Electric Work Vehicle Layout for Weight Balance and Shorter Wiring

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Solution Overview

Problem

Electric work vehicles face challenges in weight balance, center of gravity, and wiring distance due to battery placement and the positioning of electrical components, which also lead to excessive bonnet space and heat management issues.

Innovation Solution

The vehicle design includes a battery mounted on the front side with the traveling motor, power transmission unit, and inverter positioned under the driver's seat, along with a junction box and control device arranged to reduce wiring distance and bonnet length, and uses heat dissipation plates and metal plates to manage heat and improve durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of moving object

If the battery is mounted on the front side to extend cruising distance, then the power supply capacity is improved, but the weight balance in the front-rear direction deteriorates

Engineering Contradiction:
Improvecruising distanceVSAvoidweight balance
Core Design Contradiction:
Duration of action of moving objectVSStability of the object's composition

Solution Approach 1:

The patent relocates heavy components (traveling motor, power transmission unit, inverter) from the front to the rear of the vehicle, utilizing the rear dimension under the driver's seat. This spatial redistribution maintains the front-mounted battery for extended cruising distance while achieving rear-weighted balance through strategic component placement in the rear dimension.

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

2Device complexity

If the junction box is disposed below the battery, then the electrical connection is simplified, but the center of gravity position deteriorates

Engineering Contradiction:
Improveelectrical connectionVSAvoidcenter of gravity position
Core Design Contradiction:
Device complexityVSTemperature

Solution Approach 1:

The patent extracts the junction box from its conventional position below the battery and relocates it to the rear of the bonnet. This separation allows the battery to remain in its optimal position for power supply while the junction box is positioned to achieve lower center of gravity and reduced wiring distance to the operation switch.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The junction box is repositioned from a vertical arrangement (below battery) to a horizontal arrangement (rear of bonnet), changing the spatial dimension of electrical component layout. This dimensional shift simultaneously achieves lower center of gravity and shorter wiring distance to the operation switch.

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

3Device complexity

If the junction box is disposed below the battery, then the electrical connection is simplified, but the wiring distance deteriorates

Engineering Contradiction:
Improveelectrical connectionVSAvoidwiring distance
Core Design Contradiction:
Device complexityVSLength of moving object

Solution Approach 1:

The junction box is extracted from the battery vicinity and relocated to the rear of the bonnet, closer to the operation switch. This extraction reduces the wiring distance for switch control signals while maintaining simplified electrical connections through proper routing.

Inventive Principle:
Principle #2Taking out (Extraction)

4Adaptability or versatility

If the bonnet space is enlarged to accommodate components, then the component arrangement flexibility is improved, but the bonnet length deteriorates

Engineering Contradiction:
Improvecomponent arrangement flexibilityVSAvoidbonnet length
Core Design Contradiction:
Adaptability or versatilityVSLength of moving object

Solution Approach 1:

The patent merges multiple components (traveling motor, power transmission unit, inverter) into a compact integrated arrangement under the driver's seat. This consolidation achieves component arrangement flexibility within a confined space without requiring excessive bonnet length, as the integrated unit occupies vertical and lateral space rather than extending the bonnet longitudinally.

Inventive Principle:
Principle #5Merging (Combining)

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 enhances weight balance, lowers the center of gravity, shortens wiring distances, prevents excessive bonnet length, and improves heat dissipation and component durability.

Implementation Method 1

a heat dissipation plate that contacts the heat sink and that is made of metal or heat dissipation resin

Methodology Applied
Scientific EffectHeat conduction: Conduction (thermal)

Implementation Method 2

uses heat dissipation plates and metal plates to manage heat and improve durability

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP4289648A1Electric work vehicle
Publication Date: 2023.12.13 KANZAKI KOKYUKOKI MFG
  • EP4289648A1 patent drawingFigure 1
  • EP4289648A1 patent drawingFigure 2
  • EP4289648A1 patent drawingFigure 3

AI summary

[Problem] To improve the weight balance in the front-rear direction of an electric work vehicle having a configuration in which a battery is mounted on the front side, to lower the center of gravity of the electric work vehicle, to shorten the wiring distance when a main switch is switched using an operation switch, and to prevent the length of a space inside a bonnet in a front-rear direction from becoming excessively large. [Solution] An electric work vehicle 10 includes: front wheels and rear wheels 16 supported by a vehicle body frame 12; a driver's seat 51 provided above a rear end portion of the vehicle body frame 12; a traveling motor 20 for driving the rear wheels 16; a power transmission unit 22 that is integrated with the traveling motor 20, and reduces the power of the traveling motor 20 and transmits the power to an axle 24 that is joined to the rear wheels 16; and a battery that supplies power to the traveling motor 20 via a first inverter. The battery is disposed inside the bonnet mounted on the front side of the vehicle body frame 12, and the traveling motor 20, the power transmission unit 22, and the first inverter are disposed under the driver's seat 51.