Technological scheme of assembly. Development of a technological scheme for assembling a product. Specifying part positions
Quality systems certification
METHODOLOGICAL INSTRUCTIONS
on practical work students
"BUILDING A TECHNOLOGICAL SCHEME OF THE PRODUCT ASSEMBLY"
Direction of preparation: 220500 "Quality Management"
Speciality: 220501 "Quality Management"
full-time education
Developed by Ph.D., Assoc. Kashmin O.S.
Considered at a meeting of the ACC
Minutes No. _______ dated __________________ 2006
Head cafe d.t.s. prof.
Inozemtsev A.N.
1.h of the work we copy completely into the work.
Purpose and tasks of the work
Familiarize yourself with the form and procedure for filling out product specifications, study the rules for constructing assembly flow diagrams and their purpose.
a common part
Assembly - the final stage production process in mechanical engineering, it largely determines the quality of products and their release on time. The labor intensity of the nodal and general assembly is on average about 30% of the total labor intensity of the manufacture of machines. In mass and large-scale production, this share is less, and in single and small-scale production, where a large amount of fitting work is performed, the labor intensity of assembly reaches 40 ... 50%. In this regard, the correct organization, comprehensive technological study of assembly work, in terms of their content, structure, mechanization and automation, is of great national economic importance.
Technological assembly process- a process containing the installation steps and the formation of connections of the components of the workpiece or product.
subassembly- Assembly, the object of which is a component of the product.
General Assembly- assembly, the object of which is the product as a whole.
Finished part technological process, performed at one workplace is called technological operation. An operation includes all the actions of equipment and workers on one or more objects that are assembled together (operational batch).
The elements of technological operations are technological and auxiliary transitions, working and auxiliary passages, installation, position.
In addition to technological, there are also auxiliary operations, which include transportation, control, marking, lubrication, and other work. The assembly is carried out in a certain technologically and economically feasible sequence to obtain products that fully meet the requirements established for them. The increase in the output of machines must be ensured by the intensification of technological processes. Therefore, the main task of the technologist-machine builder is to build high-performance technological processes.
A great help to technologists in the development of technological processes of general and nodal assembly is provided by technological assembly schemes. These schemes reflect the structure and sequence of assembly of the product and its components. Technological assembly diagrams that are not included in the set of technological documentation according to the standards of the ESTD (Unified System of Technological Documentation) are recommended to be drawn up directly according to the product drawings before the development of the main technological documentation (technological maps of established forms).
Technological schemes simplify the design of assembly processes and allow you to evaluate the manufacturability of the product design. When constructing technological schemes, it is possible to identify the admitted design inconsistencies of the assembled product. Technological assembly schemes make it possible to clearly present the order and sequence of assembly operations, determining their content and means of mechanization. To build technological schemes, it is necessary to distinguish between types of products, the classification of which is established by GOST 2.101-68 (Fig. 1), according to which they distinguish: parts, assembly units, complexes and kits.
product any item or set of items of production to be manufactured at the enterprise is called. Definition of types of products.
Detail- a product made of a material that is homogeneous in name and brand, without the use of assembly operations.
assembly unit- a product, the components of which are to be connected to each other at the manufacturer's assembly operations (screwing, articulation, riveting, soldering, etc.).
Complex- two or more specified items, not connected at the manufacturing plant by assembly operations, but intended to perform interrelated operational functions.
Set- two or more products that are not connected at the manufacturing plant by assembly operations and represent a set of products that have a common operational purpose of an auxiliary nature. For example, a set of spare parts, a set of tools and accessories.
Products, depending on the presence or absence of components in them, are divided into:
but) unspecified(details) - having no component parts;
b) specified(assembly units, complexes, kits) - consisting of two or more components. The concept of "component" should be used only in relation to the specific product in which it is included. Any product (part, assembly unit, complex and kit) can be an integral part.
Fig.1 Types of products and their structure
Rules for constructing technological assembly schemes
The assembly of the product (its component part) begins with the base part, which is first installed in the assembly fixture (stand, panel) and to which other parts or assembly units are attached during the assembly process.
The technological process of general and nodal assemblies is presented using technological schemes that reflect the structure and sequence of assembly of the product and its components.
Examples of technological schemes of general and subassemblies are shown in the appendix.
