Method for determining reserved heat gap between carbon scraping ring and cylinder cover and engine

Abstract

The embodiment of the invention discloses a method for determining a reserved heat gap between a carbon scraping ring and a cylinder cover and an engine, and the method comprises the steps: calibrating a pre-established engine thermodynamic model based on an air inlet parameter, an exhaust parameter and an oil supply advance angle of an air cylinder, so as to determine a thermodynamic air side boundary parameter in the cylinder; based on the obtained water pump parameters, water side boundary parameters of the surface of the engine cooling system are determined; establishing a fluid-solid coupling model based on the gas side boundary parameters and a pre-established complete machine finite element model of the engine; based on the water side boundary parameters and the whole machine finite element model, establishing a heat engine coupling model; according to the fluid-solid coupling model and the heat engine coupling model, the temperature of the set part is determined; determining a temperature field based on the temperature of a set part, and establishing a multi-field coupling model in combination with the thermal field; and according to the multi-field coupling model, thermal deformation parameters of the set parts are determined so as to determine a reserved thermal gap value between the cylinder cover and the carbon scraping ring. And the reserved heat gap value is quickly and accurately determined.

Description

technical field [0001] The present application relates to the technical field of engines, in particular to a method for determining a reserved thermal gap between a carbon scraping ring and a cylinder head and an engine. Background technique [0002] The size of the reserved thermal state gap between the engine assembly parts directly affects whether the parts will be "bumped" in the thermal state, which may cause fracture failure. Therefore, how to determine the thermal state reserved gap between assembly parts is particularly important, especially if the reserved thermal gap between the scraper ring and the cylinder head is too large or too small, it will affect the service life of the engine. [0003] In the traditional assembly process, the reserved gap between the scraper ring and the cylinder head is usually designed by referring to competing models or based on experience, and this reference value has certain limitations. For example: 1. If the assembly clearance is t...

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Problems solved by technology

For example: 1. If the assembly clearance is too large, under a certain compression ratio, it will affect the thickness of the bottom plate of the cylinder head, and then affect the rigidity of the cylinder head, resulting in weakened cylinder head strength and poor fatigue resistance; 2. If the reserved amount of the assembly clearance is too small, under the condition of thermal engine, due to the impact of the gas on the high-temperature parts, the structural parts will expand due to heat, and it is easy to "eat" the small gap, and the force exerted on the cylinder liner will cause Cylinder Liner Support Shoulder Position Fatigue Fracture

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