How to read a drawing - metalwork and tool work. How to learn to read drawings quickly and correctly? How to read a mechanic's blueprints

Everything that was created by humanity at all stages of its development, all the brilliant thoughts that found their embodiment or remained the dreams of designers - one way or another, were presented in the form of drawings. Just as a literary text conveys the writer’s fantasies, so a drawing captures what came into the engineer’s mind and brought it closer to reality.

Rice. No. 1 “Example of drawings of the Eiffel Tower. France"

Today, all drawings are created using uniform rules and GOSTs, which makes them easier to read. Learning to read drawings of metal structures is not at all difficult, so if you decide to connect your hobbies or professional activity with the embodiment of metal structures, it is worth familiarizing yourself with general information on this issue, and then move on to the practice of independent reading.

KMD drawings, which are a detailed schematic representation of a metal structure, are developed taking into account certain rules set out in documents such as:

SNiP ( Building codes and rules),

SPDS (System requirements project documentation for construction),

ESKD ( one system design documentation).

Drawings of this kind include a set of data that you can use for production - marking, processing, welding and installation of metal structures.

Rice. No. 2 “Production of metal structures”

Before you start learning how to read drawings, it is advisable to independently refer to the above documents. Don’t forget to learn all the relevant GOSTs; knowledge of them will more than once help you quickly navigate reading the drawing. In addition, when creating any design drawing, special symbols.

Rice. No. 3 “Example of KM project diagram”

CM drawings are usually provided with an explanatory note, which sets out in text form the results of the calculations and decisions made, which justify these calculations. At the same time, the explanatory note contains technical and regulations, which were used to create the drawing and reference to GOST standards. This note is intended to make the diagram easier to read.

Rice. No. 4 “Example of KM project nodes”

A complete KMD project is developed according to KM and is a set of a title page with general data, statements, drawings of installation diagrams, drawings of assembly units and drawings of sending elements. At the customer’s request, the project may include: separate drawings of parts, 3D diagrams, special statements, etc.

Rice. No. 5 " Title page KMD project"

In the installation diagram you will see joints and assemblies, welded or bolted connections, which will be performed during installation. Text comments can also be given here. Also here you will find a list of shipping elements along with design diagrams or links to the drawing, so you will immediately understand which specific drawing each element belongs to. Drawings of dispatch elements are arranged in groups on a sheet. Thus, the sheet may contain drawings of elements that do not require assembly or only a structure from a bent profile.

Rice. No. 6 " Wiring diagram KMD project"

When developing diagrams of metal structures, the scale is chosen that allows you to make the drawing most understandable or easy to read, so you should not have problems understanding a professionally drawn up drawing. Please note that structures such as beams and columns can be drawn without observing scale, but maintaining the relative position of parts and holes.

Rice. No. 7 “Example of assembly drawing, KMD project”

After you have read the documentation of the drawings, you need to check the symbols and you need to know well how a particular product is designated. Rivets, holes, nodes, types of material used - all this has a letter, number or graphic designation, so it is better to consult the table if you do not already have sufficient experience in reading drawings.

Take your time, check all the values. The drawings were originally made for ease of reading and understanding, so if you take a few minutes to think about them, the further reading process will be much easier.

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Regardless of the situation in which you urgently needed to learn how to read drawings, this instruction will help you learn to understand any drawing as quickly as possible. short time. The whole point of the method is to go from big to small and not get hung up on the little things. What is not clear, immediately search on Google, since the purpose of this article is not to load you, but, on the contrary, to set the desired vector.

Step 1: learn the basics.

Types of drawings

First you need to understand what types of drawings there are. Drawings are usually divided according to their characteristics. They are like this:

• assembly drawings;
• hydraulic installation;
• electrical installation
• pneumatic assembly
• axonometric
• detailing
• parts drawings;
• plan diagrams;
• topographical;
• general types;
• theoretical;
• overall;
• installation;
• electrical circuit drawings;
• photographic drawings.

