Control of the presented products is the first detail. The procedure for presenting products to the Quality Control Department. Presentation tests. Tool set-up, monitoring and tool breakage detection

Part control is a critical step in the diesel engine repair process. The quality and cost of repair of units depend on the organization of control. With insufficiently careful control, the quality of repair of diesel engines may decrease.

overly hard detail control can cause an overrun of spare parts, as a result of which the cost of repairing diesel engines increases.

In the process of control, the technical condition of parts is determined, they are sorted into fit, requiring repair, and unfit, and, in addition, the route for repairing parts is determined.

Suitable parts that can be delivered to a diesel engine without repair are sent to a picking warehouse. Parts requiring repair are sent to the warehouse of parts awaiting repair. Parts that are subject to culling according to specifications are handed over to the scrap metal warehouse. Part of the bad parts are identified during the disassembly of the diesel engine, such as bearing shells, piston rings, head gaskets, rubber parts, paper gaskets and broken parts. These parts, without being cleaned and degreased, are sent directly to the scrap metal warehouse. Details are marked with paints during control.

So, rejected parts are marked with red paint in the place where the defect is found; parts to be repaired are marked with green paint. Suitable parts are usually not marked with paint. The most responsible of them are branded with the personal brand of the controller.

For parts such as the crankcase, crankshaft, block head and fuel pump housing, a passport is drawn up in which the results of inspection and measurement are recorded. This document also notes the main dimensions after the repair of the part. In the future, passports are filed into the diesel case.

The technical condition of the parts is determined on the basis of technical specifications. The technical specifications indicate the following data:

General characteristics of the part (material, heat treatment, hardness and main dimensions).
Possible defects of the part and methods for their detection.
Permissible part size without repair.
Limit size.
Signs of final marriage.
Part repair methods.

The general characteristics of the part are made according to the working drawing. Possible defects of the part can be detected during operation or long-term testing of machines.

The values of the limiting and permissible dimensions of the part are also determined empirically. The limiting size is called such a size at which the part is not suitable for further operation. Such a part is repaired or replaced with a new one.

Parts with wear less than the limit can be put on a diesel engine. Therefore, such wear is called acceptable, the change of which during the operation of the part until the next repair does not exceed the limit. Signs of a final marriage are the presence of irreparable corrosion and cracks, as well as a change in the geometric shape and dimensions of the part above the limit, when it cannot be restored by currently accepted repair methods.

Specifications are a guiding document and apply only to a specific make or model of engine. In the process of improving the repair on the basis of the accumulated production experience specifications correct: change the limits of permissible wear of the part and introduce new methods of repair.

Thanks to the introduction of new repair methods, the range of repaired parts is expanding. A number of parts that have not been repaired before are now being successfully restored. Workers play an important role in improving the methods of repairing parts. rationalization proposals and inventions.

However, changes to the specifications are made after repeated experimental verification and with the permission of the organization that approves this document.

In the process of control, the route of repair of the part is determined. With route technology, labor productivity increases and the cost of repairs decreases, since this method eliminates the possibility of extra operations and shortens the path of the part. In addition, the quality of repair of parts is improved and the rhythm of the release of diesel engines from repair is ensured.

The results of the control of parts are recorded in the statement. As a result of the records, the number of good, requiring repair and rejected parts is determined.

According to the results of daily records, it is judged how much the actual number of rejected parts differs from the established shift norms (shift ratio).

The shift ratio is determined by the ratio of the number of rejected parts Nv to the total number of parts Ntot of a given item:

This coefficient is set on the basis of processing a large number of statements. The found coefficients are approved by departmental organizations and can be revised in the same manner as the technical specifications.

The following methods are used to control and sort parts at repair enterprises:

External inspection to identify cracks, breakages and other damage;
checking on special devices to detect cracks not visible to the eye;
measurement of dimensions to determine the wear of working surfaces;
checking on special devices to detect bending, twisting and warping;
checking the tightness and density of parts;
spring stiffness check.

The control and sorting of parts begins with an external inspection, but the time of which reveals the presence of scratches, cracks, dents, shells and corrosion. In the process of external inspection, changes in the surface layer of the metal can also be established, for example, overheating of the part due to the presence of tint colors.

During an external examination, it is not possible to detect small cracks and internal defects, therefore, special verification methods are used for this purpose.

We thank the editors of the corporate magazine "Time of Machines" of the Corporation "Russian Machines" for providing this material.

Sergey Kondratiev, adjuster of the cylinder block shop of the Yaroslavl Motor Plant (site for the production of V-shaped engines), begins the working day with an inspection of the milling and boring machining center: he checks the oil level, control panel, operation of the pneumatic system, lubrication indicator in the hydraulic system. Then evaluates the completeness of the cutting tool. Then he comes to the control station - she immediately, two steps away, checks the measuring tool. His movements are brought almost to automatism.

