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. So that the drawing is readable. 2. From the transition lines shown conditionally, you can put dimensions that often cannot be put down on any other view or section. Here's an example. There is a difference? 1. How it can now be displayed in all of the listed CAD systems. Here's how to display it. Transition lines are shown conditionally and dimensions are shown that simply cannot be entered in other modes of displaying transition lines. Why did the regulatory inspector require this? Yes, just so that the drawings have a familiar appearance after many years of work in 2D and are readable, especially by the customer who approves them.
This is true :) this is nonsense :) in TF you can do it both ways =) there will be no noticeable difference in speed, you can even then take any copy and repaint it, change the holes, remove the holes, whatever... and the array will still remain an array - will it be possible to change the number of copies, direction, etc., cut the video or will you believe it? :) That's right, but what is the task? How to translate SW splines by points into splines by poles or something, if you think about it, this is also some change in the original geometry - are there any comments on this? :) as I understand it, the TF only translates 1 to 1, the rest can already be configured in the TF template before export in DWG - see the pic under the spoiler, or scaled in the form of AC, which in principle does not contradict the basic methods of working with AutoCAD, and since in view of the prevalence of AC in the early stages of the peak popularity of CAD implementation, it is even more familiar to the older generation: And if I still need to dig into the possibilities of exporting/importing different CAD systems: 1) how can I export only selected lines to DWG from a 2D SW drawing? (from 3D documents, SW is more or less suitable, but you still have to small window preview, clean up excess manually). Delete in advance everything that is not needed, and then export -> somehow not modern, not youthful :) 2) And vice versa, how to quickly import selected lines in AutoCAD into SW (for example, for a sketch, or simply as a set of lines for drawing)? (for TF: selected a set the necessary lines in AC -ctrl+c and then in TF just ctrl+v - that's it)
What detail are we talking about, otherwise maybe this detail should not be mirrored, but simply tied differently and it will be just right. A mirror part is the same configuration only created by a machine; you can make the configuration of the part yourself, and in some cases this may turn out to be more elegant and easier to edit later.
A hole is an open or through opening in a solid object.
The hole drawing is carried out on the basis of GOST 2.109-73 - a unified system of design documentation (ESKD).
You can download this simple drawing for free to use for any purpose. For example, for placement on a nameplate or sticker.
How to draw a drawing:
You can draw a drawing either on a sheet of paper or using specialized programs. No special engineering knowledge is required to complete simple sketch drawings.
A sketch drawing is a drawing made “by hand”, observing the approximate proportions of the depicted object and containing sufficient data for the manufacture of the product.
The design drawing with all the technological data for manufacturing can only be completed by a qualified engineer.
To designate in the drawing, you must perform the following operations:
1. Draw an image;
2. Add dimensions (see example);
3. Specify for production (read more about technical requirements below in the article).
It is most convenient to draw on a computer. Subsequently, the drawing can be printed on paper using a printer or plotter. There are many specialized programs for drawing on a computer. Both paid and free.
Drawing example:
This image shows how simple and quickly drawing can be done using computer programs.
List of programs for drawing on a computer:
1. KOMPAS-3D;
2. AutoCAD;
3. NanoCAD;
4. FreeCAD;
5. QCAD.
Having studied the principles of drawing in one of the programs, it is not difficult to switch to working in another program. Drawing methods in any program are not fundamentally different from each other. We can say that they are identical and differ from each other only in convenience and the presence of additional functions.
Technical requirements:
For the drawing it is necessary to indicate dimensions sufficient for manufacturing, maximum deviations and roughness.
The technical requirements for the drawing should indicate:
1) Manufacturing and control method, if they are the only ones that guarantee the required quality of the product;
2) Indicate a specific technological method that guarantees that certain technical requirements for the product are met.
A little theory:
A drawing is a projection image of a product or its element, one of the types of design documents containing data for the production and operation of the product.
A drawing is not a drawing. The drawing is made according to the dimensions and scale of the real product (structure) or part of the product. Therefore, to carry out drawing work, the work of an engineer with sufficient experience in producing drawing work is necessary (however, to beautifully display a product for booklets, it is quite possible that you will need the services of an artist who has an artistic view of the product or part of it).
A drawing is a constructive image with necessary and sufficient information about dimensions, manufacturing method and operation. You can download the drawing presented on this page for free.
A drawing is an artistic image on a plane created by means of graphics (brush, pencil or specialized program).
A drawing can be either an independent document or part of a product (structure) and technical requirements related to surfaces processed together. Instructions for joint processing are placed on all drawings involved in the joint processing of products.
