Oil Pressure Control Valve Calibration Without Thread Load Errors

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Solution Overview

Problem

Existing manufacturing methods for oil pressure control valves face accuracy issues due to variations in frictional forces and product characteristics, leading to potential errors in adjusting output oil pressure, and the risk of foreign object generation from axial loads on threaded portions.

Innovation Solution

A method involving a pressure adjusting step that calculates and applies an adjustment rotation amount to the adjustment screw based on differential pressure and product characteristics, without applying axial loads, using a tool that contacts the rotation transmitting portion without gaps to ensure precise adjustment of the spring load and prevent foreign object generation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the adjustment screw is rotated to adjust the spring load and output oil pressure, then the output oil pressure can be adjusted to a target value, but frictional force variations cause accuracy errors in the pressure adjustment

Engineering Contradiction:

Improveoutput oil pressure adjustment accuracyVSAvoidadjustment accuracy consistency

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The patent replaces the traditional mechanical rotation-based adjustment method with a pressurization-based adjustment method. Instead of rotating the adjustment screw to change spring load, the system applies axial force directly to the spool through pressurizing oil in the third chamber, thereby adjusting the spool position and output pressure without relying on friction-prone mechanical threading.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces oil pressure in the third chamber as an intermediary medium to transmit the adjusting force. The pressure adjusting device pressurizes this oil, which then applies force to the spool through the third chamber, enabling precise pressure adjustment without direct mechanical contact between the adjustment mechanism and the spool.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Manufacturing precision

If axial loads are applied to the threaded portions during adjustment, then the spring load can be adjusted, but foreign objects may be generated from the threaded portions

Engineering Contradiction:

Improvespring load adjustment capabilityVSAvoidforeign object generation

Core Design Contradiction:

Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The patent eliminates the need for axial loading on threaded portions by replacing the screw-based adjustment mechanism with a hydraulic pressurization system. The pressure adjusting device applies force through fluid pressure in the third chamber, avoiding mechanical thread engagement and the associated foreign object generation risk.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Ease of operation

If a tool is inserted into the rotation transmitting portion with gaps, then the adjustment screw can be rotated, but rotational accuracy is reduced leading to pressure adjustment errors

Engineering Contradiction:

Improveadjustment screw rotationVSAvoidpressure adjustment precision

Core Design Contradiction:

Ease of operationVSManufacturing precision

Solution Approach 1:

The patent replaces the rotation-based adjustment mechanism with a pressurization-based system. The pressure adjusting device directly pressurizes the oil in the third chamber, eliminating the need for rotational transmission through tools and rotation transmitting portions, thereby avoiding the accuracy losses from gap-induced rotational errors.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 approach allows for high-accuracy adjustment of output oil pressure, unaffected by frictional variations, and minimizes the risk of foreign object creation, enhancing the precision and reliability of oil pressure control valve manufacturing.

Implementation Method 1

adjusting a set load of a spring, which is configured to urge a spool in a direction away from a female threaded portion of the sleeve against a drive force

Methodology Applied

Scientific EffectElasticity: Elasticity

Implementation Method 2

sensing a pre-adjustment oil pressure, which is the output oil pressure at a pre-adjustment rotational position of the adjustment screw under the predetermined drive condition, by the pressure adjusting device

Methodology Applied

Scientific EffectPressure sensing:

Data Source

PatentUS11953103B2Manufacturing method for oil pressure control valve

Publication Date: 2024.04.09 DENSO CORP

AI summary

At a preparing stage, a tool is placed in contact with an inner wall of a rotation transmitting portion of an adjustment screw. Then, at an adjustment rotation amount calculating stage, a pre-adjustment oil pressure, which is an output oil pressure of an oil pressure control valve at a pre-adjustment rotational position of the adjustment screw under a predetermined drive condition of a drive device, is sensed, and thereafter an adjustment rotation amount of the adjustment screw from the pre-adjustment rotational position to a target rotational position of the adjustment screw, which corresponds to a target oil pressure, is calculated based on: a differential pressure between the pre-adjustment oil pressure and the target oil pressure; and a correction amount which corresponds to a product characteristic of the oil pressure control valve. Then, at a rotating stage, the adjustment screw is rotated by the adjustment rotation amount.