Repair of VAZ-2107 cylinder unit - course design

Contents

1. Analysis of structural features and working conditions of the part to be repaired

2.Typical defects of the part occurring during operation

3. Description of defect accepted for repair

4. Comparative analysis of methods of defect elimination

4.1. Metal coating

4.2. Manual and mechanized welding under flux layer

4.3. Vibration surfacing

4.4. Micro-surfacing, CO2 surfacing, powder baking

4.5. Boring

4.6. Chromium plating

4.7. Steeling

4.8. By indicators of physical and mechanical properties

4.9.By techno-economic and other indicators

5. Preparation of cylinder block

5.1. Removal and installation of VAZ engine

5.2. Disassembly of VAZ engine

6. Description of proposed route technology of facility repair with selection of process equipment

6.1. Preparation of cylinder block for boring

6.2.Boring of cylinder block and honing

7. Development of operational technologies with justification of basing methods, transition processing modes and used instrumentation

8. Cylinder block boring machines

9. Honing machine for cylinder blocks

10. Measures on labor safety and environmental protection during repair works

11. Quantitative evaluation of the recovery program of VAZ cylinder block

2.Typical defects of the part arising in the operating conditions.

The most common defects are:

1. Internal cylinder diameter wear;

2. Wear of the inner diameter of the core ring;

3. Flatness of sealing surfaces;

4. Damage to threaded holes;

5. Cracks in supports or channels.

Verification. Wash the cylinder block thoroughly and clean the oil ducts. Blow and dry with compressed air, examine the cylinder block. Cracks in supports and other places of cylinder block are not allowed.

If coolant is suspected to enter the crankcase, check the tightness of the cylinder block on a special bench. To do this, blanking the holes of cylinder block cooling jacket, force room temperature water under pressure of 0.3 MPa (3 kgf/cm2) into it. No water leakage from the cylinder block shall be observed for two minutes. If oil enters the cooling fluid, make sure that there are no cracks at the cylinder block in the zones of oil channels without complete disassembly of the engine. To do this, drain the cooling fluid from the cooling system, remove the cylinder head, fill the cylinder block cooling jacket with water and supply compressed air to the vertical oil channel of the cylinder block. If bubbles appear in the water filling the cooling jacket, replace the cylinder block. Check the density of the cylinder block connector with the head using the ruler and probe set. The ruler is installed diagonally in the plane and in the middle in the longitudinal direction, and across. Density tolerance is 0.1 mm.

4. Comparative analysis of methods of defect elimination.

Defect # 1. To eliminate wear, the cylinder must be bored and ground to the next repair size.

4.1. Metallization.

The HDMI method is not suitable for the type of recovery surface.

Ways MPl, MGP, MVCh do not approach as covering material.

Only the MED method is suitable.

4.2. Manual and mechanized welding under flux layer.

Ways NRe, NSFPL, NSFser, NSFtmo, NSFPG, and NSFLP do not approach because of big minimum admissible covering.

The NRad method is not suitable for the material type of the worn part.

There remains a method of NPg.

4.3. Vibration surfacing.

None of the methods are suitable, due to the large minimum allowable diameter of the surface to be restored.

4.4. Micro-surfacing, surfacing in CO2 medium, baking of powders.

Suitable methods are NAG and NUGAR.

The remaining methods are not suitable due to the large minimum allowable diameter of the recovery surface.

4.5. Boring.

To restore the cylinder block, the boring method is fully suitable.

4.6. Chromium plating.

In principle, almost any chroming method is suitable for restoring the part, but looking ahead note that chroming the part is further difficult to process (mechanically), so that the use of chroming is undesirable.

4.7. Ironwork.

The Gwv and Gwr methods are not suitable for the type of recovery surface.

The methods of Zhv, Zhvh, Zhuz, Zhspl, Zhmk and Zhpor are suitable for our detail.

4.8. In terms of physical and mechanical properties.

The MED metallization method is not suitable due to low endurance coefficient, adhesion and durability.

The IWG welding method is not suitable due to low durability.

4.9.By techno-economic and other indicators.

We choose from the methods of micro-surfacing (NUGi NUGar), boring and ironing the cheapest at the cost of repair. They turn out to be micro-surfacing by NUGAR, Zhspl and boring methods, but when further considering the characteristics of these methods, we conclude that the use of the iron method with the application of an alloy is beneficial, but boring is simpler and cheaper, so we choose this method .