Hydraulic-drive type variable-compression-ratio piston connection rod assembly

Abstract

The invention discloses a hydraulic-drive type variable-compression-ratio piston connection rod assembly in order to solve the problems that in the prior art, a mechanism is complex, abrasion is large and control precision is low. The hydraulic-drive type variable-compression-ratio piston connection rod assembly comprises a piston, an extension spring, a piston pin, a connection rod, a three-position four-way electromagnetic valve, a hydraulic pump, a one-way valve and other hydraulic elements. Engine oil is pumped out by the hydraulic pump, after the direction of the engine oil is changed through the three-position four-way electromagnetic valve, the engine oil sequentially flows in an oil way of the connection rod and an oil way of the piston pin, and finally a push rod ejects a small ball in the one-way valve so that the size of a main oil cavity is reduced and the compression ratio of an engine is reduced. By means of the mode that the pressure of the engine oil in the oil way on the lower portion of the piston is increased and the small ball of the one-way valve is ejected, the size of the main oil cavity is increased, and accordingly the compression ratio of the engine is increased. The compression ratio piston uses a hydraulic mechanism mode, is quick in response, high in precision and high in reliability, and meets requirements of the engine for dynamic performance and fuel economy under various working conditions.

Description

technical field [0001] The invention relates to a vehicle engine assembly, more specifically a hydraulically driven variable compression ratio piston connecting rod assembly. Background technique [0002] Automobile compression ratio refers to the degree to which the engine mixture is compressed, expressed by the ratio of the total volume of the cylinder before compression to the volume of the cylinder after compression (that is, the volume of the combustion chamber). The compression ratio has a great relationship with the performance of the engine. Usually, the low-pressure compression ratio refers to the compression ratio below 10, and the high compression ratio is above 10. Relatively speaking, the higher the compression ratio, the greater the power of the engine. Generally speaking, when the other designs of the engine remain unchanged, the higher the compression ratio, the greater the power, the higher the efficiency, and the better the fuel economy. However, if the co...

AI Technical Summary

Problems solved by technology

However, if the compression ratio is too high, the stability will decrease, the knock rate will increase, and the life of the engine will be shortened.

[0003] If the engine with high compression ratio chooses low-grade gasoline, the temperature of the cylinder will rise sharply, the combustion of gasoline will not be complete, and the machine will vibrate strongly, which will reduce the output power and damage the machine parts.

If an engine with a low compression ratio insists on using high-grade oil, the phenomenon of "delayed combustion" will occur, that is, it will not reach the self-ignition point when it is compressed to the top, and it will also have incomplete combustion, which is not good for the engine. Therefore, the R&D personnel developed Developed an engine with variable compression ratio technology, which can change the value of the compression ratio under different working conditions to meet the requirements of the engine for oil quality, thermal efficiency and power performance under various working conditions

[0004] At present, the mature variable compression ratio engines can be roughly divided into three categories: crank-and-rod mechanisms with unconventional structures, changes in the distance between the crankshaft and the top of the cylinder, and changes in the length of the piston connecting rod. However, this technology with great potential needs to control the compression ratio. A more complex structure, even a large number of modifications to the entire cylinder, which will increase the volume of the engine to a certain extent, and at the same time increase the difficulty of processing

In addition, issues such as wear, control accuracy, and sealing are very difficult

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