Practical work 18 reading assembly drawings gdz. Rules for reading assembly drawings, conventions and simplifications
Drawing. Lesson 28 (second year, grade 9). 1. Topic “Reading assembly drawings. Practical work 8 "2. Gordovaya Nadezhda Semyonovna, teacher of drawing at the Vydrinsky secondary school of the Kabansky district, Republic of Buryatia 3. Subject: drawing. 4.Microsoft PowerPoint presentation 5.Microsoft PowerPoint, Internet Explorer, own developments, didactic material, textbook by I.A.Roitman, Ya.V.Vladimirov, demonstration models, tables. 6. At drawing lessons 7. For students of grade 9 8. Volume: 14 slides, 515 Kb.
Express survey 1. What is shown on assembly drawings: an image of a part or an assembly unit? Assembly unit 2. What are assembly drawings for? To assemble an assembly unit from individual parts 3. Are cuts and sections used when making assembly drawings? Apply 4.Where on the drawings indicate the names of the parts included in the product? In the table - specifications 5. Is it necessary to apply all dimensions of the parts included in the product on the assembly drawings? No. Only overall, connecting, installation 6. What do the numbers on the shelves of leader lines mean? Numbers of parts in the drawing 7. How to hatch three adjoining parts on assembly drawings? In different directions, with a change in the distance between the hatching lines 8. How to show in the section narrow cross-sectional areas, the width of which in the drawing is 2 mm or less? Shown in black 9. Remember what it means to "read the working drawing of the part"? Imagine its three-dimensional shape, dimensions, location of all its elements. Evaluation of results: (9, 8 correct answers - "5", 6.7 correct answers - "4", 4.5 correct answers - "3")
Comparative and comparative characteristics: Working drawing Assembly drawing Performed according to ESKD standards (formats, title block, lines, fonts, etc.) Images (views, sections, cuts), conventions and simplifications are used. Serves for assembling the product from parts All dimensions are given Overall, connecting, mounting Position numbers are given Presence of a table with data - specifications
Reading a drawing of a part means: using flat images on the drawing of a part, imagine its three-dimensional shape, design, dimensions, and location of all its elements. Reading an assembly drawing means: using flat images of an assembly unit, imagine its three-dimensional structure, the shape and dimensions of its individual parts, their location and connection, as well as the principle of operation of the product.
Order of reading assembly drawings. Find the product name. Determine which images (views, sections, cuts) are given in the drawing. Using the specification, consider the images of each part, determine their geometric shape. Determine how the parts are connected to each other. Find other data given in the drawing (dimensions, technical requirements, etc.).
Conclusion: According to assembly drawings, products are assembled, in addition, according to assembly drawings, they get acquainted with the design of products, their principle of operation, and also, according to assembly drawings, products are regulated in the process of work, installed (mounted) at the workplace, repair the product.
- Figures 244-248 show assembly drawings of five different products, and Figure 249 shows visual representations of six products. Some of them are given in figures 244-248, but not all. Determine which visual images, indicated by letters, represent exactly those products that are also contained in the assembly drawings. Write down in your workbook which of the visual images shows which product. Recording form: “On a visual image A is drawn ...” (take the name of the product from the assembly drawing).
Do not forget that not all assembly drawings are given illustrative images.
- Read the assembly drawings indicated by the teacher in figures 244-248, following the sequence given in 35. Answer questions (including additional ones) in writing.
Additional questions for assembly drawings
Rice. 244. Drawing for reading
Back to Figure 244
- Why item 37 is not shaded
- Why is detail 2 cross-hatched?
Rice. 245. Drawing for reading
Back to Figure 245
- Image B-B is a section or section?
- Why is it given?
Rice. 246. Drawing for reading
Back to Figure 246
- Why was incision A - A made?
- What is the shape of item 5?
Rice. 247. Drawing for reading
Back to Figure 247
- Why is detail 3 cross-hatched?
- Why does the hatching of parts 1 and 2 have a different direction?
Rice. 248. Drawing for reading
Back to Figure 248
- Which line represents the workpiece?
- Why is a special screw (det. 3) not shaded in section A-A, but shaded in section B-B?
Complete technical drawings of one or two parts suggested by the teacher. An appropriate visual image will help you complete the work.
Rice. 249 Exercise task
Purpose and arrangement of assembly units included in practical work No. 19.
- The handle (Fig. 244) is attached to the door leaf with screws, for which holes are provided on the base (det. 1). The handle consists of a base and a handle connected with a screw (det. 3).
- Puller (Fig. 245) - a device for removing pulleys, bearings and other parts from the shafts.
