Conditional image and designation of the thread in the drawings. Calculation of the size of threaded blind holes Designation of oval holes according to GOST
The thread on the rods is depicted along the outer diameter with solid main lines, and along the inner diameter with solid thin lines.
You studied the main elements of metric threads (outer and inner diameters, thread pitch, thread length and angle) in the fifth grade. The figure shows some of these elements, but they do not make such inscriptions in the drawings.
The thread in the holes is depicted with solid main lines along the inner diameter of the thread and solid thin lines along the outer.
The thread symbol is shown in the figure. It is necessary to read like this: metric thread (M) with an outer diameter of 20 mm, third class of accuracy, right-hand, with a large pitch - “Thread M20 cl. 3 ".
The figure shows the designation of the thread “М25Х1,5 cl. 3 left "should be read as follows: metric thread, outer thread diameter 25 mm, pitch 1.5 mm, fine, third class of accuracy, left-hand.
Questions
- What lines represent the thread on the rod?
- What lines show the thread in the hole?
- How is the thread indicated in the drawings?
- Read the records “М10Х1 cl. 3 "and" М14Х1,5 cl. 3 left ".
Working drawing
Each product - machine or mechanism - consists of separate, interconnected parts.
Parts are usually made by casting, forging, stamping. In most cases, such parts are machined on metal-cutting machines - turning, drilling, milling and others.
Drawings of parts, provided with all instructions for manufacturing and control, are called working drawings.
The working drawings indicate the shape and dimensions of the part, the material from which it must be made. The drawings indicate the cleanliness of surface treatment, the requirements for manufacturing accuracy - tolerances. Manufacturing methods and technical requirements for the finished part are indicated by an inscription on the drawing.
Surface finish. Traces of processing and irregularities always remain on the treated surfaces. These irregularities, or, as they say, surface roughness, depend on the tool with which it is processed.
For example, a surface treated with a batter will be rougher (uneven) than with a personal file. The nature of the roughness also depends on the properties of the material of the product, on the cutting speed and the amount of feed during processing on metal-cutting machines.
To assess the quality of processing, 14 classes of surface cleanliness have been established. Classes are indicated in the drawings by one equilateral triangle (∆), next to which the class number is affixed (for example, ∆ 5).
Methods for obtaining surfaces of different purity and their designations in the drawings. The cleanliness of the processing of one part is not always the same; therefore, the drawing indicates where and what processing is required.
The sign at the top of the drawing indicates that there are no requirements for cleanliness of processing for rough surfaces. The sign ∆ 3 in the upper right corner of the drawing, taken in brackets, is placed if the same requirements are imposed on the surface treatment of the part. This is a surface with traces of processing with brute files, roughing cutters, an abrasive wheel.
Signs ∆ 4 - ∆ 6 - semi-finished surface, with subtle traces of processing with a finishing cutter, personal file, grinding wheel, fine sandpaper.
Signs ∆ 7 - ∆ 9 - clean surface, no visible traces of processing. Such processing is achieved by grinding, filing with a velvet file, scraping.
The ∆ 10 mark is a very clean surface, achieved by fine grinding, lapping on whetstones, filing with a velvet file with oil and chalk.
Signs ∆ 11 - ∆ 14 - surface cleanliness classes, achieved by special treatments.
Manufacturing methods and technical requirements for the finished part on the drawings are indicated by an inscription (for example, blunt sharp edges, harden, burnish, drill a hole along with another part and other requirements for the product).
Questions
- What are the icons for surface finish?
- After what kind of processing can a surface finish of ∆ 6 be obtained?
The task
Read the drawing in the figure and answer in writing the questions on the proposed form.
| Drawing Reading Questions | Answers |
| 1. What is the name of the part? | – |
| 2. Where is it used? | – |
| 3. List the technical requirements for the part | – |
| 4. What is the name of the drawing view? | – |
| 5. What conventions are there in the drawing? | – |
| 6. What is the overall shape and dimensions of the part? | – |
| 7. What thread is cut on the rod? | – |
| 8. Specify the elements and dimensions of the part | – |
"Plumbing", I. G. Spiridonov,
G.P. Bufetov, V.G. Kopelevich
A part is a part of a machine made from one piece of material (for example, bolt, nut, gear, lathe lead screw). A knot is a connection of two or more parts. The product is assembled according to assembly drawings. A drawing of such a product, which includes several units, is called an assembly, it consists of drawings of each part or unit and depicts an assembly unit (a drawing of a single ...
The dimensions on the working drawings are put down so that it is convenient to use them during the manufacture of parts and during their control after manufacture.
In addition to what is stated in 1.7 "Basic Dimensioning Information", here are some rules for dimensioning drawings.
