Inline-Six Engine Dynamic Damper Layout for Resonance Noise Reduction
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Solution Overview
Problem
Existing damping structures for inline six-cylinder engines are insufficient in fully reducing engine vibration, leading to residual radiation sound propagation into the vehicle cabin.
Innovation Solution
A damping structure is implemented where a dynamic damper is attached to the lower part of the cylinder block between the second and fourth cylinders, incorporating a stationary part, a beam part, and two mass parts to absorb vibrational energy in both vertical and lateral directions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If sound insulation material is used to cover the entire engine, then radiation sound is reduced in all frequencies, but resonance frequencies cannot be fully insulated to target level
Solution Approach 1:
The damping structure segments the vibration control approach by separating the sound insulation function into two parts: sound insulation material for general frequency range and a dynamic damper specifically for resonance frequencies. This segmentation allows each component to optimize its performance for its designated frequency range, resolving the contradiction where general sound insulation material fails at specific resonance frequencies.
Solution Approach 2:
The invention employs mechanical vibration principles through the dynamic damper, which uses an inertial mass attached via elastic members to create counter-vibrations that cancel out engine vibrations at resonance frequencies. This mechanical approach complements the passive sound insulation material, achieving full effectiveness across all frequencies including resonance peaks.
2Device complexity
If an inertial mass is attached to the integral beam, then engine vibration is reduced without increasing the size and weight of the integral beam, but vibration at resonance frequencies is not fully reduced
Solution Approach 1:
The dynamic damper is attached at a specific location on the integral beam (not specified in the patent but implied to be an optimized position), concentrating the vibration reduction effect locally at the most critical area. This local quality approach allows effective vibration reduction without requiring the entire integral beam to be larger or heavier.
Solution Approach 2:
The dynamic damper utilizes mechanical vibration principles by creating counter-vibrations through the inertial mass and elastic members, directly counteracting the engine vibrations at resonance frequencies. This mechanical vibration approach supplements the integral beam's structural damping, achieving complete vibration reduction without increasing beam size or weight.
3Device complexity
If the inertial mass is attached at an unspecified location below the integral beam, then the structure is simple, but it is difficult to fully reduce the vibration
Solution Approach 1:
The patent specifies a particular attachment location for the inertial mass on the integral beam, applying local quality by concentrating the damping effect at the most effective position. This specified location optimizes the vibration reduction effectiveness while maintaining structural simplicity, resolving the contradiction between simple configuration and effective vibration reduction.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration effectively reduces engine vibration and lowers resonance peaks, resulting in a significant reduction of engine radiation sound across various frequencies, thereby enhancing cabin comfort.
Implementation Method 1
the beam part deforms in the vertical direction due to the vibration of the two mass parts to absorb the vibrational energy in the vertical direction
Implementation Method 2
vibrational energy is inputted to the dynamic damper via the crank journal part and is absorbed by the dynamic damper
Data Source
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AI summary
A damping structure of an inline six-cylinder engine is provided, which includes pistons reciprocatably fitted in the six cylinders, respectively, a crankshaft disposed below the pistons in a vertical direction of a vehicle and coupled to the pistons via connecting rods, respectively, the crankshaft being rotatable about an axis, a cylinder block having a plurality of crank journal parts disposed below the crankshaft in the vertical direction to rotatably support the crankshaft between adjacent cylinders in the crankshaft, a flywheel fixed to a rear end of the crankshaft in the longitudinal direction of the vehicle, and a dynamic damper attached to a lower part of the cylinder block, at at least one location between two adjacent cylinders among second through fourth cylinders, the six cylinders being disposed in an order of first through sixth cylinders from a front side to a rear side in the longitudinal direction.