The main parts of the puller: the rocker (det. 1), on which the grippers (det. 3) are put on, and the pressure screw (det. 2). The limiter (det. 4) fixed with screws (det. 5) prevents the gripper from slipping off the rocker arm.
The dismantled device is installed on the protrusions of the grips. The shooting of parts is carried out by rotating the pressure screw, into the hole of which a rod (lever) is inserted for this purpose.
- Device (Fig. 246) - the jig is used when drilling holes on tiles, in this case having a rectangular ledge.
The base (det. 1) of the conductor is connected to the plate (det. 2) with pins (det. 5) and screws (det. 6). On top of the plate there is a guide sleeve (det. 3), a handle (det. 4) is screwed in from the side.
When drilling a hole, the protrusion of the workpiece is inserted into the rectangular hole of the base, the drill is guided through the sleeve from above.
- The roller (Fig. 247) serves as a support for moving heavy objects. It is used in sets of several pieces. The roller (det. 2) with a rubber tire (det. 3) is attached to the base (det. /) with a bolt (det. 4) and a nut (det. 5) with a washer (det. c).
- The consignment note jig (Fig. 248) is used when drilling, in this case, two holes with a diameter of 4.2 in the workpiece. The screw (det. 3) of the conductor is attached to the table of the drilling machine. After installing the workpiece, a plate (det. 1) is placed on it, which is fixed with a hook (det. 4). The hook provides easy and fast fastening of the conductor plate.
§ 37. The concept of detailing
Products consisting of several parts are assembled according to assembly drawings. But first, parts are made, and for this it is required to ensure the production of their drawings. The process of drawing up drawings of parts according to drawings of products consisting of several parts is called detailing.
Rice. 250. Assembly drawing and visual illustration of the stop
The essence of the detailing process will be clear from a comparison of figures 250 and 251. The stop, the drawing and visual image of which is shown in figure 250, is mentally divided into separate parts (Fig. 251, a). Figure 251, b shows the drawings of two parts, as a rule, they contain various indications, including those related to the manufacturing technology of the part. These designations are not given here. They are studied in the workshop on mechanical engineering drawing.
Rice. 251. Details of the stop: a - a visual image; 6 - drawing of a flying "hull"; c - drawing of the "rusk" part
- Read the drawing of the product in the sequence given in § 35, paying special attention to the shape of the parts, their purpose and interaction.
- Mentally disassemble the product into separate parts.
- Select standardized parts for which drawings are not drawn up.
- Determine the number of images needed when drawing each detail. At the same time, you cannot copy it from the drawing to be detailed. Screw (det. 3), for example, in Figure 250 is represented by three views. In the drawing of this part, one view is enough. Conversely, the rack (det. 1) in Figure 232 is shown in three views and a section, although the drawing of this part must contain at least five images.
- Find the mating surfaces of parts, i.e., surfaces that interact with the surfaces of other parts. These include, for example, the surface of the pin and the hole for it (Fig. 246).
For mating surfaces, dimensions must be agreed. This means that, for example, the outer diameters of the sleeve and the hole where it is pressed into should be the same in size (Fig. 248).
When detailing, especially when applying dimensions, reference books should be used. So. keyway dimensions must be selected and applied in accordance with the recommendations given in section 33.1; dimensions of threaded products in accordance with the recommendations given in sections 31.3 and 32.2. Finally, it is advisable to use the directory when something is forgotten or met for the first time. For example, in the specification of the assembly drawing, the designation was found: “Splint 1.5x15 GOST 397-79”. You do not know what shape the part has and what the numbers in this entry mean. We learn from the reference book that the part has the shape shown in Figure 252. The designation should be understood as follows: cotter pin for holes with a diameter of d = 1.5 mm, cotter pin length 15 mm.
Rice. 252. Cotter pin
The use of reference books when reading and drawing up drawings, including during tests, unloads memory, allows you to get more new information, and speeds up work.
Performing detailing, it is necessary to draw each detail on a separate sheet, the format of which depends on the selected scale. Most of the data for the title block is taken from the specification of the assembly drawing.
Let's look at an example of detailing. Figure 253 shows a visual representation of the crank. Figure 254 shows his drawing. The crank transmits movement from the connecting rod to the shaft, converting the translational movement of the piston into rotational movement of the shaft (see diagram in Fig. 255). It is an eccentrically located finger (det. 2), connected by means of a shoulder (det. 1) with a shaft (det. 3), which reports rotational movement. A connecting rod is pivotally connected to the crank pin, coming from the piston.
