What are the types of sections

2024 Author: Howard Calhoun | [email protected]. Last modified: 2023-12-17 10:16

In any manufacturing, construction industry, certain images are used to manufacture parts, structures. They represent the view of an object from different points of view and sometimes involve the use of a cut or section technique.

This approach in engineering graphics is done according to certain standards. They clearly stipulate the types of sections, allowing this technology to be brought to uniform standards. This allows engineers, workers to correctly understand such images. The quality of the entire production process and the final result of the organization's work directly depend on this. Therefore, there are special requirements for creating images.

Image execution standard

Performance of schematic images, their cuts, various types of sections, cones, beams, applying them to the drawings are regulated by various standards. The main one is the Unified System for Design Documentation (ESKD) "Images - views, sections, sections".

This GOST was introduced on January 1, 1968. It stipulates that the image is considered as a projection of an object onto a plane at a certain angle. GOST "Images - views, sections,sections" says that there should be a minimum number of such drawings. But thanks to them, the specialist should receive complete information about the object.

Therefore, according to their content, GOST divides all images into views, sections and cuts. This document also establishes the types of designations, inscriptions and signs.

GOST 2.305-08 regulates that all images must be applied to the drawing using orthogonal (rectangular) projection technology. Ideally, the object is in the middle between the observer and the design plane.

But due to the fact that some nodes and elements require consideration from a different angle, this condition is violated. Therefore, the types of sections, the drawings of which are used in production conditions, are called images. For their implementation, the standards regulate a number of simplifications and abbreviations.

The concept of view, cut and section

Sections, sections, views - these are the three main categories in the construction of engineering graphics drawings. They are different in their content. Therefore, they deserve detailed consideration.

View is a drawing of the surface of a part that is turned towards the observer. To simplify the work of an engineer, in such a figure it is allowed to indicate invisible surfaces with dotted lines.

The main view is the front view of the part. But there are other varieties as well. The part is also shown on the left, top, right, back or bottom.

A cut is a drawing of a part that is mentally cutplane (one or more). The section will show what is in the section plane and behind it.

But a section is also called such consideration of an element, in which it was cut in a certain way by a plane. But only what was in this cutting plane is shown in the figure. What is behind it is not visible in the drawing.

These definitions must be taken into account by a specialist performing technological tasks using engineering graphics.

Remote and superimposed sections

The ESKD standard reveals types, sections, sections using a certain classification. According to this approach, it is possible to better understand the statements of the standards for the implementation of graphic images of parts.

Sections are rendered or superimposed. Both of these subspecies are not included in the section.

It is preferable to use exploded sections in engineering graphics. They are usually placed in a gap between constituent elements of the same kind.

Such a contour (as well as the image that is part of the section) is applied in thick lines to the drawing. If the section is superimposed, its boundaries are indicated by solid but thin boundaries.

To designate the axis of symmetry of such images, dotted lines are used. They are applied thinly and are not marked with any letters or arrows.

But to indicate the trace of the cutting plane, you must use a thick open line. It is indicated by arrows that make it clear the direction of view.

The cutting plane itself is denotedRussian capital letters. The inscription of the type of section of wires, assemblies or parts is made according to the type "A-A".

In this case, the end and start strokes should not cross the contour. Letter designations are assigned in alphabetical order without repetitions or omissions. The font size should be 2 times larger than the numbers indicating the sizes.

The letters are parallel to the main inscription. Moreover, this does not depend on how the cutting plane is located.

Cut plane position

Depending on the position of the cutting plane, there are several types of images that are regulated by GOST. Views, sections, sections, according to generally accepted rules, are defined in space relative to the horizontal plane.

According to it, the cutting plane can pass through the object horizontally, vertically or obliquely.

In the first case, the section view is viewed transversely, parallel to the horizontal plane. In many drawings, this type of engineering drawing is called a plan. Such cuts may also be named differently in each manufacturing process.

Vertical sections involve placing the cut perpendicular to the base. And inclined varieties form a certain angle between the horizontal and cutting planes. It is different from direct.

Vertical sections are frontal (parallel to the frontal projection line) or profile (parallel to the profile projection line).

Ifthe cut is directed along the height or length of the object, this is a longitudinal section. But there is another orientation of the drawing. There are types of cross sections that have a perpendicular orientation in the space of the cutting plane, relative to the length or height of the object.

In the drawing, the position of the section is indicated by arrows and is indicated by an open line.

Number of cutting planes

For simple parts, it is enough to use only one section plane. This is enough to understand how the technician should make this part. But for complex workpieces, this is not enough. For example, there are types of beam sections that need to be mentally cut in a more complex way.

For this, the standards regulate the use of several cutting planes. They can be broken or stepped. The orientation of the planes in this matter plays an important role.

The angle at which they relate to each other determines the name. If the planes, connecting, form a right angle, this is a stepped cut. When this ratio is characterized by a different slope, the section is broken.