At Avtodiesel, as at all enterprises of the GAZ Group, operators have been are personally responsible for product quality, however, earlier the check was done the old fashioned way - selectively and already finished products. No, no, but defective parts leaked to the consumer, although this happened extremely rarely. But do not subject everything that has been done during the shift to a continuous check! Almost unrealistic, and no, the strictest control finished products does not protect against marriage. We need built-in quality elements that nip defects in the bud. The acceptance of the first part, which is actively used in the automotive component production of the GAZ Group in 2017, solved this problem.

- "Catch the defect at the crime scene!" - that's what we call the new technique, - jokes Leonid Turbanov, a leading specialist in the development of the substation of the Yaroslavl Motor Plant. - Not a single defect can now penetrate not only to the external, but even to the internal consumer - to the assembly.

The impeccable condition of the equipment is a guarantor of stable product quality, as Sergey Kondratiev says according to the written word. But behind these the right words- accumulated experience. Here the adjuster starts the machine for the first, idle run. After making sure that he is normal, Sergey sends the first block into his "womb". The iron giant rumbled - began to mill surfaces and bore holes.

After 15 minutes, our interlocutor, using a crane beam, carefully transfers the processed block to a special table for measurements. He puts on goggles, blows chips and metal dust from the workpiece with compressed air, and takes up measuring tools. They are right there, at hand, each signed and located in a separate cell.

I have been trained in measurements and I can always refer to clear and precise instructions that have been developed by quality and production system, - Sergey explains, without slowing down his movements for a moment. - I enter the measurement results in the statistical control chart and compare them with the tolerance limits.

Finally, he delivers a verdict: "Good!". Then he hangs a tag with the appropriate inscription on the part, carefully enters the date and time, and places the product in the green zone.

Now you can start the party. Sergey, according to the control plan, has 19 pieces. Then the measurement process is repeated, and the next good part with the specified manufacturing time is placed in the green zone, replacing the previous one.

What if the item was defective? - I ask Sergey an “uncomfortable” question.

In my practice, this has not happened for a long time, I always carefully monitor my machine and processing tools. But even if we imagine such a situation, then according to the instructions I will send the part to the reject insulator, I will adjust the machine - perhaps the modes have gone astray, or I will change the tool and repeat the steps again until a model part is received. And already from it I will lead the countdown of the party.

What if the 20th part is defective? - I continue to torture the guy.

I will stop the process, double-check the previous batch and look for the part with which the marriage went. Now it is much easier to do this - I know for sure what I will be looking for in just 19 products. If I cannot fix the problem with the equipment myself, I will call the master, he will contact service center and invite a mechanic or power engineer to repair. The main thing for me is to prevent defective parts from being assembled. That is what I am responsible for!

In fact, my questions are provocative, and marriage will not happen for no reason, because Sergei Kondratiev can predict its appearance in advance - when measuring, he will notice how the parameters shift, approaching the tolerance limits. In order to see the whole picture, the adjuster enters the dimensions into the statistical control map.

We enter the statistical control data into the computer and calculate a special parameter showing the degree of stability technological equipment. Based on it, we can build accurate forecasts of failures, failures or wear of the tool and prevent problems in advance, - says Igor Anikeev, controller of the UTC of the Avtodiesel cylinder block shop.

The YaMZ service center created passports for each machine with complete information: a list of main assemblies and parts, a maintenance and repair schedule, a card for checking equipment for geometric accuracy, a standard for maintenance by a mechanic and a power engineer, a stability control card, etc. This information is collected in one place , allows you to deal with problems much faster.

Sergey Valkov, YaMZ Quality Director, correctly notes that no quality control system will be successful until the operators themselves are interested in it. But interest must be accompanied by an understanding of why this or that action is needed, why it is important to follow the prescribed regulations so scrupulously.

Sergei Kondratiev is one of those conscious people. He understands the meaning of each of his actions, can sensibly explain it. All this helps not only to establish where the failure occurs in terms of parameters, but also to prevent it, while the numbers are still changing within the regulation limits, that is, when the part is still good. That is why the site of Sergey was chosen as the reference one, and it was from this site that the process of acceptance of the “first good one” stepped into other divisions of the plant.

But not all workers at first showed consciousness. While the know-how was being introduced, they were faced with the fact that someone might not sign the date and time of release of the first good one, perhaps considering this an unnecessary formality. Specialists in quality and implementation of the PS helped, who trained people.

When the operator himself carefully checks the work, controls the process, and he has the opportunity to influence it, a sense of responsibility and self-respect arises, - notes Leonid Turbanov.

Well, since there are no comments from the consumer workshop, we consistently receive 20% of the premium for excellent quality! - concludes Sergei Kondratiev. - “We” is the team of the cylinder block workshop. After all, the experience of the reference section is already widespread here, which means that the whole team works in a new way.

reference

What is First Good Part Acceptance?

Visualized quality control tool according to international standard quality management IATF 16949. In 2017, it is being implemented at all enterprises of the GAZ Group. This tool is suitable for series production when products are made not individually, but in batches and mainly for machining. They do not cover everything with such control, but only critically important processes. The main goal is to ensure that the equipment and tooling are initially configured exactly to the specified requirements. In this way, the production of suitable products can be guaranteed.

What is in the area of acceptance of the first good part?

