Oil Pump Control Valve Venting for Fail-Safe Pressure Relief

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Solution Overview

Problem

Conventional oil pump control valves experience internal pressure changes that hinder the return motion of the plunger and spool, and fail to operate during abnormal power shutdowns, leading to uncontrolled fluid pressure in the oil pump system.

Innovation Solution

The design incorporates a spool with distinct ring-shaped lands and a vent hole, along with a spool fluid channel and notch, to communicate the solenoid unit with the outside, reducing internal pressure and enabling fluid flow control during power failures through differential outer diameters of the spool portions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the solenoid unit is sealed without pressure relief, then structural simplicity is maintained, but internal pressure changes adversely affect plunger and spool return motion

Engineering Contradiction:
Improvesolenoid unit structureVSAvoidplunger return motion
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

A communication passage is introduced as an intermediary element between the solenoid unit's internal space and the external environment. This passage allows pressure equalization without requiring complex active control mechanisms, enabling the plunger and spool to return to their initial positions reliably while maintaining structural simplicity.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Use of energy by moving object

If the oil pump control valve stops during power failure, then power consumption is reduced, but fluid pressure becomes uncontrolled and adversely affects the system

Engineering Contradiction:
Improvepower consumptionVSAvoidfluid pressure control
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The valve unit is designed with inherent fail-safe characteristics where the spool automatically returns to its initial position through the communication passage that equalizes pressure. This self-service mechanism ensures that during power failures, the valve automatically transitions to a safe state without requiring external power or complex control systems, maintaining fluid pressure control while minimizing power consumption.

Inventive Principle:
Principle #25Self-service

3Reliability

If the spool outer diameters at control port and supply port are made different, then fail-safe function is achieved, but manufacturing precision requirements increase

Engineering Contradiction:
Improvefail-safe functionVSAvoidspool outer diameter tolerance
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The spool is designed with asymmetric outer diameters at different positions - a larger outer diameter at the control port and a smaller outer diameter at the supply port. This asymmetric geometry creates different pressure areas on either side of the spool, generating a natural restoring force that returns the spool to its initial position during power failures. The asymmetric design achieves fail-safe functionality through geometric configuration rather than requiring active control, though it does impose specific manufacturing precision requirements for the differential diameters.

Inventive Principle:
Principle #4Asymmetry

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 reduces internal pressure changes, ensures smooth operation of the plunger and spool, and maintains fluid control during abnormal power cuts, achieving a fail-safe function by controlling fluid flow through the valve.

Implementation Method 1

The solenoid unit has a coil for generating a magnetic field, a core for transmitting the magnetic field generated by the coil, and a plunger for reciprocating via the magnetic field transmitted to the core

Methodology Applied
Scientific EffectMagnetic field generation: Electromagnet

Data Source

PatentEP3524784B1Oil pump control valve
Publication Date: 2022.01.05 UNICK
  • EP3524784B1 patent drawingFigure 1
  • EP3524784B1 patent drawingFigure 2
  • EP3524784B1 patent drawingFigure 3

AI summary

The present invention relates to an oil pump control valve and, specifically, to an oil pump control valve allowing a discharge port and the inside of a solenoid part to communicate with each other through a spool so as to relieve pressure inside the solenoid part. The present invention has a spool flow path, a vent hole, and a spool notch, which are formed so as to allow the solenoid part to communicate with the outside regardless of the flow of fluids when the valve is operated, thereby enabling the internal pressure of the solenoid part to be relieved. In addition, in the present invention, the spool and a rod are integrated such that the axial misalignment of the spool can be prevented and a holder has different diameter such that the flow of fluids can be controlled even during an abnormal power shutdown.