When a part has several groups of holes close in size, images of each group of holes must be marked with special signs. Blackened sectors of circles are used as such signs, using their different number and location for each of the groups of holes (Fig. 6.27).
Figure: 6.27.
It is allowed to indicate the dimensions and number of holes of each group not on the part image, but on the plate.
For parts with symmetrically located elements of the same configuration and size, their dimensions in the drawing are applied once without indicating their number, grouping, as a rule, all dimensions in one place. The exception is the same holes, the number of which is always indicated, and their size is applied only once (Fig. 6.28).
Figure: 6.28.
The detail shown in fig. 6.27, has a number of holes with the same distance between them. In such cases, instead of a chain of dimensions repeating the same size several times, it is applied once (see size 23). Then, extension lines are drawn between the centers of the extreme holes of the chain and the size is applied in the form of a product, where the first factor is the number of gaps between the centers of adjacent holes, and the second is the size of this gap (see size 7 × 23 \u003d 161 in Fig. 6.27). This method of dimensioning is recommended for drawings of parts with the same distance between the same elements: holes, cutouts, protrusions, etc.
The position of the centers of holes or other identical elements, unevenly located around the circumference, is determined by the angular dimensions (Fig. 6.28, and). With a uniform distribution of identical elements around the circumference, angular dimensions are not applied, but are limited by indicating the number of these elements (Fig. 6.28, b).
Dimensions related to one structural element of the part (hole, protrusion, groove, etc.) should be applied in one place, grouping them in the image on which this element is most clearly depicted (Fig. 6.29).
Figure: 6.29.
The position of the inclined surface can be specified in the drawing with an angle size and two (Fig. 6.30, and) or three linear dimensions (Fig. 6.30, b). If the inclined surface does not intersect with the other, as in the first two cases, but is mated with a curved surface (see Fig. 6.17), the straight sections of the contour are extended with a thin line until they intersect and extension lines are drawn from the points of intersection to apply dimensions.
Figure: 6.30.
and - first case; b - second case
GOST 2.307–68 also established the rules for depicting and applying dimensions of holes in views in the absence of cuts (sections) (Fig. 6.31). These rules reduce the number of cuts that reveal the shape of these holes. This is done due to the fact that in the views where the holes are shown in circles, after specifying the diameter of the hole, they apply: the size of the hole depth (Fig.6.31, b), the size of the chamfer height and angle (Fig. 6.31, c), the size of the chamfer diameter and angle (Fig. 6.31, d), the size of the diameter and depth of the counterbore (Fig. 6.31E). If, after specifying the diameter of the hole, there are no additional indications, then the hole is considered to be through (Figure 6.31, a).
Figure: 6.31.
When sizing, the methods of measuring parts and the features of the technological process of their manufacture are taken into account.
For example, it is convenient to measure the depth of an open keyway on the outer cylindrical surface from the end, therefore, the dimension given in Fig. 6.32, and.
Figure: 6.32.
and - open; b - closed
The same size of the closed groove is easier to check if the size shown in fig. 6.32, b. It is convenient to control the depth of the keyway on the inner cylindrical surface by the size indicated in Fig. 6.33.
Figure: 6.33.
The dimensions must be affixed so that during the manufacture of the part it is not necessary to find out anything by counting. Therefore, the size stamped on the section along the width of the flat (Fig. 6.34) should be considered unsuccessful. The dimension defining the flat is shown correctly on the right side of fig. 6.34.
Figure: 6.34.
In fig. 6.35 shows examples of dimensioning by chain, coordinate and combined methods. With the chain method, the dimensions are located on a chain of dimension lines, as shown in Fig. 6.35, and. When setting the overall (overall) size, the circuit is considered closed. A closed dimensional chain is allowed if one of its dimensions is a reference, for example, overall (Figure 6.35, and) or included in the chain (Fig.6.35, b).
Reference dimensions are dimensions that are not subject to execution according to this drawing and are indicated for greater convenience in using the drawing. Reference dimensions in the drawing are marked with an asterisk, which is applied to the right of the dimension number. The technical requirements repeat this sign and write down: Size for reference (fig.6.35, a, b).
Limit deviations are not applied to the reference size included in a closed circuit. The most common are open circuits. In such cases, one dimension, for which the lowest accuracy is permissible, is excluded from the dimensional chain or the overall dimension is not affixed.
Dimensioning according to the coordinate method is performed from a preselected base. For example, in Fig. 6.35, in this base is the right end of the roller.
Most often, the combined method of dimensioning is used, which is a combination of chain and coordinate methods (Figure 6.35, r).
