Design

Combining the view with most of the section. Images - views, sections, sections

CONSTRUCTION OF SECTIONS AND SECTIONS ON DRAWINGS

The drawing of the part is formed by sequentially adding the necessary projections, cuts and sections. Initially, a custom view is created with a user-specified model, and the model orientation is set to best fit the main view. Further, the necessary cuts and sections are created for this and the following types.

The main view (front view) is selected in such a way that it gives the most complete idea of ​​the shapes and dimensions of the part.

Sections in drawings

Depending on the position of the cutting plane, the following types of cuts are distinguished:

A) horizontal, if the cutting plane is parallel to the horizontal projection plane;

B) vertical, if the cutting plane is perpendicular to the horizontal projection plane;

C) inclined - the cutting plane is inclined to the projection planes.

Vertical sections are divided into:

· frontal - the cutting plane is parallel to the frontal projection plane;

· profile - cutting plane is parallel to the profile projection plane.
Depending on the number of cutting planes, the cuts are:

· simple - with one cutting plane (Fig. 107);

· complex - with two or more cutting planes (Fig. 108)
The standard provides for the following types of complex cuts:

· stepped, when the secant planes are parallel (Fig. 108 a) and broken lines - the secant planes intersect (Fig. 108 b)

Fig.107 Simple cut

A) b)

Fig.108 Complex cuts

Designation of cuts

In the case when in a simple section the secant plane coincides with the plane of symmetry of the object, the section is not indicated (Fig. 107). In all other cases, the sections are indicated by capital letters of the Russian alphabet, starting with the letter A, for example, A-A.

The position of the cutting plane in the drawing is indicated by the section line - a thickened open line. With a complex cut, strokes are also carried out at the inflections of the section line. Arrows indicating the direction of view should be placed on the initial and final strokes, the arrows should be at a distance of 2-3 mm from the outer ends of the strokes. On the outside of each arrow indicating the direction of view, the same capital letter is applied.

The same button is used to designate cuts and sections in the KOMPAS system Section line located on the Legend page (fig.109).

Fig.109 Section line button

Connecting Half View to Half Section

If the view and section are symmetrical figures (Fig. 110), then you can connect half of the view and half of the section, separating them with a dash-dotted thin line, which is the axis of symmetry. Part of the section is usually placed to the right of the axis of symmetry separating the part of the view from the part of the section, or below the axis of symmetry. Hidden contour lines on the connected parts of the view and section are usually not shown. If the axial line separating the view and the section coincides with the projection of some line, for example, the edge of a faceted figure, then the view and the section are separated by a solid wavy line drawn to the left of the axis of symmetry if the edge lies on the inner surface, or to the right if the edge is outer .

Rice. 110 Connecting part of a view and a section

Building cuts

We will study the construction of sections in the KOMPAS system using the example of constructing a drawing of a prism, the task for which is shown in Fig. 111.

The drawing sequence is as follows:

1. By given dimensions let's build a solid model of a prism (Fig. 109 b). Let's save the model in the computer's memory in a file named "Prism".

Fig.112 Lines panel

3. To build a profile section (Fig. 113) draw a line section A-A on the main view using the button Cut line.


Fig.113 Construction of a profile section

The direction of view and the text of the designation can be selected on the control panel with the command at the bottom of the screen (Fig. 114). The construction of the section line is completed by pressing the Create object button.

Fig.114 Control panel for the command for constructing cuts and sections

4. On the Associative Views panel (Fig. 115), select the Cut line button, then specify the cut line with the trap that appears on the screen. If everything is done correctly (the cut line must be drawn in the active view), then the cut line will turn red. After specifying the cut line A-A, an image phantom will appear on the screen in the form of an overall rectangle.

Fig.115 Associative views panel

With the help of the Cut/section switch on the Property bar, the image type is selected - Cut (Fig. 116) and the scale of the displayed cut.

Fig.116 Control panel for the command for constructing cuts and sections

The profile section will be built automatically in the projection connection and with a standard notation. If necessary, the projection connection can be turned off by the switch Projection connection (Fig. 116). To set hatching parameters that will be used in the created section (section), use the controls on the Hatching tab.