Rice. 253. Crank
After reading the drawing (Fig. 254), we set according to the specification that it shows a crank. The main view and section are given. The main view contains a local section. The detail image 3 also contains a local section.
Figure 254. Assembly drawing of the crank
Detail 6 - the bolt has a head in the form of a hexagonal prism. The main dimensions of the bolt: Mb thread, rod length 25 mm. We learn this from the specification. Knowing the standard number, you can determine the "turnkey size" (it is 10 mm), head height (4 mm) and other dimensions.
Rice. 255. Scheme of the crank
Item 5 - a nut with an M6 thread has the shape of a hexagonal prism.
Part 2 is called "finger". It consists of three cylinders and a truncated cone. The conical end of part 2 is riveted, which ensures the immobility of the connection with part 1.
Key (det. 4) prismatic. The height and width of the key are 6 mm each, the length is 14 mm. We also learn this from the specification.
There are four holes in the "shoulder" part: one is conical, the second is cylindrical for a shaft with a diameter of 21 mm and two are also cylindrical for the Mb bolt. The bolt and nut are used to tighten the legs of the shoulder, which clamps the shaft. Parts 1 and 3 are connected with a parallel key.
Dimensions diameter 16 and 24 are connecting, size 160 overall.
It is not necessary to draw up drawings for parts 4,5 and 6, since they are standardized.
Thus, the drawing is read. The product is mentally disassembled into separate parts. Those of them are selected for which you need to draw up drawings, determining the required number of images, the position for the main view, marking the mating surfaces and selecting the scale.
Figure 256 shows a drawing of part 2 - a finger. In the drawing, where it is shown in connection with other details, the finger is shown in two images, and here in one, since the shape of the th is completely revealed by one view.
Rice. 256. Drawing details 2 crank
Figure 257 shows a drawing of the shoulder. Dimensions, which were not in Figure 254, were determined using an angular scale (see reference to work No. 20). The keyway dimensions 6 and 2.8 mm are taken from the reference table (see § 33).
Rice. 257. Drawing details 1 crank
The dimensions of the mating surfaces (for diameters 16 and 21) are mutually agreed.
18.08.2015 4688 575 Anufrieva Elena YurievnaLesson type:a lesson in the formation of practical skills.
Lesson Objectives: to form ideas about the algorithm for reading an assembly drawing; learn to read the simplest assembly drawings; develop spatial thinking; to continue the development of critical thinking, the acquisition of experience in communicative activity, the ability to search for the necessary information in various sources. continue the formation of positive motivation for students to study drawing, fostering tolerance towards someone else's point of view, responsibility for their actions.
Equipment:"Algorithm for reading an assembly drawing and a visual image of an assembly unit", test tasks, cards for group work.
Lesson plan:
1. Organizational moment.
2. Introduction to the topic of the lesson.
3. Repetition of the studied material.
4. Formation of practical skills (practical work on reading assembly drawings).
5. Consolidation of educational material.
6. End of the lesson.
DURING THE CLASSES
I. Organizational moment
II. Introduction to the topic of the lesson
Teacher.Having bought any thing, we often get acquainted with the rules of operation of the purchased product before we start using it for its intended purpose. Many years ago I bought this coffee grinder and, like every owner of a new thing, I first read the instruction manual. (A coffee grinder is demonstrated, a fragment of the instructions for its operation is read out, which deals with the method of adjusting the degree of grinding of coffee beans using a screw called “Screw - 7”). Where is this "important" screw - 7? The answer was immediately found when looking at the assembly drawing that accompanies the instruction text.
Of course, when dealing with the simplest mechanism or design, it is often enough just to carefully look at the product in order to understand its structure, make adjustments or minor repairs. And if we are talking about a machine, a car, an airplane? Or, for example, about cabinet furniture, an ordinary “wall”? In these cases, you must be able to work with the assembly drawing, you must be able to read it.
The topic of the lesson and its main task are reported: to learn how to read the simplest assembly drawings.
III. Repetition of the studied material / answer yes or no to the statement/
1. An assembly drawing is necessary for the manufacture of parts of an assembly unit
2. Positions, quantity, name and materials of parts included in the assembly unit - information contained in the specification
3. On the assembly drawing, the position numbers of the parts indicate on the leader lines, first the position numbers of non-standard parts, and after the standard
4. Hatching in a section for two adjacent parts is performed with lines of different thicknesses, different slopes, and the distance between the lines is the same
5. Shafts, keys, bolts, studs, all non-hollow bodies, when their cutting plane passes along their center line, are called not dissected in the drawing?
