Mechanical A0-A4 frame drawing style

Drawing dimensions A0-A4 are clearly defined in mechanical drawings. A0 is1189mm× 841mm, A 1 is 84 1mm×594mm, A2 is 594mm×420mm, and A3 is 420mm×.

First of all, common drawing tools

1. Sketchpad is a rectangular board used to fix pictures. Its requirements:

1) The board surface is flat and smooth;

2) The "leading edge" on the left side should be straight.

Commonly used drawing board specifications:

No.0 (900mm× 1200mm), 1 (600mm×900mm) and No.2 (450mm×600mm).

2. T-square T-square consists of "ruler head" and "ruler body".

Use:

1) Draw parallel lines with the sketchpad.

2) Draw corner lines and vertical lines with the sketchpad and triangle.

3. A set of triangular plates consists of two triangular plates, one 45 and the other 30 (or 60).

Use:

1) Draw vertical lines and diagonal lines with a T-square (15o angle lines): 45, 30, 60, 75, 105 and 150, etc.

2) Two triangular plates cooperate to draw parallel lines or vertical lines of known straight lines.

4. Scale scale is commonly known as "triangular ruler", and there are six commonly used scales, which are used to draw graphs of different sizes and proportions.

Note: the scale can not be used as a ruler to draw lines, but can only be used to measure sizes of different proportions.

5. Curved board Curved board is a tool for drawing irregular non-circular curves (both sides can be used).

The use method comprises the following steps:

1) ensure that at least four points (or more than four points) coincide with the edge of the curved plate, thus connecting these four points (or more than four points);

2) There should be repetition between two paragraphs.

Second, the common drawing supplies

1. Pencils There are three kinds of pencils: hard, medium and soft.

There are 13 kinds of labels: 6H, 5H, 4H, 3H, 2H, h, HB, b, 2B, 3B, 4B, 5B and 6B. Among them, 6H is the hardest, HB has moderate hardness, and 6B is the softest.

Selection and use of pencils;

1) When drawing, use H or 2H pencils and cut them into sharp cones;

2) When drawing a figure, use a pencil of B or HB to cut it into a quadrangular prism (flat shovel shape);

3) The pencil should be used from the unlabeled end, so that the soft and hard labels of the pencil can be maintained.

2. There are pros and cons between drawing paper and drawing paper. When drawing, you should choose the positive picture.

Identification method: wipe it with a rubber several times, and the side that is not easy to fluff is the front, or adopt observation method, and the reflective side is the front.

Third, common drawing tools.

1. Gauges Gauges are tools for intercepting dimensions, bisectors or circles.

Usage: When two needle tips are close together, they should be aligned.

2. Compass The compass is a tool for drawing "circle" or "arc".

1) Its accessories include: steel pin, lead pin, duckbill pin, telescopic rod, etc.

2) Usage: The steel needle end of the compass should be the end with "shoulder"; When drawing a big circle, the shoulders should be aligned parallel to the lead.

In addition to the above drawing tools and supplies, there should also be: ruler, protractor, eraser, eraser, knife, sandpaper, tape paper and so on.

IV. Size and format of drawings (GB/T14689-1993)

1. Drawing format In order to ensure the uniformity of drawing size and facilitate the binding, storage and reduction of drawings, the following provisions are made for the drawing format:

Drawing width and format (GB/T 14689- 1993)

Drawing format size and code: A0, A 1, A2, A3, A4 and A5.

2. Before drawing in drawing frame format (drawing frame line), the drawing frame line must be drawn with thick solid lines, and the drawing pattern (figure) should be within the drawing frame line.

There are two formats for boundary lines:

(1) Do not keep the binding format (2) Keep the binding format.

3. The text direction in the title bar and azimuth title bar is the direction of looking at the picture. The format, content and size of the title bar have been stipulated in the national standard (GB/T10609.5438+0-1989). Students are advised to use the title bar format shown in the figure for drawing assignments.

4. Additional symbols

1) Alignment symbol: In order to facilitate the positioning when copying or taking photos, the alignment symbol is drawn at the midpoint of each side.

