Actuator Flow Control Circuit With Bypass Valve for Asymmetric Flow
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Solution Overview
Problem
Conventional flow control systems for actuators, such as hydraulic or pneumatic cylinders, face challenges with asymmetric flow capacities, leading to the use of large and heavy valves, low utilization of flow paths, and flow instabilities.
Innovation Solution
A flow control circuit with a fluid bypass path and a controllable bypass valve allows for higher flow rates through one port without requiring a flow control valve assembly rated for those high flow rates, enabling the use of more compact and lightweight valves and improving flow stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If proportional directional valves are rated for the largest flow rates to handle asymmetric flow requirements, then the flow capacity is sufficient, but the valves become large, heavy, and costly
Solution Approach 1:
The flow control system is segmented into two parallel paths: a main flow path through the proportional directional valve and a bypass path with a separate bypass valve. This allows the main valve to be sized for lower flow rates while the bypass valve handles the remaining flow, reducing the size and weight of the main control valve.
Solution Approach 2:
The bypass valve acts as an intermediary element that diverts excess flow around the main proportional directional valve. By introducing this intermediate flow path, the system can achieve high flow capacity without requiring the main valve to be oversized, thus reducing its weight and cost.
2Quantity of substance
If proportional directional valves are rated for the largest flow rates to handle asymmetric flow requirements, then the flow capacity is sufficient, but the cost increases significantly
Solution Approach 1:
The flow control system is segmented into two parallel paths: a main flow path through the proportional directional valve and a bypass path with a separate bypass valve. This allows the main valve to be sized for lower flow rates while the bypass valve handles the remaining flow, reducing the size and weight of the main control valve.
Solution Approach 2:
The bypass valve acts as an intermediary element that diverts excess flow around the main proportional directional valve. By introducing this intermediate flow path, the system can achieve high flow capacity without requiring the main valve to be oversized, thus reducing its weight and cost.
3Measurement precision
If the spool opening is kept small to achieve required small flow rates, then flow control precision is maintained, but flow instabilities occur due to large pressure drop
Solution Approach 1:
The flow control system is segmented into two parallel paths: a main flow path through the proportional directional valve and a bypass path with a separate bypass valve. This allows the main valve to be sized for lower flow rates while the bypass valve handles the remaining flow, reducing the size and weight of the main control valve.
Solution Approach 2:
Instead of using a small spool opening that creates instability, the system uses partial action by opening the bypass valve to provide an alternative flow path. This allows the main valve to operate in a stable region while the bypass valve handles the excess flow, achieving both precision and stability.
4Quantity of substance
If conventional valves are used for asymmetric flow control, then the system can handle the flow requirements, but the utilization of flow paths is low
Solution Approach 1:
The flow control system is segmented into two parallel paths: a main flow path through the proportional directional valve and a bypass path with a separate bypass valve. This allows the main valve to be sized for lower flow rates while the bypass valve handles the remaining flow, reducing the size and weight of the main control valve.
Solution Approach 2:
The bypass valve is designed to be controllable (electric or fluidic), allowing it to dynamically adjust based on system requirements. This multi-functionality enables the bypass path to serve both as a flow augmentation path and as a means to improve overall system efficiency and response time.
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 proposed solution allows for increased flow rates through one port while reducing the size and weight of the flow control valve assembly, improving controllability and reducing flow instabilities, thereby achieving a more compact and efficient flow control system.
Implementation Method 1
The bypass valve is controllable so as to open or close the bypass valve to allow or block the flow of fluid through the fluid bypass path
Implementation Method 2
The flow control valve assembly comprises one or more valves configured to provide a flow of pressurized fluid from a pressurized fluid source to one of the first and second ports along a fluid supply path
Implementation Method 3
The flow control valve assembly is further configured to provide a flow of fluid from the other of the first and second ports to a fluid sink along a fluid return path
Implementation Method 4
The bypass path comprises a flow rate control element configured to control a flow rate in the bypass path so as to keep the flow rate in the bypass path constant independent of the load conditions
Data Source
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AI summary
A flow control circuit for an actuator is provided. The actuator comprises a first chamber (111) and a second chamber (112), wherein the first chamber experiences a volume change that is larger than a volume change experienced by the second chamber upon actuation of the actuator (110). The flow control circuit (10) comprises a first port (11) configured to be connected to the first chamber (111), a second port (12) configured to be connected to the second chamber (112), and a flow control valve assembly (20) comprising one or more valves configured to provide a flow of pressurized fluid from a pressurized fluid source (41) to one of the first and second ports (11, 12) along a fluid supply path and further configured to provide a flow of fluid from the other of the first and second ports (11, 12) to a fluid sink (42) along a fluid return path. The flow control circuit (10) further comprises a fluid bypass path (30) comprising a bypass valve (31) .