If the crankshaft is broken, will the cylinder body be deformed, and what should I do if the engine

This problem is more complex and requires the analysis of many factors and phenomena. For crankshaft fractures, there are several reasons that are usually considered: 1

First of all, judge whether there is a quality problem with the crankshaft itself. It is necessary to carry out cross-sectional analysis of the port: including material analysis (whether there are impurities at the port), fatigue analysis (to find the starting point of fracture), dimensional analysis (chamfer is too small may cause stress concentration), etc.

2.Secondly, judge whether the assembly clearance is abnormal. To check the concentricity of the crankshaft bore of the cylinder block, the size of the crankshaft pads, the axial clearance of the crankshaft, etc.

3.Abnormal combustion in the combustion chamber may also cause the crankshaft to break due to excessive load. 4.

There are other reasons for low probability. The above are the general possibilities, for your engine also need to consider:1

How many miles did the first break occur in the engine? 2.The engine has noise and vibration, and it is more likely that the crankshaft, bearing and cylinder block are unqualified; However, it is also possible that the crankshaft had already begun to crack at that time, and the deformation of the castle was built.

Does it depend on the noise that is generated when you just put on a new crankshaft? Or was it created shortly before the rupture occurred? In short, it is more complex and more difficult to determine, especially in the absence of information.

It depends.

If it is a normal boot corruption.

Generally, it does not come with a cylinder block.

If the exterior is impacted as a whole.

That will have to be checked to find out.

The deformation of the automobile cylinder head can be repaired by grinding, but the thickness of the cylinder head becomes thinner and the volume of the combustion chamber becomes smaller each time it is grindedCompression ratioenlarged, which caused a deflagration of the engine. Or simply replace the engine cylinder head with a new one. Deformation of the cylinder head will cause oil burning.

Problems such as decreased power and increased fuel consumption. When the alloy cylinder head encounters high temperature; When the tightening torque of the cylinder head bolt is uneven; When the cylinder head gasket is ablated in a large area; Other external forces will cause the cylinder head to deform.

The problem of a broken cylinder head is as follows:

1. In the driving, the long-rent beam feels that the engine is weak and it is difficult to speed up. There is an air leakage sound at the seam of the cylinder head and the cylinder block or locally.

2. After starting the bad transport machine, one cylinder or two cylinders do not work and are issued"Peng, Peng". There is a constant lack of water in the radiator and bubbles at the radiator nozzle, or there are oil beads on the surface of the cooling water.

3. Pull out the oil dipstick** oil, the oil is milky white. There are constant droplets of water coming out of the exhaust pipe.

4. The water temperature of the engine is too high. When the cylinder head gasket is severely damaged, not only does the engine power drop severely, but sometimes it even fails to start. In the event of such a failure, the cylinder can be replaced, and the oil will be more slippery.

The requirements for the warping and deformation of the plane of the cylinder block and cylinder head are: the flatness deviation of the plane on the cylinder block does not exceed within each range; The cylinder head plane is warped, and the full length of the four-cylinder engine is not exceeded, and the full length of the six-cylinder engine is one. No visible scratches or burns are allowed on the plane of the adjacent combustion chamber, and if they do not meet the above requirements, they should be trimmed.

The general method is: the protrusion near the plane screw hole of the cylinder block can be smoothed with an oil stone or flattened with a fine file. The unevenness of the cylinder block and the cast iron cylinder head can be repaired by milling and grinding, or it can be flattened with a shovel or coated with abrasive paste, and the cylinder head can be placed on the cylinder block to buckle and grind.

The warping of the spit cover can be corrected by the knocking method. The method of knocking and pressing the motor cylinder head: first put the steel sheet gasket with a thickness of about 4 times the deformation between the cylinder head and the flat plate.

Press the pressure plate in the middle of the cylinder head, tighten the bolts, make the plane of the middle of the cylinder head stick to the flat surface of the plate, and knock along the cylinder head rib with a small hammer to reduce the internal stress generated when the pressure is deformed, after staying for 5min, the pressure plate is moved to the full length of 1 3 places to knock, and then moved to the other end 1 3 places for knocking. After the plane of the cylinder head is warped, it can also be trimmed by grinding, but the thickness of the cylinder head becomes thinner each time it is grinded, the volume of the combustion chamber becomes smaller, and the compression ratio increases, which causes the deflagration of the engine. Therefore, grinding cannot exceed a certain thickness.

For example, the limit value of the height of the cylinder head of the Santana engine is. After the deformation of the cylinder head is grinding, it is easy to appear that the volume of the combustion chamber is unequal, and the volume change value should generally not be greater than 4% of the average value of each combustion chamber of the same engine. For gasoline engines, the combustion chamber volume is generally not stated, and the land burial should be less than 95% of the original factory regulations.

Otherwise, there will be unstable idle work and increased deflagration tendency. Therefore, after the cylinder head has been trimmed, the combustion chamber volume should be measured.