A thick solid line with a line width of not less than 0.5 mm and extending from the drawing boundary to about 5 mm in the drawing frame. When the center symbol is within the title bar, the part extending into the title bar is omitted.

2) Direction symbol: When the drawing and reading directions are perpendicular to the direction of the title bar, in order to clarify the drawing and reading directions, draw a direction symbol (equilateral triangle with thin solid line) at the center symbol.

Verb (abbreviation for verb) proportion

1. clause

(1) ratio: the ratio of the linear dimension of the figure to the corresponding element of the object.

Original value ratio: the ratio is 1, that is, 1: 1.

Magnification: Magnification is greater than 1, such as 2: 1.

Reduction ratio: the ratio is less than 1, such as 1: 2.

2. Proportional series

(1) Preference is given to the proportion series in table 1-2, and then the proportion series can be selected.

(2) No matter what the scale is, the marked size value should be the actual size of the object. such as

For the convenience of drawing, when drawing patterns. As far as possible, it should be drawn in proportion to the original value of the parts. If the part is too big or too small, it shall be drawn according to the priority ratio specified in table 1-2.

No matter whether the drawing is enlarged or reduced, regardless of the drawing scale, the dimensions should be marked according to the actual dimensions of the parts.

3. Scale marking

1) in the title bar.

2) Mark it below or to the right of the view name. Such as I/2: 1, B-B/5: 1, etc.

The font of intransitive verbs (GB/T14691-1993)

In addition to expressing the graphics of parts, drawings should also explain the dimensions and technical requirements of parts in words and graphics. The fonts written in the drawings must be neat, clear, evenly spaced and neatly arranged.

The number of the font, called the font height, is represented by H. Its nominal size series are: 1.8, 2.5, 3.5, 5,7, 10,14,20 mm. If writing larger characters, the font height should be increased proportionally.

1. Chinese characters are long and imitate the Song Dynasty.

2. Letters and numbers Letters and numbers can be written in italics or straight. Italic prefixes are tilted to the right, at 75 degrees from the horizontal baseline.

ABCDEFGHIJKLMNOPQRSTUVWXY Latin alphabet example

bcdefghijklmnopqrstuvwxy

Examples of Roman numerals ⅶ ⅷ ⅸ.

0 123456789 Arabic numeral example

ABCDEFGHIJKLMNOPQRSTUVWXY

Examples of Greek letters:

1) type a and type b:

Type the font: stroke width = H/ 14 (H is word height).

Type B font: stroke width = H/ 10 (H is word height).

2) Straight italics (inclined 75 to the right).

Seven. Drawing line (GB/T 17450— 1998)

Drawing lines are various types of lines used in drawing.

The form and application of 1. graphic line (as shown in table 1-4)

2. The size of graphic lines can be divided into thick and thin. Based on the width of thick line, the width of thin line should be half that of thick line. In the various charts listed in Table1–4, the width of all charts except the thick solid line should be half the width of the thick solid line. The recommended line width series are: 0. 18, 0.25, 0.35, 0.5, 0.7, 1,1.4,2? Mm, the width of thick thread is generally 0.5~2 according to the size and complexity of the pattern? Choose between mm.

3. The method of drawing lines

(1) In the same pattern, the width of similar lines should be consistent, and the length and interval of line segments should be roughly equal.

(2) When various lines intersect, they should intersect with line segments, not with points or gaps.

(3) When the dotted line intersects with the solid line, there should be a gap. The dotted arc is tangent to the solid arc, and there should be a gap.

(4) The "point" of the dotted line is a short segment, not a point. The starting end of the stippling line is a straight line segment, which should be 2 ~ 5 mm beyond the contour line.

5] When drawing the center line of a circle, the center of the circle should be the intersection of line segments. Both ends of the dotted line should be 2~5mm beyond the circle. The center line of the small circle can be replaced by a thin solid line.

[6] When the solid line overlaps with the dotted line or dash-dot line, draw the solid line; Draw a dotted line when the dotted line overlaps with the dotted line.

(7) Line drawing shall not overlap or be confused with words, numbers or symbols. When it is inevitable, you must first make sure that the words, numbers or symbols are clear. When some lines overlap each other, just draw the first line in the order of thick solid line, dotted line and dotted line.