Pedal Force Simulation Using Hysteresis-Generating Resilient Element
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Solution Overview
Problem
Existing clutch actuation systems require an over-center spring to generate the required force characteristic, and precision positioning of friction elements is necessary for effective pedal force simulation, which complicates the design and implementation.
Innovation Solution
A system that includes a pedal actuated piston with a restoring spring and an additional resilient element, where the second element elastically deforms the first element to generate hysteresis and additional counterforces, allowing for a non-linear force characteristic that can be adjusted, enabling both conventional and 'by-wire' actuation modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If an over-center spring is used to generate the required force characteristic, then the force characteristic can be achieved, but the device complexity increases
Solution Approach 1:
The patent extracts and eliminates the over-center spring from the system by replacing it with a resilient element that directly provides the required force characteristic. This removes the need for complex over-center mechanisms while maintaining the essential force generation function.
Solution Approach 2:
The patent changes the parameters of the resilient element (such as spring constant, pre-load, and geometric configuration) to directly achieve the required force characteristic without needing an over-center spring. This allows the same force profile to be obtained through parameter optimization rather than complex mechanism design.
2Stability of the object's composition
If friction elements are used for pedal force simulation, then hysteresis can be generated, but manufacturing precision requirements increase
Solution Approach 1:
The patent replaces the friction-based hysteresis mechanism with a purely elastic resilient element that generates hysteresis through its inherent mechanical properties. This substitution eliminates the need for precision positioning of friction elements while maintaining the desired hysteresis effect through the resilient element's deformation characteristics.
3Force
If a resilient element is added to the master cylinder, then pedal force simulation is improved, but the volume of the master cylinder increases
Solution Approach 1:
The patent nests the resilient element within the existing master cylinder structure, placing it in the available internal space without requiring external expansion. This allows the resilient element to be integrated into the compact existing design, improving pedal force simulation while maintaining the original volume constraints.
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 system simplifies pedal force simulation by generating a pedal force characteristic with or without hysteresis, replacing hydraulic or mechanical clutch actuation, and allows for linear, progressive, or varying force curves over pedal travel, enhancing the versatility and adjustability of the pedal force simulation.
Implementation Method 1
at least one resilient element arranged between the piston and the housing, which can be radially, axially or tangentially oversized to one another, in particular radially oversized, so that when the pedal is actuated a frictional force is generated between the first and second element
Implementation Method 2
sliding friction is generated when the pedal is actuated due to a relative movement of at least one first friction element connected to the pedal and consequently moved together with it relative to at least one second, stationary friction element
Data Source
Figure 1~4
AI summary
System for pedal force simulation, in particular for a clutch actuation system, wherein the pedal can be actuated with a pedal force and is operatively connected to a piston axially displaceable in a housing against a restoring force of a restoring spring, and the position of the pedal can be detected via a sensor and transmitted to the actuator actuating the clutch, and the piston is operatively connected according to the invention to at least one further spring element which provides hysteresis with rising and falling force profiles.