There are no unified generally accepted rules for constructing and designing assembly schemes in domestic engineering technology; different sources may contain inconsistent recommendations. Nevertheless, it is possible to formulate a number of rules that should be observed when constructing schemes and using them, based on the generally accepted requirements for clarity and unambiguity of representations.
2.1. In the diagrams, each element of the product (part, assembly unit) has its own symbol (table). The part is indicated by a rectangle, the assembly unit by a hexagon, which are divided into three zones:
in zone 1, the designation and position of the part (assembly unit) according to the drawing are affixed;
in zone 2 - the name of the part (assembly unit) according to the drawing;
in zone 3 - the number of simultaneously installed parts (assembly units). It is desirable to maintain the dimensions of the symbol of the product element indicated in the table when compiling the assembly flow chart when performing this laboratory work. In the general case, conditional elements are depicted on an arbitrary scale, the same for a given scheme.
2.2. The general assembly process is depicted in the diagram with a solid horizontal line. The beginning of the assembly line is indicated by a solid black circle Ш5 mm.
2.3. construction technological scheme general assembly start with base element product, which is located on the left side of the diagram, the symbol of the assembled object - on the right.
2.4. The nodal assembly process is depicted by a line that is drawn in the direction from the base element to the assembled object.
2.5. The assembly line is depicted as a solid main line according to GOST2.303-68.
2.6. The conditional image of assembly units, parts, as well as the installation, dismantling lines, information is made by a solid thin line in accordance with GOST 2.303-68.
2.7. The symbol for all parts directly included in the product is placed on top in the order of the assembly sequence.
2.8. The symbol for all assembly units directly included in the product is placed below.
2.9. If it is possible to simultaneously install several components of the product on its base part, their connecting lines in the diagram converge at one point.
2.10. If necessary, assembly flow diagrams are provided with footnotes explaining the nature of the assembly work (pressing, lubricating, checking the gap, refining, riveting, alignment, etc.), when they are not clear from the diagram, and the control performed during assembly.
2.11. First of all, a general assembly scheme is drawn up, and then nodal assembly schemes (in parallel), ensuring the necessary consistency and coordination of actions based on the general assembly scheme of the product.
Technological assembly schemes for the same product can be compiled in several versions, which differ in the structure and sequence of assembly elements. The accepted option is fixed by the drawn up scheme, which is one of the technological documents.
When creating new machines, it is necessary to provide for their general assembly from pre-assembled components (the principle of subassembly), which provides advantages not only in their production, but also in maintenance, operation and repair.
3. QUESTIONS TO CONTROL
3.1. Components of the technological process.
3.2. Classification of products and their components according to ESKD.
3.3. Purpose of technological assembly schemes.
3.4. Basic rules for drawing up technological assembly schemes.
4. TASK FOR WORK
Having received a product as an object of work, draw up its assembly drawing and specification, as well as build a technological scheme for assembling the assembly of the product. Make a description of the adopted assembly scheme.
5. ORDER OF PERFORMANCE OF WORK
5.1. Familiarize yourself with the instructions for the safe performance of laboratory work.
5.2. Familiarize yourself with the content of the laboratory work, task.
5.3. Get the product to do the job and the necessary tools.
5.4. Familiarize yourself with the design and purpose of the product.
5.5. Draw up an assembly drawing of the product (put the position on the assembly units and parts included in the product).
5.6. Build a technological assembly scheme.
5.7. Assemble the product and finalize the technological assembly scheme.
5.8. Write a report and submit it to the teacher.
6. REPORT INSTRUCTIONS
The report is drawn up on special forms issued by the teacher.
The graphical and textual part of the report should be done neatly in pencil, in a standard font, using drawing tools.
The report is compiled individually and signed by each student.
7. REFERENCES
1. GOST 2.101-68 ESKD Types of products.
2. GOST 2.108-68 (ST SEV 2516-80). ESKD Specification.
3. GOST 3.1407-74. ESKD Rules for the preparation of documentation for locksmith, fitter-assembly and electrical installation work.
4. Assembly and installation of engineering products: a Handbook. In 2 volumes / Ed. advice: V.S. Korsakov (prev.) and others - M .: Mashinostroenie, 1983.– T.1. Assembly of mechanical engineering products / Ed. V.S. Korsakova, V.K. Zamyatina, 1983.- 480 p.
