Thanks to technical progress, many programs were created to facilitate the work of work on the drawings. However, even the most complex and multifunctional programs cannot completely replace a person, and therefore there are many tasks that you have to solve yourself. So, quite a lot of questions occur when it is necessary to figure out the scale of the drawings. GOST sufficiently strictly regulates everything that is in the drawings, including large-scale parameters, symbols, etc. However, theoretical knowledge does not always help figure out in practice.
GOST tells us that there are several types of scales: in full size, scale zoom and scale scale. The nuance is that when creating drawings, the scale cannot be chosen at its discretion, they must accurately comply with the parameters given GOST:
GOST provides for the designation of the scale of the elements depicted in the drawings. For this, a special area is used in the lower right corner, which, as a rule, is specifically denoted. If the graph does not have the names, then the "M" letter, for example, M 1: 1, is set to digital values; M 1: 2; M 2: 1 and so on. It is important to remember that if you perform a working drawing of a typical part, then the scale is not indicated, and the column is made of docking. If you make a drawing of the part on the zoom scale, then in order to represent the real size of the part, the part is allowed in the upper left corner on the scale of 1: 1, and the size for such an image does not specify.
Of course, different values \u200b\u200bcan sometimes mislead, but in fact everything is very simple. So, if you see that the scale of 1: 100 is indicated, then the item will be 100 times more than its image. And on the contrary, if the scale is 100: 1, then the item will be 100 times less. In order to avoid unnecessary confusion, all sizes in the drawings must be specified only in a natural value, regardless of scale. Thus, the indication of the size obtained as a result of scaling is a rough error.
We understand that the scale of the drawings of GOST prescribes sufficiently strictly and non-compliance with standards can lead to what you have to redo the entire drawing. At the same time, sometimes to calculate the necessary scale is quite difficult. If you are not confident in your abilities and doubt that you can carry out the necessary calculations correctly, you can always resort to the help of specialists of our company. Our specialists have extensive experience in making various drawings according to all existing gta stations. They easily draw a part or object of any size, from the smallest to huge.
Fig. 26. Drawing of the part without sizes
Obviously, this can not be done, as there are no sizes.
Dimensions in drawings is a very responsible operation that significantly affects the ease of reading the drawing.
Dimensional rules are established by standards. ECCD (GOST 2.307-68).
When drawing dimensions, symptoms are used - S (thickness), Ø (diameter), R (radius), (square).
Dimensions are there linear and angular. Linear dimensions denote length, width, height, thickness, diameter, or radius of the measured part of the part. The angular size is denoted by the value of the angle.
Linear dimensions in drawings indicate in millimeters, but the designation unit is not applied.
The angular dimensions indicate degrees, minutes and seconds with the measurement unit designation.
The amount of sizes in the drawing should be minimal, but sufficient for the manufacture and control of the product.
For drawing sizes remote and dimensional lineswhich are carried out with a solid thin line.
Remote lines - Lines that endure the size.
Dimensional lines- The lines on which the size is made, ends at both ends of the arrows. The arrows must necessarily touch the output lines, the arrow shape is shown in Fig. 27.
Fig. 27. Shape arrows
The dimensional line is always carried out in parallel line of the contour of the part of the part, the size of which it determines and perpendicular to the remote lines. If the size is less than 12 mm, the arrows are installed outside, and if more than 12 mm, then inside (Fig. 28). The dimensional line is from the drawing contour of the part for 10 mm, the distance between the parallel dimensional lines should be at least 7-10 mm.
The remote lines go out of the ends of the dimensional line arrow by 1-5 mm. The size is placed over the dimensional line, closer to its middle.
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Fig. 28. Examples of sizes
With a vertically located dimensional line, the dimension number is written to the left of it.
The same size in the drawing is placed only once.
First, the smaller size is taken, and then more. In the drawing, dimensional lines should not intersect.
When specifying the size of the angle, the dimensional line is carried out as an arc of the circle with the center at the top of the corner.
Diameter sign It is placed in front of the dimensional number if the circle was performed completely. The dimensional line is carried out through the center of the circle. If the part has several identical holes, then the size is placed once with the number of holes (see Fig. 28).
Radius signit is placed in the case when a part of the circle was carried out, the dimensional line is carried out from the center of the arc.
Main concepts should be remembered:
1) sizes of elements -dimensions of the magnitude of cutouts, protrusions, holes, grooves;
2) coordinating dimensions - dimensions showing the location of the elements relate to the contour of the part and each other;
3) dimensions -the greatest dimensions in length, height, width.
In the drawing practice, it is necessary to perform images of very large parts (machines, ships, cars) and very small (hourly mechanisms, accurate devices).
Can I portray them in full size? Of course, it is impossible, so large items depict reduced, and small - increased. Apply scale
(Fig. 29).
Fig. 29. Zoom designation in the drawing
Scale - The ratio of linear dimensions of the subject to its valid sizes.
