Vehicle Transmission Control Device for Oil Pump Malfunction

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Solution Overview

Problem

If a malfunction occurs in the oil pump that supplies lubrication oil to a gear-shifting mechanism in a vehicle transmission system, there is a risk of seizing and damage to the lubricated parts due to poor lubrication, which existing technologies fail to adequately prevent.

Innovation Solution

The vehicle transmission control device detects a malfunction in the oil pump and switches to a power transmission path that imposes a small load on the lubricated parts, thereby reducing the risk of seizing and damage by selecting gear shift patterns that minimize the load on bearing and gear components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If ordinary shift control is continued after detecting a malfunction in the oil pump, then the gear-shifting mechanism can maintain normal operation, but there is a risk of seizing of the lubricated parts and damage due to poor lubrication

Engineering Contradiction:
Improvegear-shifting operationVSAvoidlubricated parts condition
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The control device dynamically changes the gear-shifting control strategy based on the detected malfunction state. When an oil pump malfunction is detected, the system transitions from normal shift control to a restricted mode that prohibits specific gear shifts (1st, 3rd, and reverse gears), thereby adapting the operation to the degraded lubrication condition and preventing damage while maintaining safe vehicle operation

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The control device changes the operational parameters of the gear-shifting mechanism by modifying which gear shifts are permitted. Specifically, it changes the gear selection parameters to exclude gears that would impose high loads on lubricated parts, thereby adjusting the system's operating characteristics to match the reduced lubrication capability

Inventive Principle:
Principle #35Parameter changes

2Power

If a power transmission path with large load on lubricated parts is selected during normal shift control, then the gear-shifting mechanism achieves efficient power transmission, but seizing and damage may occur if oil pump malfunction occurs

Engineering Contradiction:
Improvepower transmission efficiencyVSAvoidseizing and damage risk
Core Design Contradiction:
PowerVSObject-affected harmful factors

Solution Approach 1:

The control device applies different operational restrictions to different gear shifts based on their specific load characteristics on lubricated parts. By identifying which gears (1st, 3rd, and reverse) impose high loads on critical lubricated components, the system selectively prohibits only those specific gear shifts while allowing others, thereby locally optimizing the protection strategy for the most vulnerable areas

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The control device converts the harmful situation of oil pump malfunction into a beneficial protective measure by using the malfunction detection signal to trigger a protective control mode. The harmful lack of lubrication is countered by deliberately restricting gear selections to those with lower lubrication demands, thereby transforming the malfunction condition into an opportunity for adaptive protection

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Data Source

PatentEP3312478B1Vehicle shift control device
Publication Date: 2023.07.19 NISSAN MOTOR CO LTD
  • EP3312478B1 patent drawingFigure 1
  • EP3312478B1 patent drawingFigure 2
  • EP3312478B1 patent drawingFigure 3

AI summary

To provide a vehicle transmission control device in a vehicle provided with an oil pump for supplying lubricating oil to a gear-shifting mechanism, which is configured to be able to prevent seizing of lubricated parts and damage thereto, if a malfunction occurs in the oil pump. In a vehicle provided with a gear type transmission (1) capable of selecting a plurality of gear shift patterns, and an electric oil pump (20) for lubrication, a gear shift pattern having a small load on the lubricated parts is selected when a malfunction occurs in the electric oil pump (20).