Practical work No. 1
Development of a technological scheme for disassembly and assembly of CE
Objective
1. To study the concepts of the technology of disassembly and assembly of assembly units.
2. Learn to develop a technological scheme for disassembling and assembling the CE and arrange it in the form of a technological scheme.
Initial data
The initial data for the development of the technological scheme of assembly (disassembly) are:
Assembly drawing of the product with specification;
Specifications for assembly (disassembly) indicating the fit of mating parts, product test modes, technological instructions for the selection of parts, assembly, control and adjustment of interfaces or CE;
Repair program.
In addition to the documentation, it is desirable to have a sample of the product, on which it would be possible to perform trial disassembly or assembly according to the developed technological scheme.
1. Examine the assembly drawing and the accompanying specifications for assembly.
2. Development of a structural-technological scheme for dismantling CE.
The development of CE as a whole is carried out in a certain sequence, which is determined by the design of the product, as well as the program of the repair enterprise and its homogeneity in relation to the types and brands of machines being repaired.
When developing a disassembly scheme, the task is to divide a given node into constituent elements in such a way that disassembly can be carried out
the largest number of these elements independently of one another (in parallel).
Such a division makes it possible, when organizing repair work, to reasonably fix certain repair work for specific performers.
The disassembly scheme is built so that the corresponding assembly units are presented in it in the order in which it is possible to remove these elements when disassembling the assembly. CE and parts are depicted in the diagram in the form of rectangles indicating the index, name and number of elements. For greater clarity, a rectangle depicting an assembly unit can be distinguished by marking its outline with a double line (Fig. 1).
In the diagram, the rectangles characterizing the assembly units are recommended to be placed on the left, and the details on the right along the line.
The beginning of the disassembly is the assembly unit, and the end is the base part. For example, consider the input shaft of a car gearbox (Fig. 2).
Figure 2. Vehicle gearbox input shaft assembly
1 - input shaft; 2 - nut; 3 - retaining ring; 4 - ball bearing
radial single row; 5 - retaining ring; 6 - roller 8x20.
The report gives short description disassembly. Disassembly of the node in question is carried out in the following sequence:
Unscrew the ball bearing nut 2, remove the circlip 3, remove the ball bearing 4, remove the circlip 5 and remove the rollers from the roller bearing 6.
An example of a disassembly flow chart is shown in Figure 3.
The number of jobs is determined by the program of a particular repair company and the complexity of performing the listed operations.
 |
Fig.3. Technological scheme of disassembly of the primary shaft assembly
Disassembly must be carried out in the strict sequence provided for by the technological regulations. The basic techniques and principles of disassembly are as follows:
Assembly units are disassembled directly at the place of general disassembly, as well as at the places of their repair and assembly in accordance with the technological scheme.
First, remove parts that can be easily damaged (injection tubes, rods, levers, rods, etc.). Then, individual assembly units are dismantled, which are disassembled at other workplaces.
When removing large parts fixed with a large number of bolts, in order to avoid the appearance of cracks, all bolts and nuts are first released half a turn and only after that they are unscrewed.
Rusted connections are moistened with kerosene before unscrewing.
After disassembly, fasteners are placed in mesh baskets for subsequent washing. It is not allowed to use a chisel and a hammer to loosen bolts, nuts, fittings, etc., as this may damage them. Shaped nuts and fittings are unscrewed with special keys.
Pressed parts are removed under pressure or with the help of pullers and fixtures. In some cases, fittings, bushings and axles can be pressed out with special punches with copper tips and hammers with copper bikes.
When the bearing is pressed out of the housing, the force is applied to the outer ring, and from the shaft to the inner one. It is forbidden to use a percussion instrument.
It is advisable to place the removed parts on racks and devices for transportation to the sink, so as not to damage the work surfaces.
It is impossible to disassemble parts that are processed as an assembly during manufacture (caps of main bearings with blocks, etc.). In addition, it is forbidden to remove parts that are subject to joint balancing, as well as worn-in pairs of parts suitable for further work (bevel gears of the final drive, gears of oil pumps, etc.). Parts that are not subject to maintenance are marked, tied with wire - re-connected with bolts and placed in a separate container or kept complete in other ways.
