Model essay on mechanical graduation design 1: Application of electronic detection in the cab of construction machinery Abstract: As the main part of loader, the quality feedback rate of electrical components has been very high. On the basis of analyzing the working principles of various electrical components, the tested electrical components are classified. According to the different working principles of various electrical components, the corresponding detection scheme is put forward and the electrical detection platform is made. The tracking results show that the electronic control detection platform meets the rhythm requirements of the production line and the improvement effect is good.
Keywords: electronic detection technology; Cab; quality
Electronic detection technology is a comprehensive detection technology, which mainly includes electronic measurement system and electronic information technology [1]. With the development of science and technology, the application of electronic detection technology in all walks of life is becoming more and more common [2]. Especially its application in automobile maintenance provides an important guarantee for improving the quality of automobile maintenance. At the beginning of its birth, electronic detection technology was widely used in automobile industry, but not in construction machinery industry.
1 current situation investigation
For a long time, the loader cab, as the core business of the company, only provides customers with small cab assemblies. Painted sheet metal parts+some interior parts. In order to improve the productivity and efficiency of the production line, customers want our company to provide them with cab assemblies? On the basis of small assembly in the cab, the assembly of control components such as electrical appliances should be increased, and the product quality should not be lower than that of the original production line? The quality feedback rate is not higher than 3.5%. After several months' follow-up, it is found that the average feedback rate of only the electrical part is 7.53%, accounting for 85% of the total feedback rate. The maintenance caused by the failure of cab electrical components not only damages the rights and interests of customers, but also pays a lot of after-sales maintenance service fees and quality claim fees, which seriously affects the brand image of the company. Therefore, the quality of electrical components in loader cab needs to be improved urgently. After searching and analyzing, the main reasons for the above situation are as follows: (1) There is no testing equipment for electrical components, so the quality of purchased electrical components cannot be guaranteed; (2) The cab assembly has no testing equipment, so the quality of finished products cannot be guaranteed. According to statistics, more than 95% of electrical problems are caused by the lack of testing equipment in the cab assembly, rather than the quality problems of electrical components themselves, so this paper focuses on how to solve the second problem. Taking 50CN/855N/855, the three models with the largest output in our company, as the research object, the electrical components and cab assembly are analyzed and improved by using the tools and methods of electronic detection technology to solve the problems.
Principle analysis of cab and its electrical system
According to the customer's requirements for the quality of electrical components, through the analysis of three models, such as 50CN/855N/855, it is found that there are 73 typical cab assemblies, involving 2 1 electrical system and 10 cab main harness, which correspond to 10 electrical schematic diagram respectively. In order to obtain the characteristics of electrical appliances to be tested in the system, the 10 cab main wiring harness and its corresponding electrical schematic diagram are compared and analyzed. Through analysis, the definition of connectors used in the cab main harness mainly has the following problems: different types of connectors are used in different cab main harnesses, such as 16 core connector for cab main harness A and 48 core connector for cab main harness B; The same interface of the same connector defines different signal types in different cab main harnesses. For example, using the same 48-core connector, the No.29 interface of the cab main harness C defines the warm-up work indication signal, while the No.29 interface of the cab main harness D defines the brake air pressure alarm signal. Application of electronic detection technology in quality control of construction machinery cab (Guangxi Machinery Co., Ltd., Liuzhou, Guangxi 545007) Abstract: As the main component of loader, the quality feedback rate has always been high. On the basis of analyzing the working principles of various electrical components, the tested electrical components are classified. According to the different working principles of various electrical components, the corresponding detection scheme is put forward and the electrical detection platform is made. The tracking results show that the electronic control detection platform meets the rhythm requirements of the production line and the improvement effect is good. Keywords: electronic detection technology; Cab; The above two quality problems will lead to the following problems: (1) Increase the design and labor costs. A large number of cab main harnesses are defined for each vehicle type, but the difference is small, which is not conducive to the reasonable scheduling and distribution of human resources in the production line; (2) It increases the installation difficulty of assemblers. Because of the different definitions of wire harnesses of different models, the assembler needs to master complicated information of wire harness installation, which is prone to assembly errors. (3) It increases the complexity of manufacturing and the difficulty of maintenance. Different connector interfaces of different models increase the complexity of production and manufacturing; (4) Increase the cost of electrical inspection of cab assembly. Cab electrical test equipment must be designed and configured separately according to different main harnesses and connectors, which increases the test cost and is not conducive to standardized and unified testing. In view of the problems existing in the main wiring harness of the driver's cab, the following improvement suggestions are put forward: first, define a unified model of connectors for the plug-in interfaces of different main wiring harnesses of the driver's cab; Second, define a unified connector interface number for * * * in the main wiring harness of different cabs; Thirdly, different types of special electrical components are realized by reserving connector interfaces.
