Nowadays, along with the rapid development of China's science and technology and economy, China's machinery industry has also made greater progress. The following is a sample of my thesis about machinery, welcome to read and reference!
About mechanical thesis article 1
Analysis of mechanical design and mechanical manufacturing technology
Abstract: After the reform and opening up, China's level of scientific and technological development is getting higher and higher, the mechanical manufacturing technology in the process of combining the use of mechanical drawing, electrical engineering, computer application technology, etc. continue to develop, but there is still a certain distance from the foreign advanced technology. In this paper, the main mechanical design and mechanical manufacturing related issues are analyzed and discussed.
Keywords: mechanical design; mechanical manufacturing; measures
Introduction
Contemporary society, with the progress of society and the development of science and technology, people's demands on the quality of life are getting higher and higher, along with the more stringent standards for a variety of products, the requirements of the product to the following aspects: reasonable price, high-grade quality, convenience, diversified types, a high degree of automation, ornamental and so on. automation, ornamental and so on. Therefore, the exploration of mechanical design and mechanical manufacturing is very meaningful, can contribute to the enhancement of the nature of the product characteristics in various aspects.
First, the technical analysis of mechanical design
1, the initial plan of mechanical design design analysis
Mechanical design to carry out the initial plan of design, its work and computer software design requirements analysis is relatively similar to the design before the design of the machine design requirements for investigation and analysis, in the process of analyzing the requirements of the function of the machine should have to be mastered. To be mastered. As a basis for mechanical design, and then in the design and manufacturing process to specify the corresponding constraints.
2, mechanical design design program analysis
In mechanical design, program design is a key part of the program is also the soul of the design, which determines the success or failure of the design. In the design stage, will encounter a lot of problems, the main problem to face is the contradiction between practical and theoretical. Program design should not only meet the performance of the machine itself, at the same time, in terms of function should also be satisfied. In the design of the program, the inspectors should pay attention to the development of the machine, understanding and innovation. In the design phase, the main steps can be briefly summarized as the working principle of the definition of the machine structure to determine the design of the machine movement mode, the selection of parts and design judgment, the design of the drawing and the preliminary design of the investigation.
3, the main technical design analysis of mechanical design
Mechanical design, the most stringent requirements of the technical aspects of the design of the design drawings in this stage to proofreading, at the same time, the drawings should be calculated, the design of the general drawing and part of the sketch should be compared and checked and analyzed. In the mechanical design of each part of the design, design should be very strict checking, there can not be omissions, at the same time, in the proofreading to ensure quality. To the production of products to be mechanical, in the design, according to the product to be stereotyped design.
4, mechanical design technology development trend analysis
(1) for the mechanical design of modern mechanical products
Modern mechanical products put forward higher requirements for mechanical design, therefore, in the design of machinery, in the technical level must continue to improve. Mechanical product design to be more intelligent characteristics, the main way is to use modern design means, in the design process, the application of advanced design software and virtual design technology, the virtualization of product design, at the same time, the use of multimedia technology on the performance of the product structure simulation demonstration, in order to achieve better design results.
In the mechanical design to be more systematic, mechanical design contains a lot of parts, these parts should be organically combined together to form an overall design, at the same time, to have a certain hierarchy, after systematic design in order to achieve the design goals of mechanical products. Finally, to have modular characteristics, this concept is relatively simple in terms of design, but to ensure that the mechanical design function to achieve the modular combination, in the product design process. Mechanical product design should have characteristics, according to the characteristics of the products produced to carry out mechanical design, in this process to use the computer to build the product, at the same time, to carry out the necessary reasoning, and ultimately the formation of program design.
(2) the future development of modern mechanical design and prospect analysis
Mechanical products in terms of performance to be more excellent, therefore, in the process of mechanical design to improve the performance of the product as the goal, which is mainly reflected in the mechanical products of the excellence of the reliability of the technology and control technology. Mechanical design should be more suitable for the market development, in the fierce market competition can obtain the development space, the product should be able to expand in the market after the formation. At the same time, in the case of the changing economic environment, to continue to develop new technologies, so that the application of new technologies in mechanical design. New technology should have a certain competitive advantage, mainly reflected in the innovation of technology, cost reduction, intelligent design and so on. The application of new technologies to improve the market competitiveness of mechanical design, more favorable to the future development of enterprises.