Figure: 6.35.
a, b - chain; in - coordinate; r - combined
On the working drawings of machined parts, in which sharp edges or edges must be rounded, indicate the size of the rounding radius (usually in technical requirements), for example: Radii of roundings 4 mm or Radii not specified are 8 mm.
The dimensions that determine the position of the keyways are also affixed taking into account the technological process. In the image of the groove for the segment key (Fig.6.36, and) the size is taken to the center of the disk cutter, with which the keyway will be milled, and the position of the keyway for the parallel key is set in size to its edge (Fig.6.36, b), since this groove is cut with a finger cutter.
Figure: 6.36.
and - for a key; 6 – for prismatic
Some elements of the parts depend on the shape of the cutting tool. For example, the bottom of a blind cylindrical hole is tapered, because the cutting end of the drill has a tapered shape. The size of the depth of such holes, with rare exceptions, is affixed to the cylindrical part (Figure 6.37).
Figure: 6.37.
In the drawings of parts with cavities, the internal dimensions related to the length (or height) of the part are applied separately from the external ones. For example, in the drawing of the body, a group of dimensions that defines the outer surfaces is placed above the image, and the inner surfaces of the part are determined by another group of dimensions that are below the image (Fig. 6.38).
Figure: 6.38.
When only a part of the part surfaces are to be machined, and the rest must be "black", ie. as they turned out during casting, forging, stamping, etc., the dimensions are affixed according to a special rule, also established by GOST 2.307-2011. A group of dimensions related to machined surfaces (ie, formed with the removal of a layer of material) must be associated with a group of dimensions of "black" surfaces (ie, formed without removal of a layer of material) by no more than one size in each coordinate direction.
The body only has two surfaces to be machined. The dimension connecting the groups of outer and inner dimensions is marked on the drawing of the case with the letter A.
If the dimensions of the body cavity were set from the plane of the left end face of the part, during its processing it would be necessary to withstand the maximum deviations of several dimensions at once, which is practically impossible.
This has been discussed a lot here. I will repeat in a general sense why it is necessary to show the transition lines conditionally: 1. To make the drawing readable. 2. From the transition lines, shown conditionally, you can set dimensions that are often no longer in any view and section. Here's an example. There is a difference? 1. As now can be displayed in all the listed CAD systems. And here's how to display. The transition lines are shown conditionally and the dimensions are shown, which in other display modes of the transition lines simply cannot be set. Why was this required by the normative controller? Yes, just so that the drawings have a familiar look after many years of work in 2D and are easy to read, especially by the customer who approves them.
This is true :) this is nonsense :) in TF you can do this and so \u003d) there will be no tangible difference in speed, you can even then take any copy to repaint, change holes, delete holes, whatever ... and the array will still remain an array - it will be possible to change the number of copies, direction, etc., cut the video or believe it? :) That's right, but what is the problem? Translate as SW splines by points into splines by poles or what, if you think about this also some change in the original geometry - there are no comments on this? :) as I understand it, TF only 1 to 1 and translates, the rest can already be configured in the TF template before export in DWG - see the figure under the spoiler, or scale it in the form of AC, which, in principle, does not contradict the main methods of working with AutoCAD, and since in view of the prevalence of AC in the early stages of the peak of the popularity of CAD implementation, the age generation is even more familiar with this: And if still to get to the bottom of the export / import capabilities of different CAD systems: 1) how can I export only selected lines from a 2D SW drawing to DWG? (from 3D documents, more or less SW is adapted, but you still have to clean the excess manually in a small preview window). Delete everything that is not needed in advance, and then export-\u003e somehow not modern, not youthful :) 2) And vice versa, as selected lines in AutoCAD, quickly import into SW (for example, for a sketch, or just as a set of lines for drawing)? (for TF: selected a set of necessary lines in AC -ctrl + c and then in TF just ctrl + v - everything)
What detail are we talking about, otherwise it may not be necessary to mirror this detail, but simply tie it differently and it will be just right. A mirror part is the same configuration just created by the machine, you can make the configuration of the part yourself and in some cases it may turn out to be more elegant, it is also easier to edit later.
The dimensions of the countersinks are affixed as shown in Fig. 63, 64.
If the holes in the part are located on the axes of its symmetry, then the angular dimensions should not be set. Other holes should be coordinated with an angular dimension. In this case, for holes located along a circle at equal distances, the diameter of the center circle is set and an inscription about the number of holes is set (Fig. 65, 66).
On the drawings of cast parts requiring machining, the dimensions are indicated so that only one dimension is placed between the untreated surface - the casting base and the processed - the main dimensional base (Fig. 67). In fig. Figures 67 and 68 are drawing dimensional examples of a cast part and a similar machined part for comparison.