3 cab electrical test requirements analysis
The production line only completes the assembly of various parts in the cab, including various sheet metal parts, interiors, seats, electrical appliances, switches and wiring between various electrical appliances. As the auxiliary products of the main engine plant, the electrical appliances of the cab assembly did not generate signals, such as instrument panel and barometer, before entering the main engine plant for final assembly. According to the classification of electrical components in the cab assembly, through communication and exchange with technicians of relevant departments, the electrical inspection platform made this time should be able to achieve the following functions: providing working DC power for the cab with a voltage of (24? 2)V； With short-circuit self-protection function; It can be judged whether the cab electrical components and their circuits work normally. Through this platform, the working lights, wiring harnesses, switches, meters and other electrical components are tested to judge the electrical components in the cab and their assembly quality. The overall requirements of the system are as follows: (1) security. Prevent the system and electrical appliances from being damaged due to short circuit or open circuit of wiring harness or electrical components; (2) liquidity. Considering the inconsistent beat caused by off-line maintenance and special models, the electric inspection platform should be easy to move and can be detected in different places; (3) interchangeability. In addition to the detection of existing typical models, it should also be extensible, and once a new model appears, it can be easily applied to the detection of new models.
4 cab electrical detection scheme design
Because of the particularity of the tested electrical components in the cab assembly, it is necessary to design corresponding test schemes for different types of tested electrical components. (1) The detection scheme design of the first type electrical components is shown in figure 1, and the control switch and wiring harness have been connected. Since the electrical circuit has been formed, the electrical inspection platform can supply power to the cab, and the inspection personnel can close/open the control switch to form a closed circuit, and judge whether the working conditions of such electrical components are normal through manual observation. (2) The inspection scheme design of the second type of electrical components is shown in Figure 2. The working parts of this electrical component are located on the front and rear frames, and there is no circuit between them and the cab. Therefore, it is necessary to design a display module in the electrical inspection platform to simulate this type of electrical components, and then supply power to the cab through the electrical inspection platform, so that the inspection personnel can turn on/off the corresponding control switches to form a closed circuit, and judge whether the working conditions of this type of electrical components are normal by observing the working conditions of the display module. (3) The detection scheme design of the third kind of electrical components, which are in the cab, do not form an electrical loop with the front and rear frames, and are mainly composed of various sensors, such as temperature sensors and pressure sensors. Therefore, a resistor with a certain resistance value is connected in series in the corresponding circuit of the electrical detection platform to simulate the signals generated by such electrical components. After the signal is generated and the corresponding input is provided to the cab, it is judged whether the electrical circuit works normally by manually observing the display of the electrical components in the cab. (4) There are many models involved in the overall design of the cab electrical testing equipment, and there are as many as 10 kinds of main wiring harnesses in the cab. On the basis of designing various testing schemes for electrical components, the overall design of the scheme is emphasized, so that the equipment can be well applied to all models. In order to realize this function, the electric inspection platform adopts a segmented modular design method, that is, the 24V DC power supply and the display module are taken as a whole, and different types of main cab harnesses are connected through transition harnesses. In the transition harness, the connector interface is connected according to the actual situation of the main harness of the cab of different models. Because the electrical inspection platform needs to be on the production line for a long time, and the working environment is relatively harsh, it must meet the requirements of long-term reliable operation in complex working environment. Therefore, the main body of the equipment is made of 304 stainless steel with a thickness of1.5 mm. According to the actual demand, the system needs to have short-circuit protection function, and a leakage protector needs to be installed on the main road. In order to make the equipment easy to move, a universal wheel is installed at the bottom of the equipment, and considering that the equipment should be fixed when in use, a universal wheel with locking function should be used.