Fig.117 Construction of a horizontal section B-B and section C-C

If the selected cutting plane when constructing a section coincides with the plane of symmetry of the part, then in accordance with the standard, such a section is not indicated. But if you simply erase the section designation, then due to the fact that the view and the section in the computer's memory are interconnected, the entire section will be erased. Therefore, in order to remove the designation, you must first destroy the connection between the view and the section. To do this, by clicking the left mouse button, the section is selected, and then by clicking the right mouse button, the context menu is called up, from which the Destroy view item is selected (Fig. 97). The section symbol can now be deleted.

5. To construct a horizontal section, let's draw a B-B section line through the lower plane of the hole in the front view. The front view must first be made current by two clicks of the left mouse button. Then a horizontal section is built (Fig. 117).

6. When constructing a frontal section, a part of the view and a part of the section are compatible, because they are symmetrical figures. The outer edge of the prism is projected onto the line separating the view and the cut, so we delimit view and section of a solid thin wavy line drawn to the right of the axis of symmetry, because outer rib. The button is used to draw a wavy line. Bezier curve located on the Geometry panel drawn with the For clipping line style (Fig. 118). Sequentially specify the points through which the Bezier curve should pass. To finish the command execution, click the Create object button.

Fig.118 Selecting a line style for a break

Sectioning

A section is an image of an object that is obtained by mentally dissecting an object with a plane. The section shows only what is located in the cutting plane.

The position of the cutting plane, with which the section is formed, is indicated in the drawing by the section line, just as for sections.

Sections, depending on their location in the drawings, are divided into extended and superimposed. The removed sections are most often located on the free field of the drawing and are outlined by the main line. The superimposed sections are placed directly on the image of the object and outlined with thin lines (Fig. 119).

Fig.119 Construction of sections

Consider the sequence of constructing a drawing of a prism with an extended oblique section B-B(Fig. 117).

1. Make the front view active by double-clicking the left mouse button on the view and draw a section line using the button cutting line . Let's select the text of the inscription В-В.

2. Using the Cut line button located on the Associative Views panel (Fig. 115), which appears as a trap, indicate the secant line planes B-B. Using the Cut/section switch on the Property Bar, select the image type - Section (Fig. 116), the scale of the displayed section is selected from the Scale window.

The constructed section is located in a projection relationship, which limits its movement in the drawing, but the projection relationship can be turned off using the button projection connection.

On the finished drawing, draw center lines, if necessary, put down the dimensions.

cut called the image of an object mentally dissected by one or more planes. At the same time, the mental dissection of an object refers only to this section and does not entail changes in other images of the same object.

The section shows what is in the cutting plane and what is behind it. Depending on the number of cutting planes, the cuts are divided into:

-simple - one cutting plane;

-complex - several cutting planes.

Simple cuts

Depending on the position of the cutting plane relative to the horizontal projection plane, the sections are divided into:

Horizontal- the cutting plane is parallel to the horizontal projection plane (Fig. 22).

Rice. 22. Horizontal cut

vertical– cutting plane is perpendicular to the horizontal plane of projections: frontal and profile sections.

Frontal the incision is made with a frontal plane parallel to the frontal projection plane (Fig. 23).

Rice. 23. Vertical section (frontal)

Profile the incision is made with a profile plane parallel to the profile plane of the projections (Fig. 24).


Rice. 24. Vertical section (profile)

Horizontal, frontal and profile sections can be located in the place of the corresponding main views (top, front, left).

When the cutting plane coincides with the plane of symmetry of the object as a whole, and the corresponding images are located on the same sheet in direct projection connection and are not separated by any other images, the position of the cutting plane is not marked and the cut is not accompanied by an inscription (Fig. 23, Fig. 24). In other cases, the cuts are indicated (Fig. 22).

The position of the cutting plane is indicated on the drawing by a section line. For the section line, an open line is used according to GOST 2.303-68 (Fig. 26 a).

The direction of view is shown by arrows. The dimensions of the arrows and their position in the drawing are shown in Fig. 26 b.

Rice. 26. Image parameters of the cutting plane

The letter designation of the section includes capital letters of the Russian alphabet in order, 7…10 mm high. The letters are located next to the arrows (on the opposite side of the image outline). An inscription of the type “A-A” should be placed above the image of the section (Fig. 26 in).

