Straddle Electric Vehicle Battery Case Width Configuration

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Solution Overview

Problem

Straddle electric vehicles face a challenge in achieving high continued driving capability while allowing riders to easily sandwich the vehicle body with their knees, as the placement of batteries beneath the seat compromises space for the driving system, limiting battery size and stability.

Innovation Solution

The battery case is positioned between the steering shaft and the seat, with a smaller seat vicinity portion to accommodate the rider's knees and a larger portion extending forward or rearward, allowing for increased battery size and improved heat dissipation through air gaps, and a battery frame for stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of moving object

If the battery is placed below the seat to increase battery size and continued driving capability, then the continued driving capability is improved, but the rider cannot easily sandwich the vehicle body with the knees

Engineering Contradiction:
Improvecontinued driving capabilityVSAvoidrider's ability to sandwich vehicle body with knees
Core Design Contradiction:
Duration of action of moving objectVSEase of operation

Solution Approach 1:

The battery case is repositioned from a purely longitudinal arrangement to a three-dimensional configuration that extends in the width direction. By allowing the battery case to protrude laterally beyond the vehicle body's width, the design utilizes the width dimension to accommodate larger battery capacity without compromising the rider's knee clearance, as the protruding portions are positioned where the rider's knees do not contact during operation

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

2Duration of action of moving object

If the battery case is made larger to increase battery size, then the continued driving capability is improved, but the rider cannot easily sandwich the vehicle body with the knees

Engineering Contradiction:
Improvecontinued driving capabilityVSAvoidspace available for rider's knees
Core Design Contradiction:
Duration of action of moving objectVSArea of stationary object

Solution Approach 1:

The battery case utilizes the width dimension by protruding laterally beyond the vehicle body's main width. This dimensional transition allows the battery case to achieve larger volume and capacity while the protruding portions are strategically positioned in areas that do not interfere with the rider's knee placement, effectively decoupling battery size from rider comfort space

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

Solution Approach 2:

The battery case is designed with differentiated regions: a main body portion that integrates with the vehicle body structure and protruding portions that extend laterally. The protruding portions are specifically positioned to avoid the rider's knee contact zones, creating local quality variations that simultaneously maximize battery capacity and preserve rider ergonomics

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2774831B1Straddle electric vehicle
Publication Date: 2017.07.19 KAWASAKI JUKOGYO KK
  • EP2774831B1 patent drawingFigure 1
  • EP2774831B1 patent drawingFigure 2
  • EP2774831B1 patent drawingFigure 3

AI summary

A straddle electric vehicle (1) comprises a seat (9) on which a rider is seated in a straddle state; right and left foot steps (10) on which the rider puts feet, an electric motor (5) for generating driving power for moving the straddle electric vehicle; a battery unit (60) which is an electric power supply for activating the electric motor (5); and a battery case (80) for storing the battery unit (60). The battery case (80) is placed between the steering shaft (7) and the seat (9) in a forward or rearward direction and includes a seat vicinity portion (100) which faces the seat (9) in the forward or rearward direction. The seat vicinity portion (100) is smaller in dimension in a rightward or leftward direction than a portion of the battery case (80) which is other than the seat vicinity portion (100).