Cam Roller Operating Tool Stand for Wheel Loader

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Solution Overview

Problem

Construction machine operation devices require high operating force and are oversized due to the need for gas dampers to control the rotating speed, which increases the size and complexity of the device.

Innovation Solution

The operation device features a support member with a rotatable operating tool stand and a cam roller that uses an elastic member with varying contact surfaces to reduce the operating force, allowing the device to be downsized by eliminating the need for a gas damper, with the cam roller rotating on a contact surface that has a larger deformation area for the operating position and a smaller deformation area for the tilt-up position.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If a gas damper is used to control the rotating speed when the operation device is moved down, then the rotating speed is reduced, but the operating force is increased and the device size is increased

Engineering Contradiction:
Improverotating speedVSAvoidoperating force
Core Design Contradiction:
SpeedVSForce

Solution Approach 1:

The patent changes the physical parameters of the elastic member by varying the distance from the rotating center to the contact point on the cam roller throughout the rotation range. This parameter change allows the elastic force to naturally control the rotating speed without requiring a gas damper, thereby reducing both the operating force and device size while maintaining speed control functionality

Inventive Principle:
Principle #35Parameter changes

2Speed

If a gas damper is used to control the rotating speed when the operation device is moved down, then the rotating speed is reduced, but the device size is increased

Engineering Contradiction:
Improverotating speedVSAvoiddevice size
Core Design Contradiction:
SpeedVSVolume of moving object

Solution Approach 1:

The patent uses parameter changes in the elastic member's geometry (varying contact distance from rotating center) to achieve speed control functionality that would otherwise require a gas damper. This eliminates the need for additional volume-consuming components while maintaining the desired rotating speed control

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent extracts and eliminates the gas damper component from the system by replacing it with a cleverly designed elastic member that achieves the same speed control function through parameter changes, thereby reducing the overall device size

Inventive Principle:
Principle #2Taking out (Extraction)

3Force

If the dimension from rotating center to contact part is increased, then the operating force is reduced, but the amount of deformation of the elastic member is increased

Engineering Contradiction:
Improveoperating forceVSAvoiddimension from rotating center to contact part
Core Design Contradiction:
ForceVSLength of moving object

Solution Approach 1:

The patent applies dynamics by making the dimension from the rotating center to the contact part dynamic rather than static. The dimension changes throughout the rotation range, being larger when operating force needs to be reduced and smaller when deformation needs to be limited, allowing the system to optimize both parameters throughout the operation cycle

Inventive Principle:
Principle #15Dynamics

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 reduces the operating force required to rotate the device and allows for downsizing, improving the efficiency and safety of the operation device by minimizing the impact on the device and its components, while also simplifying the structure and reducing costs.

Implementation Method 1

an elastic member (59) that has a contact surface (60) with which the cam roller (50) comes in elastic contact in accordance with rotation of the rotating member (40)

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP3396073B1Device for operating construction machine
Publication Date: 2023.07.12 HITACHI CONSTRUCTION MACHINERY CO LTD
  • EP3396073B1 patent drawingFigure 1
  • EP3396073B1 patent drawingFigure 2
  • EP3396073B1 patent drawingFigure 3

AI summary

A left operating tool stand (39) disposed on the left side of an operator's seat (15) in a wheel loader (1) includes a support member (32), an operating tool stand (39) rotatably disposed to the support member (32) between an operating position and a tilt-up position, and an operating tool (53) disposed at a front end side of the operating tool stand (39) to operate the wheel loader (1). The operating tool stand (39) includes a rotating member (40) that is rotatably mounted about a support pin (33) as a rotational pivot, the supporting pin (33) being disposed to the support member (32), and a cam roller (50) that is rotatably disposed to the rotating member (40) and rotates together with the rotating member (40) . A dimension (B) from a rotating center (O) of the rotating member (40) to an operating position contact part (60A1) with which the cam roller (50) comes in contact is formed to be smaller than a dimension (C) from the rotating center (O) of the rotating member (40) to a tilt-up position contact part (60B1) with which the cam roller (50) comes in contact.