Shift Fork with Asymmetric Recesses for Rigidity

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional shift forks for manual vehicle transmissions lack high dimensional stability while requiring excessive material, leading to weight and manufacturing inefficiencies.

Innovation Solution

The shift fork design features pot-shaped recesses with alternating axial outer sides, where one side's recess bottom forms a section of the other side, creating a zigzag or crenellated structure for enhanced rigidity, and incorporates a metallic locking contour and magnet holding unit for improved robustness and electronic monitoring.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If conventional shift fork designs with outer edge thickenings and flat walls are used, then manufacturing is simplified, but dimensional stability is insufficient and excessive material is required

Engineering Contradiction:
Improvedimensional stabilityVSAvoidmaterial usage
Core Design Contradiction:
Stability of the object's compositionVSQuantity of substance

Solution Approach 1:

The shift fork body is segmented into alternating recesses and protrusions along the longitudinal axis, creating a modular structure where each segment contributes to both material reduction and dimensional stability. The recesses remove unnecessary material while the protrusions provide structural reinforcement at critical locations.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cross-sectional geometry transitions from conventional symmetric designs to asymmetric configurations with alternating recesses and protrusions. This asymmetric segmentation creates a structure that optimizes material distribution, providing enhanced rigidity where needed while minimizing material usage in less critical areas.

Inventive Principle:
Principle #4Asymmetry

2Strength

If more material is used to increase shift fork rigidity, then dimensional stability improves, but weight increases and manufacturing efficiency decreases

Engineering Contradiction:
ImproverigidityVSAvoidshift fork weight
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

Instead of uniformly increasing material throughout the shift fork, the invention applies material strategically at specific locations through the alternating recess and protrusion design. The protrusions are positioned at critical stress points to provide local reinforcement, while recesses remove material from areas where it is not needed, achieving high rigidity with minimal weight.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The recesses and protrusions are designed with optimized curved geometries that enhance structural efficiency. The rounded transitions and contoured surfaces distribute stresses more effectively than sharp corners, improving rigidity without requiring additional material.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Ease of manufacture

If conventional symmetric designs are used, then manufacturing is straightforward, but dimensional stability and material efficiency are compromised

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoiddimensional stability
Core Design Contradiction:
Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The shift fork is divided into repeating segments of recesses and protrusions that can be manufactured using standardized molding processes. This segmentation allows for efficient mold design and production while achieving superior dimensional stability compared to conventional symmetric designs.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention optimizes geometric parameters such as recess depth, protrusion height, and longitudinal spacing to achieve the desired balance between manufacturability and dimensional stability. These parameters are carefully selected to ensure the design can be produced efficiently while maintaining high rigidity.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2562447B1Shift fork
Publication Date: 2015.01.07 FSG AUTOMOTIVE HLDG
  • EP2562447B1 patent drawingFigure 1
  • EP2562447B1 patent drawingFigure 2
  • EP2562447B1 patent drawingFigure 3A~3B

AI summary

The invention relates to a shift fork (1) for a manual transmission of a motor vehicle, which, when arranged as intended on a shift rod of the manual transmission, has two axial outer surfaces (6, 7) oriented essentially transversely to the longitudinal axis of the shift rod.In order to provide a shift fork (1) which can be manufactured with high rigidity using the least possible amount of material, the invention proposes that recesses (8) are arranged in the axial outer surfaces (6, 7) such that at least in a partial section of the shift fork (1) the surface structure of one axial outer surface (6, 7) is essentially formed as a negative of the surface structure of the other axial outer surface (6, 7), wherein the part (16) of the shift fork (1) forming the bottom of at least one recess (8) of one axial outer surface (6, 7) forms a section of the other axial outer surface (6, 7) that is not formed as a recess (8).