Engine Control Valve Timing Response Limiting

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

In internal combustion engines with valve timing varying mechanisms, sensed valve timing abnormalities can lead to inaccurate ignition timing settings, potentially causing knocking due to excessively advanced ignition timing.

Innovation Solution

The engine control system calculates a predetermined response valve timing and limits the sensed valve timing to this value when it exceeds the actual timing, ensuring accurate ignition timing settings by constraining the sensed value to prevent deviations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the sensed valve timing is used directly for ignition timing setting, then the response speed is fast, but the accuracy deteriorates when sensing abnormalities occur

Engineering Contradiction:

Improveresponse speedVSAvoidaccuracy of ignition timing setting

Core Design Contradiction:

SpeedVSMeasurement precision

Solution Approach 1:

The patent applies beforehand cushioning by calculating a predetermined response valve timing before using the sensed valve timing for ignition setting. This response valve timing is computed by converting the sensed valve timing with a predetermined response speed, creating a buffer that prevents direct transmission of sensing abnormalities to the ignition timing setting, thus maintaining accuracy even when sensing issues occur

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

2Measurement precision

If the sensed valve timing is limited to the predetermined response valve timing, then the accuracy of ignition timing setting is improved, but the response speed to actual valve timing changes is reduced

Engineering Contradiction:

Improveaccuracy of ignition timing settingVSAvoidresponse speed

Core Design Contradiction:

Measurement precisionVSSpeed

Solution Approach 1:

The patent applies parameter changes by dynamically adjusting the response valve timing based on engine operating conditions. The predetermined response speed used in calculating the response valve timing is not fixed but varies according to engine speed, load, and other parameters, allowing the system to optimize the balance between accuracy and response speed under different operating conditions

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentEP2876285B1Control device for internal combustion engine

Publication Date: 2016.12.14 NISSAN MOTOR CO LTD

Figure 1
Figure 2
Figure 3

AI summary

There is provided a valve timing varying mechanism (VTC) to vary a valve timing. An estimated VTC conversion angle VTCNFS is calculated in accordance with a sensed VTC conversion angle VTCNOW (S15∼S19). At the time of conversion of the VTC conversion angle to the advance side or retard side, a fastest response value is calculated by conversion of the VTC conversion angle from the previous sensed value with a fastest response speed, and the sensed value (estimated value) is limited to or below the fastest response value when the current value of the sensed valve timing exceeds the fastest response value (S20, S21).