• show general view;
• section/section;
• what the part or assembly consists of;
• show mounting methods
• show all projections of the part

We divide the drawings according to the target audience:

• for the customer;
• for the builder, for production;
• drawings for students (diploma, coursework);

According to the method of use, drawings are divided into the following clusters:

• originals;
• originals;
• duplicates;
• copies;

Types and thickness of lines

Fonts and their sizes

According to GOST 2.304-81, all fonts in the drawing must have a certain angle of inclination, line thickness, height, and distance between letters. That is, you can’t just take it and write it on a drawing in any font. Besides, in different places drawing, inscriptions are made with different heights. .

Design of drawings

Depending on the type of drawing and its purpose, its design may vary. Basically, the frames and stamps differ.

Filling the stamps

The main inscription (stamp) is intended to be depicted on a sheet with a drawing of the main data:

• type and name of the part in the drawing;
• drawing scale;
• mass of the part;
• number and number of sheets;
• Full name of the contractor and inspector;
• Document Number;
• signatures;
• dates of verification and signature;
• other data.

All inscriptions, dimensions and positions of stamp elements are established by GOST 2.104-68 (forms 1, 2, 2a, 2b and applications that establish the division of the drawing into zones and the application of stamps for different paper formats.

Step 2: Visual Perception

After studying the basic concepts, you can begin to study different types drawings. This will help you read and understand them better.

Examples of finished drawings

Examples of some types of drawings are presented on our website in the section. It contains screenshots and scans, and.

Video tutorials on YouTube

Next, we recommend that you watch video tutorials on drawing in AutoCAD. You can search the web or YouTube yourself. But for our part, we want to recommend you really useful channels (not advertising)

• The educational center ITDevelopment

To begin with, this will be more than enough.

Step 3: Drafting Software

To open drawings, you need to download and install specialized vector programs on your computer, which can be divided into:

By commercial component (paid and free)

• free
  • A9CAD
  • LibreCAD
  • FreeCAD
  • DraftSight
• paid
  • KOMPAS-3D
  • AutoCAD
  • CorelDRAW Technical Suite
  • VariCAD
  • Graphite

The most popular are 3D compass and AutoCAD.

Step 4: Practice

If you do not have the time and opportunity to study this science, but need to make drawings, you can order their production from us or. We accept orders from Ukraine and the CIS countries (except Russia). Follow the link below to find out payment methods.

Getting to know the product. Using the main inscription, find out the name of the product, the scale of the image, etc.

Reading images. Determine what types, sections, sections are given in the drawing and what is the purpose of each image. Find out the position of the cutting planes with the help of which the cuts and sections are made, and if there are additional and local views, the directions of their projection.

Studying components products. Find out their names using the specification, and find out their shape and relative position using the drawing. Study the component parts of the product in order of specification item numbers, and images of parts should first be found in the view on which the item number is indicated, and then on the others. Take into account that in the presence of cuts, the same inclination and frequency of the hatching lines of its sections contribute to identifying the shape of the part.

Study of product design. Find out the nature of the connection of individual parts to each other. For permanent connections (welded, riveted, soldered, etc.), determine each element and their connection points, and for detachable connections, identify all fasteners.

Determining the sequence of assembly and disassembly of the product. This is the final stage of reading the drawing.

Let's consider an example of reading an assembly drawing of a product shown in Fig. 14.4.

The assembly drawing shows an angular cable plug, as can be seen from the main inscription. It is one of two parts of a connector used to connect an electrical cable. The connection of one part of the connector - the plug - to the other part - the socket - occurs using pin 1 and nut 2.

The assembly drawing shows four images: a full section, part of the view on the left, section A-A and local view B.

The incision reveals internal structure product, the left view makes it possible to understand the shape of the nut 2 and the cup 3. Section A - A reveals the connection of the cup 3 and the body 5. Local view B shows part of the nut 7. View B is made in the direction indicated by the corresponding arrow.

According to the specification shown in Fig. 14.5, we determine that the product consists of one assembly unit (contact), nine parts and three standard screws.

Based on the images in the drawing, we determine the shape of the parts. The body is shown in three images: in the main section, in the left view and in section А-А. The external contours of the body are cylindrical in shape with a right angle bend. The internal shape is represented by two threaded and one smooth holes.

The outer contour of glass 3 consists of three cylindrical surfaces and one conical surface with a through cylindrical hole. In this case, one cylindrical surface has two slots, shown in the view on the left.

Nut 7 has a slot (slot), shown in local view B, which is designed for screwing it into the threaded hole of the housing.

