General view drawing | The main link in creating a high-quality product

Learn how to create a high-quality general drawing and make your product perfect. This article contains all the necessary information and tips

A general drawing in engineering is usually called a document that has a graphical representation of the product, which determines the design of a particular unit or unit. From it, it becomes clear how its main components interact, what is the general principle of operation of the device. The development of general drawings of GOST 2.102 is carried out at the earliest stages of design. A general drawing is usually performed at the technical design stage, but it can also be performed at the technical proposal and draft design stage.

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General view drawing — a design document that defines the initial design of an atypical product, containing a simplified image, basic parameters and technical requirements for the product in the amount of initial data (tasks) required for the development of design documentation. A general view drawing makes it possible to identify the product and identify its components.

General view drawing basics of creation and advantages of using it

A general view drawing is the basis for developing working documentation of specifications, part drawings, and assembly drawings for the entire product or individual assembly units. A general drawing is assigned the VO code, it defines the design of products depending on the depth of design study of the product at this particular stage, the interaction of the main components of the product, and explains the principle of operation of the product. VO is not intended for manufacturing products based on it and therefore does not contain, like an assembly drawing, images of all the components and requirements for the manufactured product.

General view drawing content: what you need to know

The general drawings of GOST 2.119 contain the following components::

☑ Sections, sections, views, and other images that give a complete picture of how a particular product is designed and how its components interact.

Номера Numbers that have separate device components.

☑ Technical characteristics of the product that are necessary for the subsequent development of drawings, as well as for the convenience of comparing variants based on a general drawing.

☑ Information that describes the composition of a technical product and includes brands of parts and structural materials, names of the main components and their designations.

Справ Reference, connection, installation and overall dimensions.

☑ Main label.

☑ A diagram, if you don’t need to create it on a separate sheet.

Making a general-view drawing: step by step

From the point of view of design, general drawings practically do not differ from assembly drawings, but they have a completely different purpose. The main difference between general-view drawings and assembly drawings is their purpose. It consists in that on their basis every technically competent person can make for themselves a picture of what the design of the product is and the principle of its operation. In addition, general-view drawings allow you to assemble products and check how correctly they are made. To do this, they often include elements such as additional sections and sections, as well as some necessary dimensions.

The main image of the product in the general drawing. The product is usually placed in the working position. If the working position of the product can be any, then the main image is selected so that the selected position is convenient for assembly and gives the most complete idea of the product design.

The main image is usually made as a frontal or complex section, or with a symmetrical design-connecting half of the main view and half of the frontal section.

Main product images in the general drawing. The composition of other images is determined depending on the design features of the product and the shape of its parts. The number of images should be the smallest, but sufficient to give a complete picture of the design of the product as a whole, the interaction of its components, the design and technical forms of all parts and assembly units.

The main images of the product are located in a projection connection relative to the main one. In some cases, for more efficient use of the drawing field, some of them are placed in an empty field and marked with appropriate inscriptions indicating the direction of view.

The main images of a product in a general drawing can be either product views, sections with planes parallel to the main projection planes, or complex sections. As a rule, this is done when the images are not symmetrical in cases where the section provides more comprehensive information about the product than the view. In this case, the product view (if necessary) is placed in the free field of the drawing.

Individual images can be given at a reduced scale compared to the main image, if the shape of the depicted elements is simple and their “reading” is not difficult.

Small structural elements, using additional types, sections or remote elements, are performed on an enlarged scale.

In a general drawing, it is allowed to place an image of neighboring products that are interfaced with the object being designed (“environment”). “Environment” lines are thin lines of the missing contour. Components of the product located behind the “environment” are shown as visible. Items of” furniture “ are performed in a simplified way, providing only the necessary data to determine the installation location, methods of attaching and attaching the product. In sections and cross-sections, you can not hatch the “background”. The name or designation of the products that make up the “situation”, if they need to be indicated in the drawing, is placed directly on its image or on the shelf of the callout line drawn from the corresponding image.

Standard parts, such as screws, bolts, studs, rivets, pins, dowels, axles, handles, rods, etc., are shown undecided and not hatched when cut longitudinally. If these parts have holes, grooves, and other elements, then the drawings show them using local sections.

In general drawings, gaskets are shown blackened.

An example of setting dimensions is shown in the general drawing presented earlier.

What dimensions should be specified in the general drawing?

Dimensions and limit deviations of the product GOST 2.307–2011 in the drawing are indicated by dimensional numbers and dimensional lines.

European standard ISO 129–1: 2004 Technical drawings. Specify dimensions and tolerances. Part 1. General provisions.

