Thesis on Mechanical Graduation Design

In recent years, due to the changes in the pattern of the international construction machinery industry, China has become an important production market and consumer market within the field of construction machinery industry. The following is my graduation design thesis on machinery for your reference.

Abstract: The cab large assembly as the main components of the loader, in which the quality of the electrical components of the feedback rate has been high. On the basis of analyzing the working principle of each electrical component, the inspected electrical components are classified, according to the different working principles of each type of electrical components, the corresponding detection program and make electrical inspection platform. Tracking results show that the electric inspection platform to meet the production line beat requirements, improve the effect is good.

Keywords: electronic inspection technology; cab; quality

Electronic inspection technology is a comprehensive inspection technology, mainly including electronic measurement system and electronic information technology two aspects [1]. With the development of science and technology, the application of electronic testing technology in various industries is becoming more and more common [2]. Especially in the application of automobile maintenance, but also to improve the quality of automobile maintenance provides an important guarantee. At the beginning of the birth of electronic detection technology, it has been widely used in the automotive industry, and not much application in the engineering machinery industry.

1 status survey

For a long time, the loader cab as the company's core business, to provide customers with only the cab small assembly painted sheet metal parts + part of the interior parts. In order to improve the production line's capacity and efficiency, the customer wants our company to provide the cab large assembly in the cab on the basis of the small assembly to increase the electrical and other control components of the assembly, and requires that the product quality is not lower than the level of the original production line of the quality of the feedback rate is not higher than 3.5%. After several months of tracking found that only the electrical part of the average feedback rate reached 7.53%, accounting for 85% of the total feedback rate. Due to the cab electrical component failure caused by the return to repair, not only damage the rights and interests of customers, our company also paid a lot of after-sales repair service costs and quality claim costs, and seriously affect the company's brand image, so the quality of the loader cab electrical part of the urgent need to improve. After searching and analyzing, the main reasons for the above situation are: (1) there is no testing equipment for electrical components, the quality of electrical components can not be guaranteed; (2) there is no testing equipment for the cab assembly, which can not guarantee the quality of finished products. According to the statistics, more than 95% of the electrical problems are caused by the lack of testing equipment for the cab assembly, rather than the quality of the electrical components themselves, so this paper focuses on how to solve the second aspect of the problem. The three models of 50CN/855N/855, which have the largest output in our company, are taken as the research object, and the tools and methods of electronic testing technology are used to analyze and improve the electrical components and cab assembly to solve the problems.

2 Cab and its electrical system principle analysis

According to the customer's requirements for the quality of electrical components, through the analysis of three models such as 50CN/855N/855, it was found that *** there are 73 types of typical cab large assemblies, which involve 21 types of electrical systems, 10 types of cab main harnesses, which correspond to 10 types of electrical schematic diagrams respectively. In order to obtain the characteristics of the system need to detect electrical appliances, this paper respectively on the 10 kinds of cab main wiring harness and its corresponding electrical schematic diagrams for comparative analysis, through the analysis, the definition of the cab main wiring harness plug used there are the following major problems: different cab main wiring harnesses used by the different models of plugs, for example: the cab main wiring harness A uses sixteen-wire plugs, while the cab main wiring harness B uses Forty-eight core plug; the same plug the same number of interfaces, in different cab main harness in the definition of different types of signals, for example: the same is the use of forty-eight core plug, cab main harness C of the 29th interface is defined as a preheating indication signal, while the cab main harness D of the 29th interface is defined as a brake air pressure alarm signal. The application of electronic detection technology in the quality control of construction machinery cab Hou Yuhan (Guangxi Weixiang Machinery Co., Ltd., Liuzhou, Guangxi 545007) Abstract: The cab large assembly as the main parts of the loader, in which the quality of the electrical components feedback rate has been high. On the basis of analyzing the working principle of each electrical component, the inspected electrical components are classified, and according to the different working principles of each type of electrical components, the corresponding detection scheme is proposed and the electric inspection platform is made. The tracking results show that the electric inspection platform meets the requirements of the production line's beat, and the improvement effect is good. Keywords: electronic inspection technology; cab; quality The above two problems will lead to the following aspects: (1) Increase the design and labor costs. Each model defines a large number of but less different cab main wiring harnesses, which is not conducive to the reasonable scheduling and allocation of production line human resources; (2) Increase the difficulty of installation for assemblers. Due to the inconsistency of the wiring harness definition of each model, resulting in assembly personnel need to master the complex wiring harness installation information, prone to assembly errors; (3) Increase the complexity of manufacturing and maintenance difficulties. Different plug interfaces of different models increase the complexity of manufacturing; (4) increase the cost of cab large assembly electrical testing. Cab electrical testing equipment must be based on different main harnesses and plugs for personalized design and configuration, increasing the cost of testing, not conducive to standardization and uniformity of testing. In view of the problems of the main cab harness, the following improvement proposals: First, the main cab harness of different *** with the definition of the same plug interface with a unified model of the plug; Second, the main cab harness of different *** with the definition of the same electrical plug interface with a unified interface number; Third, the different models of the special electrical components, the use of reserved plug interface to achieve the way.

