Compact Control Valve Using Radial Spool Openings for Floating State

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional control valves used in work vehicles, such as tractors, require multiple tank port end portions to establish communication between cylinder ports and a tank, leading to increased size and length of the slidable spool and valve body, making them less compact.

Innovation Solution

A control valve design featuring a slidable spool with inner oil passages and strategically positioned openings that align with port end portions when switched to a floating position, allowing communication between cylinder ports and a tank via a single tank port end portion, reducing the number of required port end portions and valve body size.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple tank port end portions are used to establish communication between cylinder ports and tank, then reliable communication is achieved, but the valve body size and slidable spool length increase

Engineering Contradiction:

Improvecommunication reliabilityVSAvoidvalve body size

Core Design Contradiction:

ReliabilityVSLength of stationary object

Solution Approach 1:

The patent merges the functions of multiple tank port end portions into a single tank port end portion. The slidable spool is designed with multiple openings (first opening, second opening, third opening) that all communicate with a single tank port end portion, thereby reducing the valve body size while maintaining reliable communication between cylinder ports and tank through the unified tank port connection

Inventive Principle:

Principle #5Merging (Combining)

2Reliability

If multiple tank port end portions are used to establish communication between cylinder ports and tank, then communication coverage is improved, but the slidable spool length increases

Engineering Contradiction:

Improvecommunication coverageVSAvoidslidable spool length

Core Design Contradiction:

ReliabilityVSLength of moving object

Solution Approach 1:

The patent transitions from a linear arrangement of multiple tank port end portions along the spool length to a radial arrangement where multiple openings are distributed around the circumference of the slidable spool. This dimensional change allows all openings to access the single tank port end portion without increasing spool length, thereby maintaining communication coverage while reducing spool dimensions

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Data Source

PatentUS10184498B2Control valve and work vehicle having the control valve

Publication Date: 2019.01.22 KUBOTA CORP

AI summary

An inner oil passage (45) is formed inside a slidable spool (22). The slidable spool (22) defines, in its circumferential face, a first opening (46), a second opening (47) and a third opening (48). The first opening (46), the second opening (47) and the third opening (48) are communicated to the inner oil passage (45). When the slidable spool (22) is switched to a floating position (F), the first the first opening (46) is aligned with a first port end portion (25a), the second opening (47) is aligned with a second port end portion (26a), and the third opening (48) is aligned with a fourth port end portion (24a), respectively, and a first cylinder port and a second cylinder port are communicated to a tank port (24) via the inner oil passage (45).