Teaching reform and practice of mechanical design basic course under the background of large-scale engineering

Teaching reform and practice of mechanical design basic course under the background of large-scale engineering

Fundamentals of mechanical design is an important technical basic course offered by mechanical engineering majors. This course mainly studies the working principle, structural characteristics, basic design theory and calculation method of common mechanisms and parts in machinery. It not only requires students to master solid basic theoretical knowledge, but also requires students to have certain engineering consciousness and engineering practice ability. In recent years, we have reformed and practiced the teaching content, teaching methods, teaching means, practical links and assessment methods of the basic course of mechanical design with the goal of cultivating students' innovative design ability under the background of large-scale engineering and taking mechanical transmission scheme design as the main line.

First, the problems existing in the teaching of basic courses of mechanical design

1。 Lack of engineering awareness, lack of understanding of institutions and parts. The study experience of most students in China University is continuous, and they all enter the university directly from high school. They have no practical work experience, and generally do not arrange visits and internships in this course. Their understanding of machinery is limited to the scope of contact in life, and they are also accustomed to rational thinking and lack of engineering concepts. Theoretical knowledge cannot be combined with engineering practice, and teaching content is out of touch with practice.

2。 The teaching content should also be adjusted accordingly. "Fundamentals of Mechanical Design" is a traditional course with classic content, but in recent decades, mechanism and mechanical design methods have made great progress, especially the application of computers in mechanism synthesis and analysis is more common. In this part of mechanism design method, we mainly use graphical method, and analytical method is usually used as self-study content. At the same time, the teaching content should consider the needs of teaching and the actual situation of learners, and change the previous situation of too much theoretical analysis and less practical application.

3。 Teaching methods and means need further reform. Because there are many teaching contents and limited class hours, teachers usually use the method of "full hall irrigation" to teach learning content. On the one hand, students lack perceptual knowledge and it is difficult to understand what they have learned; On the other hand, because teachers are active and students are passive, it is not conducive to mobilizing students' enthusiasm and cultivating students' ability to think and solve problems independently. Although traditional teaching methods and modern teaching methods have received equal attention, these methods are not enough to make students really understand the real engineering practice and have a strong perceptual knowledge, and there are still some shortcomings in cultivating students' engineering consciousness.

4。 At present, the practical link of this course is 4 hours of experiments and 2 weeks of course design, with few practical hours and limited experiments. Generally, they are verification experiments and demonstration experiments, which are not conducive to the improvement of students' ability. Therefore, we should increase the practice class, let students contact more models and objects, combine theory with practice, and set up comprehensive and designed experiments to cultivate students' innovative consciousness and ability. Because the two-week curriculum design is classic and single, students generally lack perceptual knowledge, and there is a widespread phenomenon of copying the curriculum design, which can not meet the basic requirements of teaching.

5。 The single assessment method can not highlight the ability to cultivate students' academic performance. The final exam results are fixed for life, which is the current performance evaluation system. However, it can't fully reflect students' learning attitude and actual level. Some students don't study at ordinary times, but they can still pass the exam by surprise before the exam. Therefore, this performance evaluation system is not conducive to stimulating students' enthusiasm for learning, nor to understanding and mastering knowledge.

Second, thinking about the teaching reform of the basic course of mechanical design

1。 Strengthen engineering education, introduce engineering examples into classroom teaching, strengthen the connection between classroom teaching and engineering practice, stipulate in the new syllabus that each chapter should introduce typical engineering examples related to the course, and increase the content of mechanical innovative design methods. In teaching, we should focus on the background of large-scale projects and engineering, pay attention to cultivating students' engineering consciousness, engineering quality and engineering practice ability, and integrate engineering education with natural science education. We should pay attention to introducing the ideas and methods of solving practical engineering problems by using engineering basic theory, and strengthen the cultivation of students' engineering quality.

2。 The adjustment idea of selecting and updating teaching content is to emphasize basic knowledge, basic principles and methods, pay attention to practical application, introduce the latest achievements reflecting the development of mechanical design according to actual needs, introduce new institutions and modern mechanical design methods related to life and production, and strive to reflect the frontier of development, broaden knowledge, increase classroom information, and mobilize students' learning enthusiasm, thus improving teaching effect. In addition, all aspects of traditional mechanical design are completely completed by manpower, which greatly affects the efficiency of study and work, and it is difficult to reflect the development and update of science, technology and means. Therefore, the application scope of CAD technology in teaching is gradually expanding. First realize the CAD of drawings, and then gradually realize the CAD of design process. Through this content reform, students' enthusiasm and initiative have been obviously strengthened, which not only cultivates their computer application ability, but also cultivates their ability to solve practical engineering problems by using computers.

3。 Teaching method reform In order to cultivate students' innovative design and engineering practice ability, we adopted the teaching method of "intensive teaching and more practice, combination of coaching, autonomous learning and combination of in-class and out-of-class". The specific content is:

(1) The teaching content is small but fine. According to the practical characteristics of this course, basic concepts, basic theories and basic methods are emphasized in theoretical teaching to make knowledge easy to understand, master and remember. At the same time, leave some room for students to think and avoid spoon-feeding and spoon-feeding teaching methods.

