Stepped Piston Damping Device for Brake Pedal Travel
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Solution Overview
Problem
Damping devices in slip-controllable hydraulic vehicle brake systems lengthen pedal travel in passive operating states due to limited pressure medium absorption volume, compromising damping effectiveness in partially active or fully active states.
Innovation Solution
The damping device employs a stepped piston with variable flow cross-section and a sealing mechanism that limits pressure medium absorption volume during passive operation, allowing full absorption during active states to maintain effective damping without extending pedal travel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the pressure medium absorption volume of the damping device is increased to improve damping properties, then the damping effectiveness is improved, but the pedal travel is lengthened in passive operating state
Solution Approach 1:
The patent applies a stepped piston with variable cross-sectional area that dynamically adjusts the pressure medium absorption volume based on operating conditions. During passive braking, the piston position limits absorption volume to maintain normal pedal travel. During pressure generator operation, the piston allows full absorption volume for effective damping of pressure pulsations.
Solution Approach 2:
The invention changes the absorption volume parameter of the damping device based on the operating state. By using a stepped piston with different cross-sectional areas, the absorption volume is varied: smaller volume during passive braking to avoid pedal travel increase, and larger volume during active braking to ensure effective damping.
2Length of moving object
If the capacity of the damping device is limited to reduce pedal travel, then the pedal travel is shortened, but the damping properties become less effective in partially active or fully active braking
Solution Approach 1:
The stepped piston creates a dynamic system where the absorption volume is not fixed but adapts to operating conditions. The variable geometry allows the damping device to provide adequate damping capacity when needed while maintaining compact effective volume during passive operation.
Solution Approach 2:
The damping device is segmented into different absorption zones using the stepped piston structure. The piston divides the damping chamber into regions with different absorption characteristics, allowing selective engagement of damping capacity based on operating state.
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 enables increased pressure medium absorption volume and optimized damping properties in active states without lengthening pedal travel in passive states, enhancing overall braking performance.
Implementation Method 1
a downstream flow resistance. The latter can be designed as a constant throttle with a fixed flow cross section or as a dynamic throttle with a flow cross section that changes as a function of the pressure
Implementation Method 2
the volume of pressure medium taken up by the pressure medium capacity is not available for building up brake pressure
Implementation Method 3
a restoring force that acts on the throttle body and that has a basic position corresponding to the maximum flow cross section of the throttle body
Data Source
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AI summary
The invention relates to a damping device (10, 10', 42), in particular for damping pressure pulses in a brake circuit of a slip-controllable hydraulic vehicle brake system. Said damping device (10, 10', 42) comprises a damper chamber (18a, 52) with a pressure medium volumetric capacity which can be varied in a pressure-dependent manner and a flow resistor connected downstream thereof. It has a disadvantageous effect that the pressure medium volumetric capacity of the damping device (10, 10', 42) is not available for the brake pressure build-up in a passive braking operation, that is to say when the brake pressure is generated by the driver, and the pedal travel on a brake master cylinder of a vehicle brake system is therefore lengthened. Means (34, 34', 74) which are provided according to the invention limit the pressure medium volumetric capacity of the damping device (10, 10', 42) in the case of a passive braking operation. In the case of partially active or fully active braking operations, in contrast, the means (34, 34', 74) have no effect and the full scope of the pressure medium volumetric capacity of the damping device (10, 10', 42) is available for damping pressure pulses which occur.