Modern society in its development and economic activities actively uses graphic language, which to date there is no alternative (holographic technology that is under development).Graphic language finds its technological application by drawing projections of three-dimensional objects in two-dimensional plane.This method has an interesting history, but it is - the subject of this article.Our goal - to provide the reader with an overview of the drawing as a precise and universal tool for engineers and architects in terms of its general legal regulation.
specialist who knows the rules of design drawings must also competently guide the work of the relevant State standards, defining the basic mandatory requirements to the drawings.Also important is his expertise, allowing even for complex shaped parts with optimal visualize geometric constructions in the drawings.
What you need to know and be able to perform drawings
Firstly, it is intended that the knowledge base of the architect or engineer - artist drawings included ESKD - rules of design drawings and practical skills of optimal geometric representations projections details to display it in the drawing.
Currently, modern productive specialized programs - computer-aided design replaced the traditional "manual" plotting.However, automation still requires solid knowledge in the following state standards:
- 2.301-68 - sets the format sheets of drawings in paper or electronic form;
- 2.302-68 - determines the ratio of the size of the object shown in the drawing, to its actual size (scale);
- 2.303-68 - regulating mark lines in the figures recommended by the applicable regulations;
- 2.304-81 - establishes relevant drawing fonts;
-2.307-68 - determines the application of the drawing as the dimensions and tolerances.
important qualification requirements for the Executive drawings are:
- practical ability to use ESKD - rules of design drawings in relation to applications;
- skills geometric constructions for optimum performance of the drawings, which are then conveniently used in the manufacture of marking specific details.
Basics drawings
Development of design documentation (which regulates the creation of ESKD - rules of design drawings) is a necessary step preceding the actual production parts.
This is fundamentally important specifics: what is and what is produced;What is the default name of the product;its exact size, shape, what materials it is made.All this is important because then the design documentation will be the main guarantor of the identity of manufacturing parts, and if needed - interchangeability with analogue, issued by other manufacturers.In terms of using common tools (rules and regulations) by different manufacturers, important to maintain them ESKD - rules of design drawings.
state standards governing the drawing
We have already mentioned in this article, the terms ESKD, state standards in the context of their regulatory role for the engineer.Define their relationship.
role of regulatory control in the design of various drawings and diagrams to design documents play a specially developed at the state level uniform technological standards - GOST.These standards organization together a single system design documentation, or ESKD.
ESKD rules regulate the execution of drawings, the current in the stages of creation, the final design and the proper organization of their document as a form of documentation in the framework of the specialized enterprises and organizations, as well as in institutions of the Ministry of Education.ESKD - rules of design drawings - conformed with the international ISO standards (ie. E. The approved International standards organizations), as well as meet the requirements of a permanent international commission of standardization.
note that compliance with state standards are binding in all areas of industry, as well as research and design institutions.Accordingly, GOST - rules of design drawings - are required in the study of engineering graphics in the educational system.
Thus, despite the progress of automation in the creation of drawings, guests know should.However, we have an inkling of the direction of the main objections to our computer-literate opponents, it consists in the fact that all the rules have already met in the drawings, which should be easy to find on the Internet.
Can, doing sketching, unaware guests?No!
However, we load ahead of the curve, noting that yes, now the Internet any PC user can choose from the thousands and thousands of photos of drawings required.And then he used a special program to recognize, the desired drawing.
However, our opponents are telling the whole story.In fact, recognition programs are imperfect drawings, respectively, obtained with their help drawing known to contain significant errors.They, of course, continue to have to edit, using the knowledge of guests.
much more reasonable in this situation creatively use photos of drawings as an example, actually recreating them using specialized software - computer-aided design.The leading representative of the CAD for the past several decades is an AutoCAD development companies with world-rated «Autodesk».This program is now actively used by leading design offices.Kuhlman went down in history!
formats.State Standard 2.301-68
drawings are executed on a paper sheet having a certain, well-defined dimensions of the current guests, and measured frame for drawing (A4 size is 210 to 297 mm. See Table 1).
Table 1. Formats.
| A4 | lower side of 210 mm | large side 297mm |
| A3 | lower side of 297 mm | large side 420mm |
| A2 | lower side of 420 mm | large side 594 mm |
| A1 | lower side of 594 mm | large side 841 mm |
| A0 | lower side of 841 mm | larger side 1189 mm |
note that sometimes frame for drawing A4 deliberately restricts excess space, exceeding the size of the image.In this case, appropriate smaller format - A5 sides whose dimensions 148 by 210 mm.
visual representation of the popular formats which define the basic rules of design drawings, shown in Figure 1:
Fig.1. The ratio formats
main inscription
main label is placed on the drawings except for A4 as the long side as well as along the short.For A4 it is represented only along the short side, as this is a vertical format.
additional columns (also with the exception of A4) is placed on the long side
(Placing the title block we have shown in Figure 2.)
Fig.2.Accommodation Titleblock
decoration drawing frame regulated by its distance from the edge: on all its sides (except the left) - 5 mm.On the left is the distance from the frame to the edge of the sheet is 20 mm.The line, which frames the frame of the drawing should not already be 0.7 mm.
main inscriptions are made according to GOST № 2.104-68, which determines the size, shape, and the procedure for filling.Characteristically, it is an essential element of all kinds of drawings and diagrams.As an example we give the title block, recommended for use in training the drawings (see Fig. 3).
Figure 3. The main inscription, recommended for educational drawings
The numbers in the illustration following graphs Titleblock:
1 - the name of the product;
2 - designated as a document;
3 - How to choose the material for the manufacture of parts;
4 - requisites of the enterprise - the index.
often drawing is performed on multiple sheets.In this case, the second and all subsequent main inscription is performed in other than the first form.Her image is shown in Figure 4.
