Hydraulic Fan Drive Control for Pressure Hunching Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional hydraulic drive fan control devices experience peak pressure and pressure hunching issues, leading to damage and reduced lifespan of hydraulic equipment due to inadequate control of fan rotational speed variations, especially in dump trucks during loading and unloading operations.
Innovation Solution
A hydraulic drive fan control device comprising a variable displacement hydraulic pump, a hydraulic motor, a flow amount control valve, and a controller that adjusts the pump and valve signals based on engine rotational speed detection to maintain consistent fan rotational speed, minimizing peak pressure and pressure hunching by implementing specific control signals for different operational states.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If feedback control or PI control is used to control the rotational speed of the hydraulic drive fan, then the rotational speed control precision is improved, but peak pressure and pressure hunching are generated in the hydraulic circuit causing damage to hydraulic equipment
Solution Approach 1:
The control device predicts future engine rotational speed based on current rotational speed and acceleration, then adjusts the hydraulic pump delivery capacity in advance to match the predicted speed. This preliminary action prevents pressure fluctuations by proactively adjusting system parameters before changes occur, rather than reacting to deviations after they happen.
Solution Approach 2:
The control device continuously monitors engine rotational speed and acceleration, using this feedback to dynamically adjust the predicted rotational speed and accordingly modify the hydraulic pump delivery capacity. This closed-loop feedback mechanism ensures the fan rotational speed tracks the target speed while preventing pressure hunching through real-time adjustments.
2Reliability
If the rotational speed of the hydraulic drive fan is controlled to match target speed, then cooling performance is improved, but hydraulic equipment devices are damaged due to pressure hunching and fluctuations
Solution Approach 1:
By predicting future engine rotational speed and adjusting the hydraulic pump delivery capacity in advance, the system maintains appropriate cooling performance while avoiding the pressure fluctuations that would damage hydraulic equipment. The preliminary adjustment prevents both under-cooling and equipment damage.
Solution Approach 2:
The control device acts as an intermediary between the engine and hydraulic pump, using predicted rotational speed to mediate the connection and smoothly transmit power requirements. This intermediary control prevents direct transmission of pressure hunching to the hydraulic equipment while maintaining cooling effectiveness.
3Stability of the object's composition
If the delivery capacity of the hydraulic pump is adjusted to control fan speed, then fan rotational speed stability is improved, but pressure hunching is generated causing fluctuations in hydraulic circuit
Solution Approach 1:
The system adjusts the hydraulic pump delivery capacity in advance based on predicted engine rotational speed, achieving smooth fan speed transitions without abrupt changes. This preliminary adjustment eliminates pressure hunching by avoiding sudden capacity changes that would cause hydraulic circuit fluctuations.
Solution Approach 2:
The control device dynamically adjusts the hydraulic pump delivery capacity according to the predicted engine rotational speed and its rate of change. This dynamic adjustment maintains fan rotational speed stability while adapting to varying operating conditions without generating pressure hunching.
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 solution effectively suppresses rotational speed variations of the hydraulic drive fan, preventing peak pressure and pressure hunching, thereby reducing wear and tear on hydraulic equipment and extending their lifespan.
Implementation Method 1
a variable displacement hydraulic pump 2, which is driven by a prime mover 4 and varies a delivery capacity in response to a control signal to be inputted to a capacity variable part 2B
Implementation Method 2
a hydraulic motor 6, which is driven by pressurized oil to be delivered from the variable displacement hydraulic pump 2
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
A hydraulic drive fan control device (21) is provided with a variable displacement hydraulic pump (2), a hydraulic motor (6) that is driven by pressurized oil from the hydraulic pump (2), a hydraulic drive fan (7) that is driven by the hydraulic motor (6), a flow amount control valve (8) that changes a flow amount of the pressurized oil to be delivered to the hydraulic motor (6), a rotational speed detector (14) that detects a rotational speed of an engine (4), and a controller (16) that outputs a control signal to the hydraulic pump (2) and the flow amount control valve (8) in accordance with the rotational speed of the engine (4). The controller (16) outputs a first valve control signal to the flow amount control valve (8) and outputs a first pump control signal to the hydraulic pump (2) to rotate the hydraulic drive fan (7) at a first rotational speed, and outputs a second valve control signal to the flow amount control valve (8) and outputs a second pump control signal to the hydraulic pump (2), thereby stopping the rotation of the hydraulic drive fan (7).