3 cab electrical testing needs analysis

The production line is just to complete the assembly of the cab components, including a variety of sheet metal parts, interior parts, seats, electrical appliances, switches, and wiring between the electrical appliances, etc., cab assembly as a host plant supporting products, in the host plant assembly before entering the cab assembly of the electrical appliances have not been made before the signal, such as instrument panels, barometer, etc.. According to the classification of electrical components inside the cab assembly, through the communication and exchange with the relevant departments and technicians, the electrical inspection platform should be able to achieve the following functions: provide a working DC power supply for the cab with a voltage of (24?2)V; have a short-circuit self-protection function; and be able to determine whether the cab electrical components and their electrical circuits are working properly. Through this electric inspection platform, the work lights, wiring harness, switches, meters and other electrical components are tested to determine the quality of the electrical components and their assembly in the cab. The overall requirements of the system performance indicators are as follows: (1) Safety. Prevent damage to the system and electrical appliances caused by wiring harness or electrical components short-circuit or disconnection and other faults; (2) mobility. Taking into account the off-line rework and the inconsistency of beats caused by special models, the electrical inspection platform should be easy to move, and can be realized in different locations for inspection; (3) Interchangeability. In addition to being able to realize the detection of existing typical models, should also have scalability, once a new model appears, can be easily applied to the detection of new models.

4 cab electrical testing program design

Due to the cab large assembly of the inspected electrical components within the specificity of the different categories of the inspected electrical components should be designed for the relevant testing program. (1) The first category of electrical components testing program design shown in Figure 1, the category of testing electrical components have been connected with the control switch, wiring harness. Since it has formed an electrical circuit, it can be powered by the electrical inspection platform for the cab, and the inspector closes/opens the control switch to form a closed circuit, and manually determines whether the working condition of this type of electrical components is normal through observation. (2) The second type of electrical components testing program design shown in Figure 2, the working parts of this type of electrical appliances in the front and rear frames, did not form an electrical circuit with the driver's cab, so it is necessary to design a display module in the electrical inspection platform to simulate this type of electrical components, and then through the electrical inspection platform for the driver's cab power supply, the inspector closes/opens the corresponding control switches, so that the formation of a closed circuit, through observation of the work of the display module The inspector then closes/opens the corresponding control switch to form a closed circuit, and by observing the working condition of the display module, determines whether the working condition of the electrical components is normal. (3) The third type of electrical components testing program design, this type of testing electrical components in the cab, not with the front and rear frames to form an electrical circuit, mainly by a variety of sensors, such as temperature sensors, pressure sensors and so on. Therefore, in the electrical inspection platform corresponding to the electrical circuit connected in series with a certain resistance value of the resistance to simulate the signal generated by this type of electrical components. After the signal is generated and the corresponding input is provided to the driver's cab, the display of the electrical components in the driver's cab is observed manually to determine whether the electrical circuit is working properly. (4) Cab electrical testing equipment overall program design due to the large number of models involved, the use of the cab main harness up to 10 kinds, in the various types of electrical components based on the design of the inspection program, should focus on the overall design of the program, so that the equipment can be well used in all models. In order to realize this function, the electrical inspection platform adopts a segmented and modular design method, i.e., the 24V DC power supply and display module as a whole, connecting the main cab harnesses of different models through the transition harness. In the transition harness, the main cab harnesses of different models are connected with plug-in interfaces according to their actual conditions. As the electric inspection platform needs to be in the production line for a long time, the working environment is relatively harsh, must meet the requirements of reliable operation for a long time in a complex working environment, so the main body of the equipment is made of 1.5mm thick 304 stainless steel. According to the actual demand, the system needs to have a short-circuit protection function, the need to increase the leakage protector in the main circuit; in order to make the equipment easy to move, the bottom of the equipment to install the universal wheel, taking into account the use of the equipment should be able to fix, so it should be used with a locking function of the universal wheel