The scales of the images and their designation sets the standard (GOST 2.302-68).
natural value - 1: 1(one to one);
scales of reduction - 1: 2; 1: 25; 1: 4; 1: 5; 1:10; 1:15;
zoom scale - 2: 1; 2.5: 1; 4: 1; 5: 1; 10: 1; 15: 1.
The scale is denoted by the letter M on the drawing field, for example, M 1: 2. In the main lettering letter M is not put. Whatever the scale of the drawing, the dimensions on it are always indicated valid.
Sometimes it is necessary to determine the scale in which any object is drawn. In this case, this is followed: the size of the side (for example, a) is determined using the measuring line, it is 50 mm. The valid amount of the segment indicated on the drawing is 100 mm. Consequently, the scale is determined as the private from division 50 by 100 and is 1: 2 (Fig. 30).
Fig. 30. Definition of the size of the part in the drawing
In any computer graphics program there is a magnifying glass tool. It allows you to instantly change the scale of the image (drawing, pictures), increasing (reducing) it to the desired value (Fig. 31).
Fig. 31. Use of scale in computer programs tool "Magnaya"
Drawing font
In a wide variety of science and technology, design, man applies fonts that writes letters, numbers, conditional signs and other characters.
Font- The cover of the coding of text information.
Each type of graphic activity is characterized by certain fonts. In many cases, art elements (decorations), who give him greater expressiveness, contribute into the font.
The main types of fonts that were most often used throughout historical Development The written culture of humanity is presented in Fig. 32.
Fig. 32. Types of font
Currently popular computer fonts. In the drawings, all the inscriptions are performed in drawing font - GOST 2.304-81.
GOST sets the following font numbers: 1.8 (not recommended, but allowed); 2.5; 3.5; 5; 7; 10, as well as height, width of the letters and the distance between the letters.
For the drawings performed on A4 format, the following font numbers are recommended: 2.5; 3.5; 5; 7. Standard has been installed two types of font - capital (capital letters) and lowercase. According to the design, capital and lowercase letters can be divided into three groups (Fig. 33).
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Fig. 33. Drawing font
Capital letters:
1 group - g, p, n, t, e, c, sh, sh;
2 group - and, x, k, f, m, a, l, d;
3 Group - H, U, B, B, R, I, O, C, E, YU, F, S, B, K.
Lower case:
1 group - p, y, c, t, sh, u, and;
2 Group - Oh, A, B, B, D, YU, R, E, C;
3 Group - F, B, I, G, F, Z, K, L, M, H, X, H.
According to proportions, they can be divided into broad and narrow: wide uppercase - sh, u, g, yu, s, f; Wide line - t, sh, sh, y, s, m. Writing the letters of the drawing font is carried out on a simplified form. The number of the capital font corresponds to the height of the letters, and the width is a smaller previous number, for example, font number 7, the height of the letters - 7, the width of the letters - 5. The width of wide letters corresponds to height. Distance between letters - 2 mm.
The height of the lowercase letters corresponds to the smaller previous font number, and the width is the next previous number, for example, font number 7, the height of the letters is 5, the width is 3.5, the width of the wide letters corresponds to the height of the letters. Distance between letters is 1.5 mm.
For the correct execution of letters at the initial stage, the grid is used.
The main inscription is filled with font No. 3.5; Drawing name - font number 7 or number 5 (Fig. 34).
Fig. 34. Sample fill in the main inscription
Remember, lines do not touch the line of the frame.
Machines and some of their details, buildings and their parts have large sizes, so it is not possible to draw them in a natural amount possible. Their images have to draw in. The smallest details of the handmade hours and other mechanisms have to draw, on the contrary, on the scale of the increase.
In all cases, when it is possible, parts should be drawn in a large value, that is, on the scale of 1: 1.
After determining the page parameters, the default program displays the program view containing the entire model space occupied by the model below.
Before we start working with the species screens, it is recommended to insert the drawing format to find out which space we have. Of course, at first to insert something, you need to do something.
Please note that the drawing format is too large for a specific page layout - to make sure the layout size is incorrect, you must measure it.
Please note that the form was inserted in the form of a block, so it is enough to specify it anywhere, and everything will be allocated.
Reduce or increase images into an arbitrary number of times is not allowed. GOST 2.302-68 The following dimension scales are installed: 1: 2; 1: 2.5; 1: 4; 1: 5; 1:10; 1:15; 1:20; 1:25; 1:40; 1:50; 1:75; 1: 100; 1: 200; 1: 400; 1: 500; 1: 800; 1: 1000. In compiling the master plans of large objects, it is allowed to use the scale of 1: 2000; 1: 5000; 1:10 000; 1:20 000; 1:25 000; 1:50 000. The magnification scale is recorded in the form of a relation to a unit; The following extension is set to the standard: 2: 1; 2.5: 1; 4: 1; 5: 1; 10: 1; 20: 1; 40: 1, 50: 1; 100: 1. In the necessary cases, it is allowed to apply the scale of zoom (100l): 1, where N is an integer. In cases where the full word "scale" is missing in the record, the letter M is affixed before designation, for example, they write: M 1: 2 (scale scale), m 2: 1 (zoom scale). In fig. 1 The puck of the rectangular shape is shown in three scales: in a natural value (M 1: 1), on the scale of reduction and on the zoom scale. Linear dimensions of the last image are four times more than the average, and the area occupied by the image is sixteen times more. Such a sharp change in the image value should be considered when choosing a scale of drawing.