For more information on drawings, technical requirements for design and indication of manufacturing methods, see GOST 2.109-73. See the list of standards for the development of design documentation.
Information for ordering drawings:
In our design organization, you can design any product (both parts and assemblies), which will include a hole drawing as an element of the design documentation of the product as a whole. Our design engineers will develop documentation in the shortest possible time in strict accordance with your technical specifications.
Threads are made with a cutting tool, removing a layer of material, rolling - by extruding screw protrusions, casting, pressing, stamping, depending on the material (metal, plastic, glass) and other conditions.
Due to the design of the thread-cutting tool (for example, a tap, Fig. 8.14; dies, Fig. 8.15) or when retracting the cutter, when moving from a section of the surface with a full-profile thread (sections l) to a smooth one, a section is formed where the thread seems to move to no (sections l1), a thread run-out is formed (Fig. 8.16). If the thread is made to a certain surface that does not allow the tool to be brought all the way to it, then an under-thread is formed (Fig. 8.16.6, c). The run-out plus the undercut forms an undercut of the thread. If you need to make a full profile thread, without a run, then to remove the thread-forming tool, make a groove, the diameter of which for external threads should be slightly less than the internal diameter of the thread (Fig. 8.16, d), and for internal thread- slightly larger than the outer diameter of the thread (Fig. 8.17). At the beginning of the thread, as a rule, a conical chamfer is made, which protects the outer turns from damage and serves as a guide when connecting parts to the thread (see Fig. 8.16). The chamfer is performed before cutting the thread. The dimensions of chamfers, runs, undercuts and grooves are standardized, see GOST 10549-80* and 27148-86 (ST SEV 214-86). Fastening products. Thread exit. Runaways, undercuts and grooves. Dimensions.
Constructing an accurate image of thread turns requires a lot of time, so it is used in rare cases. According to GOST 2.311 - 68 * (ST SEV 284-76), in the drawings the thread is depicted conditionally, regardless of the thread profile: on the rod - with solid main lines along the outer diameter of the thread and solid thin lines - along the inner diameter, along the entire length of the thread, including the chamfer ( Fig. 8.18, a). In the images obtained by projection onto a plane perpendicular to the axis of the rod, an arc is drawn along the internal diameter of the thread as a continuous thin line, equal to 3/4 of the circle and open anywhere. In the images of the thread in the hole, solid main and solid thin lines seem to change places (Fig. 8.18.6).
A solid thin line is applied at a distance of at least 0.8 mm from the main line (Fig. 8.18), but not more than the thread pitch. Hatching in sections is brought to the line of the outer diameter of the thread on the rod (Fig. 8.18, d) and to the line of the internal diameter in the hole (Fig. 8.18.6). Chamfers on a threaded rod and in a threaded hole that do not have a special structural purpose are not shown in projection onto a plane perpendicular to the axis of the rod or hole (Fig. 8.18). The thread boundary on the rod and in the hole is drawn at the end of the full thread profile (before the start of the run) with the main line (or dashed if the thread is shown as invisible, Fig. 8.19), bringing it to the lines of the outer diameter of the thread. If necessary, the thread run is depicted with thin lines , carried out at approximately an angle of 30° to the axis (Fig. 8.18, a, b).
A thread shown as invisible is depicted with dashed lines of the same thickness along the outer and inner diameters (Fig. 8.19). The length of the thread is the length of the section of the part on which the thread is formed, including the run-out and chamfer. Usually, the drawings indicate only the length l of the thread with a full profile (Fig. 8.20, a). If there is a groove, external (see Fig. 8.16, d) or internal (see Fig. 8.17), then its width is also included in the length of the thread. If it is necessary to indicate the run-out or the length of the thread with a run-out, the dimensions are applied as shown in Fig. 8.20, b, c. The undercut of the thread, made all the way, is depicted as shown in Fig. 8.21, a, b. Options “c” and “d” are acceptable.
On drawings in which threads are not made (on assembly drawings), the end of a blind hole can be drawn as shown in Fig. 8.22 On cuts threaded connection in the image on a plane parallel to its axis, only that part of the thread that is not covered by the thread of the rod is shown in the hole (Fig. 8.23).
There are threads: general purpose and special ones intended for use on certain types of products; fasteners, intended, as a rule, for a fixed detachable connection components products, and running gear - to transmit movement. Right-hand threads are predominantly used; LH is added to the designation of left-hand threads. In the designation of multi-start threads, the stroke is indicated, and in brackets - the pitch and its value
The dimensions on the working drawings are marked so that they are convenient to use during the manufacturing process of parts and during their control after manufacture.
