Elastic Bus Bar Structure for Gap-Free Battery Terminal Welding

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Solution Overview

Problem

The challenge in connecting battery cells via bus bars is the difficulty in ensuring precise alignment and welding due to dimensional errors, leading to gaps and unreliable connections, especially when thick bus bars are required for high current applications.

Innovation Solution

A bus bar design with elastically deformable arm portions connected to a rod portion, allowing the distal end to adjust and weld securely to the electrode terminal, eliminating gaps and ensuring reliable connections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a power supply device is disposed in each vehicle body to supply power to auxiliary devices, then each auxiliary device can be supplied with power independently, but the device complexity and cost increase due to requiring multiple power storage devices

Engineering Contradiction:
Improvepower supply reliabilityVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The power supply system is segmented into a main power storage device in the power supply vehicle and auxiliary power storage devices in each vehicle body. The main power storage device is divided into multiple battery modules that can independently supply power to different vehicle bodies, enabling independent power supply while maintaining system manageability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A power supply device acts as an intermediary between the main power storage device and the auxiliary devices in vehicle bodies. This intermediary device receives power from the main storage device and distributes it to auxiliary devices, eliminating the need for each vehicle body to have its own large power storage device while ensuring reliable power supply.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If power storage devices are disposed in both the power supply vehicle and each vehicle body, then power can be supplied to each vehicle body independently, but the cost and device quantity increase

Engineering Contradiction:
Improveindependent power supply capabilityVSAvoidnumber of power storage devices
Core Design Contradiction:
Ease of operationVSQuantity of substance

Solution Approach 1:

Multiple power storage functions are merged into a single main power storage device in the power supply vehicle. This main device contains multiple battery modules that collectively provide power to multiple vehicle bodies, reducing the total number of power storage devices while maintaining independent power supply capability through the power supply device intermediaries.

Inventive Principle:
Principle #5Merging (Combining)

3Quantity of substance

If a large-capacity power storage device is disposed in the power supply vehicle to supply power to multiple vehicle bodies, then the number of power storage devices is reduced, but the weight and volume of the power supply vehicle increase

Engineering Contradiction:
Improvenumber of power storage devicesVSAvoidpower supply vehicle weight
Core Design Contradiction:
Quantity of substanceVSWeight of moving object

Solution Approach 1:

The large power storage device is segmented into multiple battery modules of appropriate capacity. Each module can supply power to one or more vehicle bodies, reducing the weight and volume requirements for the main power storage device while maintaining the capability to supply multiple vehicle bodies.

Inventive Principle:
Principle #1Segmentation

4Adaptability or versatility

If power storage devices with appropriate capacity are disposed in each vehicle body, then each vehicle body can be supplied with appropriate power, but the total weight and volume of power storage devices increase

Engineering Contradiction:
Improvepower supply adaptabilityVSAvoidtotal power storage device weight
Core Design Contradiction:
Adaptability or versatilityVSWeight of moving object

Solution Approach 1:

The power supply device is designed with universal functionality to work with different vehicle bodies and auxiliary devices. It can receive power from the main power storage device and distribute it to various auxiliary devices in different vehicle bodies, providing adaptability without requiring each vehicle body to have its own dedicated power storage device.

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

Data Source

PatentEP3951914B1Power supply device, electric vehicle comprising power supply device, and power storage device
Publication Date: 2026.04.08 SANYO ELECTRIC CO LTD
  • EP3951914B1 patent drawingFigure 1
  • EP3951914B1 patent drawingFigure 2
  • EP3951914B1 patent drawingFigure 3

AI summary

To weld a bus bar and an electrode terminal with certainty by bringing the bus bar and the electrode terminal into close contact with each other without forming a gap between the bus bar and the electrode terminal, provided is a power supply device that is a power supply device including a plurality of battery cells electrically connected with each other by bus bar (3). The power supply device has a structure where bus bar (3) includes: rod (4) having conductivity and extending in an arrangement direction of the battery cells; and arm (5) being elastically deformable and being connected to rod (4), arm (5) is configured such that distal end (5x) of arm (5) is welded to an electrode terminal of the battery cell, and rear end (5y) of arm (5) is connected to rod (4) so as to electrically connect the plurality of battery cells to each other via the rod, arm (5) is formed of a conductive plate that is elastically deformable, deformation gap (6) extending from rear end (5y) toward a distal end is formed between arm (5) and rod (4), and arm (5) is elastically deformable so as to displace distal end (5x) to be welded to the electrode terminal.