Brake Valve Assembly for Dynamic Rear Pressure Proportioning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vehicle braking systems face challenges in achieving precise control under adverse conditions, particularly in maintaining optimal slip levels between front and rear axles, and ensuring stability during dynamic maneuvers like cornering, while also being cost-effective and having backup features for component failures.
Innovation Solution
A brake system with a single chamber master cylinder, a plunger assembly, and a valve assembly that includes a bypass valve and check valve, allowing for selective fluid flow and pressure control between the master cylinder, plunger assembly, and wheel brakes, enabling dynamic pressure proportioning and stability control, with a manual push-through mode for backup functionality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a tandem master cylinder with two separate brake circuits is used, then braking reliability is improved through circuit separation, but device complexity increases
Solution Approach 1:
The brake system is divided into two independent brake circuits (first and second circuits) with separate master cylinders, fluid reservoirs, and wheel brakes. This segmentation allows one circuit to function independently if the other fails, improving reliability while maintaining manageable complexity through modular design
Solution Approach 2:
The system incorporates a bypass valve that automatically activates when pressure differential exceeds a threshold, providing a backup fluid path from the first circuit to the second circuit. This pre-configured safety mechanism ensures continued braking capability in case of circuit failure without requiring complex active control systems
2Measurement precision
If ABS valves with three pressure control modes are used, then braking precision is improved, but device complexity increases
Solution Approach 1:
The ABS valve is divided into separate apply valves and dump valves for each wheel brake circuit. This segmentation allows independent control of pressure application and release for each wheel, enabling precise braking control while simplifying the valve design compared to a single multi-functional valve
Solution Approach 2:
The ABS system incorporates wheel speed sensors that automatically detect wheel rotation behavior and trigger appropriate braking control actions. The system self-regulates by monitoring its own state and activating the appropriate valve modes without requiring complex external control logic
3Productivity
If Dynamic Rear Proportioning systems are used, then braking performance is improved, but device complexity increases
Solution Approach 1:
The system applies different braking pressures to front and rear wheels based on their specific requirements. The bypass valve is strategically positioned to control fluid flow between circuits, allowing optimized pressure distribution to rear wheels during braking while maintaining simple overall system architecture
Solution Approach 2:
The bypass valve acts as an intermediary mechanism that automatically balances pressure between the first and second brake circuits. By using this passive pressure-balancing device, the system achieves dynamic rear proportioning without requiring complex active control valves or sensors
4Reliability
If a bypass valve with pressure threshold control is used, then reliability is improved through automatic failover, but device complexity increases
Solution Approach 1:
The bypass valve is designed with a built-in pressure differential threshold mechanism that automatically activates when needed. The valve responds to pressure conditions without requiring external control signals, sensors, or complex logic, providing reliable failover protection while maintaining simple passive operation
Solution Approach 2:
The bypass valve utilizes hydraulic pressure differential to control its opening and closing. When pressure in the first circuit exceeds pressure in the second circuit by the threshold amount, the pressure differential automatically opens the bypass valve to equalize pressures, providing failover protection through pure hydraulic action without mechanical complexity
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 achieves optimal braking performance and stability by dynamically controlling brake pressures between the front and rear axles, providing a cost-effective solution with backup features to ensure continued operation in case of component failures.
Implementation Method 1
a bypass valve which only permits fluid flow from the first conduit to the second conduit when the fluid pressure within the first conduit is above a predetermined pressure level above atmospheric pressure
Implementation Method 2
a check valve in a parallel path arrangement relative to the bypass valve such that the check valve permits fluid flow from the second conduit to the first conduit, and prevents fluid flow from the first conduit to the second conduit
Implementation Method 3
When the brake pedal is depressed, the master cylinder generates hydraulic forces in both brake circuits by pressurizing brake fluid
Implementation Method 4
A typical hydraulic booster generates pressurized fluid for assisting in pressurizing the wheel brakes, thereby increasing the pressures generated by the master cylinder
Data Source
AI summary
A brake system with a wheel brake has a fluid reservoir and a valve assembly in fluid communication with the reservoir via a first conduit. The valve assembly is in fluid communication with the wheel brake via a second conduit. The valve assembly includes a bypass valve which only permits fluid flow from the first conduit to the second conduit when the fluid pressure within the first conduit is above a predetermined pressure level above atmospheric pressure. The valve assembly further includes a check valve in a parallel path arrangement relative to the bypass valve such that the check valve permits fluid flow from the second conduit to the first conduit, and prevents fluid flow from the first conduit to the second conduit. The brake system further includes a first source of pressurized fluid providing fluid pressure for actuating the wheel brake, wherein the first source of pressurized fluid is selectively in fluid communication with the second conduit.