Control station:

organizing equipment and visualized containers for measuring instruments - each instrument has its own place with an inscription;
the location marked in green is for the first good part;
stand for documentation - plans for control and management of the process; a sketch of the part with the designation of the processed parameters; working standard describing the actions in the acceptance process; requirements for measuring instruments and means of control; cards of statistical regulation and samples of filling in tags with the inscriptions “good” / “pending decision” / “defective”.

Workplace stand:

with regulations for tool replacement, schedules for cleaning, autonomous maintenance, maintenance of equipment by a mechanic and power engineer, a report card for the operation of equipment to calculate the overall efficiency.

Elena Vasilyeva, photo by Artem Rassadin

The criterion for the control of manufactured products is the compliance of products with the requirements of design documentation and technical documentation.

Responsibility

The head of the quality service is responsible for organizing product quality control.

Responsibility for the implementation of activities under this procedure lies with the heads of departments.

Organization Responsibility medical examination the view of the inspectors is carried by the head of the BOT and PB.

Procedure for carrying out activities

Control of the "first part"

The control of the "first part" is carried out in the press shop, in the plastics processing shop, in the assembly shops in the following cases:

At the beginning of the shift;

When installing again or after repairing a die or mold;

When changing the batch of material;

When changing a worker;

When starting the assembly line.

The “first part” is presented to the inspector for control by the workers. In the assembly shop, the “first part” is the assembly unit. The controller controls the manufactured "first part" in accordance with the requirements of the TD. The acceptance results are recorded with the entry “good” in the column “Control of the first part” of the journal “Registration of results of control (tests)” (Appendix A) and in the accompanying documentation in accordance with PSK 7530 (Identification and traceability of products).

For negative results:

The controller isolates the "first part" in accordance with CPM 8300 (Control of nonconforming products);

The adjuster adjusts the equipment until a good part is received. If he

cannot resolve the discrepancy on his own, he informs the production foreman for a decision.

The "first part" is stored at the workplace and presented with the manufactured batch for control.

When changing the tooling, the control of the “last part” is carried out, which is stored with the tooling until the next start in production.

Flying production control

Volatile control is carried out by QCD representatives at least once a

week, as well as additionally due to production needs. The business need may be:

Excess losses from the marriage of the controlled part;

Notification of the consumer about the rejection of products.

During its implementation, it is controlled:

Compliance with the requirements of CD, TD, PSK, RI;

The state of marriage zones;

Identification of material and products;

conditions and terms of storage of products in warehouses and production sites;

Compliance with the FIFO method, etc.

The task for "flying control" is drawn up by the QCD (BTK) in the form (Appendix B). In case of detection of conditions that can lead to a deterioration in product quality, the head of the BTK shop issues a "Warning of non-compliance" (Appendix B) in 2 copies. One copy is sent to the head of the department, a copy to the head of the QCD. On the basis of the "Warning of non-compliance", the head of the QCD has the right to stop the acceptance of products by notifying the head of the quality service. The head of the division has the right to stop production at any stage, as well as shipment with immediate notification of the production director.

Interoperational control

Interoperational control is carried out by Quality Control Department based on the requirements of technological processes at least once a week. The results are drawn up in accordance with Appendix B. Actions with nonconforming products identified as a result of the control are carried out in accordance with PSK 8300. Accompanying documentation is drawn up in accordance with PSK 7530.

Control of the operation by the performer

The worker in the process of work must comply with the requirements of RI and TD. If the operation being performed complies with the requirements of the TD, the worker draws up an accompanying label and (or) a route sheet in accordance with PSK 7530. If non-conforming products are detected, the worker is obliged to inform the production foreman and identify it in accordance with PSK 7530.

Final product control

Presentation of products for control is carried out in batches during the shift, but no later than 30 minutes before the end of the shift. The presentation is made at the control posts of the QCD and sites for the final acceptance of products in accordance with the approved layout of the workshop. The contours of the site are marked with white or yellow lines and the tabular "Finished products".

Products for control are presented with accompanying documentation drawn up in accordance with PSK 7530. In assembly shops with a conveyor system, final control is allowed to be carried out during the shift one by one in accordance with the requirements of RI and TD.

When accepting products, the inspector is prohibited from using the measuring tool of the worker.

The organization of the workplaces of QCD inspectors, equipping it with the necessary measuring instruments, testing equipment and documentation is carried out by the head of the workshop - the manufacturer of the products presented for control.

To OTK controllers it is forbidden to accept products:

In the absence of cleanliness and order in the workplace of the production worker;

Manufactured using faulty and non-certified measuring instruments;

Without presenting the "first part" (in the workshops in accordance with clause 4.3.1.1).

The results of product acceptance are recorded in the journal (Appendix A) and in the accompanying documentation in accordance with PSK 7530. The quality of products in the assembly shops is confirmed by the stamp of the Quality Control Department in the places provided for by the TD for the products. QCD inspectors in the workshops that carry out packaging are prohibited from pre-stamping packing lists (passports). When NP is detected further actions produced in accordance with PSK 8300.

