Excavator Gate Lock Control for Pilot Pressure Operation Errors

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Solution Overview

Problem

Existing excavator systems allow actuators to move unintentionally due to delayed detection of pilot pressure reaching a predetermined threshold, leading to unintended operations.

Innovation Solution

Incorporating a control valve system with a gate lock device, proportional valve, and control part that receives operation signals to determine and prevent operational errors by managing pilot pressure and actuator control based on the gate lock valve's state.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the system waits for pilot pressure to reach a predetermined threshold before detecting operations, then the detection is based on a reliable pressure signal, but the actuator may move unintentionally during the delay period

Engineering Contradiction:
Improvedetection reliabilityVSAvoidresponse time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The gate lock device is activated in advance to lock the control valve before the pilot pressure reaches the predetermined threshold. This preliminary action prevents any potential unintended actuator movement during the pressure buildup period, while the control unit still monitors operation member status to detect operational errors promptly once pressure is established.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If the gate lock device is activated immediately upon pressure detection, then unintended operations are prevented, but normal operations may be unnecessarily restricted

Engineering Contradiction:
Improveoperation safetyVSAvoidoperation flexibility
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The control unit continuously monitors both the pilot pressure level and the status of operation members. The gate lock device is activated only when both conditions are met: pressure reaches the predetermined threshold AND an operation member is detected in an operational state. This feedback mechanism ensures that normal operations are not unnecessarily restricted while still preventing unintended movements.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically adjusts the locking state of the gate lock device based on real-time conditions. The control valve transitions between locked and unlocked states according to the combined status of pressure detection and operation member detection, providing adaptive control that balances safety with operational flexibility.

Inventive Principle:
Principle #15Dynamics

3Measurement precision

If the system monitors both pressure and operation member status, then operational errors are accurately detected, but the system complexity increases

Engineering Contradiction:
Improveerror detection accuracyVSAvoidcontrol system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The control unit performs multiple functions: it monitors pilot pressure levels, detects operation member status, determines operational errors, and controls the gate lock device activation. By consolidating these functions into a single control unit, the system achieves high measurement precision for error detection while minimizing the increase in overall system complexity through functional integration.

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

Prevents unintended actuator operations by accurately detecting and responding to operational errors, ensuring intended operator actions are maintained.

Implementation Method 1

a proportional valve provided on the pilot line; and a control part configured to receive as input the operation signal, to control the proportional valve

Methodology Applied
Scientific EffectHydraulic pressure control: Hydraulic Press

Implementation Method 2

a gate lock valve provided on a pilot line supplying the pilot pressure to the control valve, and configured to open or close according to a state of the gate lock device

Methodology Applied
Scientific EffectValve actuation: Valve

Data Source

PatentEP4012111B1excavator
Publication Date: 2023.08.30 SUMITOMO CONSTRUCTION MACHINERY
  • EP4012111B1 patent drawingFigure 1
  • EP4012111B1 patent drawingFigure 2
  • EP4012111B1 patent drawingFigure 3

AI summary

An excavator is provided that prevents an operation of an actuator not intended by an operator. The excavator includes a control valve configured to control hydraulic oil to be supplied to an actuator, based on pilot pressure; an electric operation device configured to output an operation signal; a gate lock device; a gate lock valve provided on a pilot line supplying the pilot pressure to the control valve, and configured to open or close according to a state of the gate lock device, so as to switch between a locked state and a released state; a proportional valve provided on the pilot line; and a control part configured to receive as input the operation signal, to control the proportional valve, wherein the control part determines, in a case where the gate lock valve is in the locked state by the gate lock device and an operation is performed on the electric operation device, the operation as an operational error.