Shock Absorber Spring Unit with Limiting Member
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing shock absorbers with dual spring elements for damping force adjustment suffer from vibrations that can cause noise and durability issues due to the uninhibited action of the disk spring during certain movements.
Innovation Solution
A shock absorber design incorporating a damping force generation mechanism with a spring unit that includes a spring member acting throughout the valve body's movement and a limiting member to prevent excessive deflection, reducing vibrations and enhancing durability by ensuring continuous tension across the spring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a disk spring is used to act on the pilot valve only near the seat portion, then the damping force control is improved, but the spring vibrates due to uninhibited action during valve separation
Solution Approach 1:
The spring element is designed to dynamically switch between two operational modes: during most of the valve stroke, only the coil spring acts on the pilot valve; near the seat portion, both the coil spring and disk spring act together. This dynamic configuration allows the system to optimize damping force control near the seat while preventing vibration during valve separation by ensuring the disk spring remains inhibited throughout the separation range.
2Ease of operation
If the disk spring acts on the pilot valve during the whole stroke, then the spring control is improved, but the spring vibrates due to uninhibited action
Solution Approach 1:
The disk spring is pre-configured with an inhibited state that prevents it from acting on the pilot valve during the separation phase. This preliminary anti-action is achieved through the mechanical design where the disk spring remains compressed or constrained until the valve approaches the seat portion, at which point the inhibition is released and the disk spring engages to provide enhanced control.
3Device complexity
If only a coil spring is used for the spring element, then the structure is simplified, but the damping force adjustment range is limited
Solution Approach 1:
The spring element merges two distinct spring components with different characteristics: a coil spring that provides continuous action throughout the valve stroke for stable return force, and a disk spring that provides concentrated action near the seat portion for enhanced control and extended adjustment range. This combination allows the system to achieve broader damping force adjustability while maintaining reasonable structural complexity.
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
The solution effectively reduces spring vibrations, prevents noise, and improves durability by maintaining continuous tension across the spring, enhancing assemblability and productivity while allowing for adjustable damping force control.
Implementation Method 1
a spring unit configured to bias the valve body in a direction opposite from a direction in which the valve body is moved by the actuator. The spring unit includes a spring member configured to act on the valve body throughout a whole range of the movement of the valve body
Implementation Method 2
an actuator configured to generate a force for moving the valve body according to a current
Implementation Method 3
a limiting member configured to limit a deflection of a part of the spring member against a predetermined or more deflection of the spring member
Implementation Method 4
a piston slidably and fittedly inserted in the cylinder, and a piston rod coupled to the piston and extending out of the cylinder
Data Source
AI summary
A shock absorber including a damping force generation mechanism (30a) includes a spring member (106a) having radially extending spring portions (117) having high spring constants and circumferentially extending spring portions (118) having low spring constants. The radially extending spring portions and the circumferentially extending spring portions are integrally configured so that biasing forces thereof act dynamically linearly. An annular stepped portion limits strokes of the circumferentially extending spring portions and is provided on a cylindrical wall portion of a pilot body. As a result, within a range of damping force control, only the radially extending spring portions of the spring member are elastically deformed, whereby the durability of the spring member is enhanced, and only biasing forces of the radially extending spring portions of the spring member act on a pilot valve member, and thereby variation in a damping force is reduced so that the performance is improved.