5 cab electrical testing equipment testing process design

The electric inspection platform is the object of testing The inspection object of this electric inspection platform is 73 kinds of cab large assemblies corresponding to 10 kinds of cab main harnesses. In this paper, through the actual study of 10 kinds of cab main harness, the 73 kinds of cab large assembly inspected electrical components of the control rules to do the following to facilitate the actual operation of the inspectors, . Due to more inspected electrical components, in order to improve the efficiency of the inspectors and prevent leakage during operation, based on communication with the inspectors, the following design is made for the inspection process: (1) Turn on the electric inspection platform and the cab large assembly to be inspected, and turn on the power main switch; (2) Insert the key in the electric locking socket and dial to the ?ON? gear, turn on the power of the whole machine, and observe whether the whole machine is energized or not; (3) Toggle the rocker switches on the control panel in turn and observe whether the corresponding electrical components work normally; (4) Observe whether the air pressure gauge and timer on the control panel are displayed, and whether the cigarette lighter pops up after pressing the cigarette lighter for 5-8s; (5) Turn on/off the switches of the fan, wall lamps, receivers and air-conditioning system, and observe whether the corresponding electrical components work normally; (6) Toggle the left and right turn signal switches, horn switch, high and low beam cocking switch, and observe whether the corresponding display area of the instrument and display console has a display; (7) Observe whether the indicator light of each sensor and pressure switch in the corresponding position of the instrument is normal; (8) Record the problems found in the inspection process, turn off the electric lock, unplug the connecting wires, and repeat the above steps to carry out the next inspection.

6 Conclusion

According to the program design and manufacture of the electrical inspection platform has been put into practical application, through nearly half a year according to the validation of the process to improve the effect of good product quality has been significantly improved, and effectively solve the problem of high customer feedback rate of the cab large assembly electrical aspects of the cab large assembly electrical problems to reduce the average rate of feedback to 3.2%, the cab large assembly feedback rate of the problem of high feedback rate has been reduced to 3.2%. The problem of high feedback rate of cab large assembly has been obviously changed, saving more than 100,000 yuan for the company every year in the cost of repair and quality claims. This design idea has been extended to the 30E/40B and the upcoming mass production of H series models.

References:

[1] Tan Hao. Fabrication of wiring harness tester for heavy-duty vehicle cab [J]. Auto Electric, 2006,(8):40-44.

[2]Sun Shangyuan, Ge Yunfeng. Research on automotive wiring harness inspection system[J]. Test Technology and Testing Machine, 2007, 11(4):51-55.

Abstract: With the continuous development of the economy, the domestic highway engineering construction development speed is also gradually accelerated. Accompanied by China's urbanization process speed gradually accelerated, improve the economic management of highway engineering machinery and equipment, perfect and improve the highway engineering on mechanical equipment management and use is very necessary. But the current highway engineering machinery and equipment economic management and the use of the problem still exists more or less, therefore, constantly improve the management of highway engineering machinery and equipment, in order to effectively protect the level of mechanical construction technology. The article on the development trend of highway engineering machinery and equipment management analysis, in-depth discussion of economic management and the use of highway construction in the process of the problem, and put forward the corresponding measures to solve, in order to promote the management and use of machinery and equipment.

Keywords: highway engineering; machinery and equipment; economic management; use

1 Overview

With the continuous improvement of mechanized construction technology and level, engineering machinery and equipment has become a key part of the design of the current construction project, the construction progress of the project, the construction plan and the construction of the method of construction has a great impact. Project only select the more advanced, economic and reliable machinery and equipment, and configure the corresponding machinery and equipment, and then optimize the project construction program, you can give full play to mechanical equipment in the engineering construction efficiency, to ensure the smooth progress of the construction process, as far as possible to shorten the duration of the project construction. Mechanical equipment as a whole construction link of the important construction tools for the entire highway project, scientific and effective management and the use of engineering machinery and equipment is very important.