Design of Inspection Process for Cab Electrical Inspection Equipment
The test objects of this platform are 73 cab assemblies corresponding to 10 cab main harness. Based on the actual research of 10 cab main harness, the control rules of 73 cab assembly test electrical components are described as follows, which is convenient for inspectors' actual operation. Because there are many electrical components to be detected, in order to improve the working efficiency of inspectors and prevent missed inspection during operation, the following design is made on the basis of communication with inspectors: (1) Connect the electrical detection platform with the cab to be detected. (2) Insert the key into the socket of the electric lock and turn it to? Open? File, turn on the power supply of the whole machine and observe whether the whole machine is electrified; (3) Turn the rocker switch on the control panel in turn to observe whether the corresponding electrical components work normally; (4) Observe whether the barometer and timer on the control panel display and whether the cigarette lighter pops up after being pressed for 5-8s; (5) Turn on/off the switches of the fan, wall lamp, radio and air conditioning system, and observe whether the corresponding electrical components work normally; (6) Toggle the left and right turn signal switch, horn switch and far and near light rocker switch, and observe whether there is display in the display area corresponding to the instrument and the display desk; (7) Observe whether the indicator lights of sensors and pressure switches at the corresponding positions of the instrument indicate normal; (8) Record the problems found in the detection process, close the electric lock, unplug the connecting wire, and repeat the above steps for the next detection.
6 concluding remarks
The electrical detection platform designed and manufactured according to this scheme has been put into practical application. After nearly half a year's verification, the process improvement effect is good, the product quality has been significantly improved, and the problem of high customer feedback rate of cab assembly electrical problems has been effectively solved. The average feedback rate of cab assembly electrical problems is reduced to 3.2%, which obviously improves the problem of high feedback rate of cab assembly, saving the company maintenance costs and quality claims 10 million yuan every year. This design idea has been extended to the 30E/40B and H series cars that will be mass-produced.
References:
[1] Tan Hao. Development of the cab harness detector for heavy-duty vehicles [J]. Automotive Electrical Appliances, 2006, (8): 40-44.
Sun Shangyuan, Ge Yunfeng. Research on automotive wiring harness Detection System [J]. Testing Technology and Tester, 2007,11(4): 51-55.
Mechanical graduation design Fan Wen II: Economic application of highway engineering machinery and equipment Abstract: With the continuous development of economy, the speed of domestic highway engineering construction and development is gradually accelerating. With the gradual acceleration of urbanization in China, it is very necessary to improve the economic management level of highway engineering machinery and equipment, and improve and improve the management and use level of highway engineering machinery and equipment. However, there are still more or less problems in the economic management and use of highway engineering machinery and equipment at present. Therefore, continuously improving the management level of highway engineering machinery and equipment can effectively ensure the technical level of mechanical construction. This paper analyzes the development trend of highway engineering machinery and equipment management, probes into the problems existing in economic management and use in highway construction, and puts forward corresponding solutions, so as to promote the management and use of machinery and equipment.
Keywords: highway engineering; Mechanical equipment; Economic management; use
1 overview
With the continuous improvement of mechanized construction technology and level, construction machinery and equipment have become the key part of current architectural engineering design, which has a great influence on construction progress, construction scheme and construction method. Only by selecting advanced, economical and reliable machinery and equipment, configuring corresponding machinery and equipment, and then optimizing the project construction scheme, can we give full play to the working efficiency of machinery and equipment, ensure the smooth progress of the construction process and shorten the construction period as much as possible. As an important construction tool in the whole construction process, it is very important for the whole highway project to manage and use construction machinery and equipment scientifically and effectively.
