Load applying and testing method for fatigue strength test of piston heat engine

Abstract

The invention provides a load applying and testing method for a fatigue strength test of a piston heat engine. A piston sample piece and a testing device installed below the piston sample piece are included and the method comprises the following specific testing steps that S1, thermocouples are arranged near a piston combustion chamber throat and at the center of a piston, and the thermocouples are in signal connection with a test control system; S2, non-contact heating is conducted on the head of the piston sample piece in a fuel gas heating mode, a pre-pressing load F is applied to the head area of the piston sample piece 6, and a certain prestress is generated on the combustion chamber throat; and S3, the piston sample piece is forcibly cooled through high-pressure air, and temperature field simulation and high-low temperature conversion of the piston sample piece are achieved. The load applying and testing method has the advantages that mechanical load applying and adjusting are flexible, temperature monitoring of an examination part is accurate, piston combustion chamber throat heat engine coupling stress applying is achieved, and the reliability of a piston engine fatigue strength test result can be effectively improved.

Description

technical field [0001] The invention belongs to the technical field of engine pistons, and in particular relates to a load application and testing method for a piston thermal engine fatigue strength test. Background technique [0002] Component thermal load test is an effective method to evaluate the thermal fatigue strength and reliability of engine pistons, and it is essential in the development of piston products. The thermal fatigue test of piston parts usually adopts electromagnetic induction heating or gas heating to make the surface of the piston combustion chamber reach the predetermined temperature requirement, and then uses high-pressure air to forcibly cool it, so that the piston sample is subjected to alternating thermal loads, and the piston resistance is tested. Thermal fatigue performance. Its advantage is that the thermal load simulation is highly realizable, and the temperature field at the top of the piston is basically consistent with that of the complete...

AI Technical Summary

Problems solved by technology

The disadvantage is that the piston sample in the thermal fatigue test is in a free state, the thermal deformation of the piston is unconstrained, and the mechanical load on the top of the piston and the pin hole is missing, resulting in a large difference in the stress field of the piston compared with the real machine, especially the high temperature part of the piston. Especially at the mouth, the test results cannot fully reflect its thermal fatigue resistance

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