RU1807926C - Method for machining cylinder lining - Google Patents

Abstract

Usage: repair and manufacture of internal combustion engines, for example, tractors and cars. The essence of the invention: the sleeve is installed in the bore of the crankcase, the position of the liner relative to the hole of the crankcase is fixed with a mark, the sleeve is pressed against the block crankcase by a force equal to the force of pressing of the cylinder head during assembly of the engine, after which heating is performed a crankcase assembly with cylinder liners to a temperature corresponding to the operating temperature condition of the engine, then machining is carried out.

Description

The invention relates to the repair and manufacture of internal combustion engines (ICE), for example tractors and automobiles.

The aim of the invention is to ensure the accuracy of the geometry of the cylinder liner when the internal combustion engine is operating in the operating temperature zone.

The proposed method is carried out as follows.

Insert the cylinder liner into the bore of the crankcase to bore and pry them. In this case, the position of the sleeve relative to the opening of the crankcase is fixed with a mark. The technological head is mounted on the block crankcase and the liner is pressed against the block crankcase with a force equal to the pressing force of the cylinder head when the engine is assembled. Then, the crankcase assembly with the sleeves is heated to 85-95 ° C, i.e. in the temperature range corresponding to the operating temperature of the internal combustion engine. Then, cylinder liners are bored and then honed to the required size.

Example. Processing the cylinder liner of the YaMZ-240B engine for a repair size of 130.5 + 0.04 mm (normal size 130 l06 mm) with an allowable ovality of not more than 0.025 mm, taper not more than 0.03 mm. The liner material is special alloyed cast iron.

The proposed method for processing a cylinder liner is carried out in the following sequence.

Install rubber rings in the grooves of the cylinder liners (for some internal combustion engines in the grooves of the crankcase bore). The need to install o-rings is due to the fact that they affect the occurrence of deformation of the sleeve during its installation in the crankcase.

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Insert the cylinder liner into the bore of the crankcase for boring and honing.

Marks are applied on the end surface of the cylinder liner and the adjacent surface of the crankcase to fix the position of the cylinder liner relative to the bore of the crankcase.

The technological head is mounted on the crankcase and the nuts of the head fastening studs are tightened in the specified sequence with a normalized torque of 22-24 kg / mm using a torque wrench. This ensures that the cylinder liner is pressed against the crankcase distributed around the circumference of the liner end with a force equal to the pressing force of the cylinder head during engine assembly.

The crankcase assembly is heated with cylinder liners to 85-95 ° C. Heating is carried out in a bath with a washing solution (or water) or in a washing machine simultaneously with the washing process. During the processing of the cylinder liners, hot water is supplied to the water jacket of the crankcase to maintain the required temperature.

Bore the cylinder liner to a size of 130.404004 mm, i.e. leaving 0.10 mm allowance for subsequent honing. The boring operation can be eliminated or replaced by preliminary force honing with diamond bars with a stock removal of up to 0.5 mm. This type of processing of cylinder liners is becoming increasingly common in the repair of automotive diesel engines.

The cylinder liner is honed to an IGO.S40 size of 04 mm and with an ovality of not more than 0.025 mm and a taper of not more than 0.03 mm and other requirements established by the technical documentation.

When assembling the engine, the cylinder liner is assembled with the rings in the bore of the crankcase with the alignment of marks on the end of the liner and the surface of the crankcase. Shifting the sleeve into another bore of the crankcase is not permitted.

The cylinder head is mounted on the crankcase and the nuts of the head fixing studs are tightened with the installed TU sequence and normalized torque of 22-24 kgcm using a torque wrench.

Ensuring the required accuracy of the geometry of the cylinder liners reduces the wear rate of the liners by 1.5-2 times, i.e. It also increases engine life. In addition, this will significantly reduce cases of seizure of liners and seizure of ICE pistons.

The proposed method for processing cylinder liners can be implemented on all

enterprises for the repair of tractor and other internal combustion engines, i.e. they are usually equipped with the necessary machine tools. In addition, due to the fact that significant deformation of the cylinder liners

take place on new internal combustion engines, the use of this method can give a significant economic effect from increasing the pre-repair resource of engines. Using the proposed method

processing of the cylinder liner of the internal combustion engine due to the increased accuracy of the geometry of the cylinder liner during the operation of the internal combustion engine significantly reduces the wear rate of parts of the cylinder-piston group, therefore, it increases the overhaul and overhaul resources of the internal combustion engine.

In addition, the use of this method may eliminate the need to assign strict requirements to the geometry

landing surfaces of the crankcase under the cylinder liner during the repair and manufacture of ICEs, therefore, reduce the cost of repair and manufacturing technology.

The expected annual economic effect will be 546 thousand rubles.

Claims (1)

SUMMARY OF THE INVENTION A method of treating a cylinder liner of an internal combustion engine, comprising installing a liner in a bore of a crankcase, fixing the position of the liner relative to the opening of the crankcase with a mark and subsequent machining, characterized in that, for the purpose of to increase the accuracy of the geometry of the cylinder liner when the engine is operating in the operating temperature zone, before machining, they press the liner to the crankcase distributed around the circumference of the liner end a force equal to the force of pressing the cylinder head during engine assembly, and the crankcase assembly with the cylinder liner is heated to a temperature corresponding to the operating temperature of the engine.