Products that are not accepted by the QCD at the first presentation are sorted (or disposed of) by the manufacturer's workshop and presented again within three days. Re-submission is carried out by the production foreman with the provision of an act on the analysis and elimination of defects (Appendix D). The presentation of products according to the "Permission Card" is repeated, while the act is not issued. Number of the act or "Permission card" QCD controller put in the graph

"Controller" of the magazine (Appendix A) marked "repeatedly".

The percentage of change from the 1st presentation is calculated weekly by the heads of the BTK in one of two options (according to the number of batches or products presented) according to the formula:

K is the number of rejected batches (products); S - the number of initially presented batches (products). The quality engineer of the OAKP weekly (monthly) analyzes the “Product delivery from the 1st presentation” by the shops on the basis of a certificate provided by the heads of the BTC.

Abbreviations

CI- qualification tests

PSI- acceptance tests

PI- periodic tests

TI- type tests

CDP- chief technologist department

WGC- chief designer department

Ogmeter- department of chief metrologist

PEO- planning and Economic Department

KU- commercial management

PZ- customer representation

LCI- laboratory of control tests

The procedure for the presentation and acceptance of OTC products

St. Petersburg

Foreword

Goals and principles of standardization in Russian Federation established by Federal Law No. 184 dated December 27, 2002 "On Technical Regulation".

About the standard

1 DEVELOPED by the Open Joint Stock Company "Plant" NAVIGATOR "

2 INTRODUCED by the Open Joint Stock Company “Plant “NAVIGATOR”

3 APPROVED AND INTRODUCED......

4 INTRODUCED FOR THE FIRST TIME

This standard cannot be fully or partially reproduced, replicated and distributed as an official publication on the territory of the Russian Federation without the permission of the Open Joint Stock Company "Plant" NAVIGATOR "

1 area of use. one

3 Terms and definitions. 2

4 Designations and abbreviations. 2

5 General provisions. 3

7 Periodic tests. 6

ORGANIZATION STANDARD

Application area

The enterprise standard is an integral part of the enterprise's quality management system and is aimed at ensuring the quality of the developed and manufactured products.

The standard establishes the procedure for the presentation and acceptance of QCD products.

The standard was developed based on the requirements of GOST RV 15.307-2002, GOST RV 15.002 and OST 134-1028.

The standard is obligatory for all subdivisions presenting OTC products.

GOST R ISO 9000-2008 Quality management system. Fundamentals and vocabulary

GOST RV 15.307-2002 SRPP VT. Testing and acceptance of serial products. Key points

GOST RV 15.002 - SRPP VT. Quality management systems

OST 134-1028 -2006 Requirements for quality management systems of enterprises involved in the creation, production and operation of products

GOST R 1.5-2012 Standardization in the Russian Federation. national standards. Rules for construction, presentation, design and designation

GOST R 1.4-2012 Standardization in the Russian Federation. Organization standards. General provisions

the federal law dated November 28, 2015 No. 184-FZ On technical regulation

Terms and Definitions

In this standard, the terms of GOST R ISO 9000 and the following terms with their respective definitions apply:

test report: Document containing necessary information about the test object, the methods used, means and test conditions, test results, as well as a conclusion on the test results, drawn up in the prescribed manner.

production control: Control carried out at the stage of production.

Products: Semi-finished products, parts, assembly units and finished goods made by the Society.

product acceptance: Verification and documentary confirmation of product compliance with the requirements of technical documentation and the suitability of these products for delivery and (or) use, carried out with positive results of its quality control.

Designations and abbreviations

KD - design documentation ND - regulatory documentation

Society - open Joint-Stock Company"Plant "Navigator"

OVKiS - department of external cooperation and sales

OTK - department technical control

TD - technological documentation

TU - technical conditions

General provisions

5.1 Manufactured products, prior to their shipment or transfer to the customer (consumer), are subject to testing and acceptance in order to verify their suitability for use in accordance with the requirements established in the RD and supply contracts.

5.2 Acceptance of products is carried out by QCD employees.

5.3 For quality control and product acceptance, the following categories of tests are carried out:

bearer;

Acceptance;

Periodic.

Presentation tests are carried out in order to control products for compliance with the requirements of the technical specifications and determine the readiness of products for presentation to the VP of the Ministry of Defense of the Russian Federation.

Acceptance tests are carried out in order to control the compliance of products with the requirements of technical specifications and determine the possibility of accepting these products.

Periodic tests are carried out in order to confirm the possibility of manufacturing products according to the current design documentation and technical documentation.

5.5 To evaluate the effectiveness and feasibility of introducing the proposed changes to the design of the manufactured products and (or) the technology of its manufacture, type tests are carried out. The procedure for conducting type tests is given in GOSTRV 15.307.

5.6 Products submitted for testing and acceptance must be fully completed in accordance with the requirements of the design documentation. At the same time, the quality of purchased components used must be confirmed by the results of incoming inspection.

5.7 When testing and accepting products, it is not allowed to use test, measurement and control tools that have not passed metrological certification (verification) within the time limits established by the documentation for these tools.

