Gearbox Fork Module Assembly Using Guide Pin Alignment

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Solution Overview

Problem

The existing transmission assembly process is hindered by the cover obstructing visibility during engagement of shift forks with synchromesh mechanisms, making it difficult for assembly, especially for inexperienced workers.

Innovation Solution

A transmission configuration that includes a guide mechanism to facilitate the assembly of the fork module by guiding the second shift fork to engage with the second fixing member after the first shift fork has started engaging with the first fixing member, utilizing a pin member and guide groove for alignment, and incorporating a supporting member with bolts for positioning, allowing for easier assembly even when components cannot be seen.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the cover is attached to close the opening in the transmission case, then the transmission is protected and assembly is completed, but the cover obstructs visibility making it difficult to engage shift forks with synchromesh mechanisms

Engineering Contradiction:
Improvetransmission protectionVSAvoidease of assembly
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The transmission assembly is divided into separate modules: the transmission case with gear trains and synchromesh mechanisms is assembled first, then the cover is attached separately. This segmentation allows the main assembly to be completed before final enclosure, improving visibility during critical engagement operations while maintaining protection when closed.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The shift forks are pre-assembled on the fork rods within the cover before attaching the cover to the transmission case. This preliminary arrangement ensures proper positioning and visibility during the engagement process, allowing workers to see and adjust components before the cover obscures them.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If shift forks are engaged with synchromesh mechanisms in the conventional manner, then assembly is completed, but inexperienced workers cannot see the components making engagement difficult

Engineering Contradiction:
Improveassembly completionVSAvoidease of assembly for inexperienced workers
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

A guide mechanism consisting of guide pins and guide grooves is introduced as an intermediary between the fork module and transmission case. This guide mechanism aligns the shift forks with the synchromesh mechanisms automatically, making the engagement process intuitive and error-proof for inexperienced workers while maintaining assembly efficiency.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If multiple shift forks are engaged simultaneously, then assembly is completed efficiently, but proper alignment and engagement sequence is difficult to control

Engineering Contradiction:
Improveassembly efficiencyVSAvoidengagement alignment precision
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The guide mechanism with guide pins and guide grooves enables the fork module to self-align with the transmission case during assembly. The guide grooves automatically direct the shift forks into proper engagement positions with the synchromesh mechanisms, eliminating the need for complex alignment procedures while maintaining high precision for multiple forks simultaneously.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3203118B1Gearbox and method for assembling same
Publication Date: 2021.03.03 ATSUMITEC CO LTD
  • EP3203118B1 patent drawingFigure 1
  • EP3203118B1 patent drawingFigure 2
  • EP3203118B1 patent drawingFigure 3

AI summary

Technology is provided that contributes to an improvement in the ease of assembly of transmissions. A fork mechanism (20) is configured in which fork rods (FS1, FS2, and FS3) to which shift forks (F1, F2, and F3) are connected are each attached to a pedestal (22) so as to be moveable in an axial direction. An assembly guide portion (30) is provided on the pedestal (22) and a guide pin (19) is erected on a clutch housing (12). As a result, even in cases where an input shaft (2) and a main shaft (4), on which driving and driven gears and synchro devices are assembled, are assembled on the clutch housing (12) in a state that the driving and driven gears are engaged and, thereafter the fork mechanism (20) is assembled on this clutch housing (12), the assembly of the fork mechanism (20) on the clutch housing (12) can be easily performed.