Construction Machine Heat Exchanger Shroud Design

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Solution Overview

Problem

Conventional heat exchanging devices in construction machines, such as hydraulic excavators, have a complex shroud design that increases size, weight, manufacturing costs, and reduces assembling and maintenance workability due to the arrangement of the cooling fan, oil cooler, and radiator.

Innovation Solution

A simplified shroud design is implemented where the cooling fan partially enters the frame member, allowing sufficient gap from the oil cooler and radiator, enabling efficient air supply while preventing interference, and the shroud is detachably fixed with a simple flat plate shape, reducing size and weight.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the cooling fan is arranged at a position away from the oil cooler and radiator by a predetermined dimension, then the rotating cooling fan does not interfere with the oil cooler and radiator and cooling air is supplied to the entirety, but the shroud becomes box-shaped with complicated shape, increasing size, weight, and manufacturing cost

Engineering Contradiction:
Improvecooling performanceVSAvoidshroud shape complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The shroud is divided into a first shroud and a second shroud that are detachably coupled together. This segmentation allows the shroud to be assembled in parts, simplifying the overall structure and reducing complexity while maintaining the necessary cooling fan clearance and air supply function.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The shroud design transitions from a fixed box-shaped structure to a detachable assembly of multiple parts. This dynamic configuration enables easier assembly, disassembly for maintenance, and storage, while reducing the overall complexity of the shroud structure.

Inventive Principle:
Principle #15Dynamics

2Reliability

If the shroud is formed to cover the space among the cooling fan, oil cooler, and radiator, then ambient air is not sucked from the space, but the size and weight of the heat exchanging device increase

Engineering Contradiction:
Improvecooling efficiencyVSAvoidheat exchanging device weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The shroud is segmented into detachable parts that can be coupled together, reducing the overall material required compared to a solid box-shaped structure. This maintains the necessary air flow control while reducing weight.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The shroud uses thin plate-like structures that are detachably coupled, providing the necessary air flow control function with minimal material, thereby reducing the overall weight of the heat exchanging device.

Inventive Principle:
Principle #30Flexible shells and thin films

3Reliability

If the shroud has a complicated shape to prevent ambient air suction, then manufacturing cost increases and assembling and maintenance workability decrease

Engineering Contradiction:
Improveair flow controlVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The shroud is divided into standardizable modular parts (first and second shrouds) that can be manufactured separately and assembled. This segmentation simplifies manufacturing processes, reduces tooling costs, and improves assembly workability while maintaining air flow control function.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The detachable shroud design allows for easier manufacturing of individual parts with simpler geometries, reducing manufacturing complexity and cost compared to producing a single complicated box-shaped structure.

Inventive Principle:
Principle #15Dynamics

4Ease of operation

If the cooling fan partially enters the frame member, then the gap from oil cooler and radiator is sufficient for air supply while preventing interference, but the shroud design becomes more challenging

Engineering Contradiction:
Improveair supply efficiencyVSAvoidshroud assembly complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The shroud is segmented into detachable parts that can be positioned and coupled to achieve the optimal cooling fan clearance. This segmentation makes it easier to accommodate the partial entry configuration while maintaining sufficient air supply gaps.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The detachable shroud structure acts as an intermediary element that facilitates the partial entry configuration of the cooling fan into the frame member, providing the necessary spacing and air flow paths without direct interference with the oil cooler and radiator.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 reduces the size and weight of the heat exchanging device, lowers manufacturing costs, and enhances assembling and maintenance workability by simplifying the shroud shape and allowing easier access for cleaning and inspection.

Implementation Method 1

a cooling fan having a plurality of blades around a hub member located on one side of the engine in the left and right direction and mounted on an output shaft of the engine and generating cooling air by being driven by the engine

Methodology Applied
Scientific EffectForced Convection: Forced Convection

Implementation Method 2

a heat exchanging device including an oil cooler provided on the revolving frame so as to face the cooling fan and cooling the hydraulic oil and a radiator for cooling coolant of the engine

Methodology Applied
Scientific EffectHeat Exchanger: Heat Exchanger

Data Source

PatentEP3112538B1Construction machine
Publication Date: 2019.06.26 HITACHI CONSTRUCTION MACHINERY TIERRA CO LTD
  • EP3112538B1 patent drawingFigure 1
  • EP3112538B1 patent drawingFigure 2
  • EP3112538B1 patent drawingFigure 3

AI summary

A heat exchanging device (19) includes a fame member (20) assembled having a square frame shape by using a lower frame (21) extending in a front and rear direction and mounted on a revolving frame (5), side frames (22, 23) extending to an upper side from both ends of the lower frame (21), and an upper frame (24) extending on an upper part of the side frames (22, 23). A cooling fan (17) is disposed in a state in which each of the blades (17B) enters into the frame member (20) from an engine side end surface (20A) with respect to the frame member (20). An oil cooler (28) and a radiator (30) are mounted on a mounting surface plate (25) on an opposite side to the engine (16) and interposing said cooling fan (17) at an interval from the cooling fan (17) with respect to the frame member (20). A flat plate shaped shroud (31) surrounding each of the blades (17B) of the cooling fan (17) and forming a fan accommodating chamber (32) among the frame member (20), the oil cooler (28), and the radiator (30) is mounted on the engine side end surface (20A) of the frame member (20).