Bistable Parking Brake Valve Initial Pulse Control
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Solution Overview
Problem
Current parking brake devices face challenges in quickly regulating pressure with minimal structural complexity, leading to inefficiencies in reaching set pressure values and increased wear, air consumption, and noise due to constant solenoid valve switching.
Innovation Solution
The introduction of an initial pulse for pressurizing or venting when a desired pressure value changes, with the duration of this pulse determined from a stored multidimensional map, allowing for faster pressure regulation and reduced structural complexity by using a bistable parking brake valve with electrically actuated 2/2-way or 3/2-way solenoid valves.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If cyclic pressurizing and venting is used to control pressure, then the system can maintain pressure without measurement, but the pressure does not reach the set point as quickly and requires continuous solenoid valve switching
Solution Approach 1:
The patent applies preliminary action by using an initial pulse signal before the regular cyclic control. This initial pulse quickly pressurizes or vents the brake cylinder to reach the target pressure range, after which the cyclic control takes over to maintain the pressure. This resolves the contradiction by providing fast initial response while maintaining reliable pressure control through the subsequent cyclic operation.
Solution Approach 2:
The patent uses periodic cyclic pressurizing and venting actions to maintain pressure after the initial pulse. The control unit alternates between pressurizing and venting the brake cylinder in cycles, which maintains the desired pressure without requiring continuous full-power actuation. This periodic action provides reliable pressure maintenance while reducing energy consumption and wear compared to continuous switching.
2Reliability
If cyclic pressurizing and venting is used to control pressure, then pressure can be maintained without measurement, but continuous solenoid valve switching increases wear, air consumption, and noise
Solution Approach 1:
The initial pulse quickly establishes the target pressure, reducing the time during which cyclic pressurizing and venting must occur. This minimizes the duration of air consumption, solenoid valve switching, and associated noise while still achieving reliable pressure control through the subsequent maintenance phase.
Solution Approach 2:
The cyclic pressurizing and venting operation maintains pressure with minimal air consumption by only making small adjustments periodically rather than continuous large adjustments. The control unit intelligently manages the cycle duration and intensity to maintain pressure while minimizing air usage, solving the contradiction between reliable pressure control and air consumption.
3Device complexity
If a bistable parking brake valve with electrically actuated solenoid valves is used, then structural complexity is reduced, but pressure regulation speed may be limited
Solution Approach 1:
The control unit applies a preliminary high-intensity pulse signal to the solenoid valve to quickly move the parking brake valve to the desired state, achieving fast pressure regulation despite the simpler mechanical structure. After the initial pulse, the valve transitions to stable positions where it can maintain pressure without continuous actuation, combining speed with structural simplicity.
Solution Approach 2:
The system uses dynamic control signals with varying intensity and duration to optimize pressure regulation speed. The control unit adjusts the pulse width and amplitude of solenoid activation based on the current pressure state and target pressure, enabling the simpler bistable valve to respond as quickly as more complex valves through intelligent dynamic actuation.
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 approach enables the target pressure to be reached more quickly and efficiently, reducing wear, air consumption, and noise, while maintaining bistability even in power failures, and allowing for precise control of pressure between zero and reservoir pressure.
Implementation Method 1
first solenoid valve device (25) which can connect the first control pressure line (20) with supply pressure or with the atmosphere
Implementation Method 2
spring-loaded brake cylinders (51) which, in the released position, apply compressed air to a spring compression chamber and thus keep the spring tensioned
Implementation Method 3
An output of the parking brake valve controls a relay valve. The relay valve controls a spring brake
Data Source
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AI summary
The invention relates to a parking brake device having a bistable parking brake valve (1), at least one electrical solenoid valve device (25) controlled by an electronic control unit (52), a relay valve (31) and a spring applied brake (51) controlled by the relay valve (31), wherein the parking brake device holds stored in the electronic control unit (52) a multidimensional characteristic map, which controls the electric solenoid valve device (25) by means of an initial pulse (Pi) of predetermined duration (ti) upon change in a requested pressure setpoint (Psoll) for the spring applied brake (51). This duration (ti) is taken from the stored characteristic map. The characteristic map contains values for the duration (ti) according to the controlled desired pressure (Psoll) > a supply pressure (Pvorr) and an estimated actual pressure (Pist) or a difference pressure (delta P) which is the difference of an estimated pressure (Pist) and the desired pressure (Psoll). Thus a controlled pressure for the parking brake device is quickly achieved without a closed loop circuit.