Second, the technical analysis of mechanical manufacturing
1, the main mechanical manufacturing process
Contemporary mechanical manufacturing technology covers a wide range of technologies, including welding, clamping and so on. And modern mechanical manufacturing welding technology are: submerged arc welding welding technology, that is, under the surface of the flux by burning the arc to complete the welding welding technology; resistance welding welding technology refers to the object to be welded firmly pressed between the positive and negative poles, and then connected to the power supply, relying on the current through the surface of the welded object as well as the surrounding can be heated up by the effect of the welding process, will be melted, so that it is fused with the metal of the pressure welding process; Stud Welding Welding technology, is to make the end of the stud and the surface of the pipe or plate is tightly connected together; stir friction welding welding technology is in the welding, in addition to the welding of the stirring head, the rest of the welding consumable materials, such as flux, wire, etc. are discarded welding process; gas shielded welding technology, that is, the use of the arc to heat the welding technology.
2, advanced machinery manufacturing technology characteristics analysis
(1) globalization
In the premise of economic globalization, machinery manufacturing enterprises have spread the resource allocation to the global scope, which promotes the rapid expansion of manufacturing industry in the world wide range of growth. Modern machinery manufacturing technology is also subject to the challenges of globalization, many advanced machinery manufacturing technology is emerging. The completion of a mechanical product may be the result of division of labor in several countries or regions, so a country wants to be in a position to win in the context of economic globalization, we must make the country's manufacturing technology in the international advanced ranks, and then based on the national conditions and specific manufacturing technology reasonable allocation of mechanical products manufacturing process.
(2) systematic technology synthesis
With the progress of society, the importance of modern science and technology in machinery manufacturing is also gradually highlighted, advanced machinery manufacturing technology is a variety of modern science and technology organic combination. Advanced machinery manufacturing technology not only highlights the manufacturing technology itself, but also increases the scope of manufacturing technology. Modern machinery manufacturing technology has penetrated into the product research, design, manufacturing, production and sales of the entire chain, the application of science and technology have automation, modern management information systems, computers, etc., is a comprehensive manufacturing.
(3) constantly cater to the market economy
The traditional process of manufacturing mechanical products has been far behind the modern market demand for mechanical products, so the modern machinery manufacturing technology should be retained under the premise of the original manufacturing process to strive to innovate, and at the same time, constantly absorbing the world's advanced technology, research and development of new manufacturing technology. This will enable machinery manufacturing in the gradually competitive market economy to occupy a favorable position.
(4) in line with the new requirements of industrial development
Modern industry is developing rapidly, and a variety of new technology system is also integrated into it one after another, such as computer technology, chemical technology and other advanced modern technology are well integrated into one. Under the premise of modern industry, machinery manufacturing should continue to innovate manufacturing technology, and strive to improve the efficiency of production, and further meet customer demand, so as to be able to expand the market.
3, China's machinery manufacturing technology status and development trend analysis
Nowadays, China's machinery manufacturing industry is developing rapidly, the reason for this, mainly from the design of machinery manufacturing, manufacturing process and management, etc. to analyze: first of all, is the design of machinery manufacturing, in the more developed countries in the industry, most of the enterprises are applying advanced design theories and methodologies, but also on the design data of machinery manufacturing. Mechanical manufacturing design data for uninterrupted updates, especially the application of computer CAD software technology, but also so that more and more machinery manufacturing enterprises into the era of no drawings, but at present our country is in short supply of such similar advanced technology or the application is not widely used, the need for the relevant departments and the core machinery manufacturing enterprises to vigorously publicize and promote; second is the technical analysis of machinery manufacturing, the main development trend of machinery manufacturing is high-precision, high precision, manufacturing process and management, etc.: First is the design of machinery manufacturing. Secondly, the technical analysis of machinery manufacturing, the main development trend of machinery manufacturing is high-precision, high-precision processing, in developed countries, some advanced processing technology such as nano, electromagnetic, micro-processing and laser processing technology are widely used in the actual production and manufacturing, and at present, China's application of such high-end technology is very little or even have not been developed.
