Brake System Drag Reduction via Negative Pressure Piston Control
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Solution Overview
Problem
Conventional brake systems experience drag phenomena due to incomplete separation of brake pads from the disc, leading to reduced service life and degraded output, as they rely on frictional forces and resilience to separate the pads, resulting in unnecessary friction and brake feel degradation.
Innovation Solution
A brake system that controls the position of a pressurizing piston in a pressurizing cylinder connected to a reserve tank using a motor to create negative pressure, forcing the piston in the caliper to withdraw and maintain negative pressure, thereby ensuring complete separation of brake pads from the disc, reducing drag.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the brake pads are separated from the disc using the knock-back phenomenon and resilience of a piston seal, then the braking operation can be terminated, but a drag phenomenon occurs due to incomplete separation of the brake pads from the disc
Solution Approach 1:
The patent applies negative pressure (suction force) to pull the brake pads away from the disc, which is the opposite approach of conventional systems that rely on elastic recovery to push pads away. This inversion of the separation mechanism ensures complete pad-disc separation by actively pulling rather than passively relying on resilience, thereby eliminating the drag phenomenon caused by incomplete separation.
Solution Approach 2:
The patent utilizes hydraulic pressure differential by creating negative pressure in the wheel cylinder through a suction pump. This pneumatic-hydraulic mechanism generates a suction force that actively withdraws the piston and separates the brake pads from the disc, replacing the conventional elastic recovery mechanism and ensuring complete separation to prevent drag.
2Force
If the hydraulic pressure from the driver's foot force accumulates in the system, then braking force is generated, but the lost travel section of the stroke increases when the accumulator pressure exceeds the driver's foot force
Solution Approach 1:
The patent incorporates a control unit that monitors the position of the pressurizing piston and the pressure in the hydraulic system. When the accumulator pressure exceeds the driver's foot force, the control unit activates the suction pump to create negative pressure, which pulls the pressurizing piston back to its initial position. This feedback control prevents excessive accumulation of hydraulic pressure and maintains the piston within the optimal stroke range, reducing the lost travel section.
Solution Approach 2:
The patent dynamically changes the hydraulic pressure parameters by introducing negative pressure control. The suction pump adjusts the pressure in the wheel cylinder to maintain the pressurizing piston position within a predetermined range, preventing the piston from moving beyond the optimal stroke range and thereby reducing the lost travel section while maintaining effective braking force.
3Speed
If the accumulator pressure is significantly high and fully delivered when the driver depresses the brake pedal, then braking response is improved, but brake feel degradation occurs
Solution Approach 1:
The control unit continuously monitors the pressurizing piston position and hydraulic pressure, providing feedback control. When high accumulator pressure is detected, the system activates the suction pump to create negative pressure and pull the piston back, preventing excessive pressure delivery. This feedback mechanism maintains optimal pressure levels that ensure rapid brake response while preserving natural brake feel by avoiding over-pressurization.
Solution Approach 2:
The system uses the existing hydraulic pressure differential between the accumulator and the wheel cylinder to drive the suction pump operation. When the accumulator pressure exceeds a predetermined threshold, the pressure differential automatically triggers the suction pump to activate, creating negative pressure to regulate the system pressure. This self-regulating mechanism maintains optimal brake response and feel without requiring external intervention.
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 effectively attenuates drag by maintaining negative pressure, ensuring complete separation of brake pads from the disc, thereby reducing unnecessary friction, extending brake pad life, and enhancing brake responsiveness and feel.
Implementation Method 1
driving the motor (307) to move the pressurizing piston (303) forward to create a negative pressure, and, when creation of the negative pressure is completed, maintaining the negative pressure
Implementation Method 2
supplying a fluid in a hydraulic line to the reserve tank such that negative pressure is created to force the piston in a caliper to be withdrawn
Data Source
AI summary
A brake system may have a drag reduction function of effectively attenuating drag by controlling the position of a pressurizing piston in a pressurizing cylinder through a motor to supply a fluid in a hydraulic line to the reserve tank such that negative pressure is created to forcibly withdraw the piston in a caliper, and a method of controlling the same. The brake system may include a pressurizing cylinder connected to a reserve tank to store a fluid, a motor to move a pressurizing piston forward, and a braking control unit to receive state information about the vehicle to determine whether the vehicle is braking or traveling, execute, when the vehicle is traveling, a negative pressure creation mode of driving the motor to move the pressurizing piston forward to create a negative pressure, and execute, when creation of the negative pressure is completed, a negative pressure maintaining mode.