2010 International Conference on E-Health Networking, Digital Ecosystems and Technologies

Reform and practice on the course design of

design of machinery

LV Baozhan

School of Mechanical and Power Engineering Henan Polytechnic University

Jiaozuo, China e-mail: baozhan@hpu.edu.cn

Abstract-The present situation of the course design in design of machinery and the characteristics of personnel training and the reformational necessity were analyzed. Based on summarizing valuable experience of previous course design and reference successful measures of other universities, the standardized practice of topics, contents and scoring system of course design were put forward, aimed to enhance student innovation ability and practice ability. At the same time, the reform and practice of the course design of design of machinery were carried out. The result showed that the reform and practice can greatly enhance student's practice ability, innovation ability, and so on.

Keywords- design of machinery; course design; reform; practice; standardization

I. INTRODUCTION

The course of design of the machinery is one of the mainly technological basic courses to mechanical engineering students. It can enhance the adaptability of mechanical technology and cultivate innovation ability and practice ability to college students.

The course design of design of machinery is the last and important step during the teaching link of this course and it is the first training of mechanical engineering students to educate the ability of overall design. Through studying the course design of design of machinery, students can be cultivated the design idea of combining theory with practice, can be trained the ability of analyzing and solving practical problems by using the theories of design of machinery and rest related elective courses, can be consolidated and expanded knowledge of mechanical design.

With the expand of the enrollment scale and the conversion of the enrollment policy after 2002, higher education in China historically entered the stage of internationally-recognized popularization, which marks that the transformation from elite education to mass education will become an important theme of higher education in the future[l]. Adapt to this transformation, teaching works in university should be adjusted, especially in application­oriented institutes. These works include that changing the teaching concept and teaching method, combining the

978-1-4244-5517-1110/$26.00 ©2010 IEEE

133

TUDeyu

School of Mechanical Engineering Anhui University of Technology

Maanshan, China e-mail: tudeyu2005@126.com

inquiry teaching method with traditional teaching method and optimizing the teaching process, and so on.

Aimed at the present situation of the course design in design of machinery and the characteristics of personnel training in application-oriented institutes, the reform of course design and the research of teaching model adapting to training target have important significance. During the whole process of reform, the links of course design including topics arrangements and contents requirements and scoring system should be investigated, to avoid the appearance of great difference to student's score because of the difference of teachers.

II. TARGETS OF COURSE DESIGN OF DESIGN OF

MACHINERY

Targets of course design of design of machinery include the following aspects: [2]

• Enhance students' basic skills and application abilities to comprehensive knowledge, by designing of the whole mechanical system.

• Understand and mater the basic method and general procedure of mechanical design, and to gradually cultivate students' comprehensive design ability and structural design ability, by designing of common mechanical transmissions.

• Train basic working ability of mechanical design, these abilities include analyse, calculation, drawing, using design data( design handbook, design atlas, relative standards and specifications, etc), and so on.

• Enhance students' ability of computer aided drawing, to build the scholastic room and foster the interest scientific students, etc.

III. THE PRESENT SITUATION OF THE COURSE DESIGN IN

DESIGN OF MAC HINER Y

Now, Design period is usually three weeks at the end of term, general mechanical transmissions were used as design object during course design of mechanical design in most university. Design task is gear reducer in special transmissions, such as two-stage column gear reducer of

EDT2010

extensive form, taper- column gear reducer, worm gear transmission reducer, and so on. Design content include type selection design of motor, design of reducer, type selection design of coupling, and so on. Workload of design includes one installation diagram of transmission, one assembly drawing of reducer, each working drawing of one gear and shaft and one calculation description of design.

Through the course design, most students have great harvest, and think that the course design of mechanical design is a better opportunity not be replaced by classroom teaching to train themselves. From process and effect of teaching, there are some problem should be paid great attention and correctly handling.

• Students have insufficient understanding on essentiality of course design.

• Students lack practical knowledge of engineering. • Students have poor comprehensive application

ability to use previous-studied subjects. • We must deal with the relationship of inheritance

and innovation. • We also should have proper attitude towards

theoretical calculation and structural design.

IV. TARGETS AND THOUGHT TO REFORM OF COURSE

DESIGN

The general reform thought is taking creative design as the core, taking CAD/CAM as the main design line. At the same time to pay attention to practice and strengthen foundation.

Under the guiding of general reform thought, the course design must be gotten to three targets at the following:

• Cultivate comprehensively students' ability of basic design and creative design.

• Renew knowledge and introduce the method of CAD/CAI, to make the course design adapt to science and technology development, to use CAD during the whole course design.

• Pay attention to training and practice, to strengthen students' ability of dealing with practical problem using previous-studied knowledge.

V. REFORM MEASURES OF COURSE DESIGN

A. Sselect subjects taking a foothold on school-running characteristics and based on actual situation of our school Our school is a general university mainly serviced to coal

system, and mostly mechanical specialties take mining machinery as characteristics. During selecting topics of course design, Taking actual situation of our school into account and referring to successful experiences of other colleges, we have taken various measures under the following[4]:

134

• Design topics relating even more closely to coal industry, based on school-running characteristics

These topics mainly are common gearing of mining machinery design, such as mining chain conveyor, hanging conveyor, screw conveyor, conveyor belt of assembly shop in machine works.

• Introduce novel design topics, referring to successful experiences of other colleges

These topics mainly are new type of gearing design, such as continuously variable mechanical transmission, stepping mechanism of type of geared linkage mechanism, and so on. These topics are near to step down variable transmission, from the design workload request to types of parts and force analysis, can meet demand to basic request of students.

• Establish direct links with graduation design We select some appropriate gearing as design subjects

from graduate design recently years, such as belt conveyor of coal preparation plant, mining large-angle belt conveyor, and so on. Their gearings can be selected as the subj ects of course design.

