Cylinder block head kamaz 740

Contents

Introduction

1. Input for Process Design

1.1. Part Characteristic

1.2Technical requirements for part defects

1.3Defects of the part and their causes

1.4Technical requirements for repaired part

1.5Part Lot Size Calculation

2. Technological part

2.1 Repair route

2.2Selection of rational method of part restoration

2.3Selection of process bases

2.4Technological diagrams of elimination of each defect

2.5Technological route of part restoration

2.6Selection of equipment and process accessories

2.7Compute processing modes

2.8Security requirements during repair works

2.9Technological documentation

2.10Processing organization in the area

2.11 Calculation of quantity of technological, lifting and transportation equipment and selection of organizational equipment

2.12Site area calculation

2.13Planning the recovery site

3. Structural part

3.1The purpose and arrangement of the accessory

3.2The principle of the device operation

Conclusion

List of sources used

1. Input for Process Design

1.1. Characteristics of the part.

The cylinder head is cast from aluminum (foundry) alloy GOST 158393, has wedge-shaped combustion chambers. Pressed seats and guide bushings of valves. Valve seats are made of grey cast iron GOST 141285. To ensure high strength when exposed to impact loads. Working chamfers of seats are processed after pressing together with cylinder head. To ensure precise alignment of chamfers with holes of guide bushings of valves.

Valve guide sleeves are also made of cast iron and pressed into the cylinder head with interference. There is a groove on the outer surface of the guide bushings. Where the locking ring is inserted. It ensures accuracy of bushings position when they are pressed into cylinder head and prevents bushings from possible falling out. Holes in the bushings are processed after pressing them into the cylinder head. This provides a narrow tolerance for the diameter of the hole and the accuracy of its location with respect to the working chamfers of the seat and valve. In holes of guide bushings there are spiral grooves for lubrication. At bushings of inlet valves, grooves are cut to half the length of the hole, and at bushings of outlet valves - along the entire length of the hole.

Oil reflective caps made of heat-oil-resistant rubber with steel reinforcement ring are put on the guide bushings from above. The caps enclose the valve rod and serve to reduce oil penetration into the combustion chamber through the gaps between the guide sleeve and the valve rod.

1.3. Defects in the part and their causes.

Defect 1 - wear of cylinder block sleeves - is a result of friction between piston and sleeve. Moreover, the greatest wear of the working surface of the sleeve occurs in its upper part, where during fuel combustion, the temperature and pressure of gases increase sharply. Gases penetrate under piston rings and increase their pressure on the surface of the sleeve, and therefore cause increased wear on its mirror.

Under the influence of high temperature, the lubrication conditions of the upper part of the sleeve deteriorate, since the oil film thinning occurs. In addition, the lubricant is partially washed off with a working mixture. Such uneven wear of the diameter of the working surface of the sleeve in height is called cone-shaped.

The reason for the appearance of ovality of the working surface of the sleeve is the uneven pressure of the piston on the walls of the sleeve. In the plane perpendicular to the axis of the piston pin, this pressure is greater, therefore, the wear of the sleeve is greater.

Defect 2 - deformation of the surface mated with the cylinder head - the cause of deformation is local or general overheating.

1.4. Technical Requirements for Repaired Part

The length of the head is 585 mm, width is 230 mm, height is 200 mm. Allowable repair deviations 0.2 mm.

Process Part

2.1. Repair route.

The cylinder block head moves along the production areas of the plant according to route No. 1. On this route, the following defects are eliminated: cracks on the cooling jacket, deformation of the surface adjoining to the surface, breach of studs in threaded holes, tearing of the thread in the holes, cracks on the valve seats and wear of the working surface of the exhaust valve seats.

2.2. Choosing a Rational Way to Restore a Part

In repair practice, the restoration of worn-out automotive parts is carried out in various ways and the choice of one or another method in specific conditions is determined either by economic considerations or by the production capabilities of repair shops (the presence of appropriate technological equipment).