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Hello, the engine block is deformed, that's impossible. The cylinder gasket burns with the following phenomena: 1. The cylinder barrel and the water are boiled through the auspicious talk, and there will be a lack of rapid and disadvantageous water. 2. There is a lack of cylinder between the cylinder barrel and the cylinder barrel, and the exhaust is uneven.

Unsteady landing. 3. The cylinder barrel and the oil duct will burn the oil. Even if the gasket burns, it will not start after the flame is extinguished.

The cylinder gasket burns with the following phenomena: 1. There will be a shortage of water when the cylinder barrel is boiled through and the water is boiled.

2. There is a lack of cylinder between the cylinder barrel and the cylinder barrel, and the exhaust is uneven. The history has judged that the dispatch of vehicles is unstable.

3. The cylinder barrel and the oil duct will burn the engine oil when it burns through.

Even if the gasket burns, it will not turn off and will not start after the ignition.

If there is a lack of water to boil the pot, the cylinder gasket will burn and the cylinder head will be deformed, which can be solved by flattening the cylinder head. Only the limb is replaced within the cylinder gasket, and there is no need to thicken.

If it is the deformation of the cylinder block, it needs to be replaced, if it is the deformation of the cylinder head, Sencha can flatten the cylinder head, but the cylinder block can not be flat, and the replacement of the cylinder block is necessary to go to the vehicle management for the record, re-obtain the driving book, and to rent the cylinder block of the new spring certificate

CrankshaftThe wheel wobble is the crankshaft is broken. Because the crankshaft is often driven by serious wear, it will cause the crankshaft to bend and deform, and the crankshaft journal will lose its roundness, and then it will cause the crankshaft wheel to shake.

A crankshaft wheel is a gear or key gear mounted on the front end of a crankshaft and is usually used to drive a camshaft.

Gears, chains or toothed belts. The crankshaft wheel has a total of 58 gears, because it was originally 60 gears, and two gears were combined into one to mark the top dead center of a cylinder for signal transmission.

Development of crankshaft wheels.

The domestic demand for automobiles is strong, and the global automotive market is centered on developing countries.

Transfers, automotive parts and procurement are becoming increasingly global.

and other factors have promoted Lu Jianqing to enter China's overall automobile market and become more and more of a pillar industry of China's industrial development.

From 2007 to 2010, the total output of crankshafts in China was 4.77 million, 6.42 million, 26.33 million and 31 million respectively, of which single-cylinder engine crankshafts such as motorcycles were excluded, which still reached 4.5 million, 5.75 million, 10.32 million and 14 million.

The manifestations of bad damage to the crankshaft of the motorcycle are as follows:1. There is a murmur of great omen.

2. Easy to pull the cylinder.

3. The wear of parts is accelerated.

4. The oil feeding machine has a dangdang sound.

5. The bigger the throttle, the louder the sound.

Reasons why the crankshaft of a motorcycle is broken:

1. The main bearing and connecting rod bearing have been burned and corroded many times, and the supporting force of the ablation part is weakened.

2. The clearance of adjacent main bearings is too large.

3. The main bearing is worn too much and loosened for a long time.

4. The end clearance of the crankshaft is too large, and the sharp inspection or ablation is serious.

5. The last main bearing is ablated or the bearing is rolled.

6. The amount of crankshaft bending is too large or not centered.

7. After the cylinder block is deformed, the main bearing housing hole is not concentric.

The manifestations of bad damage to the crankshaft of the motorcycle are as follows:1. There is a lot of noise.

2. It is easy to pull the cylinder and inspect it.

3. The wear of parts is accelerated.

4. The oil chaos machine has a proper sound.

5. The bigger the throttle, the louder the sound.

Reasons why the crankshaft of a motorcycle is broken:

1. The main bearing and connecting rod bearing have been ablated many times, and the supporting force of the ablation part is weakened.

2. The clearance of adjacent main bearings is too large.

3. The main bearing is worn too much and loosened for a long time.

4. The end clearance of the crankshaft is too large or the ablation is serious.

5. The last main bearing burns the base and corrodes or the bearing rolls.

6. The amount of crankshaft bending is too large or not centered.

7. After the cylinder block is deformed, the main bearing housing hole is not concentric.

There are three main reasons why the engine hits the spine and the crankshaft breaks.

1. The bending cyclic load causes the main journal to break. There are a large number of spines at the origin of the crack, indicating that the crankshaft is subjected to a huge load during the crack formation stage. During subsequent use of the crankshaft, the crack propagates in the direction of the arrow, and eventually breaks at the connecting rod journal.

At the beginning of the work stroke of the crankshaft, the main journal fillet is subjected to compressive stress, and the connecting rod journal fillet is subjected to tensile stress.

2. At the end of the power stroke, the fillet of the main journal of the crankshaft bears the tensile stress, and the fillet of the connecting rod journal bears the compressive stress. Crankshaft fracture occurs in the case of tensile stress, so the crankshaft fracture is not caused by overload of the power stroke. After disassembling the engine, it was found that the thrust plate of the crankshaft had been broken, and the axial clearance of the crankshaft was too large.