• Compact subjects of course design from teacher's scientific research projects

Some subjects were proposed preliminarily, such as impulse mining machine of digging fossa for single hydraulic prop, forming machine for com stalk, and so on. The gearings of these machines can be modified to be used as the subjects of course design.

• Combine with mechanical creative design competitions

National and provincial mechanical creative design competitions have great attraction to undergraduates, and every competition has one design motif. We designed several subjects combined with design motif of mechanical creative design competition as course design.

B. Trigger exerted subjective activity of students, and to stand out the ability training

active pianetmy sprocket

chain drive

--:--gear reducer L ..

Figure 1. Transmission arrangement of hanging conveyor

l

J

At the beginning of course design, teachers only need to make the necessary demonstration and explanation, list out references, and encourage students to inquire the related information independently, to train induction - arrangement abilities to deal with information and data. One kind of subject was completed by one group including 3 to 5 students, and each student has different original data. The transmission arrangement and original data of hanging conveyor were shown in figurel and table 1 respectively. The design scheme was put forward by this group based on discussing adequately, and this group of students was unity and cooperation and clear division of labour, during the whole course design.

TABLE! ORIGINAL DESIGN DATA OF HANGING CONVEYOR TRANSMISSION

tittle number 1 2 3

peripheral force of active planetary 3.5 6 9

sprocket (kN) velocity of active planetary sprocket

1.1 1.0 0.9 (m/s)

tooth number of active planetary 11 9 11

sprocket

pitch of active planetary sprocket ( 80 90 100

mm)

serial number of student

C. Strengthen hand drawing training and CAD ability synchronously

With the development of computer technology, especially the abroad application of the CAD software(such as AutoCAD, ProlE, Solidworks, and so on) in machinery industry, it is a basic skill to master skillfully CAD

technology, and this skill is very important to engineering college students. To train CAD application ability, 2 to 3 courses were open in most university, and students have the foundation of CAD after learning these courses. In the course design of design of machinery in our school, assembly drawing is required draw using CAD, to strengthen and improve students' CAD application ability, and at least one part drawing is required draw by hand, to strengthen and improve students' hand drawing ability.

D. Pay attention to reply, summing-up and estimate

Reply is a way of communication each other between students and teachers, is the effective means and method to check quality of students' course design, and is also a concentration answering to common problems exposed from course design. The questions mainly include design method, design step, principle of computation, design of structure, manufacturing technology, treatment and selection of data, expression of views, implementation and application of mechanical drawing national standard, selection and marking of dimensioning tolerance, selection of material and heat treatment norm, and so on.

Good summing-up can help students to master method and step of design, to take apart gain or loss and success or failure during designing, to find problems needing attention of design in the future.

The method of estimate decides the attitude and mode of students. Course design should mouse out a set of optimum approach of result's examination and evaluation, to play a effect of excitation and building competition circumstance. Marking standard of the course design in our university was drawn up, based on summarizing valuable experience of previous course design and reference successful measures of other universities[6], and it is shown in table 2.

TABLE II. MARKING STANDARD OF THE COURSE DESIGN

No. assessment project major assessment content mark distribution score remark

rollcall and abide by work and rest time 5

reasonable progress of course design 5

1 peacetime manifestations

independence during designing 5 (25)

attitude of design and study 5

spirit of cooperation and teamwork 5

correctness of structure design 30

nattiness of drawing 5 2 quality of drawing (40)

criterion drawing 5

embodiment of innovation consciousness 5

correctness of calculation 10

3 calculation description

integrality of calculation content 5 (20)

criterion of calculation description 5

correctness of reply 5

4 manifestations in replying

virtuosity of using handbook 5 CI5)

reasonable of summary 5

5 total score

135

E. Standardize design process and unite standard of course design

At present, the course design of design of machinery is opened in many specialties, and involved large number of students and teachers. Different teachers had different requests and different marked standard in different specialties in the past, which made the evaluation result to students' course design has great disparity. Based on summarizing valuable experience of previous course design and reference successful measures of other universities, we standardized design process and united standard of course design, the obvious effects and good reactions were made by using in course design recently years.

VI. CONCLUSIONS

The course design of design of machinery plays an important role and is an important link in training mechanical innovative talents of facing the 21 st century. To fully develop their subjective initiative and to emphasize think exercise in course design have important signification in many aspects, such as cultivating the whole design consciousness and innovative consciousness, exercising computer aided drawing ability, and so on. Teachers relating

to course design should constantly study the teaching method of course design, reform reply and estimate mode of course design, improve and enhance teaching effect of course design of design of machinery, and feasibly strengthen students' engineering design ability.

136

REFERENCES

[I] L.G. Pu, M.G. Ji and G.D. Chen et ai, Design of machinery (eighth edition).Beijing: Higher Education Press, 2006.

[2] Q.S. Jin, Course design of mechanical design. Wuhan: Huazhong University of Science and Technology Press, 2007.

[3] R. Tang, yc. Dang, "The exploration of teaching reform in the curricular design of machinery design," Journal of Panzhihua University,VoI.2 1, Dec. 2004, pp. 1I2- 1 13, 120.

[4] S.H. Peng, SZ. Zhou, J Feng, "The Exploration of Teaching Reform in the Curricular Design of Machinery Design," Journal of Changchun University of Science and Technology(Higher Education Edition), VoI.3, Jun. 2008, pp.74-76.

[5] B.Y. Song, Guide book of course design of mechanical design. Beijing: Higher Education Press,2006.

[6] Z.Q. Yuan, S.D. Ni, x.D. Qi, "Study on the Standards System of course design of mechanical design and machine design foundation," China Science and Technology Information, Jui. 2007, pp.247-248.