Double Clutch Transmission Control for Shift Shock Reduction

Solution Overview

Problem

Double clutch transmission systems experience abnormal shock and noise due to frequent clutch movement and backlash conversion during downshifting, affecting shifting performance, comfort, and clutch durability.

Innovation Solution

A method of controlling a double clutch transmission that maintains the clutch engaged until just before shifting to the subsequent gear, reducing clutch movement and maintaining power transmission state to prevent shift shock and noise by synchronizing input and output shafts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the clutch is temporarily engaged before engaging the shift gear of the subsequent gear to prevent shift shock, then shift shock is prevented, but frequent clutch movement causes abnormal shock and noise and deteriorates clutch durability

Engineering Contradiction:

Improveshift shockVSAvoidclutch durability

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The transmission controller generates an order to shift to the subsequent gear before releasing the clutch. This preliminary action ensures that the gear shifting process is initiated and prepared while the clutch remains engaged, allowing the input shaft to synchronize with the output shaft before clutch disengagement, thereby preventing shift shock without requiring frequent clutch movements

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The clutch is maintained in the engaged state continuously from the preceding gear through the current gear until after the order to shift to the subsequent gear is generated. This continuous engagement eliminates frequent clutch disengagement and re-engagement cycles, preventing abnormal shock and noise while maintaining power transmission continuity

Inventive Principle:

Principle #20Continuity of useful action

2Object-affected harmful factors

If the clutch is temporarily engaged before engaging the shift gear of the subsequent gear, then shift shock is prevented, but abnormal shock and noise occur due to frequent clutch movement

Engineering Contradiction:

Improveshift shockVSAvoidabnormal shock and noise

Core Design Contradiction:

Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

The transmission controller generates an order to shift to the subsequent gear before releasing the clutch. This preliminary action ensures that the gear shifting process is initiated and prepared while the clutch remains engaged, allowing the input shaft to synchronize with the output shaft before clutch disengagement, thereby preventing shift shock without requiring frequent clutch movements

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The clutch is maintained in the engaged state continuously from the preceding gear through the current gear until after the order to shift to the subsequent gear is generated. This continuous engagement eliminates frequent clutch disengagement and re-engagement cycles, preventing abnormal shock and noise while maintaining power transmission continuity

Inventive Principle:

Principle #20Continuity of useful action

Data Source

PatentUS8771145B2Method of controlling double clutch transmission of vehicle

Publication Date: 2014.07.08 HYUNDAI MOTOR CO LTD

AI summary

A method of controlling a double clutch transmission of a vehicle to conduct a series of downshifting operations from a preceding gear to a subsequent gear via a current gear in response to deceleration of the vehicle, may include maintaining a clutch which has been in an engaged state at the preceding gear, in the engaged state until after an order to shift to the subsequent gear may be generated, when shifting from the preceding gear to the current gear, releasing the clutch after the order to shift to the subsequent gear may be generated, and engaging a shift gear of the subsequent gear after the releasing of the clutch.