Hydraulic Track Width Control for Stable Working Vehicles

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Solution Overview

Problem

Existing working vehicles face challenges in maintaining the track width within a predetermined range, as the control systems fail to effectively adjust the track width to a target value, leading to inefficiencies in operation.

Innovation Solution

A working vehicle equipped with a hydraulic actuator-driven changer and a controller that performs alternating drive and idle controls to adjust the track width to a target value, with idle time based on hydraulic fluid temperature and tilt angle, and includes a notification system when the target is reached.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the controller continuously drives the hydraulic actuator to adjust the track width, then the track width can reach the target value, but the hydraulic fluid temperature rises excessively and the system becomes unstable

Engineering Contradiction:
Improvetrack width adjustment precisionVSAvoidhydraulic fluid temperature
Core Design Contradiction:
Manufacturing precisionVSTemperature

Solution Approach 1:

The controller alternates between drive control and idle control in periodic cycles. During drive control, the hydraulic actuator is activated to adjust the track width toward the target value. During idle control, the actuator is deactivated to allow the hydraulic fluid temperature to stabilize. This periodic switching resolves the contradiction by achieving track width precision without continuous hydraulic operation that would cause excessive temperature rise.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The controller performs preliminary assessment of the track width deviation and determines whether drive control is necessary before activating the hydraulic actuator. By evaluating the current state first, the system avoids unnecessary hydraulic operations that would increase fluid temperature, while still ensuring the track width reaches the target value when needed.

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If the controller performs drive control frequently to maintain track width accuracy, then the target value is reached, but the operational time is reduced and efficiency decreases

Engineering Contradiction:
Improvetrack width accuracyVSAvoidoperational efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The controller implements periodic drive control followed by idle control, rather than continuous operation. This allows the system to achieve the necessary track width adjustments in concentrated periods, then transition to idle state to maximize operational efficiency. The periodic nature ensures accuracy is maintained while minimizing the total time the system is in active adjustment mode.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system uses the natural cooling and stabilization properties of the hydraulic system during idle periods to maintain operational readiness without active intervention. The hydraulic actuator and fluid system self-regulate during idle control, reducing the need for frequent active adjustments and improving overall productivity.

Inventive Principle:
Principle #25Self-service

3Manufacturing precision

If the controller activates the hydraulic actuator to adjust track width during work operations, then the target value is reached, but work interruptions occur and stability is reduced

Engineering Contradiction:
Improvetrack width target achievementVSAvoidwork operation stability
Core Design Contradiction:
Manufacturing precisionVSStability of the object's composition

Solution Approach 1:

The controller assesses the current track width and determines whether adjustment is necessary before initiating drive control. By performing preliminary evaluation, the system can avoid unnecessary activations during work operations, maintaining stability while still achieving the target value when genuinely needed. The controller only activates the hydraulic actuator when the track width deviation warrants intervention.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The controller uses periodic drive control with idle control intervals, timing the activations to minimize disruption to work operations. During idle control periods, the system maintains its current configuration without interruption, ensuring work stability. Track width adjustments are achieved during scheduled drive control periods rather than continuously interrupting work operations.

Inventive Principle:
Principle #19Periodic action

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 system ensures precise adjustment of the track width to the target value, enhancing operational efficiency and stability, particularly during work operations.

Implementation Method 1

a changer (35C) to be driven by a hydraulic actuator (39) to change a track width W1 of the traveling device (31)

Methodology Applied
Scientific EffectHydraulic pressure: Hydraulic Press

Data Source

PatentEP4699423A1Working vehicle
Publication Date: 2026.02.25 KUBOTA CORP
  • EP4699423A1 patent drawingFigure 1
  • EP4699423A1 patent drawingFigure 2
  • EP4699423A1 patent drawingFigure 3

AI summary

A working vehicle (1) includes a travel vehicle body (11), a traveling device (31) to support the travel vehicle body (11) such that the travel vehicle body (11) is allowed to travel, a changer (35C) to be driven by a hydraulic actuator (39) to change a track width (W1) of the traveling device (31), and a controller (61) configured or programmed to perform a first change control in which the controller (61) repeats a drive control until the track width (W1) satisfies a target value (W2), the drive control being a control to drive the hydraulic actuator (39) such that the track width (W1) reaches the target value (W2). The controller (61) is configured or programmed to perform the drive control and an idle control alternately from when the first change control is started to when the track width (W1) satisfies the target value (W2), the idle control being a control to not drive the hydraulic actuator (39) for an idle time (T).