Pedal Force Sensor Offset Load Suppression

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Solution Overview

Problem

Existing pedal operation amount detecting devices suffer from unstable detection accuracy and durability due to offset loads caused by dimension errors and backlash, leading to uneven wear in the rotational sliding portions.

Innovation Solution

A pedal operation amount detecting device is designed with a sensor member arranged on a load transmission path offset from the transmitting member, supported by parallel support pins, allowing the depression force and reaction force to be applied at overlapping positions parallel to the support axis, using a cylindrical member and bushing to stabilize the coupling pin and prevent offset loads.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the sensor member is supported by a pin in a cantilever manner, then the device structure is simple, but the operation input portion and reaction force applied portion may be offset from each other causing unstable detection accuracy and uneven wear

Engineering Contradiction:
Improvesupport structureVSAvoiddetection accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The support structure is segmented from a single pin support to a pair of pins supporting both ends of the sensor member. This segmentation allows the sensor member to be supported at multiple points, preventing offset loads and ensuring that the operation input portion and reaction force applied portion overlap, thereby improving detection accuracy while maintaining structural simplicity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The pair of pins act as intermediaries between the sensor member and the transmitting member. By introducing these intermediate support points, the system ensures proper alignment and force transmission, preventing the offset that occurs with single-pin cantilever support and eliminating the resulting detection accuracy issues.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If the operation input portion and reaction force applied portion are offset, then the sensor member can be supported with fewer components, but offset loads are generated causing unstable detection accuracy and reduced durability

Engineering Contradiction:
Improvenumber of support componentsVSAvoiddurability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The support system is segmented into multiple pin locations along the sensor member. This segmentation distributes the support function across multiple points, preventing the concentration of offset loads that would occur with fewer support points, thereby improving durability without significantly increasing complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The positional parameters of the support pins are optimized to ensure that the operation input portion and reaction force applied portion overlap. By changing the support configuration from a single pin to a pair of pins at specific locations, the system eliminates offset loads and improves reliability.

Inventive Principle:
Principle #35Parameter changes

3Volume of moving object

If the sensor member is arranged offset from the transmitting member, then the design allows for compact configuration, but offset loads may occur causing uneven wear in rotational sliding portions

Engineering Contradiction:
Improvedevice compactnessVSAvoiduneven wear
Core Design Contradiction:
Volume of moving objectVSObject-generated harmful factors

Solution Approach 1:

The pair of pins serve as intermediaries that mediate the force transmission between the offset sensor member and the transmitting member. These intermediaries ensure that even with the offset arrangement enabling compact design, the forces are properly transmitted without creating offset loads that would cause uneven wear in rotational sliding portions.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 configuration stabilizes the posture and deformation of the sensor member, improving detection accuracy and durability by preventing offset loads and uneven wear, while maintaining a compact design and allowing for easy adjustment and mounting.

Implementation Method 1

a sensor member that is arranged on a load transmission path at a position offset from the transmitting member in a direction parallel to the support axis and that is deformed by the depression force and the reaction force, and the pedal operation amount detecting device electrically detecting a deformation of the sensor member

Methodology Applied
Scientific EffectDeformation: Deformation

Data Source

PatentEP2615519B1Pedal manipulation-amount detection apparatus
Publication Date: 2018.08.08 TOYODA IRON WORKS CO LTD
  • EP2615519B1 patent drawingFigure 1(a)~1(c)
  • EP2615519B1 patent drawingFigure 2(a)~2(b)
  • EP2615519B1 patent drawingFigure 3(a)~3(b)

AI summary

It is an object to improve the detection accuracy and durability in detecting a depression force on the basis of a deformation of a sensor member arranged between a pedal arm and an output member. In the pedal operation amount detecting device 10 which the sensor member 30 is arranged on the side face of the pedal arm 18 via the pair of support pins 32, 34, and is coupled to the operating rod 22 (output member) via the clevis pin 26, and detects the deformation of the sensor member 30 by the deformation detecting means 52 such as a strain gauge, the operation input portions to which the depression force F is applied and the reaction force applied portion to which the reaction force R is applied are set at the positions that overlap with each other in the direction parallel to the support axis O. Therefore, an offset load due to an offset (deviation in position) between the operation input portions and the reaction force applied portion in the direction parallel to the support axis O is suppressed. Therefore, the posture and deformation manner of the sensor member 30 become stable, and uneven wear of the rotational sliding portions is suppressed. As a result, the detection accuracy and durability improve.