3. Construction of a technological scheme for the assembly of CE.
The assembly flow diagram, as well as the disassembly flow diagram, is an auxiliary technological document (not included in the number of mandatory technical documentation documents, which graphically shows:
The sequence of connection of parts and assembly units included in the product;
The composition of the assembly units included in the product;
Performing operations not related to the attachment of parts and assembly units (control, adjustment, filling of oil or working fluids, painting, packaging, etc.)
The technological scheme of assembly is intended for:
Disclosure of the structure of the product and the possibility of using a nodal assembly;
Formalization and algorithmization of the development of the assembly process;
Evaluation of product design from a technological point of view.
For the design of the assembly process, the most acceptable form of the assembly flow chart is the scheme that provides the ranking of assembly units by levels and orders. When compiling such a technological assembly scheme, a number of formalization descriptions and designations are also used.
1. Assembly units (CE) included in the product have different orders, ranging from 0 to N. SEO - assembly unit of zero order, is
items that do not require assembly, These include parts, bearings, products that come to the assembly from the side (purchased or assembled in other departments).
2. The order of an assembly unit is always one more than the maximum order of its constituent elements.
When determining the order of an assembly unit, consider the following:
When connecting any next part to an assembly unit, the order of the assembly unit does not increase (Fig. 4a, b).
The assembly unit moves to the next level only after the assembly units of the same order are connected (Fig. 4c).
Rules for determining the order of assembly units in general view can be written as:
Fig 4. Scheme of formation of the order of assembly units
To describe assembly units in a ranked technological assembly scheme, a rectangle is used, shown in Fig. one.
3. The following formalization designations for actions related to the assembly of product elements are used in the assembly flow chart:
Attaching an assembly unit (Fig. 5a) is indicated by an arrow at a given assembly level with transition numbering;
Attaching an assembly unit with additional actions (Fig. 56);
Actions not related to attaching an assembly unit and providing for adjustment, measurement, testing, filling with working means, balancing, painting, packaging and others (Fig. 5c);
Intermediate disassembly when using adjustment with a fixed compensator (Fig. 5d).
General assembly line 7 8 9
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Rice. 6. Technological scheme of the assembly of the shaft of the primary gearbox
4. Drawing up a list of transitions of the nodal and general assembly.
The list of transitions must begin with the listing of transitions of the general assembly.
The list of transitions of the nodal assembly is expressed in the enumeration of assembly transitions in the sequence of installation of assembly units of the corresponding order on the general assembly with their disclosure up to the first order CE. 7.
Rice. 7. Structural scheme compiling a list of transitions of the nodal and general assembly
General Assembly
1. _____________________________
2. _____________________________
Assembly CE2
Assembly CE11.
1. __________________________________________
2.______________________________________
Assembly CE12.
1.__________________________________________
2.______________________________________
The description of the route assembly technology is considered on the example of the primary gearbox shaft assembly technology.
General Assembly
1. Install the input shaft.
2. Lubricate the hole along the rollers with grease.
3. Install rollers.
4. Install retaining ring 5.
6. Install retaining ring.
7. Screw on and tighten the nut.
8. Punching the retaining ring.
Any electronic device, household appliance, even furniture in our homes are made on the basis of specially drawn up drawings. In which individual elements are drawn first, and then the assemblies of these parts are shown, ways of fastening and arranging them relative to each other are shown. People working in the assembly of products must be able to read the drawings, because they serve as a kind of guide to how to assemble the designer's plan, as well as what material and what method to make the necessary parts.
Basic concepts
The concept of "assembly drawing" means an engineering document that depicts a component unit with the necessary dimensions and technical requirements for its manufacture, as well as quality control. Such a drawing is made during the development of documentation for the product. It should give a complete picture of the location in the finished product relative to other details. The assembly drawing is carried out according to the requirements of GOST 2.102-68 "Types and completeness of design documents".
Detail - a product made according to the requirements of ESKD from one material and without the use of assembly operations.
Detail drawing - a designer's document, where there is an image of the part, all the necessary dimensions to make it, and its coating is prescribed in the technical requirements, if necessary.
What should the drawing contain?
Any assembly drawing of a part must contain the following:
How the assembly part is located in the finished product relative to other elements;
How is the fastening of parts to each other;
Overall dimensions - they will show what length, height and width the product should have;
Mounting dimensions - show the main dimensions of all the elements that are needed for the installation of the product;
Connecting dimensions - show the dimensions of the connection points with other parts or assembly units;
Reference dimensions - indicated on the drawing from reference books (on standard sizes threads, nuts, etc.);
The maximum permissible deviations in the manufacture, according to which the quality control of the product will be carried out;
Methods for attaching parts to each other, an indication of all connections and methods for their implementation;
The positions of each part in the assembly, taken out in the specification;
The scale at which the drawing is made;
Product weight.