With complex cuts, strokes are drawn at the intersections of the planes. Arrows are indicated on the final and initial of them in the direction of the observer's gaze. They are located 2-3 mm from the stroke. Letters are placed near the arrows at the intersections from the position of the outer corner. The slice itself in this case is always marked as "A-A".

Local section

Section is allowed to be performed only in onespecific location of the object. Such a limited consideration of the workpiece device is called local. It can be applied anywhere in the drawing, indicating the area of the image associated with it with an arrow. This is convenient for depicting long but permanent objects.

Such an image can be limited to the smallest break line. Wire cross-sections due to their long lengths can be done with this approach.

Such a slice is highlighted against the background of the image by a solid wavy line. These lines do not line up with other drawing boundaries.

Local section is indicated on the image as type "A". The view associated with it also has the associated letter designation.

Additional section

Images (views, cuts, sections) can be made on planes that are not parallel to the main sections of projections. They are called supplementary. This approach in engineering graphics is used when it is impossible to show any part of the object on the main views without distorting the shapes or sizes.

Such a section is signed as "A". The object corresponding to the additional section type is associated with it with an arrow and signed with a similar letter. The pointer also makes it clear where the observer is looking.

If an additional slice is located directly on the projection of the corresponding image, the inscription and the arrow do not need to be applied to the drawing.

Additional section views can be rotated. But the main position of the subjectwhile being preserved. A turn sign is added to the "A" type inscription.

Using this approach allows you to avoid drawing hatching on the drawing. It makes it difficult to understand and degrades the clarity of the image. Therefore, such techniques can improve the quality of graphics.

Symmetry

Section views can be placed in a gap that is formed between parts of one image. This can be done on the continuation of the slice plane trace. But such an approach is permissible only with a symmetrical figure, which is obtained during the dissection. The section is taken out to any part of the drawing field. Rotation is also allowed.

For symmetrical sections in the drawing, the trace of the plane is not depicted in any way. There is also no inscription on such a cut.

Asymmetrical sections are performed in a gap or superimposed on the drawing. The trace of the plane for such graphics is depicted, but they are not signed with letters. There is also no inscription.

The exploded section is outlined with a thick, solid outline. If it is applied, a thin, continuous line is used to designate it.

If an object has several identical sections, their contour is indicated by one letter. Only one slice is drawn.

Simplifications

Images (views, cuts, sections) for their ease of understanding can be simplified. Standards and norms govern this process.

For symmetrical figures, it is allowed to draw only one half of the cut or most of it with a break line. When the objecthas several identical elements, only one of them is drawn. The remaining identical parts are drawn schematically.

Projections of intersection lines can be depicted in a simplified way. But only if they do not require a detailed image.

When drawing simple figures, for example, if you need to consider the views of sections of a cone, use a certain approach to graphics. This makes the drawings easier to understand. When one surface changes with a specific pattern, it can be interrupted.

If one surface smoothly transitions into another, their boundary is not indicated or is indicated conditionally.

Non-hollow symmetrical parts and products in the drawing are shown undissected when cut longitudinally. And if the size of a part of the product in the drawing is less than 2 mm, it is depicted with a deviation from the main scale.

To indicate flat surfaces, diagonals can be drawn with solid lines.

It should also be taken into account that the permanent connections of electrical or radio devices are simplified by the standards corresponding to the type of product. These are the main simplifications that are regulated by the Unified System for Design Documentation. They are most often used to build drawings in large-scale industries where it is required to depict complex parts, assemblies or mechanisms.

Some special cases of simplifications

If in the drawing sections, sections, views are depicted for regularly changing surfaces, they can be broken. This is done in a certain way. There are three restrictions.

The first type involves usingsolid thin broken line. It can go beyond the border of the image by 2-4 mm. Also, the contour of the parts of the part can be connected by a solid wavy line or hatching.

To simplify the drawing, it is allowed to make a cut between the cutting plane and the observer with a dotted line. Complex slices are also used to improve the understanding of graphics.

When depicting the holes of some parts (gear hubs, keyways, pulleys), only their outline is given. If the recess located on the round flange did not fall into the cutting plane, it is depicted in section.

If there is an ornament, a continuous grid on the part, it is allowed to depict only a small part of it or simplify the elements of the picture.

Such methods make it possible to achieve a clean drawing, to facilitate its understanding. Indeed, the use of engineering graphics to create all kinds of objects implies the use of a single symbolic language. It should be known to every specialist whose work is related to this type of image. The quality of the final result depends on this.

Having studied the types of sections, you can understand the basic principles of their implementation and understanding. By applying the recommendations of the standards, you can achieve good cleanliness of the drawing. This makes it easier to interpret it. Understanding the difference between a view, a section and a section, knowing their classification and the technology for the correct design of the drawing, a specialist can create the correct image. It will be easily understood by a technician performing a workpiece or a finished product, and will be able to create units and parts that meet all the requirements. This process dependsthe quality of the whole production.