Trailer Valve Pressure Release for Parking Brake Fail-Safe
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing braking systems for towing vehicles face challenges in efficiently engaging and disengaging the parking lock, particularly when the control valve or redundancy valve is jammed, leading to unintended pressure retention and failure to activate the parking brake.
Innovation Solution
The system incorporates a direct connection between the pressure medium source and the trailer control valve to rapidly reduce pressure, using the trailer control valve to release pressure into an unpressurized environment, and cyclically activating/deactivating the trailer brake to empty the pressure medium source, ensuring the parking brake can be activated even with a jammed valve.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the control valve or redundancy valve is jammed in the open state, then pressure medium continues to be supplied to the brake cylinder, but the parking lock cannot be engaged due to pressure retention
Solution Approach 1:
The patent introduces a trailer control valve as an intermediary component that provides an alternative pathway to control pressure medium flow. This valve acts as a mediator between the pressure medium source and the brake system, allowing manual intervention to release pressure when the primary control valves fail, thereby enabling parking lock engagement without adding complex electronic control systems.
Solution Approach 2:
The system enables self-service through the trailer control valve that can be manually operated by the driver to drain pressure from the brake cylinder in case of valve jamming. This self-service mechanism allows the driver to independently resolve the parking brake failure without requiring external assistance or complex diagnostic systems, maintaining simplicity while improving reliability.
2Reliability
If the control valve is mechanically defective and remains in the open state, then pressure medium source cannot be emptied, but the parking brake should be activatable
Solution Approach 1:
The trailer control valve serves as an intermediary that provides an alternative control pathway independent of the defective control valve. By routing pressure medium through this intermediary valve to the atmosphere, the system bypasses the mechanical defect and enables pressure reduction, making the parking brake activatable despite the control valve failure.
Solution Approach 2:
The braking system is segmented into independent control pathways: the primary control valve path and the alternative trailer control valve path. This segmentation allows the alternative path to be activated when the primary path fails due to mechanical defects, enabling pressure reduction and parking brake activation without requiring the defective control valve to function.
3Speed
If a direct connection between pressure medium source and trailer control valve is provided, then pressure can be rapidly reduced, but additional components in the interior of the towing vehicle are added
Solution Approach 1:
The trailer control valve is designed with multi-functionality, serving both its original purpose for trailer brake control and an additional function as a pressure release valve for the parking brake system. This universal application allows rapid pressure reduction without requiring a dedicated separate component, thereby minimizing the increase in system complexity while achieving fast pressure reduction capability.
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 allows for reliable engagement of the parking brake by reducing pressure in the brake cylinders, preventing unintended pressure retention and ensuring the parking brake can be activated even if the control or redundancy valve is mechanically defective.
Implementation Method 1
a drive motor of the towing vehicle can fill the pressure medium source, e.g., by driving a compressor that draws in air, compresses it, and supplies it to the pressure medium source
Implementation Method 2
the electronic control unit is configured to control the trailer control valve system in such a way that pressure medium escapes via the trailer control valve system into a depressurized environment
Implementation Method 3
the hydraulic relief valve comprises a biasing element and is characterized in that the hydraulic relief valve is part of a non-electrical fail-safe device of the vehicle, in which the one-way valve configuration is effective when a driving mode of the vehicle is selected and the biasing element biases the hydraulic relief valve into the one-way valve configuration
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to a braking system (1) for a towing vehicle (2). The braking system (1) comprises a pressure medium source (9) for storing pressurized pressure medium, a parking brake module (5) with a control valve (6) and a redundancy valve (7), a trailer control valve system (16) for a trailer brake (3) of a trailer vehicle (4) towed by the towing vehicle (2), and an electronic control unit (25). The electronic control unit (25) is configured, in particular, to control the trailer control valve system (16) such that pressure medium escapes via the trailer control valve system (16) into a pressureless environment (U), thereby emptying the pressure medium source (9) if the control valve (6) or the redundancy valve (7) remains in an open state due to a mechanical defect, although it should be in a closed state, and if the ignition of the towing vehicle (2) and thus also a compressor (9) fails.1) are switched off for filling the pressure medium source (9).