Hydraulic Control Device Air Inflow Prevention

Solution Overview

Problem

In hydraulic control devices with fluid couplings and lockup clutches, air can enter the suction port of the oil pump when the vehicle is started after a long stop, reducing discharge efficiency and causing noise due to the communication between the fluid coupling and the suction port.

Innovation Solution

A hydraulic control device with a pressure regulation valve, discharge oil passage, lubrication oil passage, return oil passage, and a flow direction regulation valve that connects or blocks these passages based on differential pressure to prevent air from entering the suction port, ensuring air mixed with oil flows through the lubrication passage and not the return passage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the structure supplies oil drained from the pressure regulation valve to the suction port of the oil pump and to the location to be lubricated, then the lubrication system can be simplified and oil can be efficiently returned to the pump, but air remaining in the fluid coupling can travel through the oil passage and flow into the suction port of the oil pump, causing discharge efficiency to decrease and noise to be generated

Engineering Contradiction:

Improvehydraulic control device structureVSAvoidoil pump discharge efficiency

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The oil passage system is segmented into multiple independent passages: a discharge oil passage for oil discharged from the fluid coupling, a lubrication oil passage for supplying oil to lubrication points, and a return oil passage for returning drained oil to the pump suction port. This segmentation prevents air from the fluid coupling from reaching the pump suction port while maintaining efficient oil circulation and lubrication.

Inventive Principle:

Principle #1Segmentation

2Loss of energy

If the structure supplies oil drained from the pressure regulation valve to the suction port of the oil pump, then oil can be efficiently returned to the pump, but air remaining in the fluid coupling can travel through the oil passage and flow into the suction port of the oil pump, causing noise to be generated

Engineering Contradiction:

Improveoil return efficiencyVSAvoidnoise from oil pump

Core Design Contradiction:

Loss of energyVSObject-generated harmful factors

Solution Approach 1:

The oil passage system is segmented into multiple independent passages: a discharge oil passage for oil discharged from the fluid coupling, a lubrication oil passage for supplying oil to lubrication points, and a return oil passage for returning drained oil to the pump suction port. This segmentation prevents air from the fluid coupling from reaching the pump suction port while maintaining efficient oil circulation and lubrication.

Inventive Principle:

Principle #1Segmentation

3Productivity

If the structure supplies oil drained from the pressure regulation valve to the suction port of the oil pump, then oil can be efficiently returned to the pump, but air remaining in the fluid coupling can travel through the oil passage and flow into the suction port of the oil pump, causing discharge efficiency to decrease

Engineering Contradiction:

Improveoil circulation efficiencyVSAvoidoil pump discharge efficiency

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The oil passage system is segmented into multiple independent passages: a discharge oil passage for oil discharged from the fluid coupling, a lubrication oil passage for supplying oil to lubrication points, and a return oil passage for returning drained oil to the pump suction port. This segmentation prevents air from the fluid coupling from reaching the pump suction port while maintaining efficient oil circulation and lubrication.

Inventive Principle:

Principle #1Segmentation

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 solution effectively prevents air from entering the suction port of the oil pump, maintaining discharge efficiency and reducing noise by isolating the discharge and lubrication passages from the return passage when differential pressure is below a set threshold.

Implementation Method 1

allows communication between the lubrication oil passage and the return oil passage when hydraulic pressure on the return oil passage side is higher than hydraulic pressure on the lubrication oil passage side by a pressure that is equal to or higher than a set differential pressure

Methodology Applied

Scientific EffectDifferential pressure: Pressure Gradient

Data Source

PatentUS10557547B2Hydraulic control device

Publication Date: 2020.02.11 AISIN AW CO LTD

AI summary

A hydraulic control device includes: a pressure regulation valve that regulates a hydraulic pressure of oil supplied from an oil pump; a discharge oil passage through which the oil discharged from a fluid coupling flows when a lockup clutch is disengaged; a lubrication oil passage that supplies the oil from the discharge oil passage to a location to be lubricated; a return oil passage that returns the oil drained from the pressure regulation valve to a suction port of the oil pump; a connection oil passage that connects the lubrication oil passage and the return oil passage; and a flow direction regulation valve that is provided in the connection oil passage.