The cross-sectional figure is highlighted with hatching. The general graphic designation of materials in sections, regardless of the type of materials, is performed by solid thin parallel straight lines drawn at an angle 45 ° to the contour line of the image or to its axis, or to the lines of the drawing frame. Hatching lines should be applied with an inclination to the left or right, but in the same direction on all sections related to the same part. The distance between the lines is selected depending on the hatching area and the need to diversify the hatching of adjacent sections for various parts (in the drawings assembly units). For training drawings, it is recommended - 2…4 mm.

If the hatch lines drawn to the lines of the drawing frame at an angle 45 °, coincide in direction with the contour lines or center lines, then instead of the angle 45 ° take the angle 30 ° or 60. ° .

The type of hatching depends on the graphic designation of the part material and must comply with GOST 2.306–68.

oblique cut- the cutting plane is inclined to the horizontal projection plane at a certain angle (Fig. 27).

Fig.27 Oblique cut

Inclined cuts are always marked (Fig. 27) in accordance with the general rules for marking simple incisions. When designating oblique cuts, the letters are always parallel to the main inscription. It is allowed to place an oblique cut anywhere in the drawing field, as well as rotate the image for ease of construction. In this case, the sign ”” should be added to the designation of the section according to the type “A-A” (Fig. 28).

Fig.28. Reversed oblique cut.

Local called a cut that serves to clarify the device of a part in a separate limited place.

The local section is limited in the view by a wavy line. These lines must not overlap with any other lines in the image. When performing local cuts, they are not indicated (Fig. 29).

Rice. 29. Image of local cuts

Connecting a View Part to a Section Part

It is allowed to connect a part of the view with a part of the corresponding section, separating them with a solid wavy line or a solid thin line with breaks (Fig. 30).

Rice. 30. Connecting part of the view and part of the section

If at the same time half of the view and half of the section are connected, each of which is a symmetrical figure, then the dividing line is the axis of symmetry (Fig. 31). When connecting half of the view with half of the section, the section is placed to the right of the axis of symmetry, if the axis is vertical, and below the axis of symmetry, if the axis is horizontal.

Rice. 31. Joining Half View and Half Section

It is also allowed to separate the section and the view with a dash-dotted thin line (Fig. 32), which coincides with the trace of the plane of symmetry not of the entire object, but only of its part, if it is a body of revolution.

Rice. 32. Connection of view and section

With asymmetrical figures of the view and section, they are separated by a solid thin wavy line (Fig. 32).

Separation by a wavy line is also used when a dash-dotted line is superimposed on a contour line (Fig. 33).



Rice. 33. Connection of a view and a cut at faceted surfaces

The shape of many objects is such that when depicting them, it is not enough to give only a section, since sometimes it is impossible to represent the external shape of an object from a section. When depicting such objects, it is necessary to give as a cut, that is, to perform two different images, which takes a lot of time and space. Therefore, it is allowed to combine a part of the view and a part of the corresponding section on one image.

In this case, the view and section are separated by a solid wavy line.

For example, in fig. 3.12 shows two views of an object, the shape of which will not be clear if it is shown only in section. In this case, it will be easy to judge the internal structure of the object, but the external view will not be clear, since there will be no grounds for determining the height of the tide on its outer surface. Therefore, a local view is performed showing a cylindrical tide.

This example demonstrates a rational way to construct a drawing.

GOST 2.305-68 recommends, if possible, to connect half of the view and half of the section, when the view and the section are symmetrical figures. Then an image will be obtained, according to which one can judge both the external form and the internal structure of the object (Fig. 3.13).

When performing images containing a connection of half of the view and half of the corresponding section, the following rules must be observed:

The line separating half of the view and half of the section should be the axial line, i.e. dotted line.

It is also allowed to separate the section and the view with a dash-dotted line coinciding with the trace of the plane of symmetry not of the entire object, but only of its part, if this part is a body of revolution. An example of such a case is shown in Fig. 3.14, which shows part of the connecting rod. It has a cylindrical element (body of revolution), the cut on which is made only up to the axis of symmetry.

When combining half of the view and half of the section, in some cases the contour line (edges of polyhedrons) coincides with the axial line. In such cases, you need to perform part of the view and part of the section, separating them with a solid wavy line. This line should be positioned so that the edge is shown in the image. If it is located on the inner surface, then they give more than half of the section (Fig. 3.15), and if on the outer surface, then more than half of the view (Fig. 3.16).

