Plug-Type Electrical Connection Wedge Clamping

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing plug-in contact systems in power electronics suffer from poor electrical and thermal conductivity due to small contact surfaces, leading to high resistance and limited current carrying capacity, and are inadequate in withstanding vibration loads and high temperatures, with assembly requiring significant force and tool access.

Innovation Solution

A plug-in connection system utilizing a contact bolt or sleeve with a collet or clamping bolt, providing a large planar contact area for low assembly force and high conductivity, preventing relative movement through a wedge effect, and allowing concealed assembly without tool access.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If conventional spring contacts with small contact surfaces are used, then the contact system can be compact, but the electrical and thermal resistance increases leading to strong heating

Engineering Contradiction:
Improvecontact system sizeVSAvoidelectrical and thermal conductivity
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The patent merges multiple contact surfaces into a single large-area planar contact interface between the contact bolt and collet. Instead of separate point or line contacts, the entire contact surface area is utilized to create a large-area electrical and thermal conduction path, reducing resistance and heating while maintaining compact dimensions

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent transitions from point or line contact (zero-dimensional or one-dimensional contact area) to planar surface contact (two-dimensional contact area). This dimensional change dramatically increases the effective contact area for electrical and thermal conduction without significantly increasing the overall volume of the contact system

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

2Ease of operation

If plug contacts are used for concealed assembly, then tool access is not required, but the vibration resistance is insufficient for automotive applications

Engineering Contradiction:
Improveconcealed assembly capabilityVSAvoidvibration resistance
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent employs conical surfaces with precise angular geometry to create a wedge effect. The conical clamp surface and corresponding conical contact surface generate radial clamping forces that securely hold the contact bolt, preventing relative movement under vibration while allowing simple push-in assembly without tools

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The wedge effect mechanism automatically generates the necessary clamping force during the insertion process itself. As the contact bolt is pushed into the collet, the conical surfaces convert the axial insertion force into radial clamping force, securing the connection without requiring additional fastening operations or tool access

Inventive Principle:
Principle #25Self-service

3Device complexity

If point or line contact surfaces are used, then the contact system structure is simple, but the current carrying capacity is limited due to high resistance

Engineering Contradiction:
Improvecontact structure complexityVSAvoidcurrent carrying capacity
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent combines multiple contact elements into a unified large-area planar contact interface. The contact bolt and collet are designed with mating conical surfaces that create an extended contact area, merging what would otherwise be separate point or line contacts into a continuous surface for current flow, thereby reducing resistance and increasing current carrying capacity

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent utilizes highly conductive copper or aluminum materials for the contact surfaces. These high-conductivity materials are specifically selected and applied to the contact bolt and collet surfaces to minimize electrical and thermal resistance, enabling high current carrying capacity while maintaining structural integrity

Inventive Principle:
Principle #40Composite materials

4Reliability

If large clamping forces are required for vibration resistance, then the connection reliability improves, but the assembly force required increases beyond manual assembly limits

Engineering Contradiction:
Improvevibration resistanceVSAvoidassembly force
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The patent employs conical surfaces with optimized angle geometry to create a mechanical wedge effect. This wedge mechanism efficiently converts small axial insertion forces into large radial clamping forces during assembly, achieving vibration-resistant connection reliability while keeping the required assembly force within manual handling limits of less than 75 N

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The clamping force is generated dynamically during the insertion process rather than requiring pre-applied static force. As the contact bolt is inserted into the collet, the conical surfaces progressively generate increasing clamping force, with the maximum clamping force achieved automatically at full insertion without requiring sustained high assembly force

Inventive Principle:
Principle #15Dynamics

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

The system achieves low electrical and thermal resistance, high vibration tolerance, and reduced assembly force, enabling efficient electrical connections with low overall height and high current carrying capacity.

Implementation Method 1

The wedge effect creates large clamping forces, which even prevent relative movements in the μ range

Methodology Applied
Scientific EffectWedge effect: Wedge

Implementation Method 2

According to the invention, there is no point or line contact, but rather a planar contact. At the same time, it is not a conventional spring contact, so that the system according to the invention can be plugged in with very little force. Highly conductive copper or aluminum can be used for the base material, resulting in very low electrical and thermal contact resistance

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 3

Highly conductive copper or aluminum can be used for the base material, resulting in very low electrical and thermal contact resistance

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3262717B1Plug-type connection for an electrical connection
Publication Date: 2019.08.14 ROBERT BOSCH GMBH
  • EP3262717B1 patent drawingFigure 1
  • EP3262717B1 patent drawingFigure 2
  • EP3262717B1 patent drawingFigure 3

AI summary

The present invention relates to a plug-type connection (1) for an electrical connection between a first line (2) and a second line (3), comprising a contact bolt (4) which can be connected to the first line (2), a collet (5) which can be connected to the second line (3) and has a cutout (6) for inserting the contact bolt (4), has a conical collet outer face (7) and has at least n slots (8) for forming n clamping jaws, where n ≥ 1, and a clamping ring (9) with a conical clamping ring inner face (10) against which the conical collet outer face (7) bears, wherein the at least one clamping jaw can be clamped against the contact bolt (4) as a result of a relative movement between the collet (5) and the clamping ring (9).