Rebound Rubber Deformation Control for Hydraulic Shock Absorbers
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Solution Overview
Problem
The durability of rebound rubber in hydraulic shock absorbers is compromised due to pinching by the diametrical gap between the rebound sheet and the cylinder during deformation, with conventional countermeasures like chamfers and increased thickness being ineffective when thickness is limited.
Innovation Solution
A rebound rubber design featuring an inner diameter portion that inflects and an outer diameter portion that protrudes, with an inclined surface reducing axial width from the pressure receiving surface to the outer diameter surface, preventing pinching by maintaining a stable deformation attitude and promoting inflection, thereby preventing damage from the diametrical gap.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the thickness of the rebound rubber is increased to suppress deformation amount, then the rebound rubber can be prevented from being pinched by the diametrical gap, but the product shape is changed and cannot be employed
Solution Approach 1:
The rebound rubber is designed with non-uniform thickness distribution, where the thickness varies in the axial direction. Specifically, the rubber has a greater thickness at one end and gradually tapers toward the other end. This local variation in thickness allows the rubber to maintain adequate volume and resistance to pinching while preserving the overall product shape and dimensions.
Solution Approach 2:
The invention changes the thickness parameter of the rebound rubber from a uniform value to a variable value along the axial direction. By controlling the thickness distribution pattern, the rubber achieves optimal deformation characteristics that prevent pinching by the diametrical gap while maintaining the required product shape for assembly.
2Reliability
If a chamfer is attached to the rebound rubber to move it away from the gap, then pinching can be prevented, but a great chamfer cannot be attached when the thickness of the rubber is small
Solution Approach 1:
Instead of attaching a separate chamfer component or creating a uniform chamfer, the invention integrates the protective function directly into the rubber's thickness profile. The gradual thickness variation creates a built-in chamfer-like effect that is manufactured as part of the rubber molding process, eliminating the need for separate attachment steps.
Solution Approach 2:
The protective chamfer function is merged with the main body of the rebound rubber by incorporating the thickness variation directly into the rubber's geometry. This integration eliminates the need for separate chamfer components and simplifies the manufacturing process to a single molding operation.
3Object-generated harmful factors
If the rebound rubber is strongly compressed between the spring holder and rebound sheet to prevent collision contact noise, then the rubber elastically deforms greatly, but this increases the risk of pinching and damage
Solution Approach 1:
The variable thickness distribution of the rebound rubber is designed to control the deformation pattern during compression. The thicker portion absorbs more compression energy and undergoes controlled elastic deformation, reducing the transmission of collision forces and noise, while the gradual thickness transition prevents stress concentration that could lead to pinching and damage.
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 design effectively inhibits pinching and damage to the rebound rubber, enhancing its durability and stability during compression, even in products with small thickness, and allows for cost reduction.
Implementation Method 1
the rebound rubber elastically deforms so that a rubber inner diameter portion is inflected and a rubber outer diameter portion protrudes like mountains toward an outer side in a diametrical direction at the exposing time to a compressive load in an axial direction
Data Source
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AI summary
In order to improve the durability of a rebound rubber (21) by preventing damage when the rebound rubber (21) deforms and is caught in the radial clearance between a rebound seat and a cylinder, the present invention is a rebound rubber (21), which is interposed between a spring holder holding one end of a rebound spring and a rebound seat affixed to a piston rod in a rebound spring mechanism of a hydraulic shock-absorbing device, wherein the rubber pressure-receiving surface (24) is arranged radially inward with respect to the radial center line (O) of the rubber volume in a half-cut cross-sectional shape of the rubber, and thus when a compressive load in the axial direction is received, the rubber elastically deforms such that a rubber inner-diameter part (22) flexes and a rubber outer diameter part (23) bulges and protrudes outward in the radial direction.