Complete the detail drawings with the missing lines. Drawing workbook. Location of views in the drawing
3. Based on the two given views, build a third view or draw the missing lines in the drawing. Draw a technical drawing of the part.
I option II option
SUPPORT AXLE
TICKET #11
1. What is an axonometric projection? What types of axonometric projection are used to visualize an object?
2. Identify the difference between an engineering drawing and a construction drawing
1. What is an axonometric projection? What types of axonometric projection are used to visualize an object?
The word "axonometry" in translation from Greek stands for "change along the axes". There are frontal dimetric (cabinet) and isometric projections.
The cabinet projection is obtained using axonometric axes x, y and z, which are located as follows: the x-axis is horizontal, the z-axis is vertical, the y-axis is at an angle of 45o to the horizontal line. When constructing an object in a cabinet projection, the natural dimensions are set along the x and z axes, and halved along the y axis.
An isometric projection is obtained using the axonometric x, y and z axes, which are arranged as follows: the x and y axes are placed at an angle of 30o to the horizontal line, the z axis is placed vertically. When constructing in an isometric projection along the axes x, y, z, the natural dimensions of the object are laid down.
2. Identify the difference between the engineering drawing and the construction drawing.
Construction drawings call drawings and related text documents that contain projection images of a building or its parts and other data necessary for its construction, as well as for manufacturing building products and designs.
Incision serves to identify the structure of the building and the height of the floors. Vertical cutting planes usually run along window and door openings. The cuts are marked.
Above the images, inscriptions are made according to the type: “Facade”, “First floor plan”, “Section I - I”, etc.
On construction drawings, reduction scales of 1:50 are used; 1:100; 1:200; 1:400 etc.
Since the scale different images can be different, it is usually indicated next to each of them.
Dimensions on construction drawings, except for marks, are indicated in millimeters, sometimes on drawings of buildings in centimeters.
Dimension lines on construction drawings are limited to short strokes at an angle of 45o to the dimension line.
On the plans they are applied with outside. In the first row, the dimensions of the window and doorways and piers in a closed chain. In the second row - the dimensions between each pair of adjacent axes in a closed chain. In the third row - overall size between extreme axes. In addition, they put inner dimensions rooms: length, width, etc.
Drawings intended for the manufacture of various engineering products on them are called engineering.
When depicting parts on engineering drawings, views, sections and sections are used, and in some cases axonometry is also used. The number of views, sections, sections should be the smallest, but providing a complete picture of the part with the conventions and simplifications established by the standards.
The drawing of the object must give a complete picture of the shape of the depicted object, and also contain information about the methods of its manufacture. At the same time, the drawing of the object must be concise and contain a minimum number of images and text sufficient for free reading of the drawing, manufacturing a part according to it and its control.
For better understanding and reading drawings should be drawn up according to general rules. All requirements for the design of drawings, as well as the symbols contained in the drawings, must be uniform. Therefore, when drawing up engineering drawings, it is necessary to be guided by the main provisions of GOSTs " unified system design documentation.
3. Complete the front view with the missing lines. Perform an isometric view of the part.
I option II option
AXIS AXIS
TICKET #12
1. Tell us about the features of the implementation technical drawing. How does it differ from an axonometric image?
2. List the basic requirements for choosing ways to depict parts in a drawing. Selecting the main view. Determining the necessary and sufficient number of images to identify the structural shape of the part
3. Complete the front view with the missing lines. Perform an isometric view of the part
1. Tell us about the features of the technical drawing. How does it differ from an axonometric image?
Technical drawing, like axonometric projections, is used to build visual images of models and details.
A technical drawing is an image made by hand according to the rules of axonometry in compliance with the proportions “by eye”, i.e. without the use of drawing tools. This technical drawing differs from the axonometric projection. At the same time, they adhere to the same rules as when constructing axonometric projections: the axes are placed at the same angles, the dimensions are laid along the axes or parallel to them, etc.
Technical drawings give a visual representation of the shape of a model or part; it is also possible to show not only appearance, but also their internal organization by cutting a part of the part along the directions of the coordinate planes.
For greater clarity, hatching is applied to technical drawings. It is assumed that the light falls on the object from the top left. Illuminated surfaces are left light, shaded ones are covered with shading, which is the more frequent, the darker the surface of the object. Hatching is applied parallel to some generatrix or parallel to the projection axes.
The execution of a technical drawing of a part begins with the construction of an overall outline - a “cell”, performed by hand in thin lines. Then the part is mentally divided into separate geometric elements, gradually sketching all the elements of the part. Then the drawing is covered with strokes.
2. List the basic requirements for choosing ways to depict parts in a drawing: selection of the main view, determination of the necessary and sufficient number of images to identify the structural shape of the part.