The dimensions of the holes in the drawings are allowed to be applied in a simplified manner (according to GOST 2.318-81) (Table 2.4) in the following cases:
▪ the diameter of the holes in the image is 2 mm or less;
▪ there is no image of the holes in the section (section) along the axis;
▪ drawing holes according to general rules complicates the reading of the drawing.
Table 7
Simplified dimensioning of various hole types.
Hole type
d1 x l1 –l4 x
d1 x l1
d1 x l1 –l4 x
d1 / d2 x l3
Continuation of table. 7
Hole type
Example of simplified hole sizing
d1 / d2 x φ
Z x p x l2 - l1
Z x p x l2 - l1 - l4 x
The dimensions of the holes should be indicated on the shelf of the leader line drawn from the axis of the hole (Fig. 69).
2.3.2. Image, designation and dimensioning of some elements of parts
The following elements are most common: chamfers, fillets, grooves (grooves), grooves, etc.
Chamfers - conical or flat narrow cuts (blunting) of sharp edges of parts - are used to facilitate the assembly process, to protect hands from cuts with sharp edges (technical requirements
safety), making products more beautiful (technical aesthetics requirements) and in other cases.
The dimensions of the chamfers and the rules for their indication in the drawings are standardized. According to GOST 2.307-68 *, the dimensions of the chamfers at an angle of 45o are applied as shown in Fig. 70.
Figure: 70 The dimensions of the chamfers at other angles (usually 15, 30 and 60 °) are indicated by
general rules: put down linear and angular dimensions (Fig. 71, a) or two linear dimensions (Fig. 71, b).
The size of the chamfer height c is selected according to GOST 10948-64 (Table 8). Table 8
Normal chamfer dimensions (GOST 10948-64)
Chamfer height with |
|||||||||||||||||||
Note. For fixed landings, chamfers should be taken: at the end of the shaft 30 °, in the bore of the sleeve 45 °.
Fillets - rounding of external and internal corners on machine parts - are widely used to facilitate the manufacture of parts by casting, stamping, forging, increasing the strength properties of shafts, axles and other parts at the transition from one diameter to another. In fig. 74, the letter A marks the place of stress concentration that can cause a crack or fracture of the part. The fillet eliminates this hazard.
Figure: 74 The dimensions of the fillets are taken from the same series of numbers as for the value with
The radii of the roundings, the dimensions of which on a drawing scale of 1 mm or less, are not shown and their dimensions are applied, as shown in Fig. 74.
To obtain a full profile thread along the entire length of the rod or hole, a groove is made at the end of the thread for the tool to exit. There are two types of grooves. In the drawing, the details of the groove are depicted in a simplified manner, and the drawing is supplemented with an extension element on an enlarged scale (Fig. 49, 51). The shape and dimensions of the grooves, the dimensions of the runaway and undercut are set by GOST 10549-80, depending on the thread pitch p.
In fig. 75 shows an example of a groove for external metric thread, and in Fig. 76 - for internal metric threads.
Figure: 76 The dimensions of the groove are selected from the tables of GOST 10549-80 (see Appendix 5), their
Below are the dimensions of the grooves for external metric threads:
The edges of the grinding wheel are always slightly rounded, therefore, in the place of the part where an indent from the edges is undesirable, a groove is made for the exit of the grinding wheel.
Such a groove in the drawing of the part is depicted in a simplified manner, and the drawing is supplemented with a remote element (Fig. 77, 78).
The dimensions of the grooves depending on the diameter of the surface are established by GOST 8820-69 (Appendix 4).
The dimensions of the grooves for the exit of the grinding wheel can be calculated by
formulas (all dimensions in mm): |
|||
a) at d \u003d 10 ÷ 50 mm |
d1 \u003d d –0.5, |
d2 \u003d d + 0.5, |
|
R1 \u003d 0.5; |
|||
b) at d \u003d 50 100 mm |
d1 \u003d d - 1, |
d2 \u003d d + 1, |
|
R1 \u003d 0.5. |
|||
2.3.3. Surface roughness of the part
Depending on the manufacturing method of the part (Fig. 79), its surfaces can have different roughness (Tables 9, 10).
Figure: 79 Surface roughness Is a set of microroughnesses
of the processed surface, considered at the section of the standardized length (L). This length is called the base length, it is selected depending on the nature of the measured surface. The greater the height of microroughness, the greater the base length is taken.
GOST 2789-73 provides six parameters to determine the surface roughness.
Altitude: Ra - the arithmetic mean deviation of the profile; Rz - the height of the profile irregularities at ten points; Rmax is the highest profile height.
Stepper: S - average step of local profile protrusions; Sm - average step of irregularities; Ttp - relative reference length, where p - value of the profile section level.