The nut 10 on the outer diameter of the cylindrical surface has a knurl, shown in part in a sectional view of this part.

Nut 2 has a cylindrical shape with an internal thread M16x 1. There are four through holes on its cylindrical surface.

The design of the product is as follows. The cable is inserted into the housing hole 5, soldered to contact 1 through another hole and closed with a plug 6. The cable is secured in the plug using a nut 7, a seal 8 and another nut 10. A contact / is inserted into the inner hole of the glass 3 and sealed with a sleeve 4. The glass 3 passes through the smooth hole of nut 2 and is secured in the housing using three M2 screws, shown in section A-A.

The product is disassembled in the following order: unscrew screws 11, remove cup 3, remove nut 2. Unscrew the plug and nuts from the threaded holes of the housing and remove the cable.

Read the drawing general view - means finding out the purpose of this product, the structure and principle of its operation, getting a complete understanding of the shape, size and technical specifications the finished product and each part separately, i.e. determine from the drawing all the data for their manufacture and control.

When reading the general view drawing they find out mutual arrangement components of the product, methods of connecting parts, as well as geometric shapes and sizes of all elements of the product.

Assembly, installation, repair or improvement of even simple assembly units are associated with the study of the design from a general drawing.

Since working drawings are developed based on the general drawing,

of parts, it must contain a sufficient number of images to allow such drawings to be made.

The task offered to students requires them to read a general drawing and use it to make working drawings of parts (as directed by the teacher).

1. Familiarize yourself with the contents of the main inscription placed in the lower right corner of the drawing. Determine the product name, drawing number, scale, etc. from the inscription. Often the name of the product says a lot about its purpose and operating conditions (for example, “Shut-off valve”, “Pneumatic vice”, etc.).

2. Familiarize yourself with the purpose and operating principle of the depicted product using the set of design documents attached to the drawing, in particular the explanatory note and technical specifications.

3. Study the images on the drawing: find out the location of the front view (main view); establish the number of main, additional and local views in which the drawing is made; determine which sections are used in the drawing (simple or complex); set the direction of the cutting plane for each cut; note the presence of sections, extensions, etc.

4. Familiarize yourself with the contents of this product; set the name of each part and consistently find each part in the drawing (on all views, sections and sections).

Determine from the found images geometric shape And design features details.

Clarification of the shape of each part is facilitated by the fact that in all sections and sections the same part is shaded with the same slope and the same distance between the lines.

5. Establish the nature of the connection of individual parts.

For permanent connections (welded, riveted, soldered, etc.), determine each element of the connection (for example, each individual weld).

For detachable connections, identify all fasteners included in the connection.

For moving parts, it is necessary to determine the process for their re-

displacement during operation of the mechanism (interaction of parts). It is necessary to establish which surfaces of the parts are mating and along what dimensions of the surfaces the connection is made.

Based on the general view drawing, the fit of the parts is determined, guaranteeing their interaction in the product.

6. Determine which moving surfaces of parts are lubricated and how this lubrication is carried out.

7. Establish the procedure for assembling and disassembling the product. In this case, it is necessary to highlight standardized and normalized parts for which working drawings are not drawn up.

Let's consider the procedure for reading a general drawing using the example of an assembly unit shown in Fig. 10.1.

From the main inscription it is clear that the drawing shows a plug valve on a scale of 1:1.

From the description, which is usually attached to general drawings for educational purposes, you can find out that a plug valve is one of the types of pipeline fittings and is intended to change the supply of liquid (gas) passing through a pipeline. Plug valves are installed where a quick change in the supply of liquid (gas) is required, since to fully open the valve it is enough to turn the plug at an angle of 90°.

The plug tap drawing contains three images. In place of the main view there is a frontal section, which shows the interaction of the main parts.

The faucet consists of a body 1 in which a conical plug 2 is installed (when turned, it changes the cross-section or completely closes the hole in the body). Plug 2 is pressed by cover 3 to the conical surface of body 1. Bushing 4 and stuffing box 11 (felt) seal the movable connection of parts 3 and 2.

In the view on the left, a local section is made, explaining the design of the connection between the housing and the cover with screw 5.

According to the specification (Fig. 10.2), we determine the composition of the parts included in the product “Plug tap”.

