Thermal Flow Meter Terminal Design for Strain Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Thermal flowmeters face challenges in stabilizing detection accuracy due to thermal expansion differences between metallic connection terminals and resinous housings, leading to potential strain and design limitations, especially when connecting terminals to desired positions.
Innovation Solution
The thermal flowmeter incorporates a connection terminal design with multiple bent portions to reduce strain by aligning terminal connection points closer to the centerline, using a combination of first and second bent portions to manage thermal expansion and maintain accurate flow measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple bent shapes are provided in the connection terminal to enable connection from desired positions, then adaptability is improved, but device complexity increases and strain occurs due to thermal expansion difference
Solution Approach 1:
The connection terminal is divided into multiple bent portions (first bent portion and second bent portion) that can be independently configured. Each bent portion serves a specific function in routing the terminal from the housing to external connection points, allowing flexible adaptation to different installation positions while maintaining manageable complexity through functional segmentation.
Solution Approach 2:
The connection terminal utilizes three-dimensional spatial arrangement with bent portions extending in different directions and planes. This dimensional approach allows the terminal to navigate around the housing structure and reach multiple external connection positions without requiring an overly complex two-dimensional layout, effectively using spatial freedom to simplify the overall design.
2Adaptability or versatility
If multiple bent shapes are provided in the connection terminal to enable connection from desired positions, then adaptability is improved, but strain occurs in the housing due to thermal expansion difference
Solution Approach 1:
The bent portions of the connection terminal are pre-configured to accommodate and counteract the thermal expansion forces that will occur during operation. By designing the terminal with built-in flexibility through bent portions before thermal cycling occurs, the structure can absorb expansion stresses without transmitting them to the housing or flow measurement element, thereby preventing strain and maintaining detection accuracy.
Solution Approach 2:
The bent portions change the physical configuration and stress distribution parameters of the connection terminal. This geometric modification allows the terminal to flexibly accommodate thermal expansion by redistributing stresses along the bent paths rather than creating rigid stress concentrations, thereby maintaining structural integrity and measurement reliability under varying temperature conditions.
3Device complexity
If a single bent shape is provided in the connection terminal, then device complexity is reduced, but adaptability to connect from desired positions is limited
Solution Approach 1:
The connection terminal incorporates bent portions that provide dynamic flexibility in routing, allowing the terminal to adapt to different connection positions while maintaining a relatively simple overall structure. The bent portions act as flexible segments that can accommodate various installation configurations without requiring complete redesign of the terminal geometry.
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 design stabilizes the detection accuracy of the flow measurement element by minimizing deformation caused by thermal expansion differences, ensuring reliable and precise flow measurements.
Implementation Method 1
a state of a measurement object gas flowing in the sub-passage is measured by the transmission of heat between the flow measurement element and the measurement object gas
Implementation Method 2
there is a concern that a strain may occur in a housing due to a thermal expansion difference between a metallic connection terminal and the resinous housing fixing the connection terminal
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
The purpose of the present invention is to provide a thermal flow meter that makes it possible to connect a connection terminal to the outside at a desired position and makes it possible to stabilize the detection accuracy of a flow rate measurement element. A connection terminal 60 is provided on a flange 312 of a thermal flow meter 30. A terminal connection part 60 has a first bent part 60c and a second bent part 60d. The first bent part 60c has a shape that is bent from a first direction d1 to a second direction d2. The second bent part 60d has a shape that is bent from the first bent part 60c to a third direction d3. The first and second bent parts 60c, 60d are formed such that when connection pin parts 60b of a plurality of the connection terminals 60 and terminal connection parts 60a of the plurality of connection terminals 60 are projected onto a first imaginary plane F1, an imaginary line L extending along a first direction d1 passing through the projection areas 60B of each of the terminal connection parts 60a of the plurality of connection terminals 60 passes between the projection areas 61A, 65A of the connection pin parts 61, 65, from among the connection pin parts 60b of the plurality of connection terminals 60, that are positioned on both sides.