5.8 Responsibility for the quality of products presented for testing and acceptance is borne by the direct executors. The heads of the relevant department are responsible for the material, technical and metrological support of the QCD representatives participating in the testing and acceptance of these products.

5.9 The basis for making a decision on the acceptance of products is the full compliance of the products with the requirements of the RD, confirmed by the results of its control and testing, provided for by the RD for this product.

5.10 Accepted products are those that:

Withstood all the tests stipulated by the ND for it,

Completed, subjected to conservation and packaging in accordance with the requirements of the ND or the terms of contracts for its supply,

Sealed by a representative of the Quality Control Department,

And on which the documents certifying its acceptance are issued.

5.11 In the products accepted by the quality control department, it is not allowed to carry out improvements, repairs, or the elimination of errors.

5.12 The accepted products are subject to shipment to the customer or transfer to the warehouse of finished products for safekeeping. After acceptance of the QCD products up to its transfer to the customer, the head of the OVKiS is responsible for ensuring the safety of the quality and completeness of the products.

The procedure for presenting products to the Quality Control Department. Bearer tests

6.1 Presentation of products to the QCD for control, acceptance and participation of QCD representatives in product testing is carried out on the basis of the technological process.

6.2 The products are presented by the foreman of the production site (or a person authorized by the production manager) through the QCD product presentation log. The journal is drawn up in accordance with Appendix A.

6.3 Bearer tests are carried out by forces and means of the unit - the manufacturer of products in the presence of employees of the Quality Control Department of the Company.

6.4 For bearer testing and production control, products are presented with a complete set of design documentation and completed accompanying documents confirming the implementation of previous operations in the technological process.

6.5 If the product was modified during the manufacturing process, then with an uncorrected design documentation, along with it, upon presentation, notices of changes to the design documentation or a change log are attached.

6.6 Bearer tests of products are carried out to the extent and

sequences provided for in the RD for these products.

6.7 For bearer tests, products are presented that have fully passed the production control provided for technological process for its manufacture.

6.8 With positive results of the bearer tests, the QCD employees participating in the tests must:

Prepare supporting documents;

Fill in the magazine for the presentation of OTC products;

Seal the product and (or) affix the appropriate stamps on it, the method of affixing and location of which must comply with the technical specifications and technological documentation for this product;

6.9 If, according to the results of the presentation tests, the products did not pass the test, the QCD employees participating in the tests are obliged to:

Make appropriate notes in the log of the presentation of OTC products;

Make an appropriate entry in the accompanying documents for products that have not passed the test;

Isolate the product until a decision is made on its further use.

Periodic testing

7.1 Periodic tests are carried out with the participation of QCD employees. Tests are carried out in the scope and sequence established in the specifications.

7.2 The frequency of testing by the time of production of products (month, quarter, year) or by the number of manufactured products is established in the specifications for the product or in supply contracts. Products for the next periodic testing are selected by representatives of the QCD from among the products manufactured in the controlled period and passed the acceptance tests.

7.3 Specific test dates are set in the annual schedule, which is chief metrologist. The schedule should indicate the place of testing, the timing of the tests, the procedure for issuing documentation on the results of the tests.

7.4 If the product has passed periodic tests, then the quality of products of the controlled period is considered to be confirmed by tests, and the possibility of further manufacturing and acceptance of products according to the documentation on which it is manufactured is also considered to be confirmed. The period for which the results of periodic tests apply,

indicated in the act. Protocols of periodic tests are attached to the act. Forms of acts and reports of periodic tests are specified in Appendices 8, 9 of GOST RV 15.307.

7.5 If the product has not passed periodic tests, the decision on further release, shipment and the need to refine previously released products is made in accordance with the OST.

After disassembly, the degreased, washed, cleaned parts are sent to the control and sorting area. The control and sorting of car parts is one of the basic and responsible sections of the repair enterprise. This section is subordinate to the technical control department of the plant, which makes it possible to control the work of the dismantling department.

Almost all parts of disassembled units are sent to the control and sorting area. Only devices of the power supply system and electrical equipment, body parts, springs, radiators, fuel tanks, as well as frames are inspected and sorted directly in the departments where they are repaired.

The main purpose of the control is to determine the technical condition of the parts and sort them into the appropriate groups: good, bad and requiring restoration.

Specifications for control-sorting are developed on the basis of research and practical materials on wear and damage to parts and methods for their restoration and are approved by a higher organization (ministry).

Specifications are drawn up in the form of separate cards, which indicate possible defects in the part, methods for their determination, essential tool and devices for the production of control, and in some cases - and special equipment. The maps also indicate data on the amount of allowable wear, the dimensions of parts suitable for use without restoration, suitable for restoration, and the maximum dimensions of parts at which they should be rejected. At the same time, they give instructions on the permissible deviations from the correct geometric shape of parts: ovality, taper, curvature, etc.

Not only the quality of repair M, but also the technical and economic performance of the enterprise depends on the organization of work on the control and sorting of parts.