2 development trend of highway engineering machinery and equipment management
At present, the management of highway engineering machinery and equipment is gradually developing towards informationization. With the continuous development of science and technology, information management has gradually penetrated into various industries. On the basis of information management, enterprises make full use of computer technology to manage it, which makes the management of equipment more scientific and reasonable, gives full play to the value of mechanical equipment in the construction process, and then improves its use efficiency.
3 problems in the management of highway engineering machinery and equipment
In the process of highway engineering construction, the utilization rate of machinery and equipment is very low, which causes serious waste of resources, affects the construction quality and progress of the whole construction project, and also increases the construction cost of the project. The main reason is that the construction unit lacks a sound construction system and a reasonable and standardized construction machinery organization, which affects the construction quality, cost and progress of the whole project, and the mechanized equipment has not been effectively applied during the project construction. At present, the problems existing in the management of highway engineering machinery and equipment are mainly manifested in the following aspects.
3. 1 Lack of perfect mechanical equipment management mechanism.
In recent years, some construction units still lack a reasonable and effective management system for mechanical equipment, and the responsibilities of managers are unclear, and there is also a lack of corresponding management for the construction of equipment ledgers and files. A few construction units failed to register in time after purchasing new equipment, resulting in passive management and random use of mechanical equipment, which may lead to asset loss in serious cases. However, some construction units turn newly purchased equipment into outsourced equipment to avoid tax.
3.2 The utilization rate of mechanical equipment is low.
At present, the internal management departments of many construction enterprises often form their own management mode, which is difficult to implement unified management and deployment, resulting in a large number of mechanical equipment can not be used in coordination according to construction needs. Therefore, it is difficult to put a lot of equipment into highway engineering construction. Due to the strong stage of highway engineering construction, there is often a lack of equipment when the project is busy, and a large number of equipment is idle during the non-construction period, which leads to a serious backlog of assets and reduces the investment income of the project.
3.3 Failure to update mechanical equipment in time
The construction units of some highway projects have been using old equipment for construction. Compared with the new equipment, the construction speed is slow and the construction quality is poor, which affects the service life of the whole highway construction section. Therefore, highway engineering construction units should establish a relatively perfect equipment management system and set up relevant supervision departments to ensure the effective management of highway engineering equipment. In addition, the construction unit should update the mechanical equipment in time, eliminate outdated mechanical equipment, and ensure that the construction personnel use skilled operation technology and equipment to carry out related operations, thus improving the construction progress and quality of the construction unit.
3.4 The quality of mechanical equipment operators is low.
In the past, many construction units did not pay enough attention to equipment management, resulting in many incompetent construction personnel operating equipment. The construction unit only pays attention to the immediate interests, but ignores the long-term interests. At the same time, there is also a lack of education and training for equipment operators. Some operators often operate multiple machines by one person, while operating the roller, while operating the loader and paver. A few operators have a weak sense of responsibility, fail to operate in strict accordance with the relevant regulations, and fail to maintain the equipment in time, resulting in the damage of many equipment and the gradual increase of maintenance costs. In addition, due to the lack of relevant responsibility system in many construction units, the construction personnel of the project only pay attention to short-term interests and lack long-term plans, and the management and use of mechanical equipment are very uncoordinated. Construction enterprises often attach importance to the use of equipment and neglect the management of equipment. In order to meet the requirements of the construction period, most of the equipment often runs over load during the construction process, resulting in the wear and aging of mechanical equipment, which not only affects the construction quality of highway engineering, but also increases the maintenance cost of equipment.
4. Economic management and use measures of highway engineering machinery and equipment
In view of the problems existing in the economic management and use of highway engineering machinery and equipment, construction enterprises should adopt scientific methods to rationally allocate and optimize machinery and equipment in order to improve the adaptive efficiency of equipment. Therefore, in order to improve the economic management and use efficiency of equipment, the construction unit should implement management from the following aspects.