As a result of this simple operation, the drawing format was created. Contains tools to determine object sizes. It is good to revise the size of the operation, as shown below.
As you can see in the figure below, a specific area of \u200b\u200bpaper and the print area do not overlap with the drawing format.
Now that the page parameters correspond to expectations, you can start the "layout" of the drawing, that is, layout of forecasts, parts, add comments to the drawing. During the design, it is important to know that over time, design elements will be subject to changes associated, for example, with changes in shape or material arising from, for example, technological changes, modernization caused by the best adaptation to the market, etc. Which should be inserted in the same way as the drawing format is the drawing below.
TBEGIN -\u003e TEND -\u003e
Fig. 1. Comparison of various scales. Linear scale
In addition to numerical scales, linear scales are used in the draw. Linear scale There are two species: simple and transverse (Fig. 1). A simple linear scale corresponding to a numerical scale of 1: 100 is a line on which centimeter divisions are left from zero division, and the left is one of the same division divided into millimeters. Each centimeter linear scale division corresponds to 100 cm (or 1 m). Each millimeter division corresponds to the obviously one decimeter. Taking a meter of any size from the drawing, put one needle to the appropriate full division to the right of zero,
an example for division 3. Then the second needle will show how much decimeters over 3 m has a measured size. In this case, it equals 3.4 m.
Now you can start working with the species screens.
Please note that the species screen frame has changed from thin to thick, which means that you can edit the space model space from the paper space. Actions that can be performed here are no different from actions in the model space, and that the most important changes made here are reflected in the model space.
As you can see, it is impossible, because the drawing table and the change table occupy too much space. In this case, change the size of the viewing window to the smaller or insert a larger drawing format.
Now that the main look and its cross section obtained as a result of the intersection of the drawn object represented by the cutting line.
The advantages of a simple linear scale in front of the usual line are as follows:
More perfect is linear transverse scale. On the drawing, it is given for the same scale of 1: 100. Inclined lines, transverse, allow not only decimeters, but also centimeters. For example, the scale is shown 3.48 m. Linear scales are used primarily on construction and topographical drawings.
The result of the above operation is a viewing area with an uncertain step, which shows everything that is drawn in the model space, in the figure below.
Please note that at the moment there are two species screens in the drawing, only one of which is active, i.e. The one where the model space can be edited. It can be recognized by a bold frame, and the mouse cursor, which is located above it, is a cross-seater with the choice of "viewfinder" - the cursor located over inactive darts - the arrow is the drawing below.
Tend -\u003e
Fig. 2. Schedule scale
In project and production practice often use proportional (angular) scale. It is the simplest schedule. Let it be necessary to build such a schedule for a scale of 1: 5. On the horizontal straight line from point A (Fig. 2), a segment is laying equal to 100 mm; At the point in building a straight corner and on its second side, a segment is laid out, reduced 5 times (100: 5 \u003d 20 mm); Connect the resulting point with the point A. The value of 12.8 mm corresponding to 66 mm, take the circular meter directly from the graph, without calculating it and does not use the ruler. The schedule is built on millimeter paper or on paper, gravel in the cage.
You can change the inactive tipping on an active in a very simple way - just Mouse over the cursor and right-click. Intentently passed, as shown in previous chapters, has a default rectangle shape. However, nothing prevents you from identifying your own form.
However, when the ellipse is specified in the "Properties" window, there is no option of a large-scale coefficient - in the figure below. 
When creating a layer, the viewfinder was given thickness 0, 5, which was not the best, since he lost one of the characteristics of the active viewport - bold. The thickness of the frame is not important, because in front of the seal the layer can be hidden or blocked - it is only a comfort comfort.
For a scale of 1: 2.5, 40 mm is deposited on the continuation of the Cate, 1: 2-50 mm. A number of proportional scales depicted in the figure are called the scale schedule. Use them allows you to save a significant amount of time. Buing a scales schedule, use them throughout the work on the course of drawing.
This is the relationship between the natural dimensions of the object or object to the linear dimensions of the drawings of the drawings of the drawings can be expressed by the number, in which case they are called numerical scales and graphically-linear scales.
Of course, this item can be copied manually, removing unnecessary elements from it, but it can also save you a precious time.
The effect is higher - this is a viewing window, in which the single visible layer is the loop of the contour - the drawing below. 
Speaking about the text in the drawings, it is usually believed that comments to the drawings collected by the constructor in the form of compact descriptions of points complement the actuator drawing of information that cannot be transmitted as symbols or characters. These comments are usually placed on the table of drawings, although it is not a tough rule and in the absence of space - in any free place Drawing forms, of course, not to reduce the readability of the drawing.