When drawing a drawing, it is necessary to correctly determine the number of images and the position of parts on the main view.
The number of images (views, cuts, sections) should be the smallest, but fully revealing the shape of the object.
The choice of the position of the part to obtain the main image, which can be either a view or a section, has great importance. It should give the most complete idea of the shape and dimensions of the part when rational use drawing fields.
Usually the part is shown in the position it occupies during processing. Therefore, the axis of parts obtained by turning is placed horizontally. This makes it easier for the worker to manufacture the part according to the drawing, since he sees it in the same position both on the drawing and on the machine.
The choice of the position of the part in the main image largely determines the number of images in the drawing. The object is positioned so that most of its elements on the main view are depicted as visible.
1. The use of conventional signs and allows you to limit yourself to one image (view, section) of cylindrical, conical and prismatic elements (Fig. 28).
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- study and practical use rules for depicting objects - building views and simple sections in accordance with GOST 2.305–2008;
- study and practical application of the rules for applying dimensions on a drawing in accordance with GOST 2.307–2011;
- gain skills in constructing simple cuts.
- for two given types, build a third one and make a simple cut in place of the main image;
- apply required dimensions according to GOST 2.307-2011.
1.3. Order of execution
- build two types of parts on A3 format Frame (from the task);
- build a view on the left;
- determine the location of the cutting plane coinciding with the plane of symmetry of the part, and build a simple section in place of the front view;
- apply dimensions according to the rules for applying dimensions (GOST 2.307-2011) (do not copy dimensions from the task, they are given dimensions just for that so you can build images!);
- fill in the title block.
Consider the implementation of this task on the example shown in Figure 1.1.
In Figure 1.2, for greater clarity, a three-dimensional model of the task detail is presented.
Figure 1.1. Task example
Figure 1.2. Job example - 3D part model
This will help to build the missing projections of these geometric bodies, and in the future, apply the correct dimensions. They try to exclude lines of an invisible contour by applying cuts or sections! |
External surfaces:
Internal surfaces:
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Since the cutting plane coincides with the plane of symmetry, there is no need to designate such a cut! |
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The projections of the two parallelepipeds are rectangles, and the central hole is projected into circles. The upper parallelepiped has cut corners - chamfers. The left view supplements the existing two images with information about the corner cuts (chamfers) on the back box and the radii of the pairing of the two boxes. Lines of an invisible contour do not need to be depicted! |
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There should be no other invisible contour lines! |
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It is necessary to group the dimensions of a geometric element on the image in which it is most clearly represented. For example, the chamfers on the upper box are most visible in the left view (for which this species and built), which means that the dimensions on them should be in the left view. Since all rounding radii are the same in size, their value is recorded in the technical requirements. |
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I option II option
AXIS AXIS
TICKET #12
1. Tell us about the features of the technical drawing. How does it differ from an axonometric image?
2. List the basic requirements for choosing ways to depict parts in a drawing. Selecting the main view. Determining the necessary and sufficient number of images to identify the structural shape of the part
3. Complete the front view with the missing lines. Perform an isometric view of the part
Tell us about the features of the technical drawing. How does it differ from an axonometric image?
Technical drawing, like axonometric projections, is used to build visual images of models and details.
A technical drawing is an image made by hand according to the rules of axonometry in compliance with the proportions “by eye”, i.e. without the use of drawing tools. This technical drawing differs from the axonometric projection. At the same time, they adhere to the same rules as when constructing axonometric projections: the axes are placed at the same angles, the dimensions are laid along the axes or parallel to them, etc.
Technical drawings give a visual representation of the shape of a model or part; it is also possible to show not only the appearance, but also their internal structure by cutting out part of the part along the directions of the coordinate planes.
For greater clarity, hatching is applied to technical drawings. It is assumed that the light falls on the object from the top left. Illuminated surfaces are left light, shaded ones are covered with shading, which is the more frequent, the darker the surface of the object. Hatching is applied parallel to some generatrix or parallel to the projection axes.
The execution of a technical drawing of a part begins with the construction of an overall outline - a “cell”, performed by hand in thin lines. Then the part is mentally divided into separate geometric elements, gradually sketching all the elements of the part. Then the drawing is covered with strokes.
2. List the basic requirements for choosing ways to depict parts in a drawing: choosing the main view, determining the necessary and sufficient number of images to identify the structural shape of the part.
When drawing a drawing, it is necessary to correctly determine the number of images and the position of parts on the main view.
The number of images (views, cuts, sections) should be the smallest, but fully revealing the shape of the object.
The choice of the position of the part to obtain the main image, which can be either a view or a section, is of great importance. It should give the most complete idea of the shape and dimensions of the part with the rational use of the drawing field.