6.On the assembly drawing, it is allowed to place only the main view and the right side view using the necessary local sections, observing the projection relationship
7. List the name of the sizes in the order of the definitions you read
· Dimensions that determine the limiting external or internal outlines of the product
· Dimensions by which the product is fixed at the installation site
· Dimensions by which the product is attached to other products
Dimensional, installation, connecting.
8. A sketch is no different from a working drawing;
9. The sketch of the part is carried out ineye scale;
10. The working drawing of the part must containthe maximum possible number of species;
11. On the working drawings of the part withthe dimensions necessary for the manufacture and control of the manufacture of the part are set.
12. The specification indicates the weight of the parts.
13. Are simplifications applied to assembly drawings?
14. For all parts included in the assembly unit, position numbers are applied.
15. On assembly drawings, apply in all dimensions;
16. The number of part images on the assembly drawing must match the number of part images on the working drawing.
17. The specification is carried out on A4 format.
18. Images of sections of parts with a thickness or diameter of 2 mm or less are blackened;
19. Drawings containing images and data for the manufacture of parts are called assembly drawings.
20. Connections that are repeatedly found in the mechanisms of various machines are called typical.
10-14 - "3" 15-18 - "4" 19-20 - "5"
IV. Formation of practical skills
A) Familiarization of students with the algorithm for reading an assembly drawing and a visual image of an assembly unit (according to a table made on paper or a presentation slide).
Algorithm for reading an assembly drawing and a visual image of an assembly unit:
1. Define the name of the product.
2. Set the number of item names and their quantity.
3. Determine the scale of the image.
4. Analyze the number and nature of images in the drawing or on a visual representation of the assembly unit.
5. Determine the outline of each part of the assembly unit on all images of the drawing.
6. Analyze the geometric shape of each part.
7. Determine the types of connection of parts in this assembly unit.
8. Analyze and set the dimension type.
9. Identify the conventions and simplifications used on the assembly drawing or on a visual representation of the assembly unit.
10. Establish the assembly sequence of the product.
V. Consolidation and determination of the degree of assimilation of educational material by students
Work according to the textbook fig. 6.10 and 6.11 pp.80-81
VI. end of lesson
1) Summing up the lesson. Grading students for their work in class.
2) Explanation of homework: § 6.1-6.4 Draw a frontal section on A4 format, highlighting with hatching where the details of the assembly unit are needed.
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Lesson type: a lesson in the formation of practical skills.
Equipment: any item of household appliances with instructions for its operation; tables: “Details and assembly units”, “Algorithm for reading an assembly drawing and a visual image of an assembly unit”, “Assembly drawing of a toy “Dog”, “Assembly drawing of a toy “Tractor”, “Bearing”, “Bearing” (performed by the teacher) ; handouts: printouts of the "Tractor" drawing, sheets of tracing paper, sheets of handouts with unfinished images of technical drawings of parts, sheets of handouts with questions for the test verification work and answer options for them, sheets for indicating answers to the questions of the test work; projector "Bearing" for slideshow or computer, projector and interactive whiteboard; slides on the topic "Types of connections" or a Power Point presentation that includes all the information contained in the didactic tables, slides and handouts; information stand with materials on the topic "Types of connections".
Lesson plan:
1. Organizational moment - 1-2 minutes.
2. Introduction to the topic of the lesson - 5-6 minutes.
3. Repetition of the studied material - 8-10 minutes.
4. Formation of practical skills (practical work on reading assembly drawings) - 18-20 min.
5. Consolidation of educational material - 5-7 minutes
6. End of the lesson - 3-4 minutes.
DURING THE CLASSES
I. Organizational moment
The teacher greets the students and checks their readiness for the lesson.
II. Introduction to the topic of the lesson
Teacher. Having bought any thing, we often get acquainted with the rules of operation of the purchased product before we start using it for its intended purpose. Many years ago I bought this coffee grinder and, like every owner of a new thing, I first read the instruction manual. (A coffee grinder is demonstrated, a fragment of the instructions for its operation is read out, which deals with the method of adjusting the degree of grinding of coffee beans using a screw called “Screw - 7”). Where is this "important" screw - 7? The answer was immediately found when looking at the assembly drawing that accompanies the instruction text.
Of course, when dealing with the simplest mechanism or design, it is often enough just to carefully look at the product in order to understand its structure, make adjustments or minor repairs. And if we are talking about a machine, a car, an airplane? Or, for example, about cabinet furniture, an ordinary “wall”? In these cases, you must be able to work with the assembly drawing, you must be able to read it.
