Piezoelectric Pump Body with Partition Wall for Backflow Reduction
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Solution Overview
Problem
Existing fluid control devices with piezoelectric elements face issues with backflow and inadequate flow rates due to their structural limitations, which hinder efficient fluid conveyance.
Innovation Solution
A fluid control device design featuring a pump body with strategically positioned openings and nozzles, aligned with the vibration nodes and antinodes of the driving member, enhances flow rates by optimizing fluid flow paths and reducing backflow through the use of a case with vent holes and a holding member that connects the pump body to the case, allowing efficient fluid discharge and intake.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a conventional piezoelectric pump structure is used, then the device can operate with simple construction, but backflow occurs and desired flow rate cannot be obtained
Solution Approach 1:
The pump body is divided into multiple chambers (first pump chamber and second pump chamber) separated by a partition wall, allowing independent operation of each chamber. This segmentation prevents backflow by isolating fluid paths and enables each chamber to contribute to the total flow rate, resolving the contradiction between achieving high flow rate and preventing backflow.
Solution Approach 2:
The partition wall is designed with different properties at different locations: it includes a first through-hole in the first pump chamber and a second through-hole in the second pump chamber, with the second through-hole positioned lower than the first. This local differentiation creates distinct fluid flow paths and pressure zones, preventing backflow while maintaining high flow rate capability.
2Reliability
If the second through-hole is positioned lower than the first through-hole in the partition wall, then backflow is reduced, but the device complexity increases
Solution Approach 1:
The partition wall is integrated with the pump body as a single component, combining the functions of separation, flow control, and structural support. By merging these functions into one element rather than using separate components, the design achieves backflow prevention through the differentiated hole positions without proportionally increasing device complexity.
3Productivity
If multiple through-holes are provided in the partition wall, then fluid flow rate increases, but manufacturing precision requirements increase
Solution Approach 1:
The partition wall is pre-formed with the differentiated through-holes (first through-hole higher than second through-hole) during the manufacturing process, establishing the precise geometric relationship between holes before assembly. This preliminary action ensures proper alignment and positioning, allowing multiple through-holes to be provided without excessive manufacturing precision requirements during final assembly.
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 design significantly increases the flow rate and pressure of the fluid control device, achieving efficient fluid conveyance with reduced backflow, as demonstrated by the generation of 8 kPa pressure and 6 L/min flow rate.
Implementation Method 1
a piezoelectric element 115 is arranged on the first main plate 110
Implementation Method 2
the first main plate 110 undergoes a bending vibration in response to the driving member 115
Data Source
AI summary
A fluid control device includes: a case that includes a case top plate having a first vent hole, a case side plate, and a case bottom plate having a second vent hole; a pump body; and a holding member that holds the pump body relative to the case. The pump body includes a first main plate, a second main plate that faces one main surface of the first main plate, a side plate, and a driving member that is arranged on the first main plate. The first main plate includes a plurality of first openings arranged in a ring shape. The second main plate is arranged at a side of the first main plate nearer the case top plate and has a second opening at a position that overlaps the first vent hole in a plan view.