The most common parameters in technical documentation are the parameters Ra (arithmetic mean deviation of the profile) and Rz (the height of the irregularities of the profile at ten points).
Knowing the shape of the surface profile, determined by the profilograph at its base length L, it is possible to construct a roughness diagram (Fig. 80),
By the decree of the USSR State Committee for Standards dated January 4, 1979 No. 31, the date of introduction is setfrom 01.01.80
This standard establishes the rules for indicating the tolerances of the shape and location of surfaces on the drawings of products of all industries. Terms and definitions of the tolerances of the shape and location of surfaces - according to GOST 24642-81. The numerical values \u200b\u200bof the tolerances of the shape and location of surfaces are in accordance with GOST 24643-81. The standard is fully consistent with ST SEV 368-76.
1. GENERAL REQUIREMENTS
1.1. The tolerances of the shape and location of surfaces are indicated in the drawings with symbols. The type of tolerance of the shape and location of surfaces must be indicated in the drawing by the signs (graphic symbols) given in the table.|
Tolerance group |
Type of admission |
|
| Shape tolerance | Straightness tolerance | |
| Flatness tolerance | ||
| Roundness tolerance | ||
| Cylindrical tolerance | ||
| Longitudinal profile tolerance | ||
| Location tolerance | Parallelism tolerance | |
| Squareness tolerance | ||
| Tilt tolerance | ||
| Alignment tolerance | ||
| Symmetry tolerance | ||
| Positional tolerance | ||
| Intersection tolerance, axes | ||
| Overall shape and position tolerances | Radial runout tolerance Face runout tolerance Runout tolerance in a given direction | |
| Full radial runout tolerance Full face runout tolerance | ||
| Shape tolerance of a given profile | ||
| Tolerance of the shape of a given surface |
2. APPLICATION OF TOLERANCE LABELS
2.1. With a conventional designation, data on the tolerances of the shape and location of surfaces are indicated in a rectangular frame divided into two or more parts (Fig. 1, 2), in which they place: in the first - the tolerance sign according to the table; in the second - the numerical value of the tolerance in millimeters; in the third and subsequent ones - the letter designation of the base (s) or the letter designation of the surface with which the location tolerance is associated (clauses 3.7; 3.9).Heck. 1
Heck. 2
2.2. Frames should be made with solid thin lines. The height of numbers, letters and signs that fit into the frames must be equal to the font size of the dimension numbers. A graphic representation of the frame is given in the obligatory Appendix 1. 2.3. The frame is placed horizontally. If necessary, the vertical arrangement of the frame is allowed. It is not allowed to cross the frame with any lines. 2.4. The frame is connected to the element to which the tolerance belongs, with a solid thin line ending with an arrow (Fig. 3).
Heck. 3
The connecting line can be straight or broken, but the direction of the segment of the connecting line ending with an arrow must correspond to the direction of the deflection measurement. The connecting line is taken from the frame, as shown in fig. 4.
Heck. 4
If necessary, it is allowed to: draw a connecting line from the second (last) part of the frame (Fig. 5 and); end the connecting line with an arrow and from the side of the material of the part (Fig. 5 b).
Heck. five
2.5. If the tolerance refers to the surface or its profile, then the frame is connected to the contour line of the surface or its continuation, while the connecting line should not be a continuation of the dimension line (Fig. 6, 7).
Heck. 6
Heck. 7
2.6. If the tolerance refers to an axis or plane of symmetry, then the connecting line should be a continuation of the dimension line (Fig. 8 and, b). If there is not enough space, the arrow of the dimension line may be combined with the arrow of the connecting line (Fig. 8 in).
Heck. 8
If the size of the element has already been specified once, then it is not indicated on the other dimension lines of this element used to symbolize the tolerance of the shape and location. Dimension line without dimension should be considered as an integral part of the symbol for the tolerance of the shape or location (Fig. 9).
Heck. nine
Heck. ten
2.7. If the tolerance refers to the lateral sides of the thread, then the frame is connected to the image in accordance with Fig. ten and... If the tolerance refers to the thread axis, then the frame is connected to the image in accordance with Fig. ten b... 2.8. If the tolerance refers to a common axis (plane of symmetry) and it is clear from the drawing for which surfaces this axis (plane of symmetry) is common, then the frame is connected to the axis (plane of symmetry) (Fig. 11 and, b).
Heck. eleven
2.9. Before the numerical value of the tolerance, indicate: the symbol Æ, if the circular or cylindrical tolerance field is indicated with a diameter (Fig. 12 and); symbol R , if the circular or cylindrical tolerance field is indicated by the radius (Fig. 12 b); symbol T,if the tolerances of symmetry, intersection of axes, the shape of a given profile and a given surface, as well as positional tolerances (for the case when the positional tolerance field is limited to two parallel straight lines or planes) are indicated in diametrical terms (Fig. 12 in); symbol T / 2for the same types of tolerances, if they are indicated in radial terms (Fig. 12 r); the word "sphere" and the symbols Æ or R if the tolerance field is spherical (Fig. 12 d).