During the conversation, the teacher leads the ninth graders to the idea that the practical skills associated with reading an assembly drawing not only develop spatial thinking, but also help a person in his daily life.
The topic of the lesson and its main task are reported: to learn how to read the simplest assembly drawings.
III. Repetition of the studied material
A) Poll on the topics of previous lessons
Teacher. When working with a drawing, we must clearly understand what is shown on it. Engineering drawings depict a variety of products.
Do you remember what the term "product" means? (A product is any item or set of items of production manufactured at a given enterprise.)
- Drawing of what product: a part or an assembly unit, we call an assembly? (An assembly drawing is a drawing of an assembly unit consisting of several parts.)
B) Performing an oral exercise to determine whether the item shown on the Parts and Assembly Units table (or on a Power Point presentation slide) belongs to a group of parts or assembly units.<Рисунок 1 >.
To the teacher's question:“Is this a part or an assembly unit?”, - the children give monosyllabic answers like: “Detail”, “Assembly unit”.
C) Continuation of the survey
- Guys, now each of you can more consciously answer the question: “What do we call a detail?” (A part is a product made from a homogeneous material without the use of assembly operations.)
- What is an assembly unit? (An assembly unit is a product, the components of which are to be interconnected at the manufacturing plant using assembly operations: screwing, riveting, welding, soldering, gluing, etc.)
D) Determination of the names of the types of connections of parts and the fasteners included in them according to the drawings. (Showing slides on the topic “Types of connections” using the “Bearing” projector or demonstrating a Power Point presentation, including slides with images of drawings of bolted, stud, pin and other typical connections, using a computer and a multimedia projector).
Seeing this or that drawing, students pronounce the name of the type of connection depicted on it and the fasteners included in it.
Teacher. So, we know not only the names of assembly operations (riveting, welding, etc.), but also how various types of connections of parts resulting from these operations look on the drawings. In most cases, we easily determine the type of connection because we know how various fasteners are depicted on the drawing. The information posted on the stand will help you expand your understanding of the variety of fasteners and types of connections.
Draw students' attention to the stand, where, before the lesson, information should be placed on the types of connections, including those not considered during the slide show. This information should be taken from the workbook "Drawings of typical connections of parts" by T. V. Kuchukova, edited by Professor N. G. Preobrazhenskaya. Pay special attention to the screw connection and explain the meaning of the term "screw". It is not advisable to replace work with the materials of the stand by viewing slides containing similar information, since the stand in the office functions constantly, and didactic material on the topic “Types of connections” may be in the field of view of students for several weeks. This will allow them to visually remember images of the required number of types of parts connections without much effort, which will facilitate further work with assembly drawings.
IV. Formation of practical skills
A) Familiarization of students with the algorithm for reading an assembly drawing and a visual image of an assembly unit (according to a table made on paper or a presentation slide).
B) Formation of practical skills in reading the simplest assembly drawings on the example of drawings of toys: “Dog” and “Tractor”.<Рисунок 2 >, <Рисунок 3 >.
Alternate oral reading of drawings according to the algorithm (see below) in the form of a didactic conversation between the teacher and students. The work is done using paper tables or presentation slides with images of toy drawings. If the pace of the lesson is not high enough, you should limit yourself to reading only the assembly drawing of the toy. "Tractor".
(Work on stages "A" and "B" is carried out simultaneously).
Algorithm for reading an assembly drawing and a visual image of an assembly unit:
- Define the name of the product.
- Set the number of item names and their quantity.
- Determine the scale of the image.
- Analyze the number and nature of images in the drawing or on a visual representation of the assembly unit.
- Determine the outline of each part of the assembly unit on all images of the drawing.
- Analyze the geometric shape of each part.
- Determine the types of connection of parts in this assembly unit.
- Analyze and set the dimension type.
- Identify the conventions and simplifications used on the assembly drawing or on a visual representation of the assembly unit.
- Establish the assembly sequence of the product.
When working on 5 and 6 points of the drawing reading plan, one should dwell in detail on defining the outlines and analyzing the geometric shape of 1-2 parts (for example, parts pos. 3 and pos. 4 in the tractor drawing). Highlight the images of these details on the interactive whiteboard using the stylus, applying a specific chromatic color tone to stroke the projections of each detail. In this case, the contours of the projections of the parts should be drawn in those places where they are covered by images of other parts of the toy. When working with a paper table, the teacher shows the contours of the projections of parts with a pointer. Then students should complete technical drawings of parts pos. 3 and pos. 4 of the Tractor toy according to the options. Work on sheets of tracing paper, transferring to them unfinished images of technical drawings of parts from handouts (<Рисунок 4 >, <Рисунок 5 >) and completing these images. At the end of the work, tracing papers with technical drawings are pasted by students into workbooks. In the absence of an interactive whiteboard, each student who encounters difficulties in the course of working on a task can also perform a preliminary selection in the assembly drawing of the projections of one part using tracing paper and printouts of the “Tractor” drawing received from the teacher.