2 highway engineering machinery and equipment management development trend

At present, highway engineering machinery and equipment management gradually towards the direction of informationization. With the continuous development of science and technology, information technology management gradually infiltrated into various industries, enterprises in the information technology management on the basis of the full use of computer technology for its management, so that the management of the equipment has become more scientific and rationalization, give full play to the value of machinery and equipment in the construction process, and then enhance its use efficiency.

3 highway engineering machinery and equipment management problems

Construction units in the process of carrying out highway engineering construction, the use of machinery and equipment is very low, resulting in a serious waste of resources, affecting the construction quality of the entire construction project and the construction progress, while also increasing the construction cost of the project. The main reason is that the construction unit lacks a sound and perfect construction system, the lack of reasonable, standardized construction machinery organization, which affects the construction quality, cost and progress of the entire project, the guide mechanized equipment in the construction period of the project has not been effectively applied. The current highway engineering machinery and equipment management problems are mainly manifested in the following aspects.

3.1 Lack of sound mechanical equipment management organization

In recent years, some construction units still lack a more reasonable and effective mechanical equipment management system, and the responsibility of the managers is not clear, the construction of the equipment ledger, archives and information management is also a lack of corresponding work, a small part of the construction unit in the purchase of new equipment, failed to account for the work in a timely manner, resulting in the management of passive, random use of mechanical equipment, and the management of the equipment is also a lack of corresponding work. Passive, machinery and equipment used at will, a serious risk of asset loss. However, some construction units will be newly purchased equipment account into the equipment that has been purchased, as a way to avoid taxes.

3.2 Low utilization rate of machinery and equipment

At present, many construction companies within the management department often form a kind of separate and self-contained management, it is difficult to implement unified management and deployment, resulting in a lot of mechanical equipment can not be in accordance with the needs of the construction of coordinated use, so it is difficult to put a lot of equipment into the highway project construction. Due to the highway project construction phase is strong, often in the project is busy when the lack of equipment, and in the non-construction period, there are a lot of equipment idle, resulting in a serious backlog of assets, reducing the project's return on investment.

3.3 No timely update of machinery and equipment

Part of the highway project construction unit has been the use of previous equipment to carry out construction, compared with the new equipment, its construction speed is relatively slow and the quality of construction is very poor, which affects the entire highway construction section of the service life. Therefore, the construction unit of the highway project should establish a more perfect equipment management system, and set up the relevant regulatory departments to ensure that the management of highway engineering equipment can be effectively carried out. In addition, the construction unit should also timely update machinery and equipment, eliminating obsolete machinery and equipment, and then ensure that the construction personnel to use skillful operation of technical equipment for related operations, thereby enhancing the construction progress and quality of the construction unit.

3.4 Low quality of mechanical equipment operators

In the past, many construction units did not pay enough attention to the management of equipment, resulting in a lot of lack of ability of the construction staff to operate the equipment. Construction units only focus on the immediate benefits, while ignoring the long-term interests, but also a lack of education and training of equipment operators, some operators will often carry out a multi-machine operation, one side of the operation of the roller, one side of the operation of the loader and paver, and a small part of the operator's sense of responsibility is weaker, not in strict accordance with the relevant provisions of the operation, no timely maintenance of the equipment, resulting in a lot of damage to the equipment, maintenance costs are also gradually increased. The cost of maintenance also increases gradually. In addition, due to the lack of relevant responsibility system of many construction units, resulting in the construction of the project staff only focus on short-term interests, the lack of long-term plan, the management and use of machinery and equipment is very uncoordinated, the construction enterprises often pay attention to the use of the neglect of the management of the equipment, in order to meet the requirements of the construction period, most of the equipment in the construction period, often in the overloaded operation state, resulting in the mechanical equipment wear and tear aging, not only in the construction of the paver, but also in the construction of the paver. Mechanical equipment wear and tear aging, not only affect the construction quality of highway engineering, but also increase the maintenance costs of equipment.

4 highway engineering machinery and equipment economic management and use of measures

For the current highway engineering machinery and equipment economic management and the use of the process of the problem, the construction company wants to enhance the adaptive efficiency of the equipment, should use scientific measures to rationally configure and optimize the machinery and equipment. Therefore, the construction unit to promote the economic management and use of equipment efficiency, should be implemented from the following aspects of management.

