Work Vehicle Load Control via Pump Swash Plate Adjustment

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Solution Overview

Problem

Conventional load control structures for work vehicles are not suitable for a wide range of engine loads, as they either focus on small or large engine loads separately, lacking a comprehensive solution for operations across the entire load spectrum.

Innovation Solution

A load control structure that includes means for detecting engine load, swash plate position, and operating elements, with automatic control mechanisms to adjust the swash plate of both the variable displacement pump and motor between speed change positions, ensuring optimal operation across varying engine loads.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If conventional load control structures are used, then control simplicity is maintained, but comprehensive load range coverage is lost

Engineering Contradiction:
Improvecontrol structure simplicityVSAvoidload range coverage
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The control means is designed with multi-functionality, capable of performing both pump swash plate control and motor swash plate control within a single integrated system. This universal control architecture allows the system to manage the entire engine load spectrum without requiring separate control systems for different load ranges, thus maintaining control structure simplicity while achieving comprehensive load range coverage.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentUS7469534B2Load control structure for work vehicle
Publication Date: 2008.12.30 KUBOTA CORP
  • US7469534B2 patent drawing
  • US7469534B2 patent drawing
  • US7469534B2 patent drawing

AI summary

A load control structure for a work vehicle comprises: a device for detecting operating position of a manually operated speed change operating element; an engine load detection device for detecting load on an engine of the work vehicle; a swash plate position detecting device for detecting an operating position of a swash plate of a variable displacement pump of a hydrostatic continuously variable speed change device; a pump operating device for steplessly operating the swash plate of the variable displacement pump; a motor operating device for operating a swash plate of a variable displacement motor of the hydrostatic continuously variable speed change device between at least two speed change positions including a higher speed position and a lower speed position; a control device for controlling the operations of the pump operating device and the motor operating device. The control device has a automatic pump swash plate control device for controlling the operation of the pump operating device, based on detected information from the load detection device and detected information from the swash plate position detecting device, such that the greater an engine load is, greater is the extent to which the swash plate of the variable displacement pump is operated to a low speed side; and a motor swash plate control device for controlling the motor operating device so as to change the position of the swash plate of the variable displacement motor between the at least two speed change positions.