Hydraulic Drive System Relief Valve for Engine Torque Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing hydraulic drive systems for construction machinery face instability in engine load torque and exhaust gas temperature when trying to remove particulate matter from filters, leading to complex control systems and increased component counts, especially when steering and loading/unloading actuators are connected in parallel.
Innovation Solution
A hydraulic drive system that includes a pump, steering and loading/unloading actuators, a drive device to control hydraulic oil flow, and a relief valve to increase engine torque by discharging hydraulic oil to a tank, ensuring preferential operation of the steering actuator and stable load torque.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a variable throttle valve is used to adjust pump discharge pressure to increase engine load torque for PM removal, then the temperature of exhaust gas increases, but the load torque becomes unstable and the control system becomes complex
Solution Approach 1:
The invention extracts the pressure control function from the throttle valve and implements it through a relief valve that automatically discharges hydraulic oil when pressure reaches a predetermined level. This eliminates the need for complex feedback control of the throttle valve while maintaining stable engine load torque for effective PM removal.
Solution Approach 2:
The relief valve automatically regulates hydraulic pressure by discharging excess oil to the tank when the predetermined pressure is reached, creating a self-regulating system that stabilizes engine load torque without requiring complex external control mechanisms.
2Ease of operation
If variable throttle valves are provided at both steering and loading/unloading sides to preferentially drive the steering actuator, then the number of components increases, but the steering actuator can operate preferentially
Solution Approach 1:
The relief valve serves multiple functions: it controls hydraulic pressure for engine load torque regulation and simultaneously enables preferential steering operation by directing hydraulic oil flow based on system pressure requirements, eliminating the need for separate control valves at each actuator.
Solution Approach 2:
The invention combines the pressure control function and the preferential steering control function into a single relief valve system, reducing the number of components while achieving both objectives through unified pressure-based flow management.
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
Effectively removes particulate matter from filters by increasing engine torque and temperature while simplifying control and reducing the number of components needed, ensuring preferential operation of the steering actuator.
Implementation Method 1
causes the hydraulic oil from the pump to be discharged to the tank via the relief valve to increase the torque of the engine
Implementation Method 2
a pump configured to be driven by an engine and discharge hydraulic oil
Data Source
AI summary
A hydraulic drive system includes a pump, a steering actuator, a loading/unloading apparatus actuator, a drive device, a relief valve, and an input unit. The drive device: flows hydraulic oil from the pump to the loading/unloading apparatus actuator when an operating tool is operated; flows the hydraulic oil from the pump to the steering actuator when a steering has become an operated state from a non-operated state regardless of an operation of the operating tool; and causes the hydraulic oil from the pump to be discharged to a tank via the relief valve to increase the torque of an engine when an increase instruction is inputted to the input unit and the steering is in a non-operated state.