The content of the task the teacher clearly pronounces or, working with a computer presentation, displays the text with the task on the screen.
Teacher. Transfer to tracing paper an image of an unfinished technical drawing of a part from a sheet of handout. Based on the images of orthogonal projections of this part, complete its technical drawing.
If there is an interactive whiteboard to check the correctness of the execution of the graphic exercise by the students of the class, technical drawings are performed on it in turn by the two students who mastered the topic “Technical Drawing” with the highest quality and quickly completed this task. To do this, Figures 4 and 5 are displayed alternately on the screen.
The description of the shape of the remaining parts of the product is quickly carried out by the teacher himself, involving students in this work at their request.
Further work is carried out according to the algorithm in the form of a conversation. When determining the types of compounds, it is enough to consider 2-3 examples.
V. Consolidation and determination of the degree of assimilation of educational material by students
Students on the options perform test work related to reading the assembly drawing and comparing the axonometric and orthogonal drawings of the product. The work is carried out according to the cards received from the teacher.<Рисунок 6 >. (It shows cards with technical drawings for performing both I and II work options). Also, children receive cards with questions and answer options for test questions. (<Рисунок 7 >- card of the 1st variant of work;<Рисунок 8 >- card of the II option of work). Marking with asterisks the correct answers in the tables received from the teacher, students demonstrate the level of assimilation of educational material on the topics: “Sections”, “Analysis of the geometric shape of an object”, “Dimensions on assembly drawings”, etc.
Presentation slides or handouts are shown, with the help of which the teacher clarifies the content of the test work.<Рисунок 6 >.
Teacher. The axonometric drawing of the thrust bearing will be read by the guys performing the task of the first option. Accordingly, reading the bearing drawing is the task of the second option. Carefully consider the drawing of your option. Read it orally according to the algorithm for reading an assembly drawing (demonstration of a didactic table or presentation slide with an algorithm). Work with handouts that contain pictorial illustrations of the thrust bearing and bearing.
Then maps (second sheets of handouts) are shown with questions to assembly axonometric and orthogonal drawings of the thrust bearing and bearing and answers to these questions (you can also show a presentation slide). I option -<Рисунок 7>; II option -<Рисунок 8 >.
Teacher. Each student should complete the tasks indicated in the card (second sheet with handouts). Correct answers are marked with an asterisk on the third sheet of handouts. (See below)
(I option)
Third sheet of handouts(II option)
Answers to tasks
I option
(When working on question 1 (task No. 3), remind the student that we are talking only about the external shape of the object).
II option
(When working on task II, draw students' attention to the choice of an appropriate cut that emphasizes the features of the shape of the object, if the choice fell on an image with a cut).
D) Collection of cards with completed tasks.
VI. end of lesson
1) Summing up the lesson. Grading students for their work in class.
2) Explanation of homework: § 35 - to teach, task No. 69 (p. 188) to perform orally, § 34 - to repeat.
Literature:
- A. D. Botvinnikov, V. N. Vinogradov, I. S. Vyshnepolsky. Drawing. M., Astrel, 2008.
- N.G. Preobrazhenskaya, I.Yu. Preobrazhenskaya. Drawing. Reading and detailing assembly drawings. M., "Ventana-Count", 2000.
- T.V. Kuchukova. Drawing. Drawings of typical connections of parts. M., "Ventana-Count", 2001.
Gorlovka general educational
Schools I - II No. 35
Dushkina I. A.
Lesson #19(Lesson #5 in Topic #13 Reading and Detailing Assembly Drawings)
Date of ………..
Class 9
Subject: Detailing assembly drawings. Purpose and content
assembly drawing detailing process.
Lesson Objectives:
Educational: to acquaint students with the concept, purpose and content of the process of detailing according to assembly drawings, consolidating the skills of students in reading an assembly drawing and writing a drawing font, focusing on engineering professions
Educational: contribute to the education of diligence, accuracy, work culture and careful attitude to drawing tools.
Developing: contribute to the further development of memory, attention, eye; promote the development of logical, analytical and spatial thinking; to promote the development of interest in technical disciplines and design.