Heck. 12
2.10. The numerical value of the tolerance of the shape and location of surfaces indicated in the frame (Fig. 13 and), refers to the entire length of the surface. If the tolerance refers to any part of the surface of a given length (or area), then the specified length (or area) is indicated next to the tolerance and is separated from it by an oblique line (Fig. 13 b, in), which should not touch the frame. If it is necessary to assign a tolerance for the entire surface length and for a given length, then the tolerance for a given length is indicated under the tolerance for the entire length (Fig. 13 r).
Heck. 13
(Modified edition, Amendment No. 1). 2.11. If the tolerance should refer to a section located at a certain place of the element, then this section is indicated by a dash-dot line and limited in size according to the drawing. fourteen.
Heck. fourteen
2.12. If it is necessary to set the protruding tolerance field of the location, then after the numerical value of the tolerance, indicate the symbol. The contour of the protruding part of the normalized element is limited by a thin solid line, and the length and location of the protruding tolerance field - by dimensions (Fig. 15).
Heck. 15
2.13. Inscriptions supplementing the data given in the tolerance frame should be applied above the frame below it or as shown in fig. sixteen.
Heck. sixteen
(Modified edition, Amendment No. 1). 2.14. If for one element it is necessary to set two different types of tolerance, then it is allowed to combine the frames and arrange them according to the features. 17 (upper designation). If for a surface it is required to indicate at the same time the designation of the tolerance of the shape or location and its letter designation used to normalize another tolerance, then frames with both designations can be placed side by side on the connecting line (Fig. 17, lower designation). 2.15. Repeating the same or different types of tolerances, denoted by the same sign, having the same numerical values \u200b\u200band referring to the same bases, are allowed to be indicated once in a frame, from which one connecting line departs, which is then branched out to all normalized elements (Fig. 18).
Heck. 17
Heck. 18
2.16. The tolerances of the shape and location of symmetrically located elements on symmetrical parts are indicated once.
3. DESIGNATION OF BASES
3.1. The bases are indicated by a blackened triangle, which is connected with a connecting line to the frame. When making drawings with the help of computer output devices, the triangle denoting the base is allowed not to be blackened. The base triangle should be equilateral, with a height approximately equal to the font size of the dimension numbers. 3.2. If the base is a surface or its profile, then the base of the triangle is placed on the contour line of the surface (Fig. 19 and) or on its continuation (Fig. 19 b). In this case, the connecting line should not be a continuation of the dimension line.
Heck. nineteen
3.3. If the base is an axis or plane of symmetry, then the triangle is placed at the end of the dimension line (Fig. 18). In case of lack of space, the arrow of the dimension line may be replaced with a triangle denoting the base (Fig. 20).
Heck. 20
If the base is a common axis (Fig. 21 and) or the plane of symmetry (Fig. 21 b) and from the drawing it is clear for which surfaces the axis (plane of symmetry) is common, then the triangle is placed on the axis.
Heck. 21
(Modified edition, Amendment No. 1). 3.4. If the base is the axis of the center holes, then the inscription "Center axis" is made next to the designation of the base axis (Fig. 22). It is allowed to designate the base axis of the center holes in accordance with the drawing. 23.
Heck. 22
Heck. 23
3.5. If the base is a certain part of the element, then it is indicated by a dash-dot line and limited in size in accordance with the drawing. 24. If the base is a certain place of the element, then it must be determined by the dimensions according to the drawing. 25.
Heck. 24
Heck. 25
3.6. If there is no need to select one of the surfaces as the base pi, then the triangle is replaced with an arrow (Fig. 26 b). 3.7. If the connection of the frame to the base or other surface, to which the deviation of the location belongs, is difficult, the surface is designated by a capital letter inscribed in the third part of the frame. The same letter is inscribed in a frame, which is connected to the designated surface by a line, which is filled with a triangle, if the base is designated (Fig. 27 and), or an arrow if the designated surface is not a base (Fig. 27 b). In this case, the letter should be placed parallel to the main inscription.
Heck. 26
Heck. 27
3.8. If the size of the element has already been specified once, then it is not indicated on the other dimension lines of this element used for the reference designation of the base. Dimension line without size should be considered as an integral part of the base symbol (Fig. 28).