(2) Arrange the practice time appropriately. In each course, we should set aside some time to arrange corresponding exercises to consolidate and deepen the learning content. At the same time, we should arrange some phased comprehensive exercises to improve the comprehensive degree of exercises, analyze and summarize the comprehensive application of various theories and methods, and improve students' ability to solve practical problems in production by comprehensively applying what they have learned.

(3) To train and cultivate students' autonomous learning ability, it is important to teach students to learn independently, master the thinking and methods of scientific learning, always put heuristic teaching methods in the first place, and encourage students to think positively and put forward new ideas. Teachers should pay attention to put forward new questions and new ideas at the junction of old and new knowledge, stimulate students to think positively, make students make correct answers and judgments, and thus improve their autonomous learning ability.

(4) Combining in-class and out-of-class to stimulate interest in learning. Fundamentals of Mechanical Design is a course closely related to engineering practice, and special attention should be paid to integrating theory with practice in the teaching process. When explaining the practical content, organize students to go to laboratories and training bases for on-site teaching. Before on-site teaching, arrange some thinking questions for students to visit and discuss with questions, organically combine classroom theoretical knowledge with practical knowledge, and make students realize the application of various institutions in machines and the importance of this course in production.

4。 The reform of teaching methods The knowledge points of the basic course of mechanical design have a certain engineering background, that is, many problems come from engineering practice, but it is difficult for students who lack practical perceptual knowledge to explain clearly. By using multimedia technology, the combination of words, pictures, images, sounds, animations, video images and other electronic media will achieve good teaching results and visualize the parts that are difficult to express clearly by traditional teaching methods. At the same time, the use of multimedia teaching can not only deepen students' engineering awareness and cultivate their ability to analyze and solve practical engineering problems, but also make full use of effective classroom time, increase the amount of classroom information and expand the depth and breadth of teaching content. In order to further deepen students' perceptual knowledge and really get in touch with engineering practice, in teaching, the on-site teaching method is widely used, and the content closely combined with the site is arranged to organize teaching on the spot, so that students can not only listen and see, but also feel for themselves, which can play a multiplier role.

5。 Strengthening practical links and cultivating practical ability are important teaching links to stimulate students' interest in learning, deepen their understanding of knowledge and improve their practical ability. In view of the strong engineering application of this course and the weak practical links at present, we should strengthen the practical links from the following aspects.

(1) Strengthen laboratory construction, increase comprehensive and designed experiments, and supplement some new mechanisms, typical machine models and objects on the basis of the original mechanical design basic showroom. Contact the factory and collect all kinds of typical fault parts, so that students can have a perceptual understanding of the state of all kinds of fault parts. Reform the experimental teaching content with confirmatory experiment as the main content, increase comprehensive and designed experiments, and offer comprehensive and designed experiments on shafting structure scheme and mechanism motion scheme. Students can design, assemble, evaluate or measure shafting structure scheme and mechanical transmission system scheme by themselves, so as to cultivate students' engineering practice ability, hands-on ability and innovation ability.

(2) enrich the practice content, do a good job in curriculum design, and arrange a visit to the production site for a certain period of time. Before explaining various mechanisms, let students contact with mechanical objects, and take typical mechanical objects as an example to explain the transmission principle and scheme design of mechanisms.

Course design is a teaching method that integrates the theoretical knowledge and basic skills learned in this course and the pre-courses to independently complete the task of mechanical transmission or simple mechanical design. First of all, the topic selection should consider the students' training objectives, be targeted and focused. Before the design, students should be organized to disassemble, install and participate in the field, so that students can be familiar with the basic structure, overall structure, structure, function, assembly, disassembly and adjustment of mechanical devices; The connection relationship and characteristics between the parts. Then find out the standard parts and non-standard parts, make clear the relationship between the layout form and the spatial position of the transmission device, establish the three-dimensional concept, avoid copying the design and avoid the phenomenon that the design is out of touch with the production practice.

6。 Reform of evaluation method

(1) Strengthen the peacetime assessment, which consists of two parts, accounting for 45% of the total score. Part of it is attendance, academic performance, questioning performance, homework performance and experimental performance, accounting for 30%; The other part is the achievement of writing scientific papers, accounting for 15%. In the introduction class, students' interest in this course is stimulated by playing some short films on machinery. At the same time, students are assigned an extracurricular assignment, that is, writing a paper on mechanical development, requiring students to consult a certain amount of information and write according to the format of scientific papers. This not only trains students' ability to use materials and write scientific papers, but also stimulates their enthusiasm.

(2) Strengthen the ability assessment. The final examination consists of two parts, accounting for 55% of the total score. The first part is written test, which focuses on basic theories and methods, pays attention to the assessment of ability and quality, and increases the proportion of analysis questions and explanation questions, accounting for 45%; The other part is the production results of innovative works. All students should take part in innovative activities, make small inventions and small productions, accounting for 10%. Through the reform, students pay more attention to every assessment link, thus improving their interest in learning and obviously improving the teaching quality.

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