Fluid Pressure Cylinder Port Layout for Compact Cover Attachment

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Solution Overview

Problem

Conventional fluid pressure cylinders have increased size due to diametrically projecting ports and the need for threaded portions for screw engagement, making them larger in both diameter and length, and complicating the attachment and detachment of cover members.

Innovation Solution

A fluid pressure cylinder design with ports positioned more inwardly on the cylinder tube and using latching members with resilient rings for attachment and detachment, eliminating the need for screw engagement and reducing the axial and diametric dimensions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If ports are positioned on the outer circumferential surface of the cylinder tube, then pressure fluid can be supplied and discharged, but the diametral dimension of the fluid pressure cylinder increases

Engineering Contradiction:

Improvepressure fluid supply and dischargeVSAvoiddiametral dimension

Core Design Contradiction:

Ease of operationVSLength of stationary object

Solution Approach 1:

The ports are repositioned from the outer circumferential surface (radial dimension) to the inner circumferential surface (axial dimension), changing the dimensional orientation of the fluid supply and discharge paths. This allows pressure fluid to be supplied and discharged through the inner circumferential surface in the axial direction, eliminating the need for diametral projection and reducing the overall diametral dimension of the cylinder.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Reliability

If screw engagement is used to fix cover members to the cylinder tube, then secure attachment is achieved, but the axial dimension increases due to threaded portions

Engineering Contradiction:

Improveattachment securityVSAvoidaxial dimension

Core Design Contradiction:

ReliabilityVSLength of moving object

Solution Approach 1:

The threaded portions and screw engagement mechanism are completely removed from the design. Instead, the cover members are secured to the cylinder tube through engagement grooves and latching members that utilize elastic deformation of resilient rings, eliminating the need for axial projection of threaded portions and reducing the overall axial dimension.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The attachment mechanism transitions from rigid screw engagement to elastic latching using resilient rings. The latching members are formed with elastic properties that allow them to deform and engage with the engagement grooves, providing secure attachment through elastic force rather than threaded mechanical engagement, thereby reducing the axial space required.

Inventive Principle:

Principle #35Parameter changes

3Ease of manufacture

If threaded portions are provided on head cover and rod cover, then screw engagement is enabled, but the lengthwise dimension increases due to male and female threaded portions

Engineering Contradiction:

Improvescrew engagement capabilityVSAvoidlengthwise dimension

Core Design Contradiction:

Ease of manufactureVSLength of moving object

Solution Approach 1:

The threaded portions on both the head cover and rod cover are completely eliminated. The attachment system is replaced with engagement grooves on the cylinder tube and corresponding latching members on the covers, which secure the covers without requiring any threaded portions, thereby reducing the lengthwise dimension.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The mechanical screw engagement system is replaced with an elastic latching system. The latching members utilize elastic deformation to engage with the engagement grooves, substituting the threaded mechanical connection with an elastic-mechanical connection that requires less axial space.

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

The design reduces the cylinder's size by minimizing outward projections and simplifies the attachment and detachment of cover members, enhancing operational ease and space efficiency.

Implementation Method 1

latching members being engaged with respect to the cylinder tube and constituted from rings with resilient forces in a diametral direction

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS10947998B2Fluid pressure cylinder

Publication Date: 2021.03.16 SMC CORP

AI summary

In a fluid pressure cylinder, cylindrical bodies are connected to both ends of a cylinder tube, and latching rings are disposed detachably in interior of the cylindrical bodies. A head cover and a rod cover, which are accommodated in the cylinder tube, are fixed by the latching rings. Recesses, which are recessed diametrally inward, are provided on outer circumferential surfaces of the head cover and the rod cover, respectively. First and second fluid ports open respectively in the recesses, and a pressure fluid is supplied and discharged through the first and second fluid ports.