Pilot-Pressure-Controlled Flow Valve for Automotive Fluid Systems
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Solution Overview
Problem
Hydraulically actuated flow valves controlled by pilot pressure, used in automotive fluid systems, face issues with incomplete closure and potential leakage during dynamic conditions where the pressure differential falls below the minimum required, leading to system function impairment.
Innovation Solution
A fluid system incorporating a flow valve and a solenoid-actuated pilot valve, where the pilot valve has two settings to manage pilot pressure, ensuring the flow valve can securely close by utilizing a diaphragm and valve spring, and a check valve to prevent coolant backflow, maintaining system integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If an indirectly controlled flow valve is used to reduce power consumption and valve size, then energy benefits and smaller solenoid size are achieved, but the valve may not close completely or may leak fluid when the pressure differential falls below the minimum required value
Solution Approach 1:
A pilot valve is introduced as an intermediary component to control the main flow valve. The pilot valve receives a controlled pilot pressure that acts on the main valve's movable member, enabling reliable closure even when the main inlet pressure differential is insufficient. This intermediary pressure control mechanism ensures the valve closes completely without requiring high power consumption.
Solution Approach 2:
The system changes the pressure parameter by introducing a separate pilot pressure line with its own pressure source. This pilot pressure is regulated independently from the main fluid pressure, allowing the valve to maintain reliable closure capability across varying operating conditions. The movable member responds to the pilot pressure rather than directly to the main pressure differential, solving the closure reliability issue.
2Reliability
If a spring acts on the movable valve member to assist closing, then the valve can close more reliably, but the device complexity increases
Solution Approach 1:
Instead of using a mechanical spring, the invention employs hydraulic pressure (pilot pressure) acting on the movable valve member to achieve closure. This pneumatic/hydraulic approach replaces the spring mechanism, maintaining closure reliability while avoiding the added complexity of spring components, mounting structures, and associated mechanical elements.
Solution Approach 2:
The mechanical spring system is replaced with a pressure-based control system. The pilot pressure, delivered through fluid lines and acting on the movable member, substitutes for the mechanical spring force. This substitution eliminates the need for spring components and reduces structural complexity while maintaining the closing function.
3Use of energy by moving object
If the solenoid is made smaller to reduce power consumption, then energy benefits are achieved, but the solenoid may not provide sufficient force to actuate the pilot valve under all conditions
Solution Approach 1:
The system uses dynamic pressure control where the pilot valve modulates the pilot pressure in response to system conditions. The smaller solenoid actuates the pilot valve, which then controls a larger pilot pressure that acts on the main movable member. This dynamic pressure amplification allows a small solenoid to control a much larger force through the fluid pressure medium.
Solution Approach 2:
The pilot valve and pilot pressure serve as an intermediary mechanism between the small solenoid and the main flow valve. The solenoid only needs to actuate the pilot valve, which then uses the pilot pressure to actuate the main valve. This intermediary arrangement allows the small solenoid to control a much larger force through the pressure amplification effect.
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
The solution ensures secure closure of the flow valve even under dynamic conditions, preventing fluid leakage and maintaining system function by effectively managing pilot pressure and utilizing the highest system pressure to ensure the flow valve remains closed.
Implementation Method 1
The pilot valve is configured to be actuated by a solenoid for providing the pilot pressure to the control chamber
Implementation Method 2
the pilot pressure acts on the flow valve in a closing direction of the flow valve
Implementation Method 3
a spring acting on the movable valve member of the flow valve
Data Source
AI summary
In a thermal fluid system, a control valve includes a flow valve and a solenoid pilot valve. The flow valve has an inlet and an outlet; a control chamber for receiving a pilot pressure; and a valve member operable by the pilot pressure to selectively open and close a fluid path from the inlet to the outlet. The pilot pressure acts in a closing direction of the flow valve. The pilot valve provides the pilot pressure to the control chamber and is a 3/2 way valve with a first port in fluid communication with the control chamber, a second port to be connected to a pressure source, and a third port. The pilot valve has a first position connecting the first port with the second port and a second position connecting the first port with the third port.