Torque Controller for Three Pump Construction Machinery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional three-pump systems for hydraulic excavators cannot accurately control the total absorption torque of hydraulic pumps, leading to inefficient use of engine output torque due to inaccuracies in determining absorption torque during torque control of the third hydraulic pump.
Innovation Solution
A torque control apparatus that includes a first regulator for the first and second hydraulic pumps and a second regulator for the third hydraulic pump, with a controller that computes and adjusts the maximum absorption torque based on the delivery pressure of the third pump, ensuring accurate torque control and efficient engine torque utilization by using speed sensing control to adjust the maximum absorption torque available to the first and second pumps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the delivery pressure of the third hydraulic pump is directly fed back to the first regulator without correction, then the control system is simple, but the maximum absorption torque allocated to the first and second pumps becomes inaccurate when the third pump operates above a predetermined pressure
Solution Approach 1:
The patent introduces a correction value as an intermediary element between the third pump delivery pressure and the maximum absorption torque allocation. The correction value compensates for the difference between the actual absorption torque of the third pump and the reference absorption torque, enabling accurate torque allocation without directly modifying the feedback mechanism from the third pump to the first regulator.
Solution Approach 2:
The patent replaces the direct mechanical pressure feedback system with a computational control approach. Instead of using a purely mechanical linkage to allocate torque based on third pump pressure, the system uses a controller to compute the correction value and adjust the maximum absorption torque allocation accordingly, substituting mechanical directness with computational precision.
2Power
If the maximum absorption torque allocated to the first and second pumps is increased when the third pump pressure is high, then engine torque utilization improves, but the risk of exceeding total engine output torque increases
Solution Approach 1:
The patent implements a feedback mechanism where the delivery pressure of the third hydraulic pump is continuously monitored and fed back to the controller. Based on this feedback and the computed correction value, the maximum absorption torque allocated to the first and second pumps is dynamically adjusted, ensuring that the total absorption torque of all three pumps never exceeds the engine's output torque capability.
Solution Approach 2:
The patent makes the maximum absorption torque allocation dynamic rather than fixed. The allocation to the first and second pumps changes in real-time based on the third pump's operating pressure and the computed correction value, allowing the system to optimize engine torque utilization while maintaining reliability under varying operational conditions.
3Reliability
If absorption torque control is exercised on the third hydraulic pump using spring means, then the maximum absorption torque is limited, but the ability to accurately determine the actual absorption torque for allocation purposes is compromised
Solution Approach 1:
The patent establishes a reference absorption torque for the third hydraulic pump before actual operation. This reference value serves as a baseline for computing the correction value, allowing the system to accurately determine the actual absorption torque by comparing it with the predetermined reference, even when spring means are used to limit the maximum absorption torque during operation.
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
The present invention provides a torque control apparatus for a construction machine three-pump system that can accurately control the total absorption torque of first, second, and third hydraulic pumps (2, 3, 4) and effectively use the output torque of an engine. A pump base torque computation section 42 calculates a pump base torque Tr from a target rotation speed. A subtraction section 44 calculates a reference value Tf for the maximum absorption torque available to the first and second hydraulic pumps 2, 3 by subtracting a third pump reference absorption torque T3r from the pump base torque Tr. A correction torque computation section 45 calculates a correction torque value from the delivery pressure of the third hydraulic pump 4. An addition section 46 calculates a target absorption torque Tn by adding the correction torque value Tm to the reference value Tf. A first regulator 31 is controlled so as to obtain the target absorption torque Tn.