Engine Drive Check Circuit With Relay-Based Safe Start Indication

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Solution Overview

Problem

Existing engine drive checking systems for work vehicles are costly and require complex electronic devices like microcomputers, making them expensive and difficult to maintain, while also not providing clear reasons for engine startup failures.

Innovation Solution

A system using check switches and a power supply relay to ensure safe engine operation without a microcomputer, where electric power is supplied only when all switches are in safe positions, and a display indicates the switched state, allowing direct confirmation of safe driving conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a microcomputer-based engine ECU is used to determine engine start conditions, then the system can provide comprehensive safety checking and information display, but the cost increases and maintenance becomes difficult due to vulnerability to rainwater and dust

Engineering Contradiction:

Improvesafety checking functionVSAvoidmicrocomputer and peripheral devices

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the safety checking function from the complex microcomputer-based ECU system and implements it using simple check switches connected directly to the battery terminal. This removes the vulnerable microcomputer and peripheral devices while retaining the essential safety checking capability through a minimalist electrical circuit design.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces expensive and maintenance-intensive microcomputer components with inexpensive check switches and LED indicators. These simple components are robust, inexpensive to replace, and do not require protection from environmental factors like rainwater and dust, significantly reducing system cost and maintenance burden.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

2Reliability

If multiple sensor signals are input to the engine ECU for engine start determination, then comprehensive safety conditions can be monitored, but the system requires costly software and protection measures for the microcomputer

Engineering Contradiction:

Improveengine start condition monitoringVSAvoidsoftware cost and protection measures

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces the electronic/software-based monitoring system with a direct electrical circuit implementation. Check switches physically connected to the battery terminal provide monitoring of engine start conditions through simple electrical continuity, eliminating the need for software processing and microcomputer-based protection measures.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent divides the safety monitoring function into separate check switches for different safety conditions (seat position, brake status, etc.), each independently connected to the battery terminal. This segmentation allows each safety condition to be monitored separately through simple switch contacts without requiring integrated software processing.

Inventive Principle:

Principle #1Segmentation

3Device complexity

If check switches are connected directly to the battery terminal through a power supply relay, then the system becomes simpler and more maintenance-easy, but the display must clearly indicate switch states for driver awareness

Engineering Contradiction:

Improvecontrol circuitVSAvoidswitch state information

Core Design Contradiction:

Device complexityVSLoss of information

Solution Approach 1:

The patent uses LED indicators that change color or illumination state to clearly display the status of check switches. Different LED states (on/off, different colors) provide immediate visual feedback to the driver about safety condition status, preventing information loss despite the simplified control circuit.

Inventive Principle:

Principle #32Color changes

Solution Approach 2:

The patent implements immediate visual feedback through LED indicators that directly reflect the state of check switches. This feedback loop ensures the driver is continuously informed about safety conditions without requiring complex display systems, maintaining information transparency while keeping the control circuit simple.

Inventive Principle:

Principle #23Feedback

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 solution provides an inexpensive and maintenance-easy method to ensure safe engine operation by directly confirming the states of check switches, preventing engine startup in non-safe conditions and allowing drivers to recognize safe driving states through simple lighting arrangements.

Implementation Method 1

a power supply line having a power supply relay and supplying electric power to the engine controller when the power supply line is ON

Methodology Applied

Scientific EffectRelay: Relay

Data Source

PatentUS10995722B2Work vehicle having engine drive checking circuit

Publication Date: 2021.05.04 KUBOTA CORP

AI summary

A work vehicle includes an engine controller for driving an engine, a power supply line, a power supply control line, and a display signal line. When a check switch switchable into a safe position corresponding to safe drive of the engine and a non-safe position is switched to the safe position, the power supply control line renders a power supply relay ON. The display signal line transmits a signal indicative of the switched state of the check switch to a display.