Hydraulic Brake Pre-Filling Flow Control for Rapid Pedal Actuation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hydraulic braking systems with pre-filling devices struggle to effectively transfer pressurized fluid to the brake circuit when the brake pedal is actuated rapidly, leading to incomplete clearance uptake due to fluid discharge into the fluid reservoir, causing pressure drops and reduced braking efficiency.
Innovation Solution
A hydraulic braking device with a small cross-section nozzle that retards the discharge of pressurized fluid from the pre-filling conduit to the discharge compartment, ensuring that much of the fluid takes up clearance in the brake circuit before the master cylinder piston advances, even during rapid pedal actuation, by maintaining hydraulic communication between the pre-filling conduit and pressure chamber.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the brake pedal is actuated rapidly, then the braking response time is reduced, but the pre-filling device cannot transfer the whole volume of pressurized fluid into the brake circuit, causing incomplete clearance uptake
Solution Approach 1:
The patent introduces a check valve as an intermediary component in the fluid pathway between the pre-filling conduit and the discharge chamber. This check valve selectively allows fluid to flow in one direction (from the pre-filling conduit to the discharge chamber) while blocking reverse flow, thereby ensuring that pressurized fluid is effectively transferred to take up brake clearance even during rapid pedal actuation when pressure differentials are high and flow directions may reverse.
2Speed
If the brake pedal is actuated rapidly, then the braking response time is reduced, but some of the flow of pressurized fluid is discharged to the fluid reservoir instead of taking up clearance in the brakes
Solution Approach 1:
The check valve acts as a mediator that controls fluid flow direction, allowing pressurized fluid to be discharged to the fluid reservoir only when it has first performed its useful function of taking up brake clearance. This prevents energy loss by ensuring that fluid flow is directed productively during the critical clearance uptake phase, even during rapid pedal actuation.
Solution Approach 2:
The patent converts the potentially harmful effect of rapid pressure changes during fast pedal actuation into a beneficial outcome. By using the check valve, the high pressure generated during rapid actuation is redirected to force fluid through the pre-filling conduit and into the brake circuit, ensuring complete clearance uptake rather than allowing fluid to simply discharge to the reservoir.
3Reliability
If a pre-filling device is used to supply pressurized fluid, then clearance uptake is improved, but the device becomes more complex with additional components
Solution Approach 1:
The patent merges the pre-filling function with the existing servo device structure. The pre-filling conduit is integrated into the discharge chamber of the servo device, and the check valve is incorporated within this existing framework. This integration allows the pre-filling function to be achieved without adding significant structural complexity, as the new components are combined with rather than added to the existing braking system architecture.
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 ensures effective clearance uptake and increased braking pressure, maintaining optimal brake performance even at high pedal actuation speeds by preventing excessive fluid discharge and ensuring consistent pressure delivery to the brake circuit.
Implementation Method 1
a nozzle (35) configured to put the discharge chamber into communication with a discharge compartment of the braking device, said nozzle having a small cross section
Implementation Method 2
a master cylinder (70), in which a hydraulic piston (72) defines a pressure chamber (71) for containing a pressurized fluid, in which chamber a control pressure, transmitted to one or more brakes of the vehicle
Implementation Method 3
a plunger (41) defining a first and a second chamber (42, 43) of the servo device associated with communication means for establishing, in a rest condition of the braking device, hydraulic communication between the first chamber and the second chamber
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Hydraulic braking device (10) for a vehicle, comprising, in a housing (12), a master cylinder (70), a servo device and a pre-filling device. A hydraulic piston (72) of the master cylinder (70) defines a pressure chamber (71) for containing a pressurized fluid, in which chamber a control pressure, transmitted to one or more brakes of the vehicle, is generated, said pressure chamber (71) being in hydraulic communication with a discharge chamber (47) of the braking device (10) in a rest condition of the braking device (10). A plunger (41) of the servo device defines a first chamber (42) and a second chamber (43) of the servo device associated with communication means (44, 45, 46) for establishing, in a rest condition of the braking device (10), hydraulic communication between the first chamber (42) and the second chamber (43), and for intermittently interrupting said communication when the braking device (10) is actuated. A plunger piston (40) of the servo device, fixed to the plunger (41) of the servo device, is configured to advance towards the master cylinder (70) as a result of the actuation of the servo device. A shuttle piston (25) is connected to a push rod (21) that can be associated with a brake pedal, and is configured to advance towards the master cylinder (70) as a result of the actuation of the brake pedal. An inlet valve (50, 57, 59, 60, 27) of the pre-filling device is configured to allow the entry of fluid from the second chamber (43) of the servo device towards a pre-filling conduit (56) of the pre-filling device. An outlet valve (26, 58, 60, 63, 67) of the pre-filling device is configured to remain closed in a rest condition and to be opened as a result of the advance of the shuttle piston (25), putting the pre-filling conduit (56) into communication with the pressure chamber (71) of the master cylinder (70). Primary sealing means (75) are configured to interact with said plunger piston (40) of the servo device as a result of the advance of said plunger piston towards the master cylinder (70), so as to interrupt said hydraulic communication between the pressure chamber (71) and the discharge chamber (47). A nozzle (35) is configured to put the discharge chamber (47) into communication with a discharge compartment (32) of the braking device (10).