4.1 Transformation of the management concept of mechanical equipment

Under the environment of fierce competition in the market, highway construction units want to improve the efficiency of the use of equipment, should gradually change the previous management concept. At the same time, the construction unit should also be from the use of equipment generated by the economic efficiency and optimize the performance of the equipment to consider the optimization of the assets of the construction unit. With the continuous development of modern information technology, a lot of equipment has been difficult to adapt to the needs of engineering and construction, especially the needs of the road construction site, which requires road construction unit managers must adjust the management concept of machinery and equipment in a timely manner, update and optimize the assets of machinery and equipment, only in this way can enhance the use of machinery and equipment.

4.2 Regular overhaul of mechanical equipment

Highway engineering construction personnel should develop a corresponding maintenance plan, regular inspection and maintenance of mechanical equipment. At this stage, the highway project management personnel on the equipment inspection and maintenance work, mostly based on the construction personnel repair experience to judge, and rely on the past construction experience to update and overhaul equipment parts, although this overhaul is relatively simple, but in fact, this repair method is difficult to equipment within the faults of the entire investigation, but also due to the overhaul personnel may be error in judgment, the use of the equipment to bring the appropriate The main reason for this is that it is not a good idea to use the equipment for the purpose of repairing the equipment.

4.3 Enhance the utilization of machinery and equipment

Construction units want to strengthen the management of equipment, first of all, should improve the basic quality of management personnel, modern management methods and professional equipment management capabilities, and constantly enhance the professional ability of management personnel training and skills training, supplementing the new knowledge and methodology, only in this way can adapt to the development of information technology needs. For some construction technology requirements are relatively high and important machinery and equipment, construction companies should also be unified management and distribution, and specialized operation and management. For some construction technology requirements are low, the use of more frequent mechanical equipment, construction units can be handed over to the relevant departments for management, by the unit to achieve unified management. In order to ensure that the construction equipment can be put into use in a timely manner, to further enhance the integrity of mechanical equipment and utilization.

4.4 Strengthen the professional training of mechanical equipment operators

Mechanical equipment operators are the main body of the operating equipment, equipment integrity rate plays a key role. And people's ideology in many cases can guide people's behavior, therefore, want to improve the integrity of machinery and equipment, it is necessary to continue to improve the operators of the basic quality of thought, in accordance with the rules and regulations to carry out the relevant operations, and at the same time to enhance the professional knowledge of the equipment operators and operating skills, and the introduction of a number of new construction techniques and methods, in order to adapt to the needs of the development of modern machinery and equipment. Highway construction unit for some of the lower cultural quality of the operators, must strengthen the training of employees, in the operators to obtain the relevant mechanical equipment operating license before they can go on duty. Only in this way can further enhance the mechanical equipment integrity rate and utilization rate, so as to ensure that mechanical equipment in the current highway engineering construction process, can be very effective application. And equipment operators have a good quality of thought and more understanding of mechanical equipment knowledge, to enhance the integrity of the equipment and utilization is a very effective guarantee.

5 Conclusion

In short, with the development of highway business, highway engineering machinery and equipment management and use there are certain problems, some advanced equipment and construction companies gradually influx of foreign countries and participate in the domestic market competition. At the same time, a lot of advanced mechanical equipment management knowledge and management concepts to promote the reform and sound management mechanism has a great impact, and also presents a great challenge. Therefore, the relevant highway project construction management personnel should be from the economic and efficiency of mechanical equipment and other aspects of the implementation of the management, as far as possible to improve and perfect the structure of highway engineering machinery and equipment, to enhance the level of equipment and use of highway engineering road maintenance efficiency, as far as possible to do a good job from the project's asset management aspects of the management of road maintenance machinery and equipment in order to manage the management of mechanical equipment for highway engineering and the use of bringing greater economic benefits.

References:

[1]Jiang Yan. The application and management of mechanical equipment in China's highway engineering construction[J]. Value engineering,2014,(9).

[2]Yue Xinguang. Analysis of the use and management of mechanical equipment in China's highway engineering[J]. Heilongjiang science and technology information, 2013,(6).

[3]Fengkai. Measures to improve the management and maintenance of transportation engineering machinery[J]. Transportation construction and management,2015,(4).