Temperature compensation method for engine valve size measurement

Abstract

The invention discloses a temperature compensation method for engine valve size measurement, which relates to the field of workpiece measurement and aims at solving the problem that a large error exists in calibration of the actual length of the valve due to the influences of workshop temperature in the prior art. The valve size L0 at a standard temperature T0 is firstly calibrated as an actual calibration size; the actual temperature T1 of the workshop is measured; the actual size L1 at the actual temperature T1 is measured; L0=L1+(T0-T1)*alpha is obtained by a formula, wherein alpha is a thermal expansion coefficient of a valve making material; and the L0 is finally displayed on a size measurement instrument. As long as the special standard temperature is calibrated, the actual calibration size at the standard temperature can be calculated based on the formula, and the method is applicable to workshops in any temperature environment.

Description

technical field [0001] The invention relates to the field of workpiece measurement, in particular to a temperature compensation method for measuring the size of an engine valve. Background technique [0002] The function of the engine valve is to input air into the engine and discharge the exhaust gas after combustion. From the engine structure, it is divided into intake valve and exhaust valve. The function of the intake valve is to suck air into the engine and mix it with the fuel; the function of the exhaust valve is to discharge the burned exhaust gas and dissipate heat. The working conditions of the valve are very bad. First of all, the valve is in direct contact with the high-temperature gas, which is seriously heated, and it is difficult to dissipate heat, so the valve temperature is very high. Secondly, the valve is subjected to the action of the gas force and the valve spring force, as well as the impact when the valve is seated due to the inertial force of the m...

AI Technical Summary

Problems solved by technology

Moreover, the shape of the valve is composed of a flat disk part and a cylindrical long rod, which brings a big problem in the processing and manufacturing of the valve: under different room temperature conditions in different seasons of the year, the metal material Thermal expansion and contraction bring changes in external dimensions, especially for long rods such as valves, which makes it impossible to obtain a true and accurate value when the measuring equipment measures the axial direction of the valve.

[0004] For example, for a valve with a stem length of 100mm, when the factory room temperature rises from 0° to 40°, the axial geometric dimension of the valve will increase by 0.0432mm, which will cause a large error in the calibration of the actual length of the valve