After being stunned for a while, Yang Weining said: "The number of people who came to listen to the lecture today is a little unexpected, and the space may not be enough, everyone try to squeeze it, if there is really no place to sit, just sit on the ground." In addition, since there are many people, even if a few people speak, it may affect the order of the class, so I hope that everyone will be quiet at all times except when I ask for a discussion, and I will try to increase the volume as much as possible so that everyone can hear. ”

"In the first class, I told you about the origin, development, important applications, future directions and the development of various foreign CAD software, and discussed the importance and urgency of developing CAE, CAM, CAPP and other technologies on the basis of CAD. In the second lesson, we explained the basic knowledge of AutoCAD, including the AutoCAD running environment, AutoCAD installation, AutoCAD startup, AutoCAD user interface, etc. ”

And focus on explaining to you the application interface of AutoCAD, such as the title bar, located at the top of the work interface, the second line is the menu bar and the shortcut menu toolbar, the menu bar includes almost all the functions and commands of AutoCAD, the shortcut menu is also called the context tracking menu, you can use these menus to complete the drawing operation quickly and efficiently, and the shortcut menu can be displayed with a right click. The third line is the toolbar, which can enable users to easily access commonly used commands, setting modes, and intuitively realize various operations, it is a simple tool that can replace commands and drop-down menus, below the toolbar is the drawing area, the left side of the drawing area is the command area and the command window status bar, which is the window for users to have a conversation with AutoCAD, for beginners, special attention should be paid to this window. ”

"Then there is the status bar, which can indicate whether to enable orthographic mode, grid snapping, grid display and other functions when drawing, and the status bar is followed by tabs, which contain 3 selection items such as 'model', 'layout 1', 'layout 2', etc., and the last item is the tool palette, which can be customized by the user related tool panels. These are the basics of AutoCAD, which I have described in the lesson plans I have previously distributed. Some new comrades who have not attended the first two classes can borrow a lesson plan from a comrade who has listened to it. ”

Yang Weining turned on the DJS-130 computer, started the AutoCAD software, and projected the picture onto the white wall through the projector, so that everyone present had an intuitive understanding of the software.

He first reviewed the content of the first two lessons, and then reviewed the basic operation interface of AutoCAD, and then officially entered the content of the third lesson.

"Today, I'm going to officially teach you how to use AutoCAD to achieve computer drawing. CAD is the abbreviation of ComputerAidedDesign, which means computer-aided design. Together with Auto, it means that it can be applied to almost all industries related to drawing, such as construction, machinery, electronics, astronomy, physics, chemical engineering, etc. With the development of the times and the continuous progress of science and technology, the knowledge and technical application of computer graphics are becoming more and more extensive. Computer graphics have the advantages of high efficiency and high quality compared with manual drawing. In addition, some 3D drawing software also has the characteristics of strong intuitiveness and vivid imagery. I believe that AutoCAD will have a deep understanding of the improvement of the efficiency of mechanical drawing and aircraft design in the future. ”

Yang Weining paused and continued: "In AutoCAD, the idea of creating a model of a part is that the user should first draw a sketch based on the general shape of the part, and the general shape of the part can be regarded as a projection outline in the direction of the main view, and then create the basic shape of the part through the method of feature modeling, which is the basic feature of the part. Commands for feature modeling include extrude, rotate, sweep, loft, etc., such as the 'boss/extrude' command in the software, which is to stretch a sketch according to a specified size to generate a feature with added material. ”

"Let's take the 'three views of the housing part model' as an example to show you how to draw three views of a comprehensive class assembly through AutoCAD. ”

Yang Weining clicked on the computer, and a model of bearing seat parts soon appeared on the screen.

Yang Weining paused, continued: "First of all, we should carry out the shape analysis of the bearing seat, the bearing seat is made of the bottom plate, the barrel, the support plate and the rib plate and other parts are superimposed, the bottom plate is cut by the structure of round holes and fillet and other structures, the combination between the bottom plate and the rib plate is attached, the left and right sides of the support plate and the barrel are tangent, and the rib plate and the barrel intersect. ”

"So in the second step, we're going to choose the direction in which we want to project the main view. After analyzing the composition of the assembly, determine the projection direction of the main view. At this time, you can select the display transformation toolbar in the software, and select the display mode of front-facing projection, left-view projection and top-view projection, which is equivalent to the main view, left view and top view in mechanical drawing. ”

"In the third step, we need to lay out the view, draw a symmetrical centerline, determine the position of the view, and draw the skeleton. Pay attention to the three correspondences between the views, such as 'the length is right, the height is flush, and the width is equal', and note that the space between the two views should be even. Draw the base plate, fix the center of the circle, draw the round hole, starting from the top view, and draw all three views at the same time. ”

Yang Weining first drew the top view of the bottom plate, marked the dimensions, and then stretched it, gave it a thickness, entered the specific value to be stretched, and the drawing immediately changed from a two-dimensional drawing to a three-dimensional solid model.

There was an exclamation in the classroom.

The whole stretching process is similar to the animation process, which is very intuitive, and for the aeronautical engineers who are still in the era of drawing boards, this visual touch makes them realize the power of AutoCAD.

Although Yang Weining's teaching process seems a little boring, it seems to open up another world for the engineers of 611 and 132 factories here.

On the one hand, many people were shocked by Yang Weining's amazing achievements in the field of CAD, and on the other hand, these knowledge were recorded as if they were treasures

For a while, the classroom was completely silent, leaving only the sound of Yang Weining's lecture and the rustling sound of everyone taking notes.

Outside the classroom door, Gong Weijiang, Lu Wenjun, Yang Zhenguo, Tu Kai and others who had been standing for a long time were speechless.

Lu Wenjun said tentatively: "Minister Gong, do you want me to call Yang Weining out?"

Gong Weijiang waved his hand and said, "Wait for this class to end." ”

As he spoke, he turned his gaze to Yang Zhenguo on the side, and said meaningfully: "Zhenguo, you have given birth to a good son!"