Bus Bar Holder Insert Molding for Precise Stacked Positioning

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional bus bar assemblies in motors face challenges in positioning bus bars in a stacked direction, leading to increased component complexity and cost due to the need for multiple dedicated positioning members.

Innovation Solution

A bus bar assembly is designed with a plate-shaped conductor, a plate-shaped shield for magnetism shielding, and a bus bar holder that positions the bus bar and shield using insert-molding with positioning pins, allowing for vertical orientation and reduced component count through shared molds for manufacturing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional positioning members are used to position bus bars in planar direction, then positioning in planar direction is achieved, but positioning in stacked direction becomes difficult and component count increases

Engineering Contradiction:

Improvepositioning accuracyVSAvoidcomponent count

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent combines multiple positioning functions into a single integrated mold structure. The mold includes both planar positioning features (side walls and positioning ribs) and vertical positioning features (ejection pins and cavity depth control), eliminating the need for separate positioning members and reducing component complexity while maintaining positioning accuracy in both directions.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The mold is designed to perform multiple functions simultaneously: it provides planar positioning through side walls and positioning ribs, vertical positioning through ejection pins and cavity depth, and also serves as the manufacturing tooling itself. This multi-functional design replaces multiple dedicated positioning members with a single universal mold structure.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Manufacturing precision

If multiple dedicated positioning members are prepared for bus bar positioning, then positioning capability is improved, but component cost increases

Engineering Contradiction:

Improvepositioning capabilityVSAvoidcomponent cost

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent merges multiple positioning functions into the mold structure itself, eliminating the need for separate positioning members. The mold includes integrated positioning ribs, side walls, and ejection pins that collectively provide both planar and vertical positioning, reducing component count and manufacturing cost while maintaining positioning capability.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The mold serves its own positioning function by incorporating positioning features directly into its structure. The ejection pins and cavity design automatically provide vertical positioning, while the side walls and positioning ribs provide planar positioning, allowing the mold to position the bus bars without requiring additional dedicated positioning members.

Inventive Principle:

Principle #25Self-service

3Manufacturing precision

If bus bars are positioned in stacked direction, then assembly precision is improved, but manufacturing complexity increases

Engineering Contradiction:

Improveassembly precisionVSAvoidmanufacturing complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The mold structure automatically provides vertical positioning through its ejection pins and cavity depth design. The ejection pins protrude from the mold to precisely position the bus bars in the vertical direction during the molding process, eliminating the need for separate positioning mechanisms and reducing manufacturing complexity while achieving high assembly precision.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The vertical positioning of bus bars is accomplished during the mold preparation and injection stages. The ejection pins are pre-positioned in the mold to establish precise vertical locations, and the bus bars are positioned accordingly during the molding process itself, rather than requiring additional positioning steps after manufacturing.

Inventive Principle:

Principle #10Preliminary action

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 enables efficient and cost-effective manufacturing of bus bar assemblies with improved positional accuracy and reduced electrical resistance, enhancing the compactness and productivity of motor stators.

Implementation Method 1

injecting a resin into the mold after the positioning to mold the bus bar holder

Methodology Applied

Scientific EffectInjection molding:

Data Source

PatentUS11888371B2Manufacturing method of bus bar unit, bus bar unit, and motor

Publication Date: 2024.01.30 NIDEC CORP(JP)

AI summary

A method of manufacturing of the bus bar assembly includes preparing a mold, positioning a bus bar and a shield in the mold, and molding a bus bar holder. The positioning includes inserting first positioning pins into bus bar through holes to cause the first positioning pins to hold the bus bar, providing the shield in the mold in a state where a lower surface of the shield and a distal end of the first positioning pin are in contact with each other, bringing a second positioning pin into contact with an upper surface of the shield and positioning the shield in a vertical direction, and bringing a third positioning pin extending downward from a lower surface of an upper mold into contact with an upper surface of the bus bar to position the bus bar in the vertical direction.