For the teacher:
textbook "Drawing.8 - 9kl." ed. VC. Sidorenko
rebus "Detailing"
training tables containing: 1) an image of the assembly drawing of the product, 2) an image of the drawings of parts obtained in the process of detailing this assembly drawing
electronic version of tables, tasks for the game, cards (if you have the necessary equipment)
videos on detailing various products: https://www.youtube.com/watch?v=7EGiOTD1awI&list=PLElpKZ5QlQVjbn4gsXkK_8frV4PyaFA_C
chalk for work on the board.
accessories and tools.
Lesson type: combined.
During the classes
Organizational stage:
Organization of the workplace of students, the issuance of the missing teaching aids, drawing tools, supplies and materials from the office fund for work in this lesson. Check readiness for the lesson.
Checking the attendance of students.
Filling out the class journal by the teacher
Announcement of the topic of the lesson and writing in a drawing font in a notebook.
3.Updating basic knowledge
Repetition and consolidation of the studied material in previous lessons will be carried out in a playful way "Not really". You will be asked questions that require a "Yes" or "No" answer. We greet the answer “Yes” with a clap (applause), the answer “No” we mark with silence. Begin. Be careful!
1.Assembly drawing- This
a) an image of a part containing the necessary information for its manufacture - NO
b) sketches of individual parts included in the assembly unit - NO
c) a visual representation of the assembly unit - NO
d) a drawing containing an image of products from several parts that perform one or more functions, as well as data for its assembly and control - YES
2. Part connections are:
a) symmetrical - NO
b) asymmetrical - NO
c) detachable - YES
d) one-piece - YES
e) combined - NO
3.
Plug connections- This
a) connections that can be disassembled by destroying 1 - 2 parts included in their composition - NO
b) connections that can be disassembled without destroying the parts that make up them - YES
c) connections that can be disassembled by destroying all the parts, and then connected using various repairs (gluing, soldering, etc.) - NO
4. Detachable connections include:
a) bolted - YES
b) riveting - NO
c) hairpin - YES
d) welded - NO
e) keyway - YES
f) adhesive - NO
g) screw - YES
h) pin - YES
5. Reading drawings has the following stages of work:
a) the main inscription is being studied - YES
b) the images that represent the product are determined - YES
c) a visual representation of the assembly unit is performed - NO
d) the specification is studied and the shape of individual parts is determined - YES
e) a drawing of the assembly unit is being carried out - NO
f) determine how the parts are connected to each other - YES
g) additional information, inscriptions, dimensions are being studied - YES
Game over. Are there guys who have never made a mistake? Well done!
It must always be remembered that the most important thing in teaching is the establishment of truth. If you made a mistake, now you remember the correct answers.
3.
Motivation of educational activity.
Today we will deepen and systematize our knowledge of assembly drawings, which will allow us in the next lessons to successfully complete practical work on detailing an assembly drawing.
Announcement of the goals and objectives of the lesson:
Today in class we will:
To get acquainted with the concept of detailing according to the assembly drawing, its purpose and the content of the detailing process
As always, we must be attentive, think, analyze, imagine and not waste time.
Write down the date and topic of the lesson in your notebooks. We write neatly in a drawing font “Detailing assembly drawings”.
The process of drawing up drawings of parts from drawings of products consisting of several parts is calleddetailing.
Read the assembly drawing before starting detailing. This makes it possible to determine the structure of the product, the interaction of its components and their purpose. This process involves the conditional division of the product into separate parts and the execution of drawings for each of them (this is done in design offices). According to these drawings, working parts of various profiles are made in production (for example, turners), and only then in the assembly shop, assemblers assemble the product from the parts according to the assembly drawing.
Let's consider the essence of the detailing process using the example of the "Upor" assembly unit. It will become clear if we compare 2 drawings.
On the first drawing, we see an assembly drawing and a visual representation of the product, on the other, this product is divided into separate parts and working drawings of two parts are made. Let's take a closer look at these images. (Students look at the drawings)
Problematic situation.
According to the specification, we see that the assembly unit consists of 5 parts. Name them (body, cracker, screw, stud, nut) Why are the drawings made only for 2 parts?
A minute to think. your versions!
(Children must determine that the image does not contain drawings for fasteners - a screw, a stud and a nut, and their drawings and other data, as we know from previous lessons, are in special engineering reference books, because these are STANDARD parts)
Conclusion:Working drawings are not prepared for standard parts.
To facilitate the work of drawing up drawings, it is recommended to do this in this order:
Read the product drawing in the previously studied sequence, paying special attention to the shape of the parts, their purpose and interaction.
Mentally disassemble the product into separate parts.
Select standardized parts for which drawings are not drawn up.
