responsibility for fire safety lies with the head of the motor transport shop. He is responsible for conducting fire safety measures, creates a voluntary fire squad and appoints the head of the squad.

An evacuation plan for the vehicle in the event of a fire is being developed for parking and for the maintenance and repair area. Flammable liquids are delivered from the warehouse in quantities that meet the replacement capacity. Gas cylinders are stored in separate warehouses protected from thermal energy sources. The company is provided with fire extinguishing equipment: fire extinguishers, equipment and water supply with fire hoses.

The scheme of evacuation of people and equipment, developed in case of fire, is posted in a prominent place in the production room. Specially equipped spaces are reserved for smoking.

To maintain fire safety at the appropriate level, the project provides for the following measures:

maintenance of premises and workplaces in a clean and orderly manner;

do not clutter passages and passages;

store the used haze in metal boxes with tightly closing covers;

to provide a zone TO and TP with fire boards and OHP fire extinguishers - 5 and OHP - 10 at the rate of one fire extinguisher on 50 m3 of the area, but not less than two on each certain room, boxes with sand, water supplies with fire hoses;

repair shop shall be equipped with fire alarm;

compartments with increased fire hazard (paint, welding, storage, fuel equipment) are provided by fire foam generators;

conduct classes with a voluntary fire brigade to maintain fire readiness;

periodically conduct knowledge checks and briefings.

4.6 Environmental Protection

Very much attention is currently being paid to environmental protection. When developing the project, it is necessary to comply with a number of requirements that ensure environmental cleanliness:

1. Develop safety precautions with adjusted fuel equipment, prevent emissions of exhaust gases of increased concentration into the atmosphere, comply with GOST 17.22.03 - 87.

2. Wash the machines only on specially equipped sites, ensuring the collection of dirty water, its filtration and secondary use, according to GOST 17.13.13-86.

3. Strictly observe fire safety regulations.

4. Drain fuel and spent oil from engines and units only to special tanks and prevent their draining to the sewage system or to the ground.

5. All wastes of ferrous and non-ferrous metals should be sent for processing.

If these environmental requirements are met, it is possible to preserve soil, forest, nearby reservoirs from pollution and death.