Heck. 28
3.9. If two or more elements form a combined base and their sequence does not matter (for example, they have a common axis or plane of symmetry), then each element is designated independently and all letters are inscribed in a row in the third part of the frame (Fig. 25, 29). 3.10. If it is necessary to set the tolerance of the location relative to the set of bases, then the letter designations of the bases are indicated in the independent parts (third and further) of the frame. In this case, the bases are written in descending order of the number of degrees of freedom deprived by them (Fig. 30).
Heck. 29
Heck. thirty
4. INDICATION OF NOMINAL POSITIONING
4.1. Linear and angular dimensions that determine the nominal location and (or) the nominal shape of the elements limited by the tolerance, when assigning a positional tolerance, tilt tolerance, tolerance of the shape of a given surface or a given profile, are indicated on the drawings without limit deviations and are enclosed in rectangular frames (Fig. 31 ).
Heck. 31
5. DESIGNATION OF DEPENDENT TOLERANCES
5.1. The dependent tolerances of the shape and location are indicated by a conventional sign, which is placed: after the numerical value of the tolerance, if the dependent tolerance is associated with the actual dimensions of the element in question (Fig. 32 and); after the letter designation of the base (Fig. 32 b) or without letter designation in the third part of the frame (Fig. 32 r), if the dependent tolerance is related to the actual dimensions of the base feature; after the numerical value of the tolerance and the letter designation of the base (Fig. 32 in) or without letter designation (Fig. 32 d), if the dependent tolerance is related to the actual dimensions of the considered and base elements. 5.2. If the location or shape tolerance is not specified as dependent, then it is considered independent.
Heck. 32
APPENDIX 1
Mandatory
SHAPE AND SIZE OF SIGNS
APPENDIX 2
Reference
EXAMPLES OF INDICATION ON THE DRAWINGS OF TOLERANCES FOR THE SHAPE AND POSITION OF SURFACES
|
Type of admission |
Indication of tolerances of form and location by symbol |
Explanation |
| 1. Straightness tolerance | The straightness tolerance of the generatrix of the cone is 0.01 mm. | |
|
|
Straightness tolerance of the hole axis Æ 0.08 mm (dependent tolerance). | |
|
|
The surface straightness tolerance is 0.25 mm over the entire length and 0.1 mm over a length of 100 mm. | |
|
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The surface straightness tolerance in the transverse direction is 0.06 mm, in the longitudinal direction is 0.1 mm. | |
| 2. Flatness tolerance |
|
The surface flatness tolerance is 0.1 mm. |
|
|
The surface flatness tolerance is 0.1 mm over an area of \u200b\u200b100 ´ 100 mm. | |
|
|
The flatness tolerance of surfaces relative to the common adjacent plane is 0.1 mm. | |
|
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The flatness tolerance of each surface is 0.01 mm. | |
| 3. Roundness tolerance |
|
Shaft roundness tolerance 0.02 mm. |
| The roundness tolerance of the cone is 0.02 mm. | ||
| 4. Tolerance of cylindricality |
|
Shaft cylindricity tolerance 0.04 mm. |
|
|
Shaft cylindricity tolerance 0.01 mm over a length of 50 mm. Shaft roundness tolerance 0.004 mm. | |
| 5. Tolerance of the profile of the longitudinal section |
|
Shaft roundness tolerance 0.01 mm. The tolerance of the profile of the longitudinal section of the shaft is 0.016 mm. |
|
|
The tolerance of the profile of the longitudinal section of the shaft is 0.1 mm. | |
| 6. Parallelism tolerance |
|
Surface parallelism tolerance relative to surface AND0.02 mm. |
|
|
Tolerance of parallelism of the common adjacent plane of surfaces relative to the surface AND0.1 mm. | |
|
|
Parallelism tolerance of each surface relative to the surface AND0.1 mm. | |
|
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The tolerance of parallelism to the axis of the hole relative to the base is 0.05 mm. | |
|
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The tolerance of parallelism of the axes of the holes in the common plane is 0.1 mm. The misalignment of the axes of the holes is 0.2 mm. Base - hole axis AND. | |
|
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Tolerance of parallelism of the hole axis relative to the hole axis AND00.2 mm. | |
| 7. Perpendicularity tolerance |
|
Surface perpendicularity tolerance to surface AND0.02 mm. |
|
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Perpendicularity tolerance of the hole axis relative to the hole axis AND0.06 mm. | |
|
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Tolerance of perpendicularity of the axis of the protrusion relative to the surface AND Æ 0.02 mm. | |
| The perpendicularity tolerance of the smallpox protrusion relative to the base is 0, l mm. | ||
|
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The perpendicularity tolerance of the axis of the protrusion in the transverse direction is 0.2 mm, in the longitudinal direction is 0.1 mm. Base - base | |
