Work Vehicle Cooling Fan Control for Radiator Dust Removal

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Solution Overview

Problem

The existing cooling fan control devices for work vehicles like hydraulic excavators and wheel loaders face issues where the radiator may clog before the cooling fan can reverse rotate, leading to potential engine overheating, and frequent forward and reverse rotations shorten the life of hydraulic circuit components due to excessive load.

Innovation Solution

A work vehicle system that includes a refrigerant temperature sensor, an outside air temperature sensor, a thermostat, and a control device that adjusts the time intervals for forward and reverse cooling fan rotations based on temperature conditions, reducing the interval during high or low temperatures to prevent radiator clogging while managing the load on hydraulic components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the cooling fan performs forward and reverse rotation at short predetermined time intervals (e.g., every 15 minutes), then dust removal from the radiator is improved, but the load on the hydraulic motor and valve increases excessively, shortening their service life

Engineering Contradiction:
Improveradiator dust removal effectivenessVSAvoidservice life of hydraulic motor and valve
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The control device changes the time interval parameter for cooling fan rotation based on operating conditions. When the work vehicle is idling, the time interval is set to a longer period (e.g., 30 minutes or more) to reduce hydraulic circuit load. When the work vehicle is operating, the time interval is set to a shorter period (e.g., 15 minutes) to effectively remove dust from the radiator. This dynamic parameter adjustment resolves the contradiction between dust removal effectiveness and component durability.

Inventive Principle:
Principle #35Parameter changes

2Duration of action of stationary object

If the cooling fan rotates in one direction only, then the hydraulic circuit load is reduced, but dust accumulates in the radiator causing clogging

Engineering Contradiction:
Improveservice life of hydraulic circuit componentsVSAvoidradiator cooling efficiency
Core Design Contradiction:
Duration of action of stationary objectVSReliability

Solution Approach 1:

The cooling fan performs periodic forward and reverse rotation at predetermined time intervals instead of continuous unidirectional rotation. This periodic bidirectional rotation creates reverse flow that removes accumulated dust from the radiator while maintaining reasonable load on the hydraulic circuit by not rotating continuously in both directions. The periodic action balances dust removal needs with component durability.

Inventive Principle:
Principle #19Periodic action

3Duration of action of stationary object

If the time interval for forward and reverse rotation is extended (e.g., every 30 minutes), then the load on the hydraulic motor and valve is reduced, but the radiator may clog before the cooling fan reverses

Engineering Contradiction:
Improveservice life of hydraulic motor and valveVSAvoidradiator cooling efficiency
Core Design Contradiction:
Duration of action of stationary objectVSReliability

Solution Approach 1:

The control device dynamically adjusts the time interval parameter based on whether the work vehicle is idling or operating. During operation, when dust accumulation risk is higher, the time interval is shortened to ensure effective dust removal. During idling, when dust accumulation is less severe, the time interval is extended to reduce hydraulic circuit load. This conditional parameter adjustment resolves the contradiction between dust removal timing and component durability.

Inventive Principle:
Principle #35Parameter changes

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 solution effectively prevents radiator clogging and improves the durability of hydraulic pump components by adjusting the cooling fan operation intervals according to temperature conditions, reducing the risk of engine overheating and extending the life of hydraulic circuit components.

Implementation Method 1

a radiator that cools a refrigerant of the engine

Methodology Applied
Scientific EffectHeat transfer: Convection

Implementation Method 2

a radiator that cools a refrigerant of the engine

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

a cooling fan for blowing a cooling air (outside air) to the radiator

Methodology Applied
Scientific EffectForced convection: Forced Convection

Implementation Method 4

a thermostat that opens and closes a flowpath between a fully closed state and a fully opened state in accordance with the temperature of the refrigerant

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP3575568B1Work vehicle
Publication Date: 2023.04.19 HITACHI CONSTRUCTION MACHINERY CO LTD
  • EP3575568B1 patent drawingFigure 1
  • EP3575568B1 patent drawingFigure 2
  • EP3575568B1 patent drawingFigure 3A~3B

AI summary

The work vehicle includes an engine, a radiator; a hydraulic pump; a cooling fan that blows a cooling air to the radiator; a hydraulic motor which is driven by a pressure oil delivered from the hydraulic pump, and rotates the cooling fan; a directional control valve that switches a flow direction of the pressure oil from the hydraulic pump to rotate the hydraulic motor in forward and reverse directions; and a controller that controls the directional control valve so as to cause the repetitive operation of the forward and reverse rotation of the cooling fan to be performed at predetermined time intervals, in which the controller reduces the time intervals more than a normal time initially set when a relationship between the outside air temperature detected by the outside air temperature sensor and the refrigerant temperature detected by the refrigerant temperature sensor satisfies a predetermined condition.