Hydraulic Pump Speed Control for Discharge Pressure Limiting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional hydraulic control devices face challenges in maintaining the required discharge pressure of a second pump at or below a predetermined level, especially when transitioning to a control mode that keeps the target rotation speed constant, leading to reduced fuel efficiency and increased work load on the first pump due to changes in the hydraulic operation state.
Innovation Solution
The hydraulic control device includes a control part that calculates and adds an additional rotation speed to the target rotation speed of the second pump based on detected oil temperature and the ratio of the continuously variable transmission mechanism, ensuring the required discharge pressure is maintained at or below the predetermined level by accurately matching the pressure of the first oil with the estimated pressure of the third oil.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the control transitions to a mode that keeps the target rotation speed of the second pump constant, then the control complexity is reduced, but the required discharge pressure cannot be reliably maintained at or below the predetermined pressure due to changes in operation state
Solution Approach 1:
The control part continuously monitors the actual discharge pressure of the second pump and compares it with the predetermined pressure. When the actual pressure exceeds the predetermined pressure, the control part adjusts the target rotation speed of the second pump to bring the pressure back within the acceptable range. This feedback mechanism ensures reliable pressure maintenance while allowing the system to operate in a simplified constant speed mode during normal conditions.
Solution Approach 2:
The control system dynamically switches between two operational modes: a constant target rotation speed mode for normal operation, and a pressure-regulated mode when the discharge pressure exceeds the predetermined level. This dynamic adjustment allows the system to maintain simplicity during stable operation while automatically adapting to maintain pressure reliability when operational conditions change.
2Power
If the required discharge pressure is not maintained at or below the predetermined pressure, then the first pump's work load increases, but the fuel consumption increases as a result
Solution Approach 1:
The control part uses feedback from pressure sensors to monitor the discharge pressure of the second pump. When the pressure exceeds the predetermined level, the system automatically increases the second pump's rotation speed to maintain proper pressure, preventing the first pump from working harder and avoiding unnecessary fuel consumption.
Solution Approach 2:
The second pump is designed to automatically regulate its own operation based on system pressure conditions. When the discharge pressure rises above the predetermined level, the second pump self-adjusts its rotation speed to maintain pressure within acceptable ranges, thereby protecting the first pump from excessive workload and preventing increased fuel consumption without requiring external intervention.
Data Source
AI summary
Provided is a hydraulic control device in which in the rotation control of the second pump, the required discharge pressure of the second pump can be more reliably maintained below a predetermined pressure in the control that keeps the target rotation speed constant after the feedback control ends. In the rotation control of the second pump, in the control which keeps the target rotation speed constant after the feedback control ends, the rotation of the second pump is controlled by adding a predetermined addition rotation speed to the target rotation speed corresponding to the required discharge pressure. Since the required discharge pressure of the second pump can be maintained below a predetermined pressure in the fixed mode by the addition rotation speed, it can reliably obtain the effect of reducing the work load of the first pump and contribute to the improvement of the fuel efficiency of the vehicle.