3. The connecting rod journal is broken due to twisted cyclic load. In the process of converting the up and down motion of the piston into the rotary motion of the crankshaft, the crankshaft is mainly realized by the connecting rod acting on the journal of the crankshaft connecting rod. Due to the large mass of the crankshaft and the high rotational speed, the connecting rod journal of the crankshaft is prone to overload.

The starting position of the connecting rod journal fracture is at the end of the crankshaft weight reduction hole.

4. The diameter of the weight-reducing hole is very large, almost half of the connecting rod journal, and there is a sharp machining chamfer at the end of the weight-reducing hole opening, which causes the stress concentration of the connecting rod journal. Under the action of cyclic load, the connecting rod journal with concentrated stress will break. This problem can be solved by changing the position of the weight reduction hole and the machining chamfering and rounding of the weight reduction hole.

5. The crankshaft is broken due to material defects. The fracture that begins at the fillet of the connecting rod is often related to the overload of the engine's work stroke. The fracture surface was magnified, and it was found that there was a slag inclusion at the beginning of the crack, which may be caused by foreign impurities entering the molten steel during the smelting of the material.

When a crankshaft is made of material with slag inclusions, and the slag inclusions are located in a stress concentration position, cracks are easy to occur on the crankshaft.

6. In addition to slag inclusion, gaps, shrinkage holes and hydrogen embrittlement are generated in the process of crankshaft processing, which may cause stress concentration and fatigue fracture of the crankshaft during the use of the crankshaft. Therefore, in the manufacturing process of the crankshaft, non-destructive testing must be done to ensure that its material has no defects.

7. The crankshaft is the main rotating mechanism of the engine, which is responsible for transforming the reciprocating motion of the piston into its own circular motion, and usually the engine speed we call is the speed of the crankshaft.

8. The crankshaft will be worn on the contact surface between the connecting rod head and the journal due to the unclean oil and the uneven force of the journal, and if there are hard impurities with large particles in the oil, there is also a risk of scratching the surface of the journal. If the wear is severe, it is likely to affect the stroke length of the piston up and down movement, reduce the combustion efficiency, and naturally reduce the power output.

9. In addition, the crankshaft may also be burned on the surface of the journal due to insufficient lubrication or too thin oil, which will affect the reciprocating motion of the piston in serious cases. Therefore, it is necessary to use lubricating oil with appropriate viscosity and ensure the cleanliness of the oil.

Hello, it is generally caused by high temperatures.

It is necessary to open the engine disassembly analysis, it is possible to judge or approximate the cause;

If there is no biting phenomenon of crankshaft bearing and connecting rod bearing, it is mainly the quality of the crankshaft itself, you can check whether the crystal particles of the crankshaft section are delicate and uniform, whether the fracture has penetrating wounds, etc., and analyze whether it is the cause of material, processing, heat treatment, etc. (you can even do metallographic analysis);

If the size tile has bite, combined with the cross-sectional situation, is it because of the oil quality, water ingress, foreign matter, oil channel blockage, and the spalling of the tile surface caused by biting and crankshaft;

In addition, it is necessary to check whether the gap between the crankshaft and the large tile is too large or the tile is cut off and the tile is loose, resulting in the crankshaft shaking and force impact breakage;

Then check the upper part of the engine and the valve mechanism caused by faults, such as connecting rod or piston fracture and fragmentation, valve disconnection, rocker arm falling off or breaking, timing breakage, timing gear abnormality.

However, under normal circumstances, the crankshaft of a small gasoline engine of a small car is rarely broken, while the large engine of diesel engine and truck, especially the large engine with large bearings or crankshaft due to bite and wear, will have a certain proportion of broken shafts.

1. After grinding, the crankshaft destroys the R angle to form a right angle, and then breaks it when it encounters force, and 2. The main bearing hole of the cylinder block is not concentric.

There is a sand hole during casting, and fatigue begins at the sand hole when working, or there is a defect in the process during forging, and fatigue begins from the defective place, or the knife cutting the root is too heavy during processing, and fatigue begins at the root cutting, and it breaks when the fatigue reaches a certain level. I want to see a new explanation for the next bit.

One is overload, and the other is that the crankshaft is defective during production. Third, the crankshaft is seriously worn.

1. Wear and tear exceeds the limit.

Second, the gap between the shaft diameter and the bearing is too large.

Let's blow the cylinder! Is it flooded?

The deformation of the engine block can be trimmed by grinding, but each time the thickness of the cylinder head is thinner, the volume of the combustion chamber becomes smaller, and the compression ratio increases, which causes the deflagration of the engine, it is best to contact the after-sales service for maintenance.

Grinding should not exceed a certain thickness. For example, the limit value of the cylinder head height of the Santana engine is 132 60mm。

After the deformation of the cylinder head is grinding, it is easy to appear that the volume of the combustion chamber is unequal, and the volume change value should generally not be greater than 4% of the average value of each combustion chamber of the same engine.

For gasoline engines, the combustion chamber volume should generally not be less than 95% of the original factory regulations. Otherwise, there will be unstable idle work and increased deflagration tendency. Therefore, after the cylinder head has been trimmed, the combustion chamber volume should be measured.