Electrical Spring Parking Brake with Pneumatic Backup
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Commercial vehicle electric parking brakes become inoperable when the power supply fails, as they rely on electrical systems for operation, posing a safety risk during emergency stops or power outages.
Innovation Solution
An electric parking brake device with a pneumatic backup system, allowing the parking brake to be engaged and released using compressed air, independent of the vehicle's electrical state, through a combination of electropneumatic and purely pneumatic control modes, utilizing a parking brake valve arrangement with a muscle-actuable control element and external relay valves.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an electric parking brake system is used, then the parking brake can be reliably controlled during normal operation, but it becomes inoperable when power supply fails
Solution Approach 1:
The parking brake control system is segmented into two independent subsystems: an electropneumatic control mode for normal operation and a manual pneumatic control mode for emergency situations. The valve assembly is divided into separate control paths, allowing the parking brake to function through either electrical or purely pneumatic control depending on system availability.
Solution Approach 2:
A manual control element (manual valve) is introduced as an intermediary between the compressed air source and the spring-applied brake cylinder. This manual valve serves as a backup control mechanism that can directly manipulate pneumatic pressure without requiring electrical power, enabling parking brake operation during power failures.
2Reliability
If a purely pneumatic control system is added as backup, then the parking brake can operate during power failure, but the device complexity increases
Solution Approach 1:
The parking brake valve assembly is designed with multi-functionality to handle both electropneumatic and manual pneumatic control modes. The same valve assembly structure can operate in either mode depending on system requirements, eliminating the need for completely separate backup systems and reducing overall complexity.
Solution Approach 2:
The manual pneumatic control elements are integrated into the existing electropneumatic valve assembly rather than being implemented as separate standalone systems. The manual valve is combined with the electropneumatic valve components, sharing common pneumatic pathways and control mechanisms, which reduces the overall device complexity despite adding backup functionality.
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
Enables safe parking and stopping of commercial vehicles even without power, ensuring the parking brake can be actuated manually, enhancing safety and reliability by providing a pneumatic backup solution that is structurally simple and cost-effective to implement.
Implementation Method 1
Spring-applied brake cylinders which, when vented, brake the vehicle
Implementation Method 2
In the released state of the parking brake device, the at least one spring-applied brake cylinder is pressurized with the compressed air source via the parking brake valve assembly
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to an electric spring-applied parking brake device for a vehicle, preferably for a commercial vehicle, comprising a parking brake valve assembly (32) and at least one spring-applied brake cylinder (18) which can be connected to a compressed air source (6) via a supply line (7) and the parking brake valve assembly (32; 33). In the released state of the parking brake device, the cylinder is pressurized by the compressed air source (6) via the parking brake valve assembly, and in the engaged state of the parking brake device, it can be connected to a pressure sink via the parking brake valve assembly. The parking brake valve assembly is designed to be electropneumatically controlled in a first operating mode for engaging the released or engaged state.The parking brake valve assembly further comprises a muscle-operated control element and is further designed to be purely pneumatically controlled for engaging the released or engaged state in a second operating mode using the muscle-operated control element (30).