The size numbers must correspond to the actual dimensions of the object depicted, regardless of the scale and accuracy of the drawing. Dimensions are linear — length, width, height, depth, diameter, radius, arc, and angular-the dimensions of corners. Linear dimensions are indicated in the general drawing in mechanical engineering in millimeters, but the unit of measurement is not indicated in the drawing. Angular dimensions and limit deviations of angular dimensions are indicated in degrees, minutes, and seconds with the unit of measurement indicated.

It is not allowed to use simple fractions for dimensional numbers, except for dimensions in inches: thread G 1 1/2".

Overall dimensions determine the maximum distances between the points of the product outline in three coordinate directions. If there are moving parts in the product, the overall dimensions are indicated for the two extreme positions of these parts and put down by type: 140…150.

Installation and connection dimensions determine the coordinates and dimensions of the elements or components of products that are used to attach other products that work with it in a complex to this product: G 1/2 “ thread.

Reference dimensions that are not required for this graphic document and are specified for the convenience of using this document.

Reference dimensions are marked with the sign”*”, and in the technical requirements write: Dimensions for reference”. If all dimensions are reference dimensions, do not mark them with the “*” sign, but write “Dimensions for reference” in the technical requirements.

In graphic documents, products with dimensions that are technically difficult to control are marked with the sign”**”, and in the technical requirements, the inscription “**Dimensions “ is placed. instr.”.

It is preferable to apply dimensional lines outside the image contour.

The extension lines should extend beyond the ends of the arrows of the measuring line by 1–5 mm.

The minimum distance between parallel dimension lines should be 7 mm, and between the dimension line and the contour line — 10 mm and selected depending on the size of the image and the saturation of the drawing.

Elements of the HE drawing (labels, text of technical requirements, item numbers, etc.) must be executed according to the rules established by the ESKD standards for working drawings.

Table of components of the product, how to make it correctly

Names and designations of component parts of the product in HE drawings are indicated in one of the following ways::

➔ on the shelves of callout lines drawn from the part in the VO drawing. The callout lines should not intersect with each other, be non-parallel to the hatching lines (if they pass through a shaded field), and if possible, do not intersect image elements that do not include the label placed on the field. It is allowed to make callout lines with one break, as well as to draw two or more callout lines from one shelf. Labels related to an image can contain no more than two lines located above and below the callout line shelf;

➔ in the table placed in the drawing during;

➔ in the table made on separate sheets of A4 format according to GOST 2.301 as subsequent sheets of the HE drawing.

If there is a table on the shelves of callout lines, indicate the position numbers of the components of the product. Position the item number parallel to the main drawing label, grouping it into a column or row if possible on the same line.

The table of component parts of a product is usually similar in content to the specification provided for assembly drawings.

The table generally consists of graphs:

“Item” (item), “Designation”, “ Quantity “(quantity), “ Additional instructions “(additional instructions), but may include the columns “Material”, “Name”, “Mass”, etc. The graph sizes are arbitrary.

It is recommended to write the components in the table in the following order::

─ Borrowed items;

─ Purchased items;

─ Newly developed products.

The text part in the form of technical requirements and technical characteristics must be placed on the first sheet in the form of a column with a width of no more than 185 mm.

If necessary, the text is placed in one, two or more columns. The second and last columns are located to the left of the main label. You can’t place images or other tables between the text part and the component parts table (or the main label). Place the necessary tables, including technical specifications, in the form of a table, in the free field of the general drawing to the right of the images or below them.

One of the features of general-view drawings is that all images on them are executed in a simplified way, but with full compliance with all the norms and standards of the ESKD.

As for the assumptions that are acceptable for general drawings, these include the possibility of drawing the outlines of almost any component parts of the product with contour lines; the ability to avoid depicting some unimportant relationships between individual components of the structure.

At the next stage of design — working documentation-drawings of individual parts are developed on the basis of a general drawing, and then an assembly drawing with a specification, installation and dimensional drawings are developed.

A GM dimensional drawing is a document that contains a simplified (contour) image of the product. It indicates the connection, installation and overall dimensions.

Installation drawing MCH-is a document that contains a simplified (contour) image of the product. It indicates all the data that is necessary in order to perform installation (installation) in the place where the product will be used. It is also customary to refer to the category of installation drawings as drawings of foundations that are specially designed so that products are installed on them.

If the drawing is general-view, dimensional, or. if the assembly drawing is combined with the assembly drawing, then such a drawing must meet all the requirements of each individual drawing.

The working design of the machine usually includes technical documents (drawings of parts and general types, assembly, dimensional and installation drawings, diagrams, summary specifications, lists of purchased products, borrowed and normalized parts, etc.), technical specifications, operating instructions, passport, updated patent drawing, and other documents.

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