Therefore, there is still a lot of room for progress in the development of China's machinery manufacturing technology, it is worth investing more energy to research and explore; finally, the management of machinery manufacturing, in the context of the information age, the application of computer technology to implement the management has become an inevitable trend, along with the organization of the machinery manufacturing mechanism and production methods of continuous updating, fine production (LP), just-in-time production (LP), and the production system (LP), the production system (LP), the production system (LP), the production system (LP), and the production system (LP). With the continuous updating of the organizational mechanism and production methods of machinery manufacturing, fine production (LP), just-in-time production (JIT), Agile Manufacturing (AM) and Manufacturing Resource Planning (MRP Ⅱ) and other advanced management ideas came into being, and these advanced management concepts in our country is relatively rare, only a very small number of machinery manufacturing enterprises to introduce the introduction of these management mechanisms, so China's machinery manufacturing enterprises to introduce more of these advanced manufacturing management concepts to improve the effectiveness and efficiency of machinery manufacturing.
Conclusion
In summary, in order to promote the development of the machinery manufacturing industry, it is necessary to continuously improve the development and application of machinery manufacturing technology and precision machining technology. And mechanical design is very important for mechanical manufacturing, so in the process of mechanical design should be strict, to ensure the quality, to achieve high standards and high quality of mechanical production.
References
[1]Guo Jianyu. Exploration of the development direction of modern machinery manufacturing technology[J]. China Science and Technology Vertical and Horizontal, 2011(18).
[2]Chao Liu. Research on the development direction of China's mechanical design and manufacturing and its automation[J]. Henan Science and Technology, 2013(6).
[3]Chen Haiping. Trial analysis of the status quo and development direction of China's machinery manufacturing technology[J]. Value engineering, 2013(18).
Mechanical thesis 2
Analysis of elevator mechanism and mechanical structure
Abstract: With the further increase of high-rise buildings, elevators began to appear frequently in China's major shopping malls and residential buildings, elevators for people's production and life activities have brought convenience and speed, at the same time, the emergence of safety accidents and other problems for people's normal order of life has caused a serious impact on people's life, and the elevator is a very important tool for the development of the elevator. The elevator has a serious impact on people's normal life order.
Keywords: elevator; mechanical device; mechanical structure
Introduction
Elevators bring convenience and speed to people's lives, but when the elevator fails, it also brings inconvenience and even jeopardizes people's lives. Therefore, the structure of the elevator should be further studied and improved.
First, the concept of elevator and classification
1, the concept of elevator
Although the elevator is very popular, the majority of people have used the elevator, but the understanding of the elevator is only limited to the concept of a narrow aspect of the so-called narrow elevator refers to the provisions of the floor service, with the car and other vertical or inclined lifting equipment, not including the automatic walkway and escalator and so on. And escalators and so on. For the elevator in the broad sense, it mainly refers to the power-driven, can run along the rigid guide rail box or along the fixed line for the operation of the steps, steps, etc., can be lifted or parallel transportation of people or goods electromechanical equipment. It includes both the ordinary sense of the people or goods elevator, including escalators and moving walkways and so on.
