Self-Stabilizing Brake Actuation Valve for Agricultural Vehicles
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Solution Overview
Problem
Existing hydraulically actuated parking and emergency braking systems for agricultural and construction vehicles lack sufficient stability in their brake actuation valves, leading to potential accidental activation due to external forces like vibrations, which can result in unsafe driving conditions and accidents.
Innovation Solution
A brake actuation valve designed as a directional control valve with an actuating device that inherently stabilizes the control slide in its switching position, preventing external forces from changing the valve's state, utilizing self-locking mechanisms such as high-ratio gearing, stepper motors, friction devices, rack and pinion drives, or roller screw drives to maintain the set position without additional locking means.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional brake actuation valve is used, then the system is simpler, but the valve is vulnerable to external forces like vibrations causing accidental switching
Solution Approach 1:
The actuating device incorporates self-locking mechanisms (high-ratio gearing, friction devices, rack and pinion drives, or roller screw drives) that automatically maintain the control slide in its switching position without requiring additional external locking means. The system serves itself by using the actuating device's inherent mechanical properties to prevent unintended switching.
Solution Approach 2:
The actuating device acts as an intermediary between the electronic control unit and the brake actuation valve. It translates electrical signals into mechanical motion while incorporating self-locking mechanisms that mediate the connection, preventing direct transmission of vibrations from the vehicle environment to the valve's control slide.
2Reliability
If additional locking means are added to the brake actuation valve, then the valve stability improves, but the device complexity increases
Solution Approach 1:
The locking function is merged with the actuating device itself rather than being a separate component. The high-ratio gearing, friction devices, rack and pinion drives, or roller screw drives that are already necessary for precise valve actuation also provide the self-locking capability, combining two functions into one integrated system.
Solution Approach 2:
The actuating device serves multiple functions: it provides precise positioning of the control slide, translates electrical to mechanical motion, and simultaneously locks the valve in its switching position. This multi-functionality eliminates the need for separate locking mechanisms.
3Reliability
If self-locking mechanisms are implemented in the actuating device, then accidental switching is prevented, but the manufacturing complexity increases
Solution Approach 1:
The patent employs well-established mechanical self-locking principles (high-ratio gearing, friction devices, rack and pinion, roller screw drives) that are proven technologies with成熟 manufacturing processes. These mechanical solutions replace more complex electronic or hydraulic locking systems, maintaining ease of manufacture while achieving the desired safety.
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
Ensures high functional reliability by preventing unintended switching of the brake actuation valve, enhancing safety by maintaining the set position even under external influences like vibrations, thus ensuring safe parking and braking operations.
Implementation Method 1
high-ratio gearing
Implementation Method 2
self-locking mechanisms
Implementation Method 3
stepper motors
Implementation Method 4
rack and pinion drives
Implementation Method 5
roller screw drives
Implementation Method 6
self-locking mechanisms
Data Source
Figure 1
Figure 2~4
AI summary
A control device is provided for a hydraulically actuated parking and/or emergency braking device (1), preferably of an agricultural or construction tractor or system vehicle, which is equipped with a spring-applied brake cylinder (2) as the brake application device. The control device serves to control the pressure in a pressure chamber (4) of the spring-applied brake cylinder (2), being arranged between the cylinder and a pressure source (9) and comprising a brake actuating valve (16) designed as a directional control valve, which can be electronically actuated into two different switching positions. The brake actuating valve (16) is actuated via an electronic control unit (20).To design the brake actuating valve (16) such that its control slide is held in the last switched position without detent means which are to be provided in addition to its actuating device, an actuating device (18) of the brake actuating valve (16) shall be designed such that it holds the brake actuating valve (16) in at least one of its switching positions in a self-stabilizing manner, so that its control slide remains in a last set switching position without any further energization of the actuating device (18).