In the event that unusable parts, erroneously assigned to the group of suitable ones, fall into the assembly of units, this will inevitably lead to a decrease in the quality of the repair. In the event that the controller mistakenly assigns good or requiring restoration parts to the group of bad parts, then the number of good parts will be artificially reduced. Additional new parts will be required, and this in turn will lead to an increase in the cost of repairs. Control operations to determine the amount of wear and serviceability of parts are carried out by external inspection and with the help of devices and tools.

An external inspection establishes the general technical condition of the part and reveals external defects - cracks, dents, holes, scuffs, etc.

With the help of tools, the geometric dimensions of the part and its deviations from the correct geometric shape (curvature, ovality, torsion) are determined.

Hidden defects of the part are revealed with special devices and fixtures: structural changes in the material (loss of spring elasticity), shells, hairline, internal cracks, etc.

The control of latent defects is especially necessary critical details vehicles operating under alternating loads. These include crankshafts, connecting rods, piston pins, valves. Great attention should be paid to the identification of hidden defects in parts whose work is related to traffic safety.

With the help of special installations, the water jacket of the block and the cylinder head are also checked for tightness.

The control of parts usually begins with their external inspection. In this case, simple and binocular loupes are used.

Magnetic flaw detectors are used to detect hidden defects and cracks. Magnetic flaw detection is characterized by sufficiently high accuracy, simple equipment, and requires little time for testing.

The essence of the method of magnetic flaw detection is as follows: if a magnetic flux is passed through the controlled part, then if there are cracks in it, its magnetic permeability will be unequal, as a result of which the magnitude and direction of the magnetic flux will change. A local scattering flux appears, and magnetic poles appear at the crack boundaries. After removing the external magnetizing field, these poles establish their own magnetic field over the defect. By registering this local magnetic field, we thereby detect a defect.

Among various ways registration of the local magnetic field, the most widespread is the method of magnetic powder, which allows you to control the details of the most various shapes and sizes. A ferromagnetic powder is applied to the magnetized part - usually calcined iron oxide (crocus) - or poured over with a special suspension - a liquid (kerosene or transformer oil), in which a fine powder of iron oxide is in suspension. The ratio of the volumes of powder and liquids in suspensions is 1:30; 1:50.

Parts can be coated with slurry by dipping them into the slurry vessel for 1-2 min. At the same time, magnetic powder particles in the form of veins settle in places of the local magnetic field, clearly outlining the location of the defect, which is then easy to determine when examining the part.

Heat-treated parts made of alloy steels are coated with a suspension after they have been magnetized. In this case, the magnetic field in the places of defects arises due to residual magnetism. To detect surface cracks, as well as to control parts with low hardness, coating with a suspension is carried out at the moment when the parts are under the action of a magnetic field.

To detect defects in the transverse direction (transverse cracks), it is extremely important to perform longitudinal magnetization, and in order to identify longitudinal or oblique defects, it is extremely important to magnetize the part circularly.

Combined magnetization (longitudinal and circular) is also possible, ĸᴏᴛᴏᴩᴏᴇ makes it possible to detect defects in any direction in one magnetization step.

Longitudinal magnetization can be carried out in the field of an electromagnet and in the field of a solenoid, and circular magnetization can be carried out by passing a constant or alternating current a large force through a part or through a metal rod passed through a hollow part, for example, a piston pin.

After checking by magnetic flaw detection methods, the parts must be demagnetized. Demagnetization of parts is carried out on the same device on which they were magnetized, or with a special device - a demagnetizer. The quality of demagnetization is checked using a special device or by dusting the part with steel powder. A completely demagnetized part does not attract powder.

With the help of magnetic flaw detection, only parts made of ferromagnetic materials (steel, cast iron) can be inspected. To control parts made of non-ferrous metals, this method unsuitable.

In recent years, a fluorescent method has been used to detect cracks. The essence of the method of fluorescent flaw detection is as follows. Parts to be controlled are immersed in a bath of fluorescent liquid for 10-15 min or a fluorescent liquid is applied to the surface of the part with a brush. Possessing good wettability, this liquid penetrates into the cracks in the parts and lingers there. After 10-15 min the fluorescent liquid is washed off for several seconds from the surface of the parts with a jet of cold water at a pressure of about 2 atm; then the parts are dried with heated compressed air.

Drying and slight heating of the part contribute to the release of the fluorescent liquid from the crack to the surface of the part and its spreading along the edges of the cracks. For better detection of cracks, the surface of the dried part is powdered with fine dry powder of silica gel (SiO 2) and kept in air for 5-30 min. Excess powder is removed by shaking or blowing. Dry microporous silica gel powder further draws the fluorescent liquid out of the cracks. Powder impregnated with liquid, adhering to the edges of cracks, when irradiated with ultraviolet rays, begins to glow with a bright yellow-green light.

The following mixture is used as a fluorescent liquid: light transformer oil (vaseline oil, velosite, etc.) - 0.25 l, kerosene - 0.5 l, gasoline - 0.25 l and dye - defectol of green-golden color in the form of a powder: - 0.25 ᴦ. The mixture is kept until the powder is completely dissolved.