Figure 4. The title block for the second and subsequent sheets of drawing graphs
it (they are numbered in the figure) are filled according to the above explanation of the figures for the main signs of the first sheet.
designations in the drawings
By definition, called a scaled drawing graphic image products, where the dimensions and specifications.The information includes a drawing is sufficient for the production referred to in the definition of the product.
rules applying dimensional values to the drawings in the industry regulated by GOST № 2.307-68.This is a rather delicate point in the design drawings.After all, only one missed size makes difficult drawing a blank in unclaimed work.
themselves sizes drafting divided into several types.The first group - the size of the workers.This is information that is used directly in the production.The second - the size of reference (indicated by an asterisk (*)).They are used to working with an engineering drawing.
dimension a drawing with the help of dimension lines.The designations are applied to the drawings in compliance with accepted scale.Its value is in the title block - in a separate column.We define the concept of scale: it is identified with the ratio of the actual size of the object to the size of its image.If possible, it is preferable to the scale of one to one, however, as you know, for different sizes of the details necessary to either reduce or increase.Eligible zoom determined by GOST 2.302-68 cm (see. Table 2).
Table 2. The scale used in drafting
scale selection criterion is to further the usability of the drawing.
Lines
In the drawings different types of lines, each of which has a specific purpose.Use of lines in the drawings is defined by GOST 2.303-68.
thick solid line is used to mark the main visible contours of the displayed object.Thickness for her determined within 0.5-1.4 mm and subsequently selected value is indicated by the letter S. Why is the value assigned to a dummy variable?The fact is that in the future the thickness of the rest of the lines will measure the thickness of the core.
dashed lines represent the outlines invisible.Its thickness is within s / 3-s / 2.The length of the stroke is within the range of 3-8 mm, and the distance between them - 3-4 mm to the same length of all strokes in the drawing must be equal area, however, the same applies to the gap separating them.
thin solid line in demand for display or extension lines or size.Its thickness is the same as the thickness of the dashed lines: s / 3-s / 2.
continuous wavy line is applied to the place drawing parts, where by virtue of a significant size and monotonous forms of a particular piece of detail is expedient to designate a break this fragment.Its thickness - as s / 3 - s / 2.
thin dashed line represents the line of symmetry - the axial and center.(It was agreed that if such a line passes through the center of the circle, in the heart of the bar should be, but not the point.)
drawing assembly
Making assembly drawing has its own characteristics.Often item or mechanism has a rather complex structure consists of several parts joined together by riveting, welding, or other rigid assembly.In the drawings, those compounds 1-3 parts make out as the main assembly drawing, which shows only the size of the main parts.To him the individual drawings are enclosed all the rest of the parts with their size.
Sketches technical documentation
diverse and informative technological drawing.Drawings assembly - is not the only element of technological documentation.It also includes sketches and technology.It is guided by, the material can be determined, from which the product is made, as well acquainted with methods of its assembly and mounting.
dimensional tolerances in the drawings
dimensional designations in the drawings are accompanied by an indication of permissible tolerances during machining of the workpiece.Such deviations may be labeled or numbers, such as 19 + 0.014, or by quality class.("Qualitea" - in English "quality").
Qualitet (or the degree of deviation that can be tolerated) is called the conditional level of accuracy.Such levels, there are only 19. Within each quality class with an increase in linear dimensions of the products themselves for their tolerance, expressed in millimeters, is also increasing.The most accurate feel Qualitet №01, and the least accurate - №17 (except 01 th quality class, there are also "zero", and the 1st.).Qualitet from the nominal size is designated by the letter H, if it is positive and, respectively, h, if it has a negative value.The numbers following the letter just means the number of used quality class.For example, the designation 28H7 should be read as: nominal size of 28 mm, the tolerance - * 7.
Making working drawings
Blueprint is characterized by a minimum number of parts of the projections, which gives an idea of its shape and the elements.Blueprint also carries information about the material and construction, for example, generally at a scale of either 1 to 10 or 1 to 15. Table 3 presents the symbols of such materials.
Table 3. Symbols
Rules for working drawings contain specific organizational recommendations to issue technical documentation optimally.Of course, an engineer, doing drawings, should strive to (of course, if possible) to execute them in a uniform format.Choosing zoom, it takes the main criterion for readability image detail.
be appreciated that the scale is not a basis to determine the size of the working drawing.
Execution of working drawings of the major elements that have a lattice structure, has its own characteristics.It contains two types of dimensions: the general geometric lattice structure features in a smaller scale, and grid elements themselves - on a scale larger.
Regarding the working drawings curvilinear elements crucial indication of answering the question: "Dimensions are represented by a scribe line?".For bent sheet, for example, such a reference point is the neutral line.And folds in this case do not show in the degree measurements, and by providing them the rectangular triangle with legs of length specified in the working drawings.
in the working drawings each detail is given a number.Monotonous parts are always identified with the same number.However, in the latter case, be careful, because they can meet and mirror-symmetrical parts.They can not designate one number.
Architectural drawings
According to the procedure, which regulates the rules of making construction drawings (GOST 21.501-93), the basic structure of the building, its steps and flying on the architectural drawings are attached to the coordinate axes.Performs same axis and the dashed lines are numbered.
On the left side of the drawing endure the longitudinal axis and to the right - cross.Numbering transverse axes made in Arabic numerals, and longitudinal - Russian letters.
Remote and dimension lines used for the dimension of the architectural drawing.The smallest articulation floor is applied on the first dimension line on the drawing (design rules architectural drawings, GOST 21.501-93).Then - in ascending order.The last dimension line visualizes the information on the size of the building between the extreme axles.