The numeric scale is denoted by the fraction and shows the multiplicity of decrease as well as an increase in the size of the objects of the objects in the drawing. It is dependent on the purpose of drawings as well as the complexity of the forms of depicted objects and structures in the drawing, when drawing up drawing documents, use scale:
Reduce 1:2; 1:2.5; 1:4; 1: 10; 1:15; 1:20; 1:25; 1: 40; 1:50; 1:75; 1: 100; 1:200; 1:400; 1:500; 1:800; 1:1000;
Filling the drawing table is one of the last steps to create an executive drawing. The layout of the protrusions and their resins are already defined, the material from which the item is made is known, and this figure will be checked and tested - in a word, all the data necessary for its completion is known. Of course, this is not a rule, the table can be filled at the beginning, but then almost certainly some data will be changed, and you will have to remember to view and update the entire table, and often do not remember it.
Zoom:2:1; 2.5:1;4:1; 5:1; 10:1; 20:1; 40:1; 50:1; 100:1;
The image in a natural value of 1: 1. In the process of designing the master plans of large objects, the following scales are used: 1:2000; 1: 5000; 1:10000; 1:20000; 1: 25000; 1:50000
.
If the drawing is performed on one scale, then indicate its value in the graph of the main inscription drawing by type 1: 1; 1: 2; 1: 100 and so on. If the image is made in the drawing, the scale is made on the scale, which differs from the specified scale in the main inscription drawing, then in this case, indicate the scale of the type M 1: 1; M1: 2 And so on under the appropriate image name.
When drafting construction drawings and using a numeric scale, it is necessary to make calculations to determine the size of the lines segments that are applied in the drawing. For example, if the length of the object is 4000 millimeters, and 1: 50 numeric scale, in order to calculate the length of the length of the segment, 4000 millimeters are necessary to divide on (degree of reduction) 50, and to postpone the resulting value of 80 millimeters in the drawing.
In order to reduce the calculations use a large-scale line or build a linear scale (see Figure 4 A) in a 1:50 numeric scale. At the beginning of the direct line in the drawing and there are several times the base of scale is deficked. The base of scale is the value that is obtained by dividing the unit adopted in this case (1 m \u003d 1000 mm) to the size of the reduction of 1000: 50 \u003d 20 millimeters.
On the left side, the first segment is separated into several equal parts, so that each division corresponds to the integer. If it is divided into ten equal parts, each division will correspond to 0.1 meters, if the 0.2 meters are divided into five parts.
In order to use a built linear scale, for example, to take the size of 4650 millimeters, it is necessary to put one foot of the measuring circulation for four meters, and put another one on the sixth and a half to the left of zero fractional division. In the case when accuracy is insufficient, a transverse scale is used.
A transverse scale allows you to determine the size with a certain error. The error may be to the hundredths of the main unit of measurement. Figure 4b shows an example of determining the size of 4.65 m. The hundredths take on the vertical segment and the tenths on the horizontal.
In the case when an arbitrary scale is used and it is necessary to construct a reduced or enlarged image of an object performed according to a specified drawing format use an angular scale or as it is also called proportional. Angular scale can be built as a rectangular triangle.
The ratio of the cathets of such a rectangular triangle is equal to the variety of changes to the scale of the image (H: H). If it is necessary to change the scale of the image using an angular scale, using only abstract values \u200b\u200band does not calculate the dimensions of the item depicted. For example, when you need a specified drawing to portray on an enlarged scale.
We build a rectangular triangle for this (see Figure 4 V) ABC. For such a triangle, the vertical catat is equal to the segment of some direct, which is taken on a given drawing. Horizontal watches AV is equal to the length of the segment on the scale of the increased drawing. In order to increase the desired one segment of a straight line on a given drawing, for example, a segment H, it is necessary to postpone it in parallel cathetue of the aircraft scale (vertically), between the hypothenuisa of the speakers and carnet av.
In this case, the increased size of the desired segment will be equal to the size of H, taken (horizontally) on the side of the Angular scale. Angle scale is also used when transferring values \u200b\u200bfrom one numeric scale to another.
Scale
scale Reduction:
magnification scale:
The main lines of the drawing, the features of their drawing in accordance with GOST.
In order for the drawing to be expressive and easily read, it must be decorated with lines of various thickness and drawing. The lines and their destination are set GOST 2.303-68 *.
The main line of drawing is the line of the visible contour. The thickness of the solid main line S must be between 0.5 to 1.4 mm depending on the size and complexity of the image, as well as on the format and appointment of the drawing.
