Parallel Relief Valves for Engine Oil Circuit Pressure Control
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Solution Overview
Problem
Existing engine oil circuit relief devices experience high oil pressure and energy loss at low temperatures, leading to reduced fuel efficiency, due to the serial connection of temperature-sensitive and oil pressure control valves, which results in large control variations and difficulty in fine-tuning oil pressure.
Innovation Solution
A relief device with an oil pressure relief valve and a temperature-sensitive relief valve disposed in parallel, allowing independent operation based on discharge pressure and oil temperature, enabling precise control of oil pressure and relief amount across varying temperature ranges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the temperature-sensitive relief valve and oil pressure relief valve are connected in series, then the relief pressure can be adjusted according to temperature, but the control variation becomes large and fine control of oil pressure becomes difficult
Solution Approach 1:
The patent divides the relief valve system into two independent parallel valves: a temperature-sensitive relief valve (50) that responds only to temperature changes, and an oil pressure relief valve (51) that responds only to pressure changes. This segmentation allows each valve to perform its specific function independently, preventing the accumulation of control variations that would occur in a series connection, and enabling fine control of oil pressure through the pressure-sensitive valve alone.
2Ease of operation
If the second control valve controls oil pressure instead of flow rate, then the valve can operate as an ON/OFF valve, but it becomes difficult to perform fine control
Solution Approach 1:
The patent separates the control functions into two independent valves with distinct characteristics. The temperature-sensitive relief valve (50) operates as a simple ON/OFF valve based on temperature, while the oil pressure relief valve (51) provides fine control based on pressure. This segmentation allows each valve to excel at its specific control task without the limitations of trying to perform both functions in a single valve.
3Reliability
If the first control valve performs relief at high oil pressure, then the discharge pressure per unit rpm increases during low temperature periods, but this causes large energy loss and reduced fuel efficiency
Solution Approach 1:
The temperature-sensitive relief valve (50) performs preliminary relief action when oil temperature is low, preventing the oil pressure from rising to levels that would cause excessive energy loss. By acting beforehand based on temperature detection, the system avoids the need to maintain high discharge pressure during low-temperature periods, thereby reducing energy loss and improving fuel efficiency while still ensuring adequate pressure when needed.
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
This configuration maintains consistent oil pressure characteristics across temperatures, prevents energy loss, and enhances fuel efficiency by allowing stepless control of oil pressure, reducing the need for additional components and simplifying the device design.
Implementation Method 1
a temperature-sensitive relief valve that performs the oil relief by sensing an oil temperature of the oil and opening and closing steplessly
Implementation Method 2
an oil pressure relief valve that performs oil relief with movement of a valve body by pressure of oil
Data Source
AI summary
[Problem] To provide a relief device for an oil circuit of an engine provided with an oil pressure relief valve and a temperature-sensitive relief valve, with which it is possible for oil to be relieved (expelled) at the intended pressure regardless of the oil temperature, and with which it is possible to simplify the configuration. [Solution] The relief device comprises an oil pump (9), an upstream channel (61) provided from a discharge side of the oil pump (9) to an engine (E), an oil pressure relief valve (A) for relieving oil due to the valve body being moved by oil pressure, and a temperature-sensitive relief valve (B) for relieving oil by sensing the oil temperature and continuously opening and closing. The oil pressure relief valve (A) and the temperature-sensitive relief valve (B) are arranged in parallel in the upstream channel (61).