Vehicle Brake Device Master Cylinder Orifice Dynamics
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vehicle brake devices face challenges in achieving high regenerative efficiency and fuel efficiency when the brake pedal is stepped on quickly, as they prioritize regenerative brake force over hydraulic brake force, leading to delayed application of base hydraulic brake force.
Innovation Solution
The vehicle brake device incorporates an orifice in the master cylinder's port to restrict brake fluid flow during quick pedal stepping, increasing back pressure and allowing early generation of base hydraulic brake force, while maintaining high regenerative efficiency during non-quick stepping by restricting base hydraulic brake force generation until the piston moves beyond a predetermined position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the base hydraulic brake force is restricted while the piston moves from the first position to the second position to maximize regenerative brake force, then regenerative efficiency and fuel efficiency are improved, but the response time for hydraulic brake force application deteriorates during quick braking
Solution Approach 1:
The patent makes the brake fluid flow restriction dynamic by providing an orifice at the port that adaptively restricts flow based on piston movement speed. During quick braking, the orifice restricts flow to enable early hydraulic brake force generation, while during normal braking, the restricted flow maintains regenerative brake force priority. This dynamic flow control resolves the contradiction between rapid response and energy efficiency.
Solution Approach 2:
The patent changes the flow resistance parameter at the port by introducing an orifice with specific dimensions. This parameter change creates back pressure that affects piston movement and brake fluid flow differently based on the speed of pedal depression, enabling the system to distinguish between quick and normal braking and adjust the balance between regenerative and hydraulic brake forces accordingly.
2Use of energy by moving object
If the port is positioned at a second position spaced from the first position to enable regenerative brake force generation, then fuel efficiency is improved, but the base hydraulic brake force generation is delayed
Solution Approach 1:
The orifice acts as an intermediary element at the port that mediates between the need for delayed hydraulic brake force generation (to maximize regenerative braking) and the need for rapid response (for safety). By creating controlled back pressure, the orifice enables the piston to overcome the pressure differential earlier during quick braking, thus bridging the gap between these conflicting requirements.
3Speed
If the orifice restricts brake fluid flow during quick pedal stepping, then base hydraulic brake force is applied earlier, but back pressure increases
Solution Approach 1:
The patent converts the harmful effect of increased back pressure (which would normally oppose piston movement and delay brake force generation) into a beneficial effect. By strategically positioning the orifice and sizing it appropriately, the back pressure created during quick braking actually helps build the pressure differential needed for the piston to move rapidly, thus accelerating brake force application while maintaining energy efficiency.
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 solution enables the coexistence of high regenerative efficiency and fuel efficiency by early application of base hydraulic brake force during quick braking, while maintaining high regenerative efficiency during non-quick braking, thus optimizing brake force application across different pedal manipulation states.
Implementation Method 1
the port is provided with an orifice that is configured to restrict the flow of brake fluid from the master cylinder to the reservoir tank at the time of a quick stepping of the brake pedal but not to restrict the flow at the time of a non-quick stepping
Implementation Method 2
a hydraulic brake device that generates a base hydraulic pressure by a master cylinder in dependence on the stepping-on of a brake pedal and that applies the generated base hydraulic pressure directly to wheel cylinders
Data Source
AI summary
In a vehicle brake device, a port is provided at a hydraulic chamber of a master cylinder and communicates with a reservoir tank. A piston movable in the hydraulic chamber for closing the port is provided with at least one piston-side port that faces on the port when at a first position. When a brake pedal is stepped on from a retracted state to move the piston from the first position to a second position spaced from the first position by a predetermined distance, the hydraulic chamber is blocked from the communication with the reservoir tank. The at least one piston-side port is provided therein with an orifice, so that the hydraulic pressure in the hydraulic chamber is raised at the time of a quick stepping of the brake pedal but is allowed to flow to the reservoir tank without being raised at the time of a non-quick stepping.