When combining half view and half section, the view is always located on the left, and the section is always on the right, if the axis of symmetry is vertical. When aligned along the horizontal axis of symmetry, the view is located on top, and the cut is on the bottom (Fig. 3.17).

Attention! Test number 1.

In which case the image of the cut is made correctly?

The answer is on page 23.

The rules for depicting objects (products, structures and their constituent elements) in drawings for all industries and construction are established by GOST 2.305 - 2008 * “Images - views, sections, sections”.

Images of objects must be performed using the method of rectangular (orthogonal) projection. In this case, the object is placed between the observer and the corresponding projection plane. When constructing images of objects, the standard allows the use of conventions and simplifications, as a result of which the specified correspondence is violated. Therefore, the figures obtained during the projection of an object are called not projections, but images. As the main projection planes, the faces of a hollow cube are taken, in which an object is mentally placed and projected onto it. internal surfaces faces. The edges are aligned with the plane (Figure 2.1). This projection results in the following images: front view, top view, left view, right view, rear view, bottom view.

The image on the frontal plane is taken as the main one in the drawing. The object is positioned relative to the frontal plane of projections so that the image on it gives the most complete picture of the design features of the object and its functional purpose.

Consider main image selection on the example of such an object as a chair. Let's depict its projections schematically:

Let's reason: the functional purpose of the object - the object serves to sit on it. In which of the figures this purpose is most clear - probably, this is figure 1 or 2, the 3rd is the least informative.

The design features of the object - there is a seat directly, a backrest, for the convenience of sitting on a chair, located at a certain angle relative to the seat, legs that place the seat at a certain distance from the floor. In which of the figures these features are most clearly represented? Obviously this is Figure 1.

Conclusion - we choose projection number 1 as the main view, as the most informative and most complete information about the functional purpose of the chair and its design features.

In a similar way it is necessary to reason when choosing the main image of any subject!

Images in the drawing, depending on their content, are divided into views, sections, cuts.

View - the image of the visible part of the surface of the object facing the observer.

The types are divided into basic, local and additional.

Main types — images are obtained by projecting an object on a projection plane. There are six of them in total, but most often I use the main three to obtain information about the subject: horizontal π 1, frontal π 2 and profile π 3 (Figure 2.1). With this projection, you get: front view, top view, left view.

The names of the views in the drawings are not inscribed if they are located in a projection relationship (Figure 2.1). If the top, left, and right views are not in projection connection with the main image, then they are marked on the drawing with an inscription of the “A” type. The direction of gaze is indicated by an arrow, denoted by a capital letter of the Russian alphabet. When there is no image on which the direction of view can be shown, the name of the species is inscribed.

Figure 2.1 Formation of the main species

Local view - an image of a separate limited place on the surface of an object on one of the main projection planes. A local view can be placed in any free place of the drawing, marking it with an inscription of the type “A”, and the associated object image must have an arrow indicating the direction of view, with the corresponding letter designation (Figure 2.2 a, b).
a
b

Figure 2.2 - Local views

The local view can be limited by the cliff line, if possible in the smallest size (Figure 2.2, a), or not limited (Figure 2.2, b).

Additional views- images obtained on planes not parallel to the main projection planes. Additional views are performed in cases where any part of the subject cannot be shown on the main views without distorting the shape and size. An additional view is marked on the drawing with an inscription of type “A” (Figure 2.3, a), and an arrow with the corresponding letter designation is placed on the object associated with the additional view (Figure 2.3, a), indicating the direction of view.

When an additional view is located in direct projection connection with the corresponding image, the arrow and the inscription above the view are not applied (Figure 2.3, b). The secondary view can be rotated while maintaining the position adopted for this item in the main image. At the same time, the sign (“Turned”) is added to the inscription “A” (Figure 2.3, c).

The main, local and additional views serve to depict the shape of the outer surfaces of the object. Their successful combination allows you to avoid dashed lines, or reduce their number to a minimum. To reduce the number of images, it is allowed to show the necessary invisible parts of the surface in views using dashed lines. However, revealing the shape of the internal surfaces of an object with the help of dashed lines makes it much more difficult to read the drawing, creates prerequisites for its incorrect interpretation, complicates the application of dimensions and symbols, so their use should be limited and justified. To identify the internal (invisible) configuration of an object, conditional images are used - cuts and sections.

Figure 2.3

2.2 Cuts

A cut is an image of an object mentally dissected by one or more planes..

