Duplex-Winding Spring Arrangement for Compact Throttle Valve Control
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Solution Overview
Problem
Conventional motor-driven throttle valve control devices have a prolonged axial length due to the serial arrangement of return and default springs, which complicates the limp-home mode operation and valve lock prevention.
Innovation Solution
A duplex-winding spring arrangement with different coil diameters is used, where a smaller coil diameter spring is located inside a larger coil diameter spring, reducing the axial length and allowing for a more compact design while maintaining the necessary spring forces for both return and default functions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If one spring member with serially arranged return spring and default spring is used, then the limp-home mode and valve lock prevention functions are achieved, but the axial length is prolonged
Solution Approach 1:
The patent applies the nesting principle by placing the smaller-coil-diameter spring inside the larger-coil-diameter spring, creating a concentric arrangement where one spring is nested within the other. This allows both springs to occupy the same axial space simultaneously, reducing the overall axial length while maintaining both the return spring and default spring functions.
Solution Approach 2:
The patent transitions from a one-dimensional serial arrangement (springs arranged end-to-end in the axial direction) to a two-dimensional concentric arrangement (springs arranged side-by-side in the radial direction). By utilizing the radial dimension, both springs can function simultaneously without increasing axial length, effectively moving the problem solution to another spatial dimension.
2Reliability
If one spring member with serially arranged return spring and default spring is used, then the fail-safe functions are achieved, but the throttle body becomes larger and heavier
Solution Approach 1:
The concentric nesting arrangement of the two springs with different coil diameters allows both fail-safe functions to be integrated within a compact volume. The smaller spring is nested inside the larger spring, maximizing space utilization and reducing the overall volume and weight of the throttle body while maintaining both return and default spring functions.
Solution Approach 2:
The patent merges two separate spring functions (return spring and default spring) into a single integrated spring member structure. By forming both springs from continuous spring wire in a concentric arrangement, the design combines multiple functions into one compact component, reducing the overall size and weight compared to using separate spring members.
3Device complexity
If serial arrangement of springs is used, then the结构简单 (structure is simple), but the axial length is prolonged
Solution Approach 1:
The patent maintains structural simplicity while reducing axial length by nesting the smaller spring inside the larger spring. This concentric arrangement is mechanically simple yet effective, allowing both springs to function independently without complex interconnections, while significantly reducing the axial footprint compared to serial arrangement.
Solution Approach 2:
The patent resolves the contradiction between structural simplicity and compact size by changing the spatial arrangement from axial (one-dimensional) to radial (two-dimensional). The concentric springs are arranged side-by-side in the radial direction rather than end-to-end in the axial direction, maintaining mechanical simplicity while achieving compact dimensions.
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 arrangement reduces the axial length of the spring mechanism, enabling a more compact and lightweight throttle body, improving the limp-home mode functionality and preventing valve lock, while also reducing the influence of terrestrial magnetism on the magnetic sensor, thus enhancing the accuracy of air flow control.
Implementation Method 1
a spring having one diameter has a return spring function to apply a spring force in a closing direction to the throttle valve, while the spring having the other diameter has a default spring function to apply a spring force on the default opening side
Data Source
AI summary
A spring to ensure default opening is constituted by a single piano wire where a return spring with a larger coil diameter and a default spring with a smaller coil diameter are connected via a connection arm formed with a spring hook. The spring with a smaller coil diameter is inserted in the spring with a larger coil diameter thereby the springs are overlapped in an axial direction as a duplex-winding spring structure. Further, a magnetic sensor is provided in a position inside the both spring with a larger coil diameter and spring with a smaller coil diameter.