Basic rules for making assembly drawings
The execution of the assembly drawing is done in accordance with the requirements of GOST 2.109-73. If it is necessary to designate rotating or moving parts of the product, then it is allowed to show them either in the extreme or in the intermediate position. In this case, the required dimensions must be specified. If reading the assembly drawing becomes difficult, then some parts can be shown separately by making the necessary signatures indicating positions.
When performing sections or cuts on the same part, it is necessary to maintain the same slope of the lines and the distance between them when hatching.
If the cut is made at the junction of two different parts, then the hatching at the cut site of each of them is applied in different directions or with different distances between the inclined lines.
If necessary, the drawing indicates the roughness, permissible deviations from the norm for some specific parts or holes. There are also a number of standard parts for which you can not produce separate drawings, but if there is a lack of necessary information, they are placed on the assembly drawing field.
If the joining of individual parts must be ensured by fitting or selection, then appropriate signatures are made.
Specifying part positions
All components of the assembly unit are numbered according to GOST 2.109-73.
Each component, as well as the materials used, standard products must have their own serial number, which is assigned to them when drawing up a specification for this assembly drawing.
All positions in the drawing are indicated by leader lines that are drawn from each individual part or material. The end of the line, which is located on the image of the part itself, thickens with a dot. The line itself and the leader shelf are depicted as a continuous thin line. The positions indicate all visible parts. Positions of invisible parts are indicated on additional views or sections.
Position inscriptions are made parallel with respect to the main inscription in the drawing frame. Also, the positions should be placed outside the contour of the parts, they can be grouped.
If the same part is present on the assembly drawing several times, then its position is put only once, and in brackets next to the number it is indicated how many times it is repeated on the drawing.
Position numbers are indicated in a font that is 2 sizes larger than in the specifications and frame.
Crossing of lines when placing positions is not allowed, and they should not have the same direction as the hatch lines.
Simplifications and symbols in the drawings
When performing an assembly drawing, you can use valid symbols and simplifications.
On the drawings, you can not show chamfers, grooves, fillets, small protrusions, recesses, etc., as well as some gaps if they are small.
If in the drawing it is necessary to depict those parts of the product that are closed with a lid or shield, then the latter may not be shown. An inscription is also added indicating which position detail is not shown.
If the same component (wheel, support) is used several times in the product, it is allowed to show its image only once.
Soldering, gluing or welding spots can be shown as uniform surfaces. In this case, the boundaries between the sections of different parts are left.
Also, according to GOST 2.315-68, fastener details are shown in a simplified way.
Specification
This is a design document, which prescribes the full composition of the assembly product in accordance with GOST 2.108-68. This document is executed on A4 format separately for each assembly. It sequentially signs all the components of the assembly unit.
Based on the general case, the specification is made up of the following sections in succession: documentation, assembly parts, parts, standard products, other products, materials, kits.
It is not necessary that all sections be present in every specification. If one of them is not filled out, it is simply not prescribed. The name of the section is written, skipping two lines from the last entry of the previous one, in the middle of the column - the name, underlined by a thin straight line.
Items are listed in alphabetical order. The numbering of positions goes from the first section through the entire document. Also, in the corresponding column, GOST or the designation of an individual part and their number in this assembly are indicated.
The sequence of execution of assembly drawings
The assembly drawing is performed either already with finished product, or first they make a sketch of the parts in programs such as SolidWorks, Kompas 3D, and only then the drawings themselves are created from them.
Before you start drawing, you need:
To study the details, the principle of operation of the product and its purpose;
Determine the order in which the finished product will be assembled;
Make a plan with the designation of all components;
Select the most informative images for placement on the drawing field, make the minimum number additional species and cuts;
Based on the size of the selected image, the number of views and sections, choose the most appropriate format size;
Fill in the frame of the drawing;
Complete the outline of all images, check the work done;
Apply all dimensions, position numbering, sign everything;
Write technical requirements for the manufacture of parts according to this drawing;
Fill out the specification.