The section shows what is located in the cutting plane and what is located behind it.

2.2.1 Section classification

Depending on the number of cutting planes sections are divided into (Figure 2.4):

  • simple- with one secant plane (Figure 2.6);
  • complex- with several cutting planes (Figure 2.9, 2.10).

Figure 2.4 - Section classification

The position of the cutting plane is shown on the main image with a thick open line (1.5s, where s is the thickness of the main line). The length of each stroke is from 8 to 20 mm. The direction of view is shown by arrows perpendicular to the strokes. The arrows are drawn at a distance of 2-3 mm from the outer ends of the strokes. The name of the cutting plane is indicated by capital letters of the Russian alphabet. The letters are applied parallel to the horizontal lines of the main inscription, regardless of the position of the arrows (Figures 2.5, 2.6, 2.9, 2.10, 2.11).

If, when performing a simple cut that is in a projection connection with the main image, the cutting plane coincides with the plane of symmetry, then the cutting plane is not displayed, and the cut is not signed.

Figure 2.5 - Designations of cuts in the drawing

Figure 2.6 - A simple section: a) - frontal; b) - local

Depending on the cutting plane positions relative to the horizontal projection plane, the sections are divided into:

  • horizontal - the cutting plane is parallel to the horizontal projection plane (Figure 2.7, b);
  • vertical - cutting plane perpendicular to the horizontal projection plane (Figure 2.7, c, d);
  • oblique- the cutting plane makes an angle with the horizontal projection plane that is different from the right one (Figure 2.8).


Figure 2.7 a - Model of the part "Crank"

Figure 2.7 b - A simple horizontal section

Vertical cuts are called:

  • frontal , if the cutting plane is parallel to the frontal projection plane (Figure 2.7, c);
  • specialized, if the cutting plane is parallel to the profile plane of the projections (Figure 2.7, d).

Figure 2.7 c - Simple frontal section

Figure 2.7 d - A simple profile section

Figure 2.8 - Oblique cut

Complex cuts are divided into:

  • stepped , if the cutting planes are parallel (stepped horizontal, stepped frontal) (Figure 2.9);
  • broken lines if the cutting planes intersect (Figure 2.10).

Figure 2.9 - Complex - Stepped cut

Figure 2.10 - Complex - Broken cut

The cuts are called:

  • longitudinal if the cutting planes are directed along the length or height of the object (Figure 2.7, c);
  • transverse if the cutting planes are directed perpendicular to the length or height of the object (Figure 2.7, d).

Sections that serve to clarify the structure of an object only in separate, limited places are called local .

Figure 2.11 a - Examples of cuts

Figure 2.11 b - Examples of performing cuts combined with views

2.2.2 Making cuts

Horizontal, frontal and profile sections can be located in the place of the corresponding main views (Figure 2.11, a, b).

Part of the view and part of the corresponding section may be connected, separating them with a solid wavy line or a line with a break (Figure 2.11, b). It must not coincide with any other graphic lines.

If half of the view and half of the section are connected, each of which is a symmetrical figure, then the dividing line is the axis of symmetry (Figures 2.11, b; 2.12). It is not possible to connect half of the view with half of the section, if any line of the image coincides with the axial line (for example, an edge). In this case, connect a large part of the view with a smaller part of the section or a large part of the section with a smaller part of the view.

It is allowed to separate the section and the view by a dashed-dotted thin line coinciding with the trace of the plane of symmetry not of the entire object, but only of its part, if it represents a body of revolution. When connecting half of the view to half of the corresponding section, the section is placed to the right of the vertical axis and below the horizontal one (Figure 2.12).

Figure 2.12

Figure 2.13

Local cuts are highlighted in the view by solid wavy lines. These lines must not coincide with any other lines in the image (Figure 2.13).

Section figures obtained by different cutting planes during execution complex cut, do not separate one from the other by any lines.

A complex stepped section is placed in the place of the corresponding main view (Figure 2.9) or anywhere in the drawing.

With broken cuts, the secant planes are conditionally rotated until they coincide in one plane, while the direction of rotation may not coincide with the direction of view. If the combined planes turn out to be parallel to one of the main projection planes, then a broken section can be placed in the place of the corresponding view (Figure 2.10).

When the cutting plane is rotated, the elements of the object located behind it are drawn as they are projected onto the corresponding plane, with which the alignment is performed. It is allowed to connect a stepped section with a broken line in the form of one complex section.

