Compact Throttle Device with Parallel Sensor Shaft

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Solution Overview

Problem

Conventional throttle devices are too large, making them difficult to mount on straddled vehicles due to their extended size in the direction of the throttle shaft.

Innovation Solution

A compact throttle device design featuring a throttle body with an intake passage, a throttle shaft, a drive motor with a parallel drive shaft, a rotary member, transmission members, and a sensor shaft parallel to the throttle shaft, allowing for efficient rotation and position detection without extending the device's size, with stopper mechanisms to maintain accurate position sensing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the throttle position sensor is disposed on the extension of the throttle shaft, then the sensor can detect the rotation angle of the throttle shaft, but the device becomes large in size

Engineering Contradiction:
Improvethrottle position detection accuracyVSAvoiddevice length in throttle shaft extending direction
Core Design Contradiction:
Measurement precisionVSLength of moving object

Solution Approach 1:

The sensor shaft is arranged parallel to the throttle shaft rather than on its extension, changing the spatial dimension from linear extension to parallel arrangement. This allows the throttle position sensor to detect the rotation angle of the sensor shaft (which reflects throttle shaft position) without extending the device length in the throttle shaft direction, thus resolving the contradiction between measurement precision and device size.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

A sensor shaft is introduced as an intermediary component that rotates in response to throttle shaft rotation (transmitted through the drive motor and transmission members). The throttle position sensor then detects the rotation angle of this intermediary sensor shaft instead of directly measuring the throttle shaft, enabling accurate position detection while maintaining a compact device structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Length of moving object

If the sensor shaft is arranged parallel to the throttle shaft, then the device size is reduced, but the transmission mechanism becomes more complex

Engineering Contradiction:
Improvedevice length in throttle shaft extending directionVSAvoidtransmission mechanism complexity
Core Design Contradiction:
Length of moving objectVSDevice complexity

Solution Approach 1:

The drive motor serves multiple functions: it directly rotates the throttle shaft to control the throttle valve opening, and simultaneously rotates the sensor shaft through the transmission members to enable position detection. This multi-functionality reduces the need for separate actuation mechanisms, offsetting the added complexity of the parallel shaft arrangement with operational efficiency.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The transmission members serve dual purposes: they transmit rotational force from the drive motor to the throttle shaft for throttle control, and simultaneously transmit rotational force to the sensor shaft for position sensing. By merging these transmission functions into a single mechanism, the patent reduces overall system complexity despite the parallel shaft configuration.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP4484734A1Throttle device and straddled vehicle including the same
Publication Date: 2025.01.01 YAMAHA MOTOR CO LTD
  • EP4484734A1 patent drawingFigure 1
  • EP4484734A1 patent drawingFigure 2~3
  • EP4484734A1 patent drawingFigure 4~5

AI summary

There is discloseda small throttle device and a straddled vehicle including the same;. throttle device (10) including a throttle shaft (21), a drive motor (41) having a drive shaft (22) parallel with the throttle shaft (21), a rotary member (24) configured to rotate integrally with the drive shaft (22), a first transmission member configured to transmit rotational force of the rotary member (24) to the throttle shaft (21), a sensor shaft (23) parallel with the throttle shaft (21), a throttle position sensor (42) configured to detect a rotation angle of the sensor shaft (23), and a second transmission member configured to transmit the rotational force of the rotary member (24) to the sensor shaft (23); The throttle shaft (21), the drive shaft (22), and the sensor shaft (23) being disposed at positions parallel with one another, so that it is not necessary to dispose the throttle position sensor (42) on an extension of the throttle shaft (21), by which the throttle device (10) can be smaller in an extending direction of the throttle shaft (21).