Below are the most simple examples assembly drawings.
How to read assembly drawings
Reading assembly drawings implies, first of all, a preliminary study of information about how the product is arranged and how it works.
Understand the principle of operation and what this product is intended for, based on the inscriptions in the frame of the document;
Determine what components the product consists of according to the specification;
Understand why each individual detail is needed, its features of location and work in relation to other elements;
Determine the sequence in which the product will be disassembled and assembled (reading the main inscription in the frame, the contents of the drawing and its features, correlating information in the specification and on the drawing field);
Examine the description of the finished product or its analogue;
Find out how the individual parts are attached to each other.
General arrangement drawing detailing
Detailing an assembly drawing is a rather painstaking and difficult job. Having only a general assembly of the part, it is necessary, on the basis of this drawing and specification, to make drawings of all parts, and choose the most convenient angle for their implementation and applying all the necessary sizes and designations.
What size a separate part will be, they will find out based on the scale of the general drawing and the size of this part on it. The dimensions of the standard parts are taken from the standards reference, not from the drawing data.
Detailing an assembly drawing usually consists of three stages:
Reading an assembly drawing that has a general view;
Defining the shapes of individual parts;
Drawing of every detail.
The assembly diagram is a graphical representation of the composition and the sequence of connecting the elements and parts of the product in the form of symbols (Fig. 3). The diagram facilitates the development of a route technical process, giving a clear, visible idea of the product assembly sequence. The diagram shows all the parts, assembly units and basic materials included in the device. The scheme of the assembly composition is shown in the form of steps corresponding to the stages of assembly according to the principle "from simple to complex".
The selected rational assembly route is graphically designed as a flow chart with a base part. The scheme itself is presented in the graphic part of the course project.
The technological scheme of assembly with the base part shows in what sequence and by what processes it is necessary to attach to each other and fix the elements included in the product during its assembly. The stator with cover pos.2 was chosen as the base part
5. Technological assembly process um.
Check by external inspection the parts and assemblies entering the assembly at a magnification of 6-9 times for the absence of dirt, burrs, scuffs, sharp edges and mechanical damage. Check the availability of accompanying documentation for parts and assemblies.
Interoperational storage of parts: the stator, the cover with the stator, the housing and the rotor, as well as the assembled device, should be carried out in desiccators with an indicator desiccant.
Ultrasonic wash all parts that have been fully machining, except for the stator with cover.
Re-preserve the sh / p according to the instructions specified in the technical specifications for ball bearings.
Store the sh/n parts at the workplace according to the instructions specified in the specifications for ball bearings.
Select pairs of ball bearings in terms of stiffness so that in terms of the displacement of the outer ring relative to the inner ring in the axial direction under a load of 1 kg, they do not differ from each other by more than 0.0005 mm.
In the socket of the cover, position 2, ensure the fit of the outer ring of the w/n with a force of 0.2 ... 1 kg. Before checking the seating force, the outer ring of the s/n must be installed in the seat of the cover so that the outer end of the ring coincides with the plane of the end of the cover.
Fasten the housing with the cover with 6 screws through the washers.
Install the screw pos.6 beforehand.
Fasten the flange pos.5 with 6 screws.
On the necks of the rotor pos. 1, ensuring a fit with a force of 5 ... 10 kg, press on the inner rings of the s/n. On the seating surfaces of the rotor, traces from the landing of ball bearings are allowed in the form of scratches with a purity of at least 7.
Install the nuts pos. 9 on the rotor necks and crimp them on the rotor Ø 3.5 into the groove.
Perform dynamic balancing of the rotor.
Preparatory.
Flushing.
Locksmith.
Control.
Assembly.
Assembly.
assembly
Adjusting.
The centers of drilled holes (with a diameter and depth up to 2 mm) should be located at a distance of 2÷3 mm from the end face of the ring made of VNZh7-3 alloy (balancing plane).
Check dynamic balancing.
Wipe the rotor assembly with the inner rings of the s/n from grease, metal dust and other contaminants.
Control.
Permissible unbalance 0.01 gcm 2 .
In the socket of the housing, position 3, ensure the fit of the outer ring of the w/n with a force of 0.2 ... 1 kg. Before checking the seating force, the outer ring of the s/n must be installed in the seat of the housing so that the outer end of the ring coincides with the plane of the housing sleeve.