Drawing lines.
| Name | Thickness line | Main appointment | |
| Solid main | S (0.5 to 1.4) | The line of the visible contour; transition lines visible; Line contour of the section (rendered and included in the cut). | |
| Solid thin | From S / 3 to S / 2 (from 0.2-0.5 to 0.3-0.75) | Lines of the contour of the accompanying section; Lines dimensional and remote; hatch lines; tuning lines; shelves of lines of calls and underline the inscriptions; lines for image of border details; lines limit remote elements on types, cuts and sections; transition lines depicted; folding lines on sweeps; The axis of projections, traces of planes, line construction of characteristic points with special builds. | |
| Solid wavy | Cliff line; View and cut line lines | ||
| Strich | Invisible contour lines; The transition lines are invisible. | ||
| Bar-dotted thin | Line axial and centers; cross sections, which are axes of symmetry for superimposed or transmitted sections; lines for image parts of products in extreme or intermediate positions; Lines for the image of the sweep aligned with the view. | ||
| Rock-dotted thickened | From S / 2 to 2 / 3S (from 0.3-0.75 to 0.4-1) | Lines denoting surfaces subject to heat treatment or coating; Line for the image of elements located in front of the secular plane. | |
| Open | From S to 1.5S (from 0.6-1.5 to 0.9-2.25) | Lines of sections | |
| Solid Thin with Flames | From S / 3 to S / 2 (from 0.2-0.5 to 0.3-0.75) | Long lines of the cliff | |
| Barchpunctive with two dots thin | From S / 3 to S / 2 | Folding lines on sweeps; Lines for images of parts of products in extreme or intermediate positions and for the image of the sweep aligned with the view |
Barc-dotted lines must end with strokes, not points. The center of the circle should be marked by crossing strokes. In circles with a diameter of less than 12 mm barcode dotted lines used as a center, should be replaced with solid thin lines. Dimensional numbers and inscriptions should not intersect the drawing lines.
For the framework of the drawings, tables, the main inscriptions and specifications, solid lines of the thickness s should be applied.
Drawing fonts
In addition to dimensional numbers and other technical documents, in addition to dimensional numbers, various labels are applied both in the Graphs of the main inscription and on the drawing field - inscriptions with image designation, as well as related to individual elements of the image or building. The inscriptions must be clear and clear.
GOST 2.304-81 * Sets drawing fonts for inscriptions applied from hand in drawings and technical documents of all industries and construction.
The tilt of the letters and numbers of this font to the base of the string is approximately 75 degrees.
Basic inscriptions, headlines, names are allowed to write with straight letters. Inscriptions can only be performed from capital letters or in combination of uppercase.
The font size is determined by the height H of capital letters (in millimeters).
The following font sizes are set: 2.5; 3.5; five; 7; 10; fourteen; twenty; 28; 40.
When writing numbers and letters, you should keep in mind the following:
for all text, the thickness of the stroke lines should be the same;
the lower processes of the letter D and the top sign of the letter should be performed due to the gaps between the lines, and the lower and side processes of the letters C and Sh - due to the gaps between the rows and letters;
the capital letter in the word with lowercase letters should have the same thickness of the lines as in lowercase letters;
the height of the lowercase letters is 7/10 from the height of the capital;
the width of most capital letters is 6/10 H
width of the letters a, d, m, x, s, y - 7 / 10h, and letters w, f, u, b - 8 / 10h
the width of the lowercase letters and Arab numbers, except for the number 1, is 5/10h
Figure 1 should be placed at a normal distance from adjacent numbers and letters.
the distance between the lines should be at least the height of the lowercase letters.
with the apparent increase in the gaps between adjacent letters, for example, g and a, g and a, p and d, t and l, etc., these intervals should be reduced.
Choosing the main type of detail.
The performance of the drawing starts from the selection of the main image.
The main requirement for the main image it should transmit the most complete picture of the form and dimensions of the part.
As the main image (front view), both front-up section and a combination of type and cut is used.
Flat parts made of sheet material are depicted in one projection, showing their contour images, the thickness of the part is indicated by the conditional record.
For the manufacture of shaped parts made of sheet material, accurate sweeps or approximate blanks for stamped parts with hood are flat parts made of flat material.
The number of images (species, cuts, sections) of the subject in the drawing should be the smallest, but sufficient to detect its external and inner form and should be able to rationally apply the dimensions.
In some cases, one projection with an appropriate conditional sign, delivered at the dimensional number, gives a complete picture of the form of the depicted object. So, for example, a diameter sign indicates that the item shown is the body of rotation; The square sign indicates that the displayed object has the form of a prism with a normal cross section in the form of a square; The word "sphere", written before the diameter icon suggests that the surface is spherical; The symbol "S" (thickness) before the dimensional number replaces the second projection of the part, having a parallelepiped form, etc.
After analyzing the part of the part, you can determine which images are necessary for an exhaustive transfer of external and internal forms of this part. For most parts of the machines and mechanisms, it is enough to perform 3 images, given that the product can be used for the image of invisible contours, you can combine parts of the species with parts of the corresponding cuts, apply complex cuts, etc.
The choice of the main image (especially for the drawing of the part) is the most important stage of work on the drawing. If you make an error at this stage, then nothing else compensates for it. The drawing will be understood by a properly experienceful person, but reading takes a lot of time. A less experienced will not only spend even more time, but it may not be incorrect to understand the content of the drawing, which will lead to a production marriage.