The source of ultraviolet rays are mercury-quartz lamps, the light of which is passed through a special light filter.

The fluorescent method can detect deep cracks (luminous in the form of wide bands), as well as thin and microscopic cracks (luminous in the form of thin lines). Noteworthy is ultrasonic flaw detection. Various types of ultrasonic flaw detectors are known. The method is based on the fact that during the propagation of elastic vibrations, the interface between two media (air - metal) causes reflection of vibrational energy. After an external examination and detection of hidden defects, the geometric dimensions of the parts are checked. Parts are usually measured in places of greatest wear. To determine the place of measurement of parts, it is extremely important to know the nature of their wear.

Consider the nature of the wear of some parts. During operation of the engine, the working surface of the cylinders wears out unevenly. In length, it wears out on a cone, with the greatest wear observed in the upper part of the cylinder, at a distance of approximately 10 mm from the top of the cylinder block. In a plane perpendicular to the axis, the cylinder wears out into an oval. The largest axis of the oval lies in a plane perpendicular to the axis of the crankshaft.

The wear of the cylinders on the cone is explained by the following reasons.

1. The gases formed during the combustion of fuel exert pressure on the piston rings, as a result of which the specific pressure of the latter on the cylinder wall sharply increases. The upper compression ring exerts a particularly high specific pressure (about 30 kg / cm 2), due to which the lubricant is squeezed out between the outer surface of the piston ring and the surface of the cylinder and a semi-dry friction is created.

2. As a result of the loose fit of the piston rings to the cylinder walls, gases breaking through the leaks during compression and combustion of the working mixture blow off the oil film, worsening the lubrication conditions for the rubbing surfaces of the rings and the cylinder.

3. The high temperature that occurs during the combustion of the working mixture leads to a sharp decrease in the viscosity of the oil, which reduces the strength of the oil film.

4. Reducing the speed of the piston, and hence the piston rings, in the upper part of the cylinder when the direction of piston movement changes also contributes to increased wear of the cylinders in the upper part.

5. The upper part of the cylinder walls in contact with hot gases is corroded.

Increased wear of the cylinder is also facilitated by the low temperature of the cylinder, caused by a violation of the thermal regime of the engine, as well as frequent stops and starts of the engine, especially in winter.

The wear of the cylinder on the oval occurs as a result of the following reasons:

a) uneven deformation of the piston when it is heated during engine operation;

b) irregular shape cross section cylinder as a result of uneven deformation of its walls when heated;

c) piston pressure on the cylinder wall under the action of a lateral normal force, which is one of the components of the gas pressure force on the piston.

The connecting rod journals of the crankshafts of engines wear out more than the main ones. This is due to the more difficult operating conditions of the connecting rod journals.

The necks wear out on a cone and on an oval. Wear on the cone is explained by elastic deformations of the crankshaft during its operation, and wear on the oval is due to the action of gas pressure forces and inertial forces acting in the same plane passing through the axis of the cylinders. The smallest axis of the oval is in the plane of the location of the cheeks of the crankshaft.

Camshaft journals wear on the oval as a result of the forces generated by valve lift acting on the camshaft in one direction.

At the splined shafts of gearboxes, as well as at the splined tips of the cardan shafts, wear of the splines along the width occurs. The surface of the front side of the spline wears in the direction of rotation of the shaft. This is due to the fact that this surface transmits force during the operation of a gear (spline) connection.

When measuring cylinder diameters, an indicator caliper is usually used. It is extremely important to measure the cylinders at the top, in a place corresponding to the extreme position of the upper piston ring, where wear is greatest.

Measurements are made in two mutually perpendicular directions: parallel to the axis of the crankshaft and perpendicular to it.

The amount of wear is determined by the largest diameter.

The measurement results are recorded in a special passport. On the basis of the data obtained, it is established under which repair size the cylinders of the block should be processed and whether it needs to be lined.

Pistons of engines entering overhaul, do not control, since all of them must be replaced with new ones (they have wear that exceeds the allowable).

Piston pins are measured with micrometers or special brackets. In the same way, the diameters of the valve stems and pushers are measured.

The camshaft is checked with a bending indicator. When installing it, it is extremely important to pay attention to the serviceability of the center holes. In a similar way, bending checks are made for crankshafts, axle shafts, gearbox shafts, etc. Valve springs are controlled in length and for elasticity. The suitability of a spring is judged by the magnitude of the force, which is extremely important for compressing it to a certain length.

Measurement of the diameters of the main and connecting rod journals of the crankshaft is carried out with a micrometer. The necks should be measured in two belts located near the fillets in two mutually perpendicular directions: in a plane passing through the axes of the main and corresponding connecting rod journals, and in a plane perpendicular to it. The measurement results are recorded in the passport. As with the control of engine cylinders, these data serve as the basis for determining under which repair size the crankshaft journals should be machined.

At connecting rods, the diameters of the holes of the upper and lower heads are measured. Measurements are made by indicator calipers. The hole of the lower head for the liners is measured in two mutually perpendicular directions: along the axis of the connecting rod and perpendicular to it.