|
|
The perpendicularity tolerance of the hole axis relative to the surface is Æ 0.1 mm (dependent tolerance). | |
| 8. Tilt tolerance |
|
Surface slope tolerance relative to surface AND0.08 mm. |
|
|
Hole axis tilt tolerance relative to surface AND0.08 mm. | |
| 9. Alignment tolerance |
|
Alignment tolerance of the hole relative to the hole Æ 0.08 mm. |
|
|
The alignment tolerance of the two holes relative to their common axis is Æ 0.01 mm (dependent tolerance). | |
| 10. Tolerance of symmetry |
|
Symmetry tolerance of the groove T0.05 mm. Base - plane of symmetry of surfaces AND |
|
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Hole symmetry tolerance T0.05 mm (dependent tolerance). The base is the plane of symmetry of the surface A. | |
|
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Symmetry tolerance of smallpox holes relative to the general plane of symmetry of the grooves AB T 0.2 mm and relative to the general plane of symmetry of the grooves VG T0.1 mm. | |
| 11. Positional tolerance |
|
Positional tolerance of the hole axis Æ 9.06 mm. |
|
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Positional tolerance of hole axes отверст 0.2 mm (dependent tolerance). | |
|
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Positional tolerance of axes of 4 holes Æ 0.1 mm (dependent tolerance). Base - hole axis AND(tolerance dependent). | |
|
|
Positional tolerance of 4 holes Æ 0.1 mm (dependent tolerance). | |
|
|
Positional tolerance of 3 threaded holes Æ 0.1 mm (dependent tolerance) in the area located outside the part and protruding 30 mm from the surface. | |
| 12. Axis intersection tolerance |
|
Hole Intersection Tolerance T0.06 mm |
| 13. Radial runout tolerance |
|
The radial runout tolerance of the shaft relative to the cone axis is 0.01 mm. |
|
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Radial runout tolerance of the surface relative to the common axis is superficial AND and B 0.1 mm | |
|
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Radial runout tolerance of a surface area relative to the hole axis AND0.2 mm | |
|
|
Hole radial runout tolerance 0.01 mm First base - surface L.The second base is the axis of surface B. The end runout tolerance relative to the same bases is 0.016 mm. | |
| 14. Tolerance of face runout |
|
End runout tolerance at a diameter of 20 mm relative to the surface axis AND0.1 mm |
| 15. Runout tolerance in a given direction |
|
Runout tolerance of the cone relative to the hole axis ANDin the direction perpendicular to the generatrix of the cone 0.01 mm. |
| 16. Tolerance of full radial runout |
|
Radial runout tolerance relative to the common axis is superficial ANDand B0.1 mm. |
| 17. Tolerance of full face runout |
|
The tolerance of the full face runout of the surface relative to the surface axis is 0.1 mm. |
| 18. Tolerance of the shape of a given profile |
|
Shape tolerance of a given profile T0.04 mm. |
| 19. Tolerance of the shape of a given surface |
|
Tolerance of the shape of a given surface relative to surfaces A, B, C, T 0.1 mm. |
| 20. Total tolerance of parallelism and flatness |
|
The total tolerance of parallelism and flatness of the surface relative to the base is 0.1 mm. |
| 21. Total perpendicularity and flatness tolerance |
|
The total tolerance of squareness and flatness of the surface relative to the base is 0.02 mm. |
| 22. Total slope and flatness tolerance |
|
The total tolerance of the slope and flatness of the surface relative to the base 0.05 mi |
In previously issued documentation, the tolerances of alignment, symmetry, and displacement of the axes from the nominal position (positional tolerance), indicated by signs, respectively 
or text in the specification should be understood as radial tolerances. 2. An indication of the tolerances of the shape and location of surfaces in text documents or in the technical requirements of the drawing should be given by analogy with the text of the explanation to the symbols for the tolerances of the shape and location given in this annex. In this case, the surfaces to which the tolerances of the shape and location belong or which are taken as the base should be designated by letters or their design names should be carried out. It is allowed to indicate a sign instead of the words "tolerance dependent" and instead of indications before the numerical value of symbols Æ; R ; T; T / 2 notation in text, for example, “axis positional tolerance of 0.1 mm in diametric expression” or “symmetry tolerance of 0.12 mm in radial expression”. 3. In the newly developed documentation, an entry in the technical requirements for the tolerances of ovality, taper, barrel and saddle shape should be, for example, the following: “Tolerance of ovality of the surface AND0.2 mm (half difference of diameters). In the technical documentation developed before 01.01.80, the limiting values \u200b\u200bof ovality, taper, barrel and saddle shape are determined as the difference between the largest and smallest diameters. (Modified edition, Amendment No. 1).
