Vibration theory based manifold thermal shield support mounting positioning method

Abstract

The invention relates to a vibration theory based manifold thermal shield support mounting positioning method. The method includes: by exhaust manifold modal experiments, arranging a plurality of acquisition point positions on objects as many as possible, and performing modal analysis to extract modal frequencies and modal shapes corresponding to the modal frequencies; calculating according to an ADDOFD (average driving degrees of freedom displacement) method to obtain values corresponding to acquisition point characteristic displacements; performing weighted displacement method calculation according to weights to obtain a point position minimum in displacement in welding of a connection support and a thermal shield. Thermal shield supports welded according to the vibration theory based manifold thermal shield support mounting positioning method are less prone to breakage off the manifolds.

Description

technical field [0001] The invention relates to a method for installing and positioning a manifold heat shield bracket, in particular to a method for installing and positioning a manifold heat shield bracket based on vibration theory. Background technique [0002] The manifold heat shield is generally installed on the manifold through a connecting bracket. One end of the connecting bracket is connected to the heat shield bracket with bolts, and the other end is welded on the surface of the manifold body. For each specific manifold, heat shield, and heat shield support, it has its own natural frequency as a whole. When these natural frequencies are close to the excitation frequency output by the engine, the manifold assembly will occur. Resonance, if the mounting position of the connecting bracket is such that it is at the peak of the mode shape, then the welding of the connecting bracket is easy to break. At present, the major manufacturers' research on preventing the break...

AI Technical Summary

Problems solved by technology

For each specific manifold, heat shield, and heat shield support, it has its own natural frequency as a whole. When these natural frequencies are close to the excitation frequency output by the engine, the manifold assembly will occur. Resonance, if the mounting position of the connecting bracket is such that it is at the peak of the mode shape, then the welding part of the connecting bracket is easy to break

At present, the major manufacturers' research on preventing the breakage of the connecting bracket between the engine manifold and the heat shield is mainly focused on optimizing the shape of the heat shield bracket, and has not specifically analyzed and studied the welding position of the bracket. The installation and positioning position of the connecting bracket still stays on the installation and positioning requirements based on the space position. With the determination of the shape of the heat shield support, that is, the determination of its own vibration mode frequency and mode shape, and the limitation of the space position, the connection The problem of bracket fracture is difficult to overcome by optimizing the shape of the heat shield bracket

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