Integrated Pedal Simulator in Master Cylinder
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Solution Overview
Problem
The existing electronic brake systems with separate pedal simulators increase in volume and complexity, making them difficult to install in vehicles due to the need for longer master cylinders and complicated flow passage connections.
Innovation Solution
A master cylinder design that integrates a pedal simulator within the cylinder, using a simulation chamber and valve to provide reaction force while minimizing length and simplifying flow passage connections, allowing for reduced valve count and improved installation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the pedal simulator is installed separately from the master cylinder, then the electronic brake system can provide proper pedal feel, but the system volume increases and installation becomes difficult
Solution Approach 1:
The pedal simulator is integrated into the master cylinder by positioning it within the cylinder body, specifically utilizing the space formed by the piston's movement. The simulator's reaction force piston is arranged to move within the same cylindrical space as the main piston, merging two functional components into a single compact unit that provides both braking pressure generation and pedal feel feedback without increasing overall system volume
2Volume of stationary object
If the pedal simulator is mounted to the master cylinder, then the system volume is reduced, but the master cylinder length increases making installation difficult
Solution Approach 1:
Instead of extending the master cylinder in the longitudinal direction (increasing length), the pedal simulator is arranged to operate within the radial space created by piston movement. The reaction force piston moves within the same cylindrical bore as the main piston, utilizing the radial dimension and the space between the piston and cylinder wall rather than extending the overall length of the component
3Length of moving object
If the pedal simulator is integrated into the master cylinder, then the master cylinder length is reduced, but the connection structure of flow passages becomes more complex
Solution Approach 1:
The first master chamber serves dual functions: it generates braking pressure through the main piston and simultaneously provides hydraulic pressure to the pedal simulator's reaction force piston. This multi-functional design eliminates the need for separate flow passages dedicated solely to the simulator, as the same hydraulic chamber (first master chamber) serves both the primary braking function and the pedal feel feedback function
4Productivity
If the pedal simulator is integrated into the master cylinder, then productivity is improved by reducing valve count, but the simulation chamber requires careful design to maintain proper flow control
Solution Approach 1:
The simulation valve utilizes the existing hydraulic pressure differential between the first and second master chambers to automatically control flow to the pedal simulator. When the main piston moves forward to generate braking pressure, the pressure differential automatically opens the simulation valve to supply pressure to the reaction force piston. The system self-regulates flow control through its inherent hydraulic pressure relationships without requiring complex external control mechanisms
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 integration reduces the overall length of the master cylinder, simplifies the connection structure of flow passages, and decreases the number of valves, enhancing productivity and ease of installation while maintaining proper pedal feel and braking performance.
Implementation Method 1
the reaction force spring and the damping member which are pressurized in response to movement of the reaction force piston, thereby providing reaction force
Data Source
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AI summary
A master cylinder and an electronic brake system including such a master cylinder are disclosed. The master cylinder (100) includes a cylinder body (120) connected to a reservoir (130) and provided with a bore (121a,121b) one end of which is opened in a longitudinal direction, a piston (154) configured to be movable forward and backward within the bore (121a), and at least one master chamber (123a) configured to discharge a pressure medium in response to a displacement of the piston (154). The master cylinder (100) includes a pedal simulator (150) provided in the bore (121b). The pedal simulator (150) is spaced apart from the master chamber (123a) by a predetermined distance and is directly pressurized by a brake pedal (110,112,151) thus providing a reaction force. The simulation chamber (150a) formed in the bore (121b) is separated from the master chamber (123a) by the piston (154). A simulation passage (156) connects the master chamber (123a) to the simulation chamber (150a). A simulation valve (157) is provided in the simulation passage (156) and controls a flow of a pressure medium from the master chamber (123a) to the simulation chamber (150a) in response to an opening/closing operation thereof.