Electromechanical Brake Booster Dual Spring Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In electromechanical brake boosters, when the electromechanical actuator fails, the vehicle driver must exert muscle power to tension all return springs, reducing the actuating force available for the master brake cylinder due to the cumulative spring force, leading to delayed brake release and potential vehicle roll-out.
Innovation Solution
The brake booster employs two return springs, where one with a smaller spring force resets the muscle force transmission element, allowing the driver to actuate the master brake cylinder with more muscle power when the electromechanical actuator fails by only needing to overcome the weaker spring, thereby increasing the available actuating force.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple return springs are used to reset the brake booster, then the brake booster can be reset effectively, but the driver must exert more muscle power to actuate the brake when the electromechanical actuator fails
Solution Approach 1:
The return spring system is segmented into two distinct groups: one return spring acts on the muscle force transmission element (pedal rod), while the other return spring(s) act on the booster body or actuator assembly. This segmentation allows the driver to only overcome the force of the first return spring when actuating the brake manually, while the other return springs reset the actuator without opposing the driver's input force.
Solution Approach 2:
The pedal rod serves as an intermediary element that connects the driver's input to the master brake cylinder. By positioning one return spring to act on the pedal rod rather than directly on the actuator assembly, the system creates a mechanical pathway where the driver's force is applied against only one return spring, while the other return springs reset the actuator through a different mechanical pathway.
2Speed
If a strong return spring is used to ensure quick brake release, then the brake releases quickly, but the driver experiences delayed perception of brake release due to the strong spring force
Solution Approach 1:
The return spring force is segmented into two separate mechanical pathways: one pathway (through the pedal rod) provides gentle feedback to the driver, while the other pathway (through the booster body) enables rapid actuator reset. This segmentation allows the brake to release quickly through the actuator pathway without creating strong opposing forces that would delay the driver's perception of release through the pedal pathway.
3Force
If the return spring force is reduced to ease driver actuation, then the driver can actuate the brake more easily, but the brake release time increases
Solution Approach 1:
The return spring system is divided into two functional groups with different force characteristics: one return spring with lower force acts on the pedal rod to ease driver actuation, while other return springs with higher force act on the booster body to ensure rapid brake release. This segmentation allows both contradictory requirements to be satisfied through different mechanical pathways.
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 ensures quicker brake release and reduced driver effort when the electromechanical actuator fails, maintaining vehicle control and safety by maximizing muscle power for brake actuation.
Implementation Method 1
The restoring spring can generally be understood as an elastically deformable element that is tensioned when the brake booster is actuated and, as stated, returns the brake booster to its initial position after actuation
Implementation Method 2
The other restoring spring or the other restoring springs also reset the brake booster, but do not act on the muscle force transmission element
Data Source
Figure 1
AI summary
The invention relates to an electromechanical brake force booster (1) for a hydraulic vehicle brake system. The invention proposes that the brake force booster (1) be formed with two restoring springs (11, 12), one of which acts on an electromechanical actuator (16) and the other of which restoring springs (12) acts on a pedal rod (4). In the event of failure of the electromechanical actuator (16), only the other spring (12), which preferably has a relatively low spring force, must be compressed using muscle force. The force loss in the event of actuation exclusively by muscle force is reduced.