Control the fit of the outer ring of the s/n until it stops in the seat of the body pos.3 by sending it under an axial load of 15 kg. The case pos.3 is suitable for assembly if a force of 15 kg causes a relative movement of the microcator needle during 3-fold measurement by no more than 0.0004 mm.
Assembly.
Control.
If there is a greater displacement, it is allowed to remove the ring, additional grinding of the socket and re-measurement. Checking the delivery of the w / w to the body is carried out before each assembly.
Assemble the stator ball bearing with cover and housing according to the specifications for the ball bearing.
Lubricate ball bearings with grease VNII NP-228B OST 38 01438-87 at a dose of 20 ± 2 mg.
To ensure the non-parallelism of the body plate, pos. 3 with respect to the cover pos. 2 within the limits indicated on the drawing, it is allowed to finish the plastic before technological tests while maintaining the cleanliness and geometric shape of the surface.
Install clamp pos.4
Set the axial preload w / n. The value of the axial preload of the ball bearings is set according to the elastic deformation of the bottom (membrane) of the instrument housing. To determine the elastic deformation of the membrane of the device housing, it is necessary to apply an axial load P to the membrane, the value of which is equal to the value of the axial interference of the ball bearings according to technical requirements to the device.
Tighten the screw pos.6 finally.
Lock the screw pos.6 through the flange pos.5 with clamps pos. 4.
Control.
Check axial tension.
Screws 7,8,11 put on enamel EP-275.
In two diametrically located slots of the screw pos. 6 and on the cylindrical surface of the part pos. 5 opposite the slots of the screw pos. 6 apply enamel EP-275.
Dry the device at a temperature of +80°C - 1.5 ÷ 2 hours.
Carry out technological tests according to specifications.
Put the device in a container.
Hand over to the warehouse of finished products.
Assembly.
assembly.
Adjusting.
Assembly.
Thermal.
Control.
Transfer.
§13. Construction of assembly schemes.
After studying the assembled product, technological schemes of the general and nodal assembly are drawn up.
The primary element of the product is a part, which is characterized by the absence of any detachable or permanent connections.
Technological assembly systems are built separately for the general assembly of the product and the assembly of each of its nodes. The scheme begins with a basic element and ends: for a general assembly - with a product, for a nodal one - with a node.
The base element is called the element (part or assembly) from which the assembly begins. Assembly schemes should reflect the structure and sequence of completing the product or assembly. The assembly process is depicted by a horizontal line, which is drawn in the direction from the base element to the object being assembled. On top, in the order of the assembly sequence, the designations of the parts included in the product are located, and on the bottom of the assembly units
the name of detail
Drawing No. (GOST) Quantity
With a product sample, drawing up an assembly diagram is simplified, since the assembly sequence can be established during trial disassembly.
General and nodal assembly begins with the installation of the base element on a stand, workbench or assembly fixture. If the product has several dimensional chains, then the assembly should begin with the most complex and responsible chain, the links of which are the constituent links of other simpler chains. In each dimensional chain, the assembly is completed by installing those connection elements that form its closing link. And this assembly sequence must be clearly and clearly reflected in the assembly flow chart. Assembly diagrams should be provided with inscriptions or footnotes explaining the nature assembly connections and, performed during assembly, control. For example: press in, tighten with a certain torque, adjust the position, check the gap, etc.
If individual assembly units or assemblies are subjected to partial or general assembly according to the general assembly conditions, then this type additional work is also reflected by an additional inscription on the assembly diagram.
Assembly schemes can have several options that differ in structure and assembly sequence. The choice of option is affected by: the complexity and cost of assembly; the required number of collectors; ease of assembly; the possibility of mechanization and automation of the assembly site.
According to the accepted assembly schemes, the main assembly operations are identified. The content of such an operation is set in such a way that at each workplace a work that is homogeneous in nature and technologically complete is performed. This contributes to a better specialization of assemblers and an increase in their productivity. The content of the operation also depends on the type of production and the type of assembly (in-line, non-in-line). With in-line assembly, the duration of the operation must be equal to or a multiple of the release cycle. In serial production, the content of the operation is taken in such a way that, when assembling products of various names, periodically replaced in batches, to ensure the most complete loading of jobs. In single-piece and small-scale production, the bulk of the assembly work is performed on the general assembly, and only a small part of them is performed on individual assembly units.