To restore the part, the following repair process diagram is adopted:

1) editing;

2) restoration of dimensions of landing belts;

3) troubleshooting of the support bead;

4) restoration of the internal working surface;

5) galvanizing the outer surface;

6) control.

2.6. Selection of equipment and process equipment.

Operation-Mills the broken surface of the engine cylinder block head abutment. The length of the head is 585 mm, the width is 230 mm.

The work can be carried out by an end mill d = 250 mm with insert legs made of hard alloy BK8. The fit plane is milled "as clean." Based on the overall dimensions of the part and using the certificate data of the machines, we choose the vertical milling machine 6H11 with the working surface of the table 1000x250 mm

2.9. Process documentation.

Execution of process documents is the final stage of process development. The project document set shall include:

1) cover sheet, form 2 GOST 3.11052005;

2) roadmap (MK), form 1 and 16 GOST 3.11182003;

3) machining operating cards (OC), form 2 or 3 and 2a GOST 3.14042009;

4) sketch maps (PE), form 7 and 7a GOST 3.11052005;

5) operational cards of metalwork, slesarnosborochny, recovery work, form 1 and 1a GOST 3.14072009 "ESTD. Forms and requirements for filling in and drawing up documents for technological processes (operations) specialized in assembly methods ";

6) Operational technical control cards, Form 2 and 2a GOST 3.15022012 "AETD. Forms and rules for issuing documents for technical control ";

7) process map of chemical, electrochemical coatings and chemical treatment, form 1 and 1a GOST 3.14082009 "AETD. Forms and rules of documents for technological processes of coating production ";

8) thermal treatment process map, Form 1 and 1a GOST 3.14052011 "AETD. Forms and requirements for filling in and drawing up documents for thermal processing processes. "

2.10. Organization of technological processes in the area.

The designed area is intended for milling works. The cylinder head is being repaired in this milling area.

Design Part

3.1. Purpose and arrangement of the accessory.

Cylinder head cover. It has a protective function. It contains the oil-filling neck of the engine oil. Rubber gasket is used to provide sealing when the cover is attached to the HSC.

Gasket the cylinder head. It performs a function at the location of the head adjoining the cylinder block. It is disposable, so you always need to change it, making repairs or maintenance. Do not save on the gasket, since later it will cost more.

Cavity. It houses the chain tensioner and camshaft drive located in the front part of the HBC.

Threaded holes. They are located in the housing and are designed for spark plugs or nozzles.

Combustion chambers.

Location for gas distribution mechanism.

In the upper part there are places for support washers of valve springs and housing of camshaft bearings and valve bushings.

There are also holes in the housing for fixing the outlet and inlet manifolds.

During production of HBC, guide bushings of valves and seats are installed in it. The installation technique is such that the cold parts are inserted into the heated head body. Due to this, after equalizing the temperatures, greater tension is achieved in the joint of the parts.

3.2. The principle of operation of the device.

The head is a part that is fixed and, in fact, does not work. The parts placed in it work - camshafts, valves and much more.

The pulley from the belt rotates rotates the camshafts, they in turn open and close the valves .

Conclusion

During the course design process, the process of restoring the cylinder block head of the KamAZ740 engine was developed. The part operation conditions and possible defects were analyzed. Possible recovery methods for each defect were analyzed.

The main defect is deformation of the surface mated with the cylinder block head. From the possible methods of restoring the main defect, the optimal method was chosen - the method of restoring by milling.

Necessary equipment, process equipment, cutting and measuring equipment are selected for performance of technological operations

tools. The production program for restoring the cylinder block head was calculated, the justification for the organization of the workplace and the choice of the planning solution was given. The developed planning solution enables efficient implementation of the process of restoring the cylinder head.

Evaluation of the repairability of the part showed that the head of the cylinder block of the KamAZ740 engine has good repairability.

The technical and economic evaluation of the project was carried out according to the main indicators, which makes it possible to talk about the high economic efficiency of restoring the operability of the engine cylinder head by the chosen methods and means of production.

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