Consider the order of choosing the main image, conventionally dividing it into three stages.
1. Determination of the direction of the view (direction of projection) to form the main image.
2. Determination of the content of the main image.
3. Selection of the position of the main image.
On assembly drawings, the main image should display the relative position of the main parts of the product, usually hidden from the observer view. Therefore, this image is a cut, like most other images placed in the drawing.
Complex cuts.
The incision made by several secant planes is called complex.
If the complex incision is obtained using parallel planes, then it is called a step, if the secant planes intersect, then broken.
The position of the secular plane indicates the drawing of the cross section. For the cross section of the open line should be applied. With a complex section, the strokes are also carried out in the cross-section links.
With broken cuts, the secant planes are conditionally rotated to align in one plane, while the direction of rotation may not coincide with the direction of the view. If the combined planes are parallel to one of the main projection planes, then the broken section is allowed to be placed on the place of the corresponding view. When the split plane is rotated, the items of the object, located behind it, should be drawn up as they are projected to the appropriate plane, to which combined.
(The cuts can be placed anywhere in the drawing, as well as with a turn to a position corresponding to this item on the main image. In the latter case, the word "turned" should be added to the inscription.
The separation of the section and the type of the bar-dotted thin line, which coincides with the next symmetry plane is not the entire object, but only its parts if it is a rotational body.)
Thin walls like ribs stiffness, as well as handwheel spokes are shown unfinished if the secant plane is directed along the axis or the long side of this element.
Also, details like bolts, screws, rivets, etc., with a longitudinal section show not dissected. If there is a hole or other plane in such details, you need to perform a local incision.
Local section
If you want to identify the form of an item on little plot Details, incision all the details can not be done. In this case, only part of the corresponding cut is shown. A section that serves to find out the subject of the subject only in a separately limited place is called local. The local incision is isolated on the form of a solid wavy line, which should not be coincided with any other lines of the image.
Section.
Cross section
(Sections that are not part of the cut are divided into rendered and superimposed. The submitted section is depicted at the free area of \u200b\u200bthe drawing, if possible, close to the view to which it belongs. It is allowed to portray this section in the break between the parts of the same species.
The axis of the symmetry of the made or superimposed section is indicated by a barc-dotted thin line without designation with letters and arrows. It is allowed to place a section anywhere in the drawing field, as well as with a turn. In the latter case, the word "turned" must be added to the inscription.
GOST 2.306-68 * Provides a special type of hatching for different materialsFrom which the details are made.)
15. Drainity of sections, their design in the drawing.
Cross section An image of a flat figure, resulting in the thought dissection of the object with a plane or several planes.
On the section shows only what is obtained directly in the securing plane.
In accordance with GOST 2.303-68, an open thickened line will be applied for the cross section line indicating the direction of the view direction and the designation of it with the same capital letters of the Russian alphabet, and the cross section itself is accompanied by an inscription on type aaa. In construction drawings, the cross section line instead of letters is allowed to use numbers, as well as to inscribe the name of the cut. The length of the arrow is selected in the range of 10-25 mm. The arrows are applied at a distance of 2-3 mm from the end of the thickened stroke. The initial and final thickened strokes should not cross the contour of the image. For complex sections, the ends of the open line are allowed to connect the thin bar-dotted line. In construction drawings, with symmetric sections, an open line is used with the designation of it, but without the arrows.
Sections that are not part of the cut are divided into rendered and superimposed. The submitted section is depicted at the free place of drawing, if possible, not far from the view to which it belongs. It is allowed to depict this section in the gap between parts of the same species.
The imposed cross section is located directly on the form of an item.
The cross section should be given preferences before superimposed. The contour of the subsection should be depicted with solid main lines, and the contour of the accompanying section - with solid thin lines, with the line of the object image at the location of the superimposed section, are not interrupted.
The axis of the symmetry of the made or superimposed section is indicated by a barc-dotted thin line without designation with letters and arrows. It is allowed to place a section anywhere in the drawing field, as well as with a turn. In the latter case, the word "turned" must be added to the inscription. For asymmetric sections located in the break or superimposed, the cross-section line is carried out with arrows, but the letters are not denoted.
On species and cuts are allowed to simplify the projection of the intersection of surfaces, if the exact constructions are not required.
GOST 2.306-68 provides a special type of hatching for various materials from which items are made.
The difference is cut from section.
If the subject to cut down the plane, mentally reject the cut-off part of it, located in front of the secular plane, and to proper on the plane of the projections the remaining part from the part side of the plane, then such a projection is called a cut.
Consequently, the incision is an image of the subject mentally dissected by one or several planes, and the mental dissection of the subject only applies to this section and does not entail a change in other images of the same subject. The section shows what lies in the secant plane (section) and what is located behind it.
The cross section is the image of a flat figure, resulting from the thought dissection of the object with a plane or several planes.