The product consists of 11 types of components, which include five original parts, five standard products and one material. All original parts are included in the product in a single copy. There is no drawing for part 5 “Gasket”, but the dimensions and shape of the part are explained in the specification.

Let's start getting acquainted with the original parts of the crane with the body. Studying the shape of this part in each view and comparing the views with each other, let us imagine an image of the body.

Since in the views the image of the body is partially covered by the image of the parts located inside or by the upper parts, it is necessary to supplement and combine into a single image all the available images of the body elements in the drawing.

The central part of the body has the shape of a truncated cone, which has pipes on the right and left. At the end of the right pipe there is a G1 cylindrical pipe thread. There is a flange at the end of the left pipe triangular shape with three through cylindrical holes Ø9. On top of the body there is a round flange with four threaded holes for attaching the cover.

The described shape of the body is comparable to the image in Fig. 10.3. The housing drawing is given in the appendix. 14.

Having dealt with the image of the main part (body 1), let's move on to studying the remaining parts (2, 3, 4). First, we will consider each of them in detail on the assembly drawing.

Plug 2 consists of a truncated cone with a radial hole and a cylindrical rod with a shank square section. Oval shape holes are determined by the view on the left, and square shape the shank can be read from the top view (Fig. 10.1). The shape of the plug is shown in Fig. 10.4 (a drawing of the plug is given in Appendix 15).

An image of cover 3 (Fig. 10.1) is shown in Fig. 10.5. Let's determine the shape of the cover elements from the assembly drawing and compare them with the image in Fig. 10.5 (a drawing of the cover is given in Appendix 15).

Rice. 10.4 Fig. 10.5

Determine the shape of the “Bulb” part yourself from the images available in the drawing (Fig. 10.1), then compare with the drawing given in the appendix. 17.

Every time you read a general view drawing, you must compare the drawing of a separate part with its image on the assembly drawing.

After the shape of the individual parts has been studied, it is necessary to establish how the parts are connected to each other and the possibility of movement of one part relative to another.

Thus, analyzing the relative position of the parts in Fig. 10.1, we determine that cover 3 is attached to the body using four screws 5.

On the cover 3 there is an oil seal sleeve 4, which ensures sealing of the felt packing 11. The oil seal is pressed against the cover using studs 9 and nuts 6.

The only moving part in this mechanism is the plug, which can rotate around its axis.

The valve in the drawing is shown in the open position.

Instructions

When reading a drawing, look at the frame in which it is framed. In the main frame, find information about the name of the part or assembly unit, its number and the material from which it is made (if it is a part). In the case of an image of an assembly unit, you will see in the “Name” column of the main inscription a line in which there will be “Assembly drawing”.

Pay attention to the scale of the image, which should be indicated in the title block of the drawing. It shows how many times the image in the drawing is reduced or enlarged relative to the real object. When designing, magnification scales are used (for example, 2:1, 4:1), which means that the image in the drawing is enlarged compared to the real object. The reduction scale (for example, 1:2, 1:10), in turn, shows how much the image in the drawing is reduced compared to the object.

Find the main view of the depicted object. Most likely, a number of sizes will be printed on it (including dimensions). Take a close look at this view. Pay attention to the cuts and sections, if any, as they give an idea of internal form details. The area of ​​the part or assembly that falls within the plane of the cut or section is shown as shaded in the drawings. Some cuts and sections are presented separately, and they are designated in capital letters with a hyphen (for example, A-A, B-B).

For a more accurate representation of the object, use other views shown in the drawing. Most likely it will be a left view and a top view. Additional views are indicated by capital letters (for example, D or G).

Please pay attention to the dimensions provided. They are usually indicated with tolerances that characterize the accuracy of manufacturing a part or assembly unit. The drawing of the part must also include surface roughness symbols.

Read technical requirements. This is the text located above the main title of the drawing. It carries information about the manufacture, storage and operation of the object.

Technological documentation includes route and operational maps. When reading the route map, pay attention to General requirements, presented to a part or assembly. Next you will see the sequence of operations that are necessary to manufacture a particular object. The numbers before the name of the operation characterize the number of the workshop, workplace and the number of the operation itself. Then the sequence of actions is listed, and at the end of the operation the tools and devices used are indicated.