Damper Control for Wheel Loaders Using Bucket State Feedback

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Solution Overview

Problem

Conventional damper operation control systems for working vehicles, such as wheel loaders, fail to consistently maintain the loaded burden during travel due to vibration, leading to potential falls and deteriorated riding quality, as they rely solely on vehicle speed and operating position for accumulator connection.

Innovation Solution

A damper operation control device and method that activates the damper mechanism by detecting when the bucket is loaded, ensuring the accumulator connects to the lift cylinder only when the bucket is laden, thereby stabilizing the vehicle and preventing burden loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the accumulator is connected to the lift cylinder based only on vehicle speed and forward/reverse lever position, then the damper mechanism can be activated during travel, but the connection is released even when the bucket is loaded, causing burden to fall

Engineering Contradiction:
Improveburden stabilityVSAvoidcontrol condition complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The control device monitors the actual state of the bucket (loaded or unloaded) and uses this feedback information to determine whether to activate the damper mechanism. This ensures the accumulator connects only when burden is present, preventing burden fall while maintaining simple control logic based on real-time bucket state rather than complex combinations of vehicle speed and lever position

Inventive Principle:
Principle #23Feedback

2Reliability

If the damper mechanism is activated whenever the bucket is loaded, then burden stability is improved, but the hydraulic power is wasted when the bucket is empty

Engineering Contradiction:
Improveburden stabilityVSAvoidhydraulic power efficiency
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The damper mechanism is designed to be dynamically activated or deactivated based on the bucket's loading state. The switching valve responds to real-time conditions, connecting the accumulator only when burden is detected and isolating it when the bucket is empty. This dynamic control optimizes hydraulic power usage by engaging the damper function only when actually needed for burden stabilization

Inventive Principle:
Principle #15Dynamics

3Ease of operation

If the accumulator is constantly connected to absorb vibration, then riding quality is improved, but the hydraulic system becomes less responsive to operational changes

Engineering Contradiction:
Improveriding qualityVSAvoidhydraulic response speed
Core Design Contradiction:
Ease of operationVSSpeed

Solution Approach 1:

The damper mechanism operates periodically rather than continuously, activating only during specific conditions when the bucket is loaded and vehicle is traveling. The switching valve opens and closes based on detected loading states, providing vibration absorption when needed while maintaining hydraulic system responsiveness and efficiency during non-operational periods

Inventive Principle:
Principle #19Periodic action

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

This approach effectively reduces burden loss and improves riding quality by ensuring the damper mechanism is activated only when the bucket is loaded, efficiently utilizing hydraulic power and maintaining stability during travel.

Implementation Method 1

absorb vibration generated in a vehicle body

Methodology Applied
Scientific EffectVibration: Vibration

Implementation Method 2

connect the fluid pressure lift up cylinder to the accumulator

Methodology Applied
Scientific EffectHydraulic Accumulator: Hydraulic Accumulator

Implementation Method 3

hydraulic pump that generates hydraulic energy

Methodology Applied
Scientific EffectHydraulic Press: Hydraulic Press

Data Source

PatentEP2543777B1Damper operation control device for a work vehicle, and damper operation control method
Publication Date: 2017.10.04 KOMATSU LTD
  • EP2543777B1 patent drawingFigure 1~2
  • EP2543777B1 patent drawingFigure 3
  • EP2543777B1 patent drawingFigure 4

AI summary

A boom pivotably supported on a vehicle body, a bucket pivotably supported on a tip end of the boom, a lift cylinder 118 which drives the boom, an accumulator 117 connected to the lift cylinder 118 through a branched oil passage 146a, a switching valve 115a connected to the branched oil passage 146a between the lift cylinder 118 and the accumulator 117 to switch between a connected state and a disconnected state between the lift cylinder 118 and the accumulator 117, and a controller 111 which performs switch control of the switching valve 115a are provided. The controller 111 is provided with a state detecting unit which detects whether the bucket is in a loaded state, and a switching valve control unit which switches the switching valve 115a to the connected state when the state detecting unit detects that the bucket is in the loaded state. According to this, it is possible to realize decrease in falling of a loaded burden and improvement in riding quality together with efficient use of force generated by a hydraulic pump 141.