Work Vehicle Engine Torque Control for Exhaust Purification

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Solution Overview

Problem

Existing exhaust gas purification systems for work vehicles with hydraulic pumps driven by engines face challenges in smoothly managing engine output and fuel efficiency when the reducing agent solution runs low, leading to jerky vehicle movement and increased fuel consumption.

Innovation Solution

A work vehicle equipped with a variable displacement hydraulic pump, an exhaust gas purification device using a reducing agent solution, and a control unit that adjusts engine output torque and rotational speed based on the reducing agent solution's remaining amount, with specific threshold-based adjustments to prevent engine stall and optimize fuel efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the engine is controlled to low output when reducing agent solution is low, then exhaust gas purification is maintained, but vehicle movement becomes jerky and fuel consumption increases

Engineering Contradiction:
Improveexhaust gas purificationVSAvoidvehicle movement smoothness
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent applies dynamics by making the engine output control adaptive rather than fixed. The control unit dynamically adjusts engine output based on real-time detection of reducing agent solution levels, operation state, and engine rotational speed, enabling smooth transitions that prevent jerky vehicle movement while maintaining exhaust gas purification.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of engine output control from a simple on/off or fixed threshold approach to a multi-parameter adaptive control system. By considering operation state and engine rotational speed alongside reducing agent solution levels, the system optimizes the balance between purification reliability and operational smoothness.

Inventive Principle:
Principle #35Parameter changes

2Speed

If the engine rotational speed change amount increases during operation state change, then engine output response is faster, but vehicle movement becomes jerky and fuel consumption worsens

Engineering Contradiction:
Improveengine response speedVSAvoidvehicle movement smoothness
Core Design Contradiction:
SpeedVSEase of operation

Solution Approach 1:

The system dynamically adjusts engine rotational speed changes based on current operation state. Rather than applying fixed speed changes, the control unit adapts the rate and magnitude of speed adjustments to match the current operational context, ensuring responsive yet smooth vehicle movement transitions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements feedback control by continuously monitoring engine rotational speed, operation state, and reducing agent solution levels. The control unit uses this feedback to modulate engine output changes, preventing excessive speed variations that would cause jerky movement while maintaining adequate response speed.

Inventive Principle:
Principle #23Feedback

3Reliability

If only engine output torque is decreased without adjusting rotational speed, then exhaust gas purification is maintained, but engine stall may occur and fuel efficiency deteriorates

Engineering Contradiction:
Improveexhaust gas purificationVSAvoidfuel efficiency
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent changes the control approach from adjusting only torque to simultaneously adjusting both torque and rotational speed parameters. This dual-parameter adjustment optimizes fuel efficiency by matching engine operating conditions to appropriate speed-torque combinations while preventing engine stall and maintaining exhaust gas purification.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system dynamically coordinates torque and rotational speed adjustments based on real-time operating conditions. The control unit optimizes the combination of torque reduction and speed adjustment to maintain purification effectiveness while improving fuel efficiency and preventing engine stall.

Inventive Principle:
Principle #15Dynamics

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution ensures smooth vehicle operation and improved fuel efficiency by gradually reducing engine output torque and rotational speed as the reducing agent solution decreases, preventing engine stall and encouraging timely replenishment.

Implementation Method 1

an exhaust gas purification device that purifies nitrogen oxide in exhaust gas discharged from the engine using a reducing agent solution stored in a reducing agent tank

Methodology Applied
Scientific EffectChemical reduction: Reduction

Data Source

PatentEP2857603B1Work vehicle
Publication Date: 2017.11.29 K C M
  • EP2857603B1 patent drawingFigure 1
  • EP2857603B1 patent drawingFigure 2
  • EP2857603B1 patent drawingFigure 3A

AI summary

A work vehicle including a front work device, contains: a variable displacement hydraulic pump (11) that is driven by an engine (190) and supplies pressure oil to an actuator that drives the front work device; an exhaust gas purification device that purifies nitrogen oxide in exhaust gas discharged from the engine using a reducing agent solution stored in a reducing agent tank; a remaining amount detection device (10a) that detects a remaining amount of the reducing agent solution in the reducing agent tank; and a control unit that decreases output torque of the engine and also decreases a rotational speed of the engine in a rated point according to decrease of the remaining amount of the reducing agent solution detected by the remaining amount detection device (10a).