Determine the number of images needed when drawing each detail. However, you cannot copy it from the drawing to be detailed.
(Children themselves must answer that the number of views in the drawing should be MINIMUM, but SUFFICIENT for manufacturing the part. To reduce the number of images, there are various conventions, signs, you can still apply cuts, sections. For example, cylindrical surfaces can be depicted with 1 view in combination with a cut , and the assembly drawing contains 2 or 3 views and all views have this element.In the drawings under consideration, the part is a cracker, which is made in the frontal and profile views, and when the working drawing is made, the part is shown in the frontal section and horizontal view. If students find it difficult to make such a conclusion, the teacher helps)
Find the mating surfaces of parts, i.e., surfaces that interact with the surfaces of other parts (for example, in keyed joints, a key and a keyway on a shaft). It is imperative to use reference books, especially if you met the part for the first time, or something was forgotten. This helps relieve memory from the abundance of information, speeds up the work, or vice versa, will give you more information.
For example, in the specification of the assembly drawing, there was a designation: “Splint 1.5 x 15 GOST 397-79”. You do not know what shape the part has and what the numbers in this entry mean. We learn from the reference book that the part has such a shape. The designation should be understood as follows: cotter pin for holes with a diameter of d = 1.5 mm, cotter pin length 15 mm.
Detailing of each part must be done on separate sheets. Their format depends on the scale.
The main inscription must be filled out using the specification data.
5. Practical work (together with the teacher)
The figure shows a visual representation of the crank. The crank transmits the movement from the connecting rod to the shaft, converting the forward movement of the piston into rotational movement of the shaft.
The scheme of the crank
The figure below shows a drawing of the crank. It is an eccentrically located finger (det. 2), connected by means of a shoulder (det. 1) with a shaft (det. 3), which reports rotational movement. A connecting rod is pivotally connected to the crank pin, coming from the piston.
Reading a drawing
After reading the drawing, we establish according to the specification that it shows a crank. The main view and section are given. The main view contains a local section. The detail image 3 also contains a local section.
Detail 6 - the bolt has a head in the form of a hexagonal prism. The main dimensions of the bolt: Mb thread, rod length 25 mm. We learn this from the specification. Knowing the standard number, you can determine the "turnkey size" (it is 10 mm), head height (4 mm) and other dimensions.
Detail 5 - a nut with a Mb thread has the shape of a hexagonal prism.
Part 2 is called "finger". It consists of three cylinders and a truncated cone. The conical end of part 2 is riveted, which ensures the immobility of the connection with part 1.
Key (det. 4) prismatic. The height and width of the key are 6 mm each, the length is 14 mm. We also learn this from the specification.
There are four holes in the "shoulder" part: one is conical, the second is cylindrical for a shaft with a diameter of 21 mm and two are also cylindrical for the Mb bolt. The bolt and nut are used to tighten the legs of the shoulder, which clamps the shaft. Parts / and 3 are connected with a parallel key.
Dimensions diameter 16 and 24 are connecting, size 160 overall.
It is not necessary to draw up drawings for parts 4, 5 and 6, since they are standardized.
Execution of drawings
The “Finger” part is made in one view, since its shape is fully revealed, although it is shown in 2 projections on the assembly drawing.
The next detail is "Shoulder". The drawing is shown below. Note. Dimensions appeared on it that were not indicated on the assembly drawing. They are defined using the angular scale. We will learn how to do this in the next lesson.
The “Shaft” part is not performed, since its shape is well known, and the dimensions of the keyway 6 and 2.8 mm, which it contains, are taken from the reference table
The dimensions of the mating surfaces (for diameters 16 and 21) are mutually agreed.
Detailing done.
6. Homework:
Read the textbook material on pages 195-198
Disassemble verbally detailing in fig. 237, 238
A creative task, at the request and choice of students, to compose a crossword or rebus with the keyword "Detailing"
The teacher gives a general description of the learning activity in the lesson; at the same time informs them about the achievement of the objectives of the lesson, identified shortcomings and ways to eliminate them;
objectively evaluates the results of collective and individual work, marks the best.
Reflection:
Today I invite you to evaluate your condition after the lesson according to the schedule.
8. In a free minute - watching a video(link in the lesson equipment) if you have the necessary equipment
Application
№1 Assembly drawing and visual image "Stop"
No. 2. Separate parts of the "Stop" and drawings of parts 
No. 3. Cotter pin
No. 4 Crank
No. 5. Assembly drawing of the crank
No. 6 Scheme of the crank
No. 8 Detail drawing 2 cranks
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