2, the classification of the elevator
2.1 According to its running speed to points, the elevator can be divided into four categories: low-speed, fast, high-speed and ultra-high-speed elevators. For the low-speed elevator, it mainly refers to the running speed of small 1m/s elevator, most of the freight elevator running speed are in this speed range; fast elevator refers to the running speed of 1m/s-2m/s between the elevator, usually, within 15 floors of the multi-storey passenger elevator as well as residential elevator running speed are in this range; high-speed elevator refers to the running speed of 2m/s-4m/s between the elevator, in high-rise office buildings, the running speed of the elevator is between 2m/s-4m/s, the running speed of the elevator is between 2m/s-4m/s. The elevator can be divided into four categories: low-speed, fast, high speed and ultra-high speed elevator. High-speed elevator mainly refers to the running speed of 2m/s-4m/s between the elevator, high-rise office buildings are often this type of elevator; and ultra-high-speed elevator running speed more than 4m/s, mainly used for partition control in high-rise buildings.
2.2 According to the different uses of the elevator, it can be divided into passengers, cargo, medical, miscellaneous, sightseeing, vehicles and ships and other types of elevators, in addition to the commonly used elevators, there are many types of more special elevators, for example, building construction elevators, inclined elevators, and elevators for three-dimensional parking lots and so on.
Second, the mechanical structure of the elevator and the analysis of the main devices
1, the door system
The main task of the door system is to close the elevator car space door and the floor door of each floor in the process of the elevator to avoid passenger accidents. Door system is one of the key points of elevator safety, the door system must guarantee a few points are: in the car does not rise to the floor door and stop before the floor door automatically lock (a shopping mall has been elevator due to accidental failure of the floor door lock, the results of a customer who took the elevator to look at also did not look at the door to go in); in the process of the car movement car door must be automatically closed.
2, traction system
The main purpose of the traction system is to pull the car up and down to the elevator rider specified number of floors. The traction system mainly consists of guide wheel, speed limiting wheel, traction cable, traction machine and so on. The traction machine, commonly known as the elevator host, is the device that provides power for the elevator. The elevator host can be divided into AC traction machine and DC traction machine according to its motor; it can be divided into gearless traction machine and gear traction machine according to its deceleration; it can be divided into low, medium, high and ultra-high speed traction machine according to its speed; it can be divided into horizontal traction machine and vertical traction machine according to its structure. The elevator car and the counterweight is through the same rope hanging on the same traction sheave. The weight of the car and the weight of the counterweight to produce friction between the traction sheave and the traction rope, the traction machine drives the traction sheave to rotate so that the friction drives the car up and down.
3, car system
The car is our usual into the elevator compartment space. The car is generally composed of the bottom of the car, the door, the top of the car, the wall and other components. The car is the only passenger space among the four major spaces. The walls opposite the roof and doors are usually mirrored, and a monitoring device is installed at the top of the car. Car is the elevator's load-bearing and carrying space is also our most familiar space, but we do not know is the bottom of the car and weighing device, can accurately weigh the total weight of all the occupants on the elevator, once the total weight exceeds the rated weight of the elevator, it will sound an alarm, and many elevators have now changed the original monotonous warning tone into a voice alarm to prompt the elevator is currently in the super life stopping Running state, must make adjustments to the important. At this time, as long as you go down one or several people as long as not more than the rated weight elevator can continue to run.
4, guidance system
The guidance system of the elevator is mainly composed of guide rails, guide rail frame, guide boots and so on. The function of the guidance system is to limit the freedom of the car and the counterweight, constrain the counterweight and the car to run on their respective rails, so as to avoid collision, because the counterweight and the car are actually very close to each other, and it is very easy to collide if it is not constrained. In the accidental power failure, traction rope breakage and other accidents, the guidance system can be stuck in the car on the guide rail to prevent it from doing a free-fall type of fall, thus causing personal injury. The guide rail can control the elevator direction of the elevator, control the movement of the car and the counterweight in the horizontal aspect, make the car and the counterweight in the shaft in a reasonable position to avoid tilting. There are 4 guide rails in the elevator shaft***, 2 guided for the counterweight frame and 2 guided for the car. The fixing of the guide rails is realized by using bolts, nuts and ballast plates. And the distance between the guide rail frame needs to be controlled in 3-5m long guide rail, and the number must be more than 2. Guide rail in the safety clamp action, can be used as a clamped support parts, support the car or counterweight.
