Cylindrical Vibration Isolator Mass Projection Positioning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Cylindrical vibration isolating devices with mass projections on elastic legs, particularly in engine mounts, face durability issues due to cracking caused by excessive strain during vibration, especially in inverted V-shaped designs where the mass projection overlaps with restraint lines, leading to reduced durability.
Innovation Solution
The mass projection is positioned outside the inner restraint line and intermediate line, with at least half of its surface area located outside these lines, ensuring it is in a region of lower strain, thereby preventing cracking and enhancing durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the mass projection is provided on the elastic leg to suppress bending resonance, then the vibration isolation performance is improved, but the durability of the mass projection deteriorates due to cracking at the base caused by excessive strain
Solution Approach 1:
The patent repositions the mass projection from a location overlapping with restraint lines to a location outside the inner restraint line and intermediate line. This spatial relocation in the radial dimension eliminates the strain concentration problem while preserving the vibration suppression function, as the mass projection continues to resonate with the elastic leg's bending vibration without being subjected to excessive strain from restraint line overlap.
2Duration of action of stationary object
If the mass projection is positioned to avoid restraint lines, then the durability is improved, but the arrangement space becomes more limited
Solution Approach 1:
The patent defines specific positional requirements for the mass projection: it must be located outside the inner restraint line and outside the intermediate line. This localized quality specification provides clear design guidance that simplifies the arrangement process. By establishing these boundary conditions, the patent transforms a complex positioning problem into a straightforward design rule that ensures both durability and functional effectiveness.
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 arrangement significantly reduces strain on the mass projection, preventing cracks and improving durability even at higher vibration frequencies, making the engine mount more practical and durable.
Implementation Method 1
a mass projection provided in the elastic leg such that the mass projection resonates in a frequency range that the elastic leg causes bending resonance
Implementation Method 2
the elastic leg 4 is connected along and to the periphery of the inner cylinder 2 by vulcanized welding or the like, and the connected portion forms an inner restrained portion 6
Data Source
AI summary
A cylindrical vibration isolating device having an inner cylinder, an outer cylinder surrounding the inner cylinder, an elastic leg having a pair of right and left leg portions to connect the inner cylinder and the outer cylinder and, when viewed in the axial direction of the inner cylinder, being formed in a substantially inverted V-shape while placing the inner cylinder in an intermediate position, and a mass projection being provided in the elastic leg such that the mass projection resonates in a frequency range that the elastic leg causes bending resonance. The mass projection is provided outside of an inner restraint line that is a perpendicular line passing an outermost point of an inner restrained portion that is a connected portion between the inner cylinder and the elastic leg.