Switchover Valve for Commercial Vehicle Emergency Braking
Solution Overview
Problem
Current brake systems for commercial vehicles face challenges in ensuring safe emergency braking and reliable parking brake function, especially when there is a failure in one of the compressed air circuits, particularly due to complex and error-prone electrically controllable valve devices.
Innovation Solution
The implementation of a brake system with a switchover valve controlled by an electronic control unit to redirect compressed air from an intact circuit to the service brake cylinder for emergency braking, while maintaining the parking brake valve in a stable state to prevent interference with emergency braking, and incorporating a locking mechanism to secure switching states and prevent unintended venting or release.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the parking brake valve device is equipped with additional functionality to support emergency braking, then the emergency braking capability is improved, but the device complexity increases and reliability decreases
Solution Approach 1:
The system separates the parking brake valve device from the emergency braking function by introducing a dedicated switchover valve. The parking brake valve device maintains its original simple two-position design for reliable parking brake control, while the switchover valve handles the emergency braking function by switching compressed air supply between circuits. This segmentation prevents functional interference and maintains reliability of both systems.
Solution Approach 2:
The switchover valve acts as an intermediary component that mediates between the second compressed air circuit and the service brake cylinder. It enables emergency braking by redirecting compressed air from the intact second circuit to the service brake cylinder when the first circuit fails, without requiring modifications to the parking brake valve device.
2Adaptability or versatility
If the parking brake valve device is equipped with additional functionality to support emergency braking, then the emergency braking capability is improved, but the device complexity increases
Solution Approach 1:
The system separates the parking brake valve device from the emergency braking function by introducing a dedicated switchover valve. The parking brake valve device maintains its original simple two-position design for reliable parking brake control, while the switchover valve handles the emergency braking function by switching compressed air supply between circuits. This segmentation prevents functional interference and maintains reliability of both systems.
3Adaptability or versatility
If compressed air is redirected from the second compressed air circuit to the service brake cylinder for emergency braking, then the emergency braking function is enabled, but the parking brake function may be interfered with
Solution Approach 1:
The switchover valve acts as an intermediary component that mediates between the second compressed air circuit and the service brake cylinder. It enables emergency braking by redirecting compressed air from the intact second circuit to the service brake cylinder when the first circuit fails, without requiring modifications to the parking brake valve device.
Solution Approach 2:
The system separates the parking brake valve device from the emergency braking function by introducing a dedicated switchover valve. The parking brake valve device maintains its original simple two-position design for reliable parking brake control, while the switchover valve handles the emergency braking function by switching compressed air supply between circuits. This segmentation prevents functional interference and maintains reliability of both systems.
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 safe emergency braking and maintains the reliability of the parking brake function even in the event of a circuit failure, reducing the risk of valve errors and ensuring the vehicle can be brought to a safe stop without compromising the parking brake's effectiveness.
Implementation Method 1
incorporating a locking mechanism to secure switching states and prevent unintended venting or release
Implementation Method 2
at least one switchover valve which can be controlled by an electronic control unit and via which compressed air from the second compressed air circuit can be supplied to the at least one service brake cylinder
Implementation Method 3
the at least one parking brake valve device is designed such that the switching state of the parking brake valve device which pressurizes the at least one parking brake cylinder can be maintained during the emergency braking
Data Source
Figure 1
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AI summary
The brake assembly has a change over valve (28) which is controlled by an electronic control unit (10,12), over which an emergency brake compressed air is fed from compressed air cycle in case of loss of pressure, caused by a fault, in the pressurized air circuit (16) of an operating brake cylinder (26). A parking brake valve device (22) is arranged such that a parking brake cylinder filling position of the parking brake valve device is maintained during the emergency braking. An independent claim is also included for a method for steering a brake assembly for a commercial vehicle.