Usually the part is shown in the position it occupies during processing. Therefore, the axis of parts obtained by turning is placed horizontally. This makes it easier for the worker to manufacture the part according to the drawing, since he sees it in the same position both on the drawing and on the machine.
The choice of the position of the part in the main image largely determines the number of images in the drawing. The object is positioned so that most of its elements on the main view are depicted as visible.
1. The use of conventional signs and allows you to limit yourself to one image (view, section) of cylindrical, conical and prismatic elements (Fig. 28).
2 . If you need to select a flat surface on the image of the part, then it is marked with thin solid intersecting lines (diagonals) (Fig. 28).
3. Thanks to the application symbols thickness (s3) and length (L300) of the part, flat and long objects can be shown in one projection (Fig. 10).
4 . To shorten the image of a long detail without changing the scale, apply a gap using solid wavy lines for this. At the same time, the dimension line is not broken (Fig. 28).
Complete the front view with the missing lines. Perform an isometric view of the part.
I option II option
13.1. A method for constructing images based on the analysis of the shape of an object. As you already know, most objects can be represented as a combination of geometric bodies. The investigator, in order to read and execute the drawings, you need to know. how these geometric bodies are depicted.
Now that you know how such geometric bodies are depicted in the drawing, and have learned how vertices, edges and faces are projected, it will be easier for you to read the drawings of objects.
Figure 100 shows a part of the machine - a counterweight. Let's analyze its shape. What geometric bodies known to you can be divided into? To answer this question, remember characteristics inherent in the images of these geometric bodies.
Rice. 100. Part projections
In Figure 101, a. one of them is highlighted in blue. What geometric body has such projections?
Projections in the form of rectangles are characteristic of a parallelepiped. Three projections and a visual image of the parallelepiped, highlighted in Figure 101, a in blue, are given in Figure 101, b.
In Figure 101, in in gray another geometric body is conventionally selected. What geometric body has such projections?
Rice. 101. Part shape analysis
You have met with such projections when considering images of a triangular prism. Three projections and a visual image of the prism, highlighted in gray in Figure 101, c, are given in Figure 101, d. Thus, the counterweight consists of a rectangular parallelepiped and a triangular prism.
But a part has been removed from the parallelepiped, the surface of which in Figure 101, e is conditionally highlighted in blue. What geometric body has such projections?
With projections in the form of a circle and two rectangles, you met when considering images of a cylinder. Therefore, the counterweight contains a cylinder-shaped hole, three projections and a visual representation of which are given in Figure 101. e.
Analysis of the shape of an object is necessary not only when reading, but also when making drawings. So, having determined the shape of which geometric bodies the parts of the counterweight shown in Figure 100 have, it is possible to establish an expedient sequence for constructing its drawing.
For example, a drawing of a counterweight is built like this:
- on all types, a parallelepiped is drawn, which is the base of the counterweight;
- a triangular prism is added to the parallelepiped;
- draw an element in the form of a cylinder. In the top and left views, it is shown with dashed lines, since the hole is invisible.
Draw a detail called a sleeve according to the description. It consists of a truncated cone and a regular quadrangular prism. The total length of the part is 60 mm. The diameter of one base of the cone is 30 mm, the other is 50 mm. Prism attached to greater ground cone, which is located in the middle of its base measuring 50X50 mm. The height of the prism is 10 mm. A through cylindrical hole with a diameter of 20 mm was drilled along the axis of the bushing.
13.2. The sequence of building views on the detail drawing. Consider an example of constructing views of a part - a support (Fig. 102).
Rice. 102. Visual representation of the support
Before proceeding with the construction of images, it is necessary to clearly imagine the general initial geometric shape of the part (whether it will be a cube, a cylinder, a parallelepiped, or others). This form must be kept in mind when constructing views.
The general shape of the object shown in Figure 102 is a rectangular parallelepiped. It has rectangular cutouts and a cutout in the form of a triangular prism. Let's start depicting the detail with it general form- a parallelepiped (Fig. 103, a).
Rice. 103. The sequence of constructing views of the part
Projecting the parallelepiped on the planes V, H, W, we get rectangles on all three projection planes. On the frontal projection plane, the height and length of the part, i.e., dimensions 30 and 34, will be reflected. On the horizontal projection plane, the width and length of the part, i.e., dimensions 26 and 34. On the profile plane, the width and height, i.e. 26 and 30.
Each detail measurement is shown without distortion twice: height - on the frontal and profile planes, length - on the frontal and horizontal planes, width - on the horizontal and profile projection planes. However, you cannot apply the same dimension twice in a drawing.
All constructions will be done first with thin lines. Insofar as main view and the top view are symmetrical, with axes of symmetry marked on them.