2.3 Sections

Section called the image of a figure obtained by mentally dissecting an object by a cutting plane(Figure 2.14).

On the section, only what falls directly into the cutting plane is shown.

The secant planes are chosen so as to obtain normal cross sections.

Sections are divided into:

  • sections included in the section (Figure 2.15, a);
  • sections not included in the section Figure 2.15.b).

Those not included in the section are divided into:

  • rendered(Figures 2.14, a; 2.14, c; 2.15, b; 2.16, a; 2.17, a; 2.18);
  • superimposed(Figures 2.14b; 2.16b; 2.17b).

Remote sections are preferable and they can be placed in a gap between parts of the same type, on the continuation of the trace of the cutting plane with a symmetrical section figure, anywhere in the drawing field, and also with a turn (Figures 2.14, a, c; 2.15, b; 2.16, a; 2.17, a; 2.18, a).

To depict the trace of the secant plane on the drawing, a thick open line is used with arrows indicating the direction of view, and the secant plane is designated in capital letters of the Russian alphabet. The section is accompanied by an inscription according to type A-A(Figure 2.14).

The ratio of the sizes of arrows and dashes of an open line should correspond to Figure 2.14. The start and end strokes must not cross the image outline.

Letter designations are assigned in alphabetical order without repetition and, as a rule, without gaps. The size of the font of alphabetic designations should be approximately two times larger than the size of the digits of the dimensional numbers. The letter designation is placed parallel to the main inscription, regardless of the position of the cutting plane.

In the general case, when the section is located in any free place on the drawing, the position of the trace of the cutting plane is depicted as indicated above, and the image of the section is accompanied by an inscription corresponding to the name of the cutting plane (Figure 2.14, a; 2.15, b).

In the cases shown in the Figures: 2.14, b, c; 2.17, a, b; 2.18, a (sections superimposed; sections made in a break in the view; sections made on the continuation of the trace of the cutting plane) - for symmetrical sections the trace of the secant plane is not depicted and the section is not accompanied by an inscription.

Figure 2.14 a

Figure 2.14 b

Figure 2.14 in

For asymmetric sections , located in a gap, or superimposed, the trace of the cutting plane is depicted, but they are not accompanied by letters (Figure 2.16). The section is also not accompanied by an inscription.

The outline of the exploded section is drawn with a thick solid line (main line), and the outline of the superimposed section is drawn with a thin solid line, while the outline of the view is not interrupted.
a b

Figure 2.15
a b

Figure 2.16

Figure 2.17 a,b

a b

Figure 2.18

For several identical sections of the same object, the section lines are designated by one letter and one section is drawn. If at the same time the cutting planes are directed at different angles, then the “Rotated” sign is not applied (Figure 2.19).

The structure of the designation of the position of the cutting plane in the drawing is shown in fig. 21.

Rice. 21. The structure of the designation of the position of the cutting plane

Arrows used to indicate the direction of view should have the same shape and size as the arrows to indicate views (see Figure 8). Please note that the direction of the arrows when indicating the position of the cutting plane must correspond to the direction of view when constructing the view, within the boundaries of which the section will be completely or partially located.

4.4. Aligning Sections with Views

There should be a minimum number of images in the drawing. To reduce the number of images, overlapping of sections with views is used. In most cases, the cut is combined with the view that is located in the direction of the observer's gaze on the projection plane, parallel to which the cutting plane is oriented. The frontal section is placed in the place of the front or back view (see Fig. 13), the horizontal one is in the place of the top or bottom view (see Fig. 14), the profile is placed in the place of the left or right view (see Fig. 15).

There are three possible combinations:

a complete section is placed within the boundaries of the view, i.e., a complete alignment of the section is performed

with corresponding view, as in Fig. 13, 15, 18. Such a combination is done when the section is an asymmetrical figure, and there are no visible contours of structural elements in the view, the shape of which needs to be revealed;

within the boundaries of the view, a part of the view and a part of the corresponding section are located, separating them with a solid wavy line (Fig. 22). Such a combination is performed when the cut or view is asymmetric figures and there are visible contours of structural elements in the view, the shape of which needs to be revealed (in Fig. 22, in order for the shape of the groove on the front wall of the object to be clear, it is necessary to leave a visible part of the view in front with this groove). As a rule, with such a combination, simple cuts are not indicated;

half of the view and half of the corresponding section are located within the boundaries of the view, separating them with a dash-dotted line, which is the axis of symmetry of the view and the section (Fig. 23). Thus, this combination option can be applied only if the full view and the full section separately are symmetrical figures. Then half of the symmetrical image is easy to understand the full shape. It is customary to place the view to the left of the axis of symmetry, and the section to the right or the view to be placed from above, and the section from below. The designation of the cuts in this case is

produced according to the rule set out in subsection. 4.3.