In addition to what is stated in paragraph 1.7 “Basic information on applying dimensions,” here are some rules for applying dimensions in drawings.
When a part has several groups of holes that are 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 group of holes (Fig. 6.27).
Rice. 6.27.
It is allowed to indicate the dimensions and number of holes in each group not on the image of the part, but on the plate.
For parts that have symmetrically located elements of the same configuration and size, their dimensions are shown on the drawing once without indicating their quantity, grouping, as a rule, all dimensions in one place. The exception is identical holes, the number of which is always indicated, and their size is applied only once (Fig. 6.28).
Rice. 6.28.
The part shown in Fig. 6.27, has a row of holes with the same distance between them. In such cases, instead of a dimensional chain repeating the same size several times, it is applied once (see size 23). Then, extension lines are drawn between the centers of the outer holes of the chain and the size is applied in the form of a product, where the first factor is the number of spaces between the centers of adjacent holes, and the second is the size of this gap (see size 7 × 23 = 161 in Fig. 6.27). This method of applying dimensions is recommended for drawings of parts with the same distance between identical 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, A). With uniform distribution of identical elements around the circumference angular dimensions are not applied, but are limited to indicating the number of these elements (Fig. 6.28, b).
Dimensions related to one structural element details (hole, protrusion, groove, etc.) should be applied in one place, grouping them in the image in which this element is most clearly depicted (Fig. 6.29).
Rice. 6.29.
The position of the inclined surface can be specified in the drawing by the size of the angle and two (Fig. 6.30, A) or three linear dimensions (Fig. 6.30, b). If the inclined surface does not intersect with another, as in the first two cases, but mates 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 intersection points to apply dimensions.
Rice. 6.30.
A - first case; b – second case
GOST 2.307–68 also established rules for depicting and drawing the dimensions of holes in views in the absence of sections (sections) (Fig. 6.31). These rules make it possible to reduce the number of cuts that reveal the shape of these holes. This is done due to the fact that in views where holes are shown in circles, after indicating the diameter of the hole, the following is applied: the size of the depth of the hole (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 indicating the diameter of the hole there are no additional instructions, then the hole is considered through (Fig. 6.31, a).
Rice. 6.31.
When setting dimensions, take into account the methods of measuring parts and features technological process their manufacture.
For example, it is convenient to measure the depth of an open keyway on an outer cylindrical surface from the end, so the size given in Fig. 6.32, A.
Rice. 6.32.
A - open; b– closed
The same size of a closed groove is easier to check if the size indicated in Fig. is applied. 6.32, b. It is convenient to control the depth of the keyway on the inner cylindrical surface according to the size indicated in Fig. 6.33.
Rice. 6.33.
Dimensions must be set in such a way that during the manufacture of the part you do not have to figure out anything by calculations. Therefore, the size marked on the section along the width of the flat (Fig. 6.34) should be considered unsuccessful. The size that defines the flat is correctly shown on the right side of the figure. 6.34.
Rice. 6.34.
In Fig. Figure 6.35 shows examples of dimensioning using 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, A. When specifying 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 (Fig. 6.35, A) or included in the circuit (Fig. 6.35, b).
Reference dimensions are those that cannot be made according to a given drawing and are indicated for greater convenience in using the drawing. Reference dimensions in the drawing are marked with an asterisk, which is placed to the right of the dimension number. In the technical requirements, repeat this sign and write: Size for reference(Fig. 6.35, a, b).
There are no maximum deviations for a reference size included in a closed circuit. Open circuits are the most common. In such cases, one dimension for which the smallest accuracy is permissible is excluded from the dimensional chain or the overall dimension is not indicated.
Dimensions using the coordinate method are made from a pre-selected base. For example, in Fig. 6.35, V The right end of the roller serves as this base.
The most often used is a combined method of dimensioning, which is a combination of chain and coordinate methods (Fig. 6.35, G).
Rice. 6.35.
a, b – chain; V– coordinate; G– combined
On working drawings of machined parts for which sharp edges or edges must be rounded, the value of the rounding radius is indicated (usually in the technical requirements), for example: Rounding radii 4 mm or Unspecified radii 8 mm.