Now we will show cutouts on the projections of the parallelepiped (Fig. 103, b). It is more expedient to show them first on the main view. To do this, set aside 12 mm to the left and right of the axis of symmetry and draw vertical lines through the points obtained. Then, at a distance of 14 mm from the upper edge of the part, draw segments of horizontal lines.
Let's build projections of these cutouts on other views. This can be done using communication lines. After that, in the top and left views, you need to show the segments that limit the projections of the cutouts.
In conclusion, the images are outlined with lines established by the standard, and dimensions are applied (Fig. 103, c).
- Name the sequence of actions that make up the process of constructing types of an object.
- What is the purpose of projective communication lines?
13.3. Construction of cutouts on geometric bodies. Figure 104 shows images of geometric bodies, the shape of which is complicated various kinds cutouts.
Rice. 104. Geometric bodies containing cutouts
Details of this form are widespread in technology. To draw or read their drawing, one must imagine the shape of the workpiece from which the part is obtained, and the shape of the cutout. Consider examples.
Example 1. Figure 105 shows a drawing of the gasket. What is the shape of the removed part? What was the shape of the piece?
Rice. 105. Gasket Shape Analysis
After analyzing the drawing of the gasket, we can conclude that it was obtained as a result of removing the fourth part of the cylinder from a rectangular parallelepiped (blank).
Example 2. Figure 106, a is a drawing of a plug. What is the form of its preparation? What resulted in the shape of the part?
Rice. 106. Building projections of a part with a cut
After analyzing the drawing, we can conclude that the part is made from a workpiece cylindrical shape. A notch is made in it, the shape of which is clear from Figure 106, b.
And how to build a cutout projection on the left view?
First, a rectangle is drawn - a view of the cylinder on the left, which is the original shape of the part. Then build the projection of the cutout. Its dimensions are known, therefore, points a", b" and a, b, which define the projections of the notch, can be considered as given.
The construction of profile projections a", b" of these points is shown by communication lines with arrows (Fig. 106, c).
Having set the shape of the cutout, it is easy to decide which lines in the view on the left should be outlined with solid thick main lines, which with dashed lines, and which should be deleted altogether.
13.4. Construction of the third view. You will sometimes have to complete tasks in which you need to build a third one according to the two available types.
In Figure 108, you see an image of a bar with a cutout. Two views are given: front and top. It is required to build a view on the left. To do this, you must first imagine the shape of the depicted part.
Rice. 108. Drawing of a bar with a cutout
Comparing the views in the drawing, we conclude that the bar has the shape of a parallelepiped with a size of 10x35x20 mm. A cut is made in the parallelepiped rectangular shape, its size is 12x12x10 mm.
The view on the left, as you know, is placed at the same height as the main view to the right of it. We draw one horizontal line at the level of the lower base of the parallelepiped, and the other at the level of the upper base (Fig. 109, a). These lines limit the height of the view on the left. Draw a vertical line anywhere between them. It will be a projection of the rear face of the bar onto the profile projection plane. From it to the right, we set aside a segment equal to 20 mm, i.e., we limit the width of the bar, and draw another vertical line - the projection of the front face (Fig. 109, b).
Rice. 109. Construction of the third projection
Let us now show a cutout in the part in the left view. To do this, set aside to the left of the right vertical line, which is the projection of the front face of the bar, a segment of 12 mm and draw another vertical line (Fig. 109, c). After that, we delete all auxiliary construction lines and outline the drawing (Fig. 109, d).
The third projection can be built on the basis of the analysis geometric shape subject. Let's see how it's done. In Figure 110, a two projections of the part are given. We need to build a third.
Rice. 110. Building a third projection from two data
Judging by these projections, the part is composed of a hexagonal prism, a parallelepiped and a cylinder. Mentally combining them into a single whole, imagine the shape of the part (Fig. 110, c).
We draw an auxiliary straight line on the drawing at an angle of 45 ° and proceed to the construction of the third projection. You know what the third projections of a hexagonal prism, a parallelepiped and a cylinder look like. We draw successively the third projection of each of these bodies, using communication lines and axes of symmetry (Fig. 110, b).
Note that in many cases it is not necessary to build a third projection on the drawing, since the rational execution of images involves the construction of only the necessary (minimum) number of views sufficient to identify the shape of the object. In this case, the construction of the third projection of the object is only an educational task.
- You are familiar with different ways construction of the third projection of the object. How do they differ from each other?
- What is the purpose of the constant line? How is it carried out?
Rice. 113. Tasks for exercises
Rice. 114. Tasks for exercises
Graphic work No. 5. Building a third view from two data
Build a third view based on two data (Fig. 115).
Rice. 115. Tasks for graphic work № 5