Notes: 1. If part of the view and part of the corresponding section or half of the view and half of the section are combined, then dashed lines are not drawn on the part of the view.

2. If, when combining symmetrical parts of the view and section in one image, any line (for example, an edge) coincides with the axis of symmetry, then this line (edge) should be shown, and then the view of the section is separated by a solid wavy line, which is drawn to the left (Fig. 24, a) or to the right (Fig. 24, b) of the axis of symmetry.

On fig. 13 ... 16, 20 examples were given with one section of objects. For objects of complex shape, several cuts have to be made (Fig. 18, 25 ... 27), and individual cuts sometimes have to be placed outside the views in the free field of the drawing.

Rice. 22. Combination of asymmetrical view and section

Rice. Fig. 24. Combination of symmetrical view and section, when the edge coincides with the axis of symmetry: a - the edge is shown in the section; b - the rib is shown in the view

Rice. 27. Making cuts in the front, top and left views (full cuts are placed on the views)

4.5. Complex cuts

Revealing the shape of the internal cavities of objects with a complex internal structure using simple cuts leads to the need to make a large number of them, which makes it difficult to read the drawing. In such cases, complex incisions are used. Complicated cuts are always marked.

Complicated cut called a cut that is obtained using two or more secant planes. Complex cuts are divided into stepped and broken.

stepped cut- this is a cut formed by several parallel cutting planes (Fig. 28).

When constructing a section, the secant planes are combined into one, and the stepped section takes the form of a simple one. Stepped cuts, as well as simple ones, can be horizontal, frontal, profile and inclined (Fig. 28 ... 31).

The position of each secant plane is indicated by strokes of an open line, the transition points from one plane to another (step) are performed with the same strokes. At the initial and final strokes indicate the direction of the observer's gaze with an arrow and put the same letter. That is, despite the fact that there are several cutting planes, letter designations they are the same.

On a stepped section, the line of transition from one plane to another (step) is not shown. A drawing can have several stepped sections.

Note. The right plane (see Fig. 28) can intersect both the lower and upper square holes.

Rice. 28. Formation of a frontal stepped incision

Rice. 29. Horizontal stepped cut

One should not strive to reveal the entire internal structure of an object with one complex cut. To form a stepped cut, it is recommended to use no more than three secant planes.

Rice. 32. Combining half of the stepped section with half of the front view

A broken cut is a cut formed by two intersecting cutting planes (Fig. 33). The first secant plane is chosen parallel, and the second one is inclined with respect to the main projection plane. When performing a broken cut, the inclined cutting plane is conditionally rotated to coincide with the first cutting plane, and from this position, the resulting section figure is projected onto a projection plane parallel to it. When rotating an inclined cutting plane, the elements of the object visible behind it do not need to be rotated, but their image should be built in direct projection connection with the projection plane onto which the projection is made. In a similar way, a rectangular groove is built on top of the cylindrical protrusion of the object (see Fig. 33), which is not connected with an inclined cutting plane. An exception to this rule is when the visible elements are structurally related to the distance

cut element. In such a case, these elements visible behind the cutting plane are rotated together with the cut element (Fig. 34).

Broken cuts, depending on which projection plane (on which view) they will be located, are divided into frontal, horizontal and profile.

The position of each cutting plane is indicated by the strokes of an open line. Such strokes are also placed at the intersection of the cutting planes. At the initial and final strokes indicate the direction of the observer's gaze with an arrow and put the same letter. Please note that the letter of the oblique stroke, regardless of the inclination of the plane, is depicted directly.

Note. On fig. 33, the inclined cutting plane can intersect both the bottom and top holes. The construction of a broken cut will be the same in both cases.

Rice. 33. Formation of a frontal broken incision

Rice. 34. Projection of elements structurally related to an inclined cutting plane