5, weight balance system
This system mainly includes counterweight, compensation rope, compensation device and compensation cable. The wire rope used for counterweight is connected with the car through the traction sheave and guide sheave, and is responsible for balancing the load of the car and elevator in the process of operation. For the counterweight value, it should be configured strictly according to the rated capacity of the elevator to ensure that the elevator is in an optimal working condition as far as possible. If the traction height of the elevator is greater than 30m, the differential weight of the traction rope will affect the stability of the elevator's operation and its balance, therefore, the addition of compensation devices must be carried out, for example, compensation chain and compensation cable and so on.
6, mechanical devices
Elevator as a vertical transportation, safety must be absolutely guaranteed. Here mainly introduces the speed limiter, safety clamp, buffer and terminal override protection device.
6.1 Speed limiter and safety clamp
The speed limiter can reflect the actual running speed of the car or counterweight, when the running speed of the elevator reaches or exceeds the set limit value (generally more than 115% of the rated speed), the speed limiter stops the operation, and with the help of the friction in the rope sheave or the rope clamping mechanism to lift up the connecting rod installed in the car beam, sends out a signal through mechanical action, cuts off the control circuit, and forces the safety clamp to stop the operation. Cut off the control circuit, at the same time forcing the safety clamp action, so that the car is forced to stop on the guide rail, only when all the safety switches are reset, the car is lifted upwards, the safety clamp can be released. When the safety clamp is not restored to the normal state, the elevator can not be used. So the speed limiter is the elevator overspeed and in overspeed to reach the critical value, the role of detection and manipulation.
6.2 Buffer
The buffer is the last safety device in the limit position of the elevator. When all the protection measures fail, the car with large speed and energy will rush to the bottom or top floor, resulting in serious consequences of machine destruction and death. The purpose of setting buffer is to absorb and consume the energy of the car. Generally in the counterweight side and car side are respectively equipped with buffer. The type of buffer has spring type and hydraulic type. Because the spring buffer needs to release the elastic deformation energy after the impact, the rebound, resulting in buffer instability, so it is generally only used for rated speed 1m/s above the low-speed ladder. Hydraulic buffer, is to consume energy in the way of buffer, so there is no rebound phenomenon, buffer process is relatively smooth, and the noise is small, so in the fast and high-speed elevator is commonly used.
6.3 Terminal overrun protection device
The function of terminal overrun protection device is to avoid the failure of the elevator's electrical system, which causes the car to cross the upper and lower end stations to be able to continue to run, resulting in the occurrence of accidents, such as the top, the bottom and so on. The terminal override protection device is usually installed on the upper and lower terminal bracket of the car guide rail, which is mainly composed of deceleration switch, limit switch, limit switch, and is equipped with components such as hitting plate, touching wheel and steel wire rope, etc. The hitting plate is used to protect the elevator when the elevator is out of control. When the elevator is out of control, the hitting plate will touch the deceleration switch due to the running of the car, so that the contact inside the switch sends out the command signal to stop the elevator. If the elevator cannot be stopped in this way, it is necessary to use the action of the limit switch to make the elevator run in the opposite direction. If the elevator still cannot be stopped, the limit switch will disconnect the power and the elevator will stop quickly.
Conclusion
In summary, although the elevator's mechanical structure is relatively simple, but its degree of mechatronics is relatively high, the application of automation technology is also relatively advanced, elevator control circuits and process complexity is high. However, the same as any other electromechanical system, the elevator device and mechanical structure between there are many problems. Therefore, the existing elevator still needs to be further improved, the traditional traction rope traction elevator should be transformed into a magnetic suspension track power traction elevator, and the use of fixed track to fix the elevator, in order to ensure the safety of the elevator use process.
References
[1] Ye Anli. Elevator control technology [M]. Beijing: Mechanical Industry Press, 2007.
[2] Ding L. Q. The dynamic characteristics of traction elevator and its safety in the use of elevator. Research on dynamic characteristics of traction elevator and its simulation platform development [D]. Hangzhou:Zhejiang University, 2005.