The dimensions that determine the position of the keyways are also set taking into account the technological process. In the image of the groove for the segment key (Fig. 6.36, A) the size to the center of the disk cutter with which the keyway will be milled is taken, and the position of the groove for the parallel key is set to the size to its edge (Fig. 6.36, b), since this groove is cut with a finger cutter.
Rice. 6.36.
A - for segment key; 6 – for prismatic
Some part elements depend on the shape cutting tool. For example, the bottom of a blind cylindrical hole turns out to be conical because the cutting end of the drill has a conical shape. The depth of such holes, with rare exceptions, is marked along the cylindrical part (Fig. 6.37).
Rice. 6.37.
In drawings of parts with cavities, internal dimensions related to the length (or height) of the part are applied separately from the external ones. For example, in a housing drawing, a group of dimensions defining the outer surfaces is placed above the image, and internal surfaces the details are determined by another group of sizes located below the image (Fig. 6.38).
Rice. 6.38.
When only part of the surfaces of a part are subject to machining, and the rest should be “black”, i.e. such as they turned out during casting, forging, stamping, etc., the dimensions are set according to a special rule, also established by GOST 2.307-2011. The group of sizes related to machined surfaces (i.e., formed with the removal of a layer of material) must be related to the group of sizes of “black” surfaces (i.e., formed without removing a layer of material) by no more than one size in each coordinate direction.
The housing has only two surfaces that need to be machined. The size connecting the groups of external and internal dimensions, marked on the housing drawing with the letter A.
If the dimensions of the housing cavity were set from the plane of the left end of the part, when processing it it would be necessary to withstand maximum deviations of several dimensions at once, which is practically impossible.
The threads on the rods are depicted along the outer diameter with solid main lines, and along the inner diameter with solid thin lines.
Essential elements metric thread(outer and inner diameters, thread pitch, thread length and angle) you studied in fifth grade. Some of these elements are indicated in the figure, but such inscriptions are not made on the drawings.
Threads in holes are depicted with solid main lines along the internal diameter of the thread and solid thin lines along the outer diameter.
The thread symbol is shown in the figure. It should be read like this: metric thread (M) with an outer diameter of 20 mm, third class of accuracy, right-handed, with a large pitch - “Thread M20 class. 3".
In the figure, the thread designation is “M25X1.5 class.” 3 left" should be read as follows: metric thread, outside diameter thread 25 mm, pitch 1.5 mm, fine, third class of accuracy, left.
Questions
Each product - a machine or mechanism - consists of separate, interconnected parts.
Parts are usually made by casting, forging, and stamping. In most cases, such parts are machined on metal-cutting machines - lathes, 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 and the requirements for manufacturing accuracy - tolerances. Manufacturing methods and technical requirements To finished part indicated by the inscription on the drawing.
Cleanliness of surface treatment. On treated surfaces there are always traces of processing and unevenness. These irregularities, or, as they say, surface roughness, depend on the tool used to process.
For example, a surface processed with a garnish will be rougher (uneven) than after processing with a personal file. The nature of roughness also depends on the properties of the material of the product, on the cutting speed and feed rate when processing on metal-cutting machines.
To assess the quality of processing, 14 classes of surface cleanliness have been established. Classes are designated in the drawings by one equilateral triangle (∆), next to which the class number is indicated (for example, ∆ 5).
Methods for obtaining surfaces of different cleanliness and their designation in the drawings. The cleanliness of processing one part is not the same everywhere; therefore, the drawing indicates where and what kind of processing is required.
The sign at the top of the drawing indicates that for rough surfaces there are no requirements for cleanliness of processing. 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 bastard files, roughing cutters, and an abrasive wheel.
Marks ∆ 4 - ∆ 6 - semi-clean surface, with barely noticeable traces of processing with a finishing cutter, personal file, grinding wheel, fine sandpaper.
Marks ∆ 7 - ∆ 9 - clean surface, without visible traces of processing. This treatment is achieved by grinding, filing with a velvet file, or scraping.
Mark ∆ 10 - a very clean surface, achieved by fine grinding, finishing 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 are indicated in the drawings with an inscription (for example, blunt sharp edges, harden, burnish, drill a hole together with another part, and other requirements for the product).
Questions
Exercise
Read the drawing in the figure and answer the questions in writing using the form provided.
| Questions for reading a drawing | 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 type? | – |
| 5. What conventions are there in the drawing? | – |
| 6. What is the general shape and size 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 a single piece of material (for example, a bolt, nut, gear, lead screw lathe). A node 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 assemblies, is called an assembly drawing; it consists of drawings of each part or assembly and depicts an assembly unit (a drawing of a single...