On the section shows only what is obtained directly in the securing plane.
The incision differs from the section that it shows not only what is in the securing plane, but also what is guided by it.
Application of scales in the image of the drawings.
Scale It is called the ratio showing how many times the size of the line of the line in the drawing is smaller or more the value of the corresponding line segment in nature.
Scale are numerical and graphic. The latter are divided into linear, transverse and angular.
When drawing drawings, using the numerical scale, it is necessary to produce arithmetic calculations to determine the values \u200b\u200bof the segments of lines applied in the drawing.
To reduce calculations and for the speed of obtaining the amount of segments of lines applied in the drawing at a specific scale, use a scale line or build a linear scale corresponding to numerically.
A transverse scale makes it possible to express or determine the size with the error to the hundredths of the main unit of measurement.
In cases where it is required to construct an enlarged or reduced image performed according to a given drawing, the scale of which can be arbitrary, apply an angular scale.
The scale of the drawing depends on the design of the drawing. As well as the complexity of the forms of the subject and facilities, their size.
According to GOST 2.302-68, the following scales apply when performing drawings:
scale Reduction:
1: 2; 1: 2.5; 1: 4; 1: 5; 1:10; 1:15; 1:20; 1:25; 1:40; 1:50; 1:75; 1: 100; 1: 200; 1; 400; 1: 500; 1: 800; 1: 1000; for the image in the natural value of M 1: 1;
magnification scale:
2:1; 2.5:1; 4:1; 5:1; 10:1; 20:1; 40:1; 50:1; 100:1.
When designing master plans of large objects, it is recommended to use the scale of 1: 2000; 1: 5000; 1: 10,000; 1: 20000; 1: 25000; 1: 50,000.
The scale, indicated in the main inscription drawing intended for this, is denoted by type 1: 1; 1: 2, etc., and in other cases - by type M 1: 1; M 1: 2, etc.
This article covered the main questions about aK make a drawing, extent of drawings, drawing up drawings, etc.
The problem of drawing up the drawing on their own, often arises from students of primary courses engaged in the specialties of the technological direction or receiving education in the field of artistic design or those design. The rules that must be followed when creating drawn works are recorded in Gosstandart. They should be known and adhere to anyone who gets education in these directions. However, the rules of the State Standard were published for industrial use, so in the drawings, sometimes small deviations from the established norms are allowed.
Any drawing is drawn up on a sheet of paper, standardized value, limited frame. This framework is applied by applying the line of the middle thickness to the markup marked on the sheet.
For drawings of a different format, a certain sizes of the frame-delated frames are installed:
Each smaller drawing is obtained by reducing the values \u200b\u200bof the previous format by two times.
The inscription in the drawing is located in the corner located on the right. It indicates:
When using A4 format, the main inscription is placed with the smallest side. If the format used is greater than A4, then the inscription can be placed on any side.
To do simpled drawing, You can either portray the item that will be presented in the future, on paper, in the form of a drawing in three projections, or have it before your eyes in the original.
When you see the details in the form of a three-dimensional drawing useful:
If the sequential steps of the above algorithm were performed correctly, a copy of the original depicted on paper will correspond to it. If there were no similarity, it was not possible, it would be necessary to make adjustments to the size chains.
The dimensional chain is the cumulative size of a certain part of the image of the subject, which cannot be distorted into a large or smaller side. Of course, depending on what purpose you are pursuing by depicting the subject in the figure, the accuracy of compliance with dimensions may vary. For example, in domestic purposes, it happens, deviates within one to one and a half millimeters, and this is often acceptable. In the technical draw, dimensional chains are established taking into account various factors.
The correct creation of the drawing is not only in compliance with the external similarity applied to Watman or recreated in computer Program Images with a real object. For technical purposes it is necessary that all image dimensions coincide with the original. In this regard, the concept of admission to accuracy was introduced.
Tolerances in size, which indicate technical drawings, are indicated taking into account the articulation of two adjacent parts with each other. A whole system of tolerances have been developed, taking into account how the parts interact with each other (rolling or still interaction), as well as the nature of the probable movements during their assembly or disassembly (often, rarely, ever), and so on.
Drawings are 2-dimensional architectural schematic sketches that are shown on the size of the design of the building. On materials that will be used in construction. Training reading drawings is important for builders and any employees who hire architects for their compilation.
Standard drawings usually have three design projections in which the x, y, z coordinate points are located on the axis. However, with their composition, the scaling remains and the same thing is set for all.
It is intended to test the observations of each subject or the part in the geometric isometry at a certain angle of view. This often occurs in the industrial-building branches, and in the design development of artistic - technical design items. Therefore, it is worth introducing the object of the drawing flat in a certain projection.
And the additional detail is the projection relationship of various images of the drawing object. If all the elements of both configurations are built not as it is necessary with large-scale distortions, which will lead to a mismatch of a copy of the drawing with originals. Therefore, it is necessary to comply with a number of rules in the process of drawing up the projection:
Measurement is carried out using a ruler - for simple, caliper or micrometer - for complex parts, for all dimensional elements. Install their mutual location for each of the projections of the part. Match the results obtained with the real image of the part. With error corrections. The total measurement measurements are performed on the original object or its drawing layout. If all data is true and coincide, then there were properly read schemes and drawings.