4. 1 change the management concept of mechanical equipment
In the fierce market competition, if highway construction units want to improve the efficiency of equipment use, they must gradually change their previous management concepts. At the same time, the construction unit should also consider the asset optimization of the construction unit from the aspects of economic benefits generated by using equipment and optimizing equipment performance. With the continuous development of modern information technology, a lot of equipment has been difficult to meet the needs of engineering construction, especially the needs of highway construction sites, which requires the managers of highway construction units to adjust the management concept of mechanical equipment in time, update and optimize the assets of mechanical equipment, and only in this way can the utilization rate of mechanical equipment be improved.
4.2 Regular maintenance of mechanical equipment
Highway engineering construction personnel should formulate corresponding maintenance plans and regularly check and maintain machinery and equipment. At present, highway engineering managers mostly judge the inspection and maintenance of equipment according to the maintenance experience of construction personnel, and rely on previous construction experience to update and maintain equipment parts. Although this maintenance method is relatively simple, it is difficult to find out all the faults in the equipment, and it may also bring corresponding hidden dangers to the use of the equipment due to the misjudgment of the maintenance personnel.
4.3 Improve the utilization rate of mechanical equipment
In order to strengthen equipment management, the construction unit should first improve the basic quality of managers, modern management science and professional equipment management ability, continuously strengthen professional ability training and skills training for managers, and supplement new knowledge and methods. Only in this way can it meet the needs of the development of information technology. For some machinery and equipment with high technical requirements and great importance, construction enterprises should also carry out unified management and distribution, and special personnel should operate and manage them. For some mechanical equipment with low technical requirements and frequent use, the construction unit can hand it over to the relevant departments for management, and the unit can realize unified management. Therefore, the construction equipment can be put into use in time, and the intact rate and utilization rate of mechanical equipment are further improved.
4.4 Strengthen the professional training of mechanical equipment operators.
The operator of mechanical equipment is the main body of operating equipment and plays a key role in the intact rate of equipment. And people's ideas can guide people's behavior in many cases. Therefore, in order to improve the intact rate of mechanical equipment, it is necessary to constantly improve the basic ideological quality of operators, carry out related operations according to rules and regulations, improve the professional knowledge and operating skills of equipment operators, and introduce more new construction technologies and methods to meet the development needs of modern mechanical equipment. Highway construction units must strengthen the training of some operators with low cultural quality, and operators must obtain relevant mechanical equipment operation certificates before taking up their posts. Only in this way can we further improve the intact rate and utilization rate of mechanical equipment and ensure the effective application of mechanical equipment in the current highway engineering construction process. Moreover, the equipment operators have good ideological quality and better understanding of mechanical equipment, which is a very effective guarantee for improving the intact rate and utilization rate of equipment.
5 conclusion
In a word, with the development of highway, there are some problems in the management and use of highway engineering machinery and equipment, and some advanced foreign equipment and construction enterprises are gradually pouring in to participate in the domestic market competition. At the same time, many advanced mechanical equipment management knowledge and management concepts have great influence on promoting the reform and perfection of its management mechanism, and also pose great challenges. Therefore, the relevant highway engineering construction managers should implement management from the aspects of economy and efficiency of machinery and equipment, strive to improve and perfect the structure of highway engineering machinery and equipment, enhance the level and efficiency of highway maintenance equipment, and do a good job in the management of highway maintenance machinery and equipment from the aspect of project asset management, so as to bring greater economic benefits to the management and use of highway engineering machinery and equipment.
References:
[1] Jiang Yan. Application and management of mechanical equipment in highway engineering construction in China [J]. Value Engineering, 20 14, (9).
[2] Yue. Analysis on the use and management of highway engineering machinery and equipment in China [J]. Heilongjiang Science and Technology Information, 20 13, (6).
[3] Feng Feng. Measures to improve the management and maintenance level of traffic engineering machinery [J]. Traffic Construction and Management, 20 15, (4).