Dump Truck Hydraulic Valve Switching for Hoist and Fan Timing

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Solution Overview

Problem

Existing dump truck technologies lack the ability to switch the destination of hydraulic oil supply between the hoist cylinder and fan motor at appropriate times, leading to inefficiencies in operations.

Innovation Solution

A dump truck equipped with a selector valve that can be controlled by a controller to switch between positions for supplying hydraulic oil to either the hoist cylinder or the fan motor, based on pressure thresholds and operational states, ensuring timely and efficient distribution of hydraulic oil.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the selector valve is switched only when the vessel is seated, then the switching operation is simple, but the timing of hydraulic oil supply cannot be optimized for different operational conditions

Engineering Contradiction:
Improveswitching operation simplicityVSAvoidhydraulic oil supply efficiency
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The control unit continuously monitors the operational state of the dump truck (vessel position, engine speed, cooling water temperature) and uses this feedback information to automatically determine the appropriate timing for switching the selector valve, optimizing hydraulic oil supply based on real-time conditions rather than fixed seating position only

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The control unit predicts the need for hydraulic oil supply to the fan motor in advance by monitoring engine parameters and cooling water temperature trends, switching the selector valve proactively before the actual need arises, ensuring immediate hydraulic oil availability when cooling is required

Inventive Principle:
Principle #10Preliminary action

2Temperature

If the selector valve switches to fan motor early, then cooling operation starts earlier, but hydraulic oil may be supplied unnecessarily when not needed

Engineering Contradiction:
Improvecooling operation timingVSAvoidhydraulic oil waste
Core Design Contradiction:
TemperatureVSLoss of energy

Solution Approach 1:

The control unit continuously monitors engine parameters and cooling water temperature to determine the actual need for cooling, switching the selector valve to the fan motor only when these parameters indicate genuine cooling requirements, thereby avoiding unnecessary hydraulic oil consumption

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The control unit uses changes in engine operating parameters (speed, load, cooling water temperature) as triggers for switching the selector valve, optimizing the timing of hydraulic oil supply to the fan motor based on actual thermal conditions rather than fixed operational states

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If the selector valve switches based on multiple parameters, then the timing precision is improved, but the control system complexity increases

Engineering Contradiction:
Improveswitching timing accuracyVSAvoidcontrol system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The control unit performs multiple functions using a single integrated system: it monitors vessel position, engine speed, cooling water temperature, and automatically controls the selector valve switching, eliminating the need for separate control mechanisms for each parameter and reducing overall system complexity despite handling multiple inputs

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

Enables precise timing of hydraulic oil distribution, enhancing the usability and efficiency of dump truck operations by preventing damage to hydraulic components and optimizing vessel lifting and cooling operations.

Implementation Method 1

a hydraulic pump for discharging a hydraulic oil by a driving force of the engine

Methodology Applied
Scientific EffectHydraulic pump: Pump

Implementation Method 2

a selector valve capable of being switched between positions of a first position for supplying the hoist cylinder with the hydraulic oil discharged from the hydraulic pump and a second position for supplying the fan motor with the hydraulic oil discharged from the hydraulic pump

Methodology Applied
Scientific EffectValve: Valve

Implementation Method 3

a hoist cylinder for raising and lowering the vessel by the hydraulic oil supplied from the hydraulic pump

Methodology Applied
Scientific EffectHydraulic cylinder: Hydraulic Press

Implementation Method 4

a fan motor for driving a fan that supplies the radiator with the cooling air by the hydraulic oil supplied from the hydraulic pump

Methodology Applied
Scientific EffectHydraulic motor:

Implementation Method 5

a radiator for transferring heat between a cooling air and a coolant to be supplied to the engine

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Data Source

PatentEP4309952B1Dump truck
Publication Date: 2026.01.28 HITACHI CONSTRUCTION MACHINERY CO LTD
  • EP4309952B1 patent drawingFigure 1
  • EP4309952B1 patent drawingFigure 2
  • EP4309952B1 patent drawingFigure 3

AI summary

Provided is a dump truck capable of switching a destination of supply of hydraulic oil from a hoist cylinder to a fan motor at an appropriate time. A dump truck comprising: a hydraulic pump for discharging a hydraulic oil by a driving force of the engine; a hoist cylinder for raising and lowering a vessel by the hydraulic oil supplied from the hydraulic pump; a fan motor for driving a fan that supplies a radiator with cooling air by the hydraulic oil supplied from the hydraulic pump; a selector valve capable of being switched between a first position for supplying the hoist cylinder with the hydraulic oil discharged from the hydraulic pump and a second position for supplying the fan motor with the hydraulic oil; and a controller configured to, in a case where the selector valve is in the first position, determine whether an inflow pressure of the hydraulic oil flowing into the selector valve is less than a threshold value, and in a case of determining that the inflow pressure is less than the threshold value, switch the selector valve from the first position to the second position.