It does not matter what scale of the drawings made, all attention is drawn to the base base and its size. When writing a certain number, the unit is not shown, which is standard. To designate the details parameters apply a dimensional trajectory with a number on it. It is drawn parallel to the part of the part and is limited to arrows. The minimum distance between the dimensional line and the part circuit is 10 mm.
How to get help in purchasing self-technical skills? To master the skills of reading the drawing tables, it is necessary to conduct a course of study and practical work. Repairs a simple design household appliances, To produce a new and old element of details. At the same time, it is also necessary to make primitive drawings.
Find out how to read the drawings correctly, and then learn to represent a flat picture in a drawing in bulk form. The skills of reading drawings help competently produce all kinds of items, collect them from knots, the final product, get the entire device, model and much more.
The format of the sheet with the drawing is determined by the length of the line drawing on the edge of the sheet. Internal components with distances 2 cm from the left side and 5 mm from others. It is worth sticking to accurate calculations of the drawing so that when they are reading, there are no disagreements arise, what the part looks like.
Drawing frame formats are divided into basic and additional directions. The first type includes all the schemes obtained by reducing the lines twice from point A0. The dimensions for the drawing A1 are carried out so that when the largest axis is separated by two, a rectangle, similar to the initial sample, was obtained. The designation of standard formats consist of letters and numbers from one to five.
The first place was taken by those drawings that were made using automated design programs. For different designs and details. This applies to two systems - Auto - Cad and Compass. They read the drawings of another type. And the image of the entire node is set. And after the design of parts included in the assembly unit is performed. Thanks to their work with whole libraries of source data. After all, they include profile normalized and standardized elements. Using it in the work, the developer is able to insert a fragment into the workpiece, controlling separate parameters, Fix the drawing under new source data.
Required requirements and features. Let's start with the fact that the scale is the ratio of linear dimensions of the image applied to the drawing or map to the actual size of its size on the ground or subject. The use of it extremely facilitates the compilation of maps and drawings, because it is not always convenient and it is possible to portray the item in its natural value. There are details with big sizes that do not allow them to draw on paper, and it happens that the item is very small and to display it on paper with all the nuances, it is necessary to significantly increase its size. In the cases presented apply a decrease and increase in scale.
Several generally accepted scales of reduction:
For example, the scaling option is 1: 4. The number that stands first is the unit, indicates the actual dimensional characteristics of the subject, while the second number, in this case, the four, is indicating how many times these valid dimensions have been reduced. As an image of a very small subject, an increase in scale is used, and it is as follows: 2: 1; 2.5: 1; 50: 1. With this option, to find out the valid size dimensions, the dimensions specified in the drawing are divided into the first number reflected on the scale.
In order to portray the item or part on a sheet of paper, first, you need to find out its true dimensions. This can be done by removing the measurements from the item depicted on the drawing with the help of the line, and then to estimate how much it is necessary to reduce or increase its real dimensions when it is applied to the paper sheet. Drawings, in the main mass, are used in construction and in the development of details and structures. Application scaling, allows designers and designers to portray on a sheet of paper and a huge building, and a reduced accurate copy of the aircraft.
How to choose the right and, most importantly, the right scale when working with drawings? Most inexperienced people, facing such a question, as a rule, allow quite a lot of errors. However, this can be avoided thanks to the experience gained with time or you can seek help to the teacher.
When drawing up drawn work and schemes, it is necessary to follow certain standards, reflected in GUT - the document, which includes the generally accepted rules for applying images, inscriptions, tables and technical requirements. With the help of these rules, any specialist who can read the drawings will be able to read the drawings. It greatly facilitates communication, in the construction and production of parts, designers with workers performing the task according to the drawing. In addition to scale, other information regarding the subject is applied to the drawing. The basic rules for drawing up drawings and schemes should be known:
If you use all the rules presented above, you can create a really high-quality drawing job that any specialist will be able to read.
The process of training any work required for certification on the construction, design and architectural specialties studied in the highest educational institutions, implies the manufacture of drawings. Production of drawing is a rather simple task. Its creation is required, taking into account compliance with certain rules. In addition, any intensive work must be framed on sheets of a certain size.
The drawing format is limited to the framework of the performance, which are applied to the minimum thickness line.
Designed work allows students to take into account the size of all applicable in the formats. By separating work into two parts, the drawing is drawn up comprising the following characteristics:
For other drawings formats, the rules also set parameters of the sizes of them:
Also, according to GOST, it should be taken into account the possibility of using other formats used as a supplement to the drawings manufactured by students, which are formed as a result of working on changing the main parameters to the side of magnification. At the same time, to create them, the value is used, the size used in the basic formats, and the coefficient of the changes produced must be an integer.
