Supercharger Control Device Thermal Management via Hydraulic Pump Torque Restriction

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Solution Overview

Problem

Recent engine downsizing has increased the load on superchargers in work machines, leading to elevated temperatures that can cause control device failure, with existing technologies failing to adequately address the heat influence on these devices.

Innovation Solution

A work machine equipped with a variable geometry supercharger, a variable displacement hydraulic pump, and a control system that includes a temperature detection device and a main control device to restrict the maximum absorbing torque of the pump and adjust the cooling fan's rotational speed based on the supercharger control device's temperature, thereby reducing heat stress.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If engine downsizing is implemented to meet exhaust gas regulations, then emission compliance is improved, but the load on the supercharger increases leading to higher temperatures and potential control device failure

Engineering Contradiction:
Improveexhaust gas emission complianceVSAvoidcontrol device reliability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The control device monitors the temperature of the supercharger control unit in real-time and adjusts the hydraulic pump's absorbing torque based on this feedback. When temperature exceeds a predetermined threshold, the system reduces the pump's torque output to lower heat generation, thereby preventing control device failure while maintaining emission compliance through the variable geometry turbocharger.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically changes the operating parameters of the hydraulic pump by adjusting its absorbing torque based on temperature conditions. The main control device modifies the pump's torque output parameter in response to temperature feedback, creating a adaptive control strategy that prevents overheating while maintaining supercharger performance for emission compliance.

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If the supercharger load is increased to meet exhaust gas regulations at slow rotation, then emission compliance is improved, but the temperature of the control device increases potentially causing failure

Engineering Contradiction:
Improveexhaust gas emission complianceVSAvoidcontrol device temperature
Core Design Contradiction:
Object-affected harmful factorsVSTemperature

Solution Approach 1:

The temperature detection device continuously monitors the control device temperature and provides feedback to the main control device. When the temperature reaches a predetermined threshold, the system activates a control strategy to reduce the hydraulic pump's absorbing torque, thereby lowering heat generation and preventing temperature-related failure while maintaining emission compliance.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system takes preliminary action by monitoring temperature trends and proactively reducing the pump's absorbing torque before the temperature reaches critical levels that would cause control device failure. This preventive measure counteracts the heat generation from increased supercharger load, ensuring continuous operation while meeting emission requirements.

Inventive Principle:
Principle #9Preliminary anti-action

3Temperature

If the hydraulic pump's absorbing torque is reduced to lower control device temperature, then temperature control is improved, but the working device performance may be affected

Engineering Contradiction:
Improvecontrol device temperatureVSAvoidworking device performance
Core Design Contradiction:
TemperatureVSProductivity

Solution Approach 1:

The system implements dynamic control of the hydraulic pump's absorbing torque based on real-time temperature conditions. The main control device adjusts the pump's torque output dynamically, increasing it when temperature is acceptable to maximize working device performance and reducing it when temperature exceeds thresholds to prevent control device failure, thereby optimizing both performance and temperature control.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the hydraulic pump's operating parameters (absorbing torque) based on temperature conditions. By dynamically adjusting this parameter, the system can optimize performance when temperature is acceptable and prevent overheating when temperature exceeds thresholds, balancing working device performance with temperature control through parameter adaptation.

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 configuration effectively reduces the temperature of the supercharger control device, prolongs its lifespan, and prevents potential failures, ensuring continuous operation while meeting exhaust gas regulation requirements.

Implementation Method 1

a variable geometry supercharger (50) having changeable supercharge pressure

Methodology Applied
Scientific EffectVariable geometry turbo: Turbine

Implementation Method 2

a temperature detection device configured to detect the temperature of the supercharger control device

Methodology Applied
Scientific EffectTemperature detection:

Implementation Method 3

a main control device configured to restrict, in case the temperature of the supercharger control device is higher than a first temperature, a maximum absorbing torque of the work hydraulic pump

Methodology Applied
Scientific EffectTorque restriction control:

Implementation Method 4

a cooling fan configured to cool the supercharger control device

Methodology Applied
Scientific EffectForced convection cooling: Forced Convection

Data Source

PatentEP3396130B1Work machine
Publication Date: 2023.04.12 HITACHI CONSTRUCTION MACHINERY CO LTD
  • EP3396130B1 patent drawingFigure 1
  • EP3396130B1 patent drawingFigure 2
  • EP3396130B1 patent drawingFigure 3A~3B

AI summary

To reduce increase of the temperature of a control device of a supercharger and increase the lifetime of the control device of the supercharger, a work machine includes a variable geometry supercharger having changeable supercharge pressure and a working device. The work machine includes a variable displacement work hydraulic pump configured to be driven by an engine and supply pressure oil to an actuator configured to drive the working device; a supercharger control device configured to control the supercharger; a temperature detection device configured to detect the temperature of the supercharger control device; and a main control device configured to restrict, in case the temperature of the supercharger control device is higher than a first temperature, a maximum absorbing torque of the work hydraulic pump as compared to case the temperature of the supercharger control device is lower than the first temperature.