The wear of the gear teeth in terms of thickness is determined by a caliper gauge or special templates. The gear teeth wear out unevenly, therefore, during the control, it is extremely important to measure at least three teeth, mutually located approximately at an angle of 120 o.

For bevel gears, the thickness of the teeth is measured at the end, in the place of the largest module.

The warping of the plane of contact between the block head and the cylinder block is checked on the control plate using a feeler gauge.

At repair plants, to increase the productivity of inspectors, save expensive universal measuring tools, improve the quality of control (eliminate errors in measuring dimensions), scaleless rigid measuring tools are used: plugs, brackets and templates.

Control measuring tools for all parts subject to control are selected in sets based on technical specifications for control-sorting. These tools are recommended to have sets for parts of various units and assemblies: engine, gearbox, steering, etc. The presence of kits greatly facilitates the control process.

The water jackets of the head and cylinder block are checked for tightness, which must be broken (cracks, shells on the walls).

The tightness test is carried out on special stands with water under pressure 4 kg1cm 2 within 2 min. On such stands, not only cylinder blocks are usually tested, but also block heads, ᴛ.ᴇ. they are universal.

The controller must pay attention to the fact that the parts that are not subject to depersonalization for production reasons are delivered as a set.

Based on the external inspection of the parts and the measurements made, in accordance with the technical specifications for the control-sorting, the controller determines which group it is extremely important to attribute this or that part to.

Details based on their condition are sorted into three groups:

1. Suitable, allowed for further operation without restoration.

2. Subject to restoration, wear and damage of which are eliminated by mastered this enterprise restoration methods, or at another repair company, where these parts are restored in the order of cooperation, if it is economically feasible.

3. Worthless parts that cannot be restored due to their condition, wear or damage, as well as those restoration of which under these conditions is not economically feasible.

In order not to mix up the details in production conditions different groups, they are marked with paint of a certain color. For instance, fit - green, requiring restoration - yellow or white, unusable - red.

When inspecting parts, you have to deal with a wide variety of types of wear and damage to parts. The existing specifications for the control and sorting of parts provide for more than 50% of all control operations by the method of external inspection. For this reason, inspectors must be technically competent, qualified, able to give a correct assessment of the condition of any part, correctly determine which group it should be assigned to. This is an important condition for ensuring high-quality and cost-effective repairs. For parts of the first group, i.e., fully fit and within the limits of permissible wear, the technical specifications are stable due to the extreme importance of ensuring the obligatory interchangeability of parts when assembling components and assemblies and the required quality of repair. For details of the second and third groups, ᴛ.ᴇ. recoverable and unusable, technical conditions should be considered as guiding material, since the definition of "parts unsuitable for restoration" is conditional and depends on the degree of equipment of the repair enterprise and the methods of restoration of parts mastered by it. In the latter case, the specifications for control-sorting must be adjusted. All changes made to the technical specifications are subject to approval by a higher organization (ministry).

Sort results for each part name are included in the defect list.

Troubleshooting sheets are prepared for all units and nodes M. One form of the sheet is usually filled out for several sets of a given unit or node, for example, for all engines disassembled in a given shift.

In the defect list, the number of good parts of each item to be restored, and unusable - rejected parts, is put down.

The list is divided into four separate parts. The first, which lists all the parts that have passed the control, their catalog number and the results of the control, is the main one.

The second, which indicates the number of suitable parts, enters the acquisition site along with these parts and serves as the basis for their accounting.

The third, which indicates the number of parts requiring restoration, together with the parts enters the warehouse of parts awaiting restoration, and serves as the basis for their accounting.

The last, fourth part of the statement, which indicates the number of unusable parts, is rented together with the latter to the scrap metal warehouse.

Troubleshooting sheets are not only accounting and reporting documents, but also technical documents, on the basis of statistical processing of which it is possible to determine the replacement ratios and recovery ratios of parts.

Part replacement ratio- this is the ratio of the number of unusable parts to the number of all parts of a given name in the lot.

The replacement and restoration coefficients serve as initial data in the design of repair enterprises, and are also used for calculations production activities operating enterprises and allow you to find out the need of the repair enterprise for new parts (to replace rejected ones).

On the basis of these data, applications are made for new parts coming from outside, and the scope of work for the manufacture of parts at this enterprise is also established. With the help of recovery factors, you can determine the amount of work to restore parts.

Since all the parts coming from the disassembly pass through the inspection and sorting area, the defect lists make it possible to control the work of the dismantling department (the number of parts and the quality of the disassembly).

Parts rejected during the inspection are necessarily sent to the scrap metal warehouse. It is necessary to exclude the possibility of getting these parts into the assembly.

From the group of rejected parts, some enterprises single out parts that are used as blanks for the manufacture of other parts.

After checking for each part to be restored, the defector, based on a combination of defects, assigns a technological route.

The technological route is the sequence of elimination of a certain complex of defects. The route is marked on the part with a number or letter P, if it is a rare route.

Detail control - concept and types. Classification and features of the category "Control of parts" 2017, 2018.

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