Cylinder Pressure Sensor Elastic Housing Segmented Crystals

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Solution Overview

Problem

Existing cylinder internal-pressure sensors face challenges with high fragility of single crystal materials, complex machining requirements, reduced yield and productivity, potential for nonconformities like cracks under engine vibrations, and variability in detection accuracy due to dimensional and angular variations of cuboid chip bodies.

Innovation Solution

A ring-shaped cylinder internal-pressure sensor with a housing unit composed of elastic outer and inner cylinder portions, a pressure-receiving ring block, and support ring block, using single crystal pressure detection elements with spacers for alignment and stress balance, and bonding layers for adhesion and alignment control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If single crystal material is used for pressure detection element, then heat resistance and piezo-electric characteristics are improved, but fragility and machining difficulty increase

Engineering Contradiction:
Improveheat resistanceVSAvoidfragility
Core Design Contradiction:
TemperatureVSStrength

Solution Approach 1:

The pressure detection element is divided into multiple cuboid chip bodies arranged in a ring shape, rather than using a single large single crystal. This segmentation reduces the size of each crystal piece, making them less fragile and easier to handle while maintaining the required heat resistance and piezo-electric properties.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses composite construction by arranging multiple single crystal chip bodies in a ring configuration and bonding them together. This composite approach allows each small chip to retain single crystal properties while the overall structure gains improved mechanical strength and reduced fragility through the distributed arrangement.

Inventive Principle:
Principle #40Composite materials

2Reliability

If single crystal material is used for pressure detection element, then piezo-electric characteristics are improved, but manufacturing complexity and machining requirements increase

Engineering Contradiction:
Improvepiezo-electric characteristicsVSAvoidmachining complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The pressure detection element is divided into multiple cuboid chip bodies arranged in a ring shape, rather than using a single large single crystal. This segmentation reduces the size of each crystal piece, making them less fragile and easier to handle while maintaining the required heat resistance and piezo-electric properties.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of machining a single complex ring-shaped pressure detection element, the patent uses multiple identical or similar cuboid chip bodies that are copied and arranged in a ring. This standardization of individual components simplifies manufacturing processes and reduces machining complexity for each unit.

Inventive Principle:
Principle #26Copying

3Adaptability or versatility

If ring-shaped pressure detection element is used, then integration with functional components is improved, but susceptibility to vibration-induced cracks increases

Engineering Contradiction:
Improveintegration capabilityVSAvoidvibration resistance
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The pressure detection element is divided into multiple cuboid chip bodies arranged in a ring shape, rather than using a single large single crystal. This segmentation reduces the size of each crystal piece, making them less fragile and easier to handle while maintaining the required heat resistance and piezo-electric properties.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses composite construction by arranging multiple single crystal chip bodies in a ring configuration and bonding them together. This composite approach allows each small chip to retain single crystal properties while the overall structure gains improved mechanical strength and reduced fragility through the distributed arrangement.

Inventive Principle:
Principle #40Composite materials

4Ease of manufacture

If cuboid chip bodies are used for pressure detection element, then manufacturing ease is improved, but dimensional and angular variations increase

Engineering Contradiction:
Improvemanufacturing easeVSAvoiddimensional consistency
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent employs preliminary alignment and positioning structures in the housing unit that ensure correct orientation and spacing of the cuboid chip bodies before final bonding. This preliminary action compensates for dimensional and angular variations, ensuring consistent performance despite manufacturing tolerances of individual chips.

Inventive Principle:
Principle #10Preliminary action

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

Enhances manufacturing ease, improves yield and productivity, reduces nonconformities, ensures stable attachment and operation, and improves detection accuracy by stabilizing pressure transmission and protecting components from temperature and vibration.

Implementation Method 1

an elastic portion (2es) of the outer cylinder portion (2e) and an elastic portion (2is) of the inner cylinder portion (2i)

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

at least one or more pressure detection elements (5a, 5b, 5c, 5d, 5e, 5f) in contact with one electrode portion (4) provided on a rear surface (3r)

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentEP2693185B1Cylinder internal-pressure sensor for engine
Publication Date: 2019.07.31 CITIZEN WATCH CO LTD
  • EP2693185B1 patent drawingFigure 1~2
  • EP2693185B1 patent drawingFigure 3~4
  • EP2693185B1 patent drawingFigure 5~6

AI summary

A cylinder internal-pressure sensor is provided with a housing unit 2 composed of an outer cylinder portion 2e and an inner cylinder portion 2i having elastic portions 2es and 2is having elasticity in an axial direction Fs formed on an intermediate portion Xm in the axial direction Fs; a pressure-receiving ring block portion 3 hermetically fixed between the outer cylinder portion 2e and the inner cylinder portion 2i located on the fronts of the elastic portions 2es and 2is and faced with the rear of the elastic portions 2e and 2i through the elastic portions 2e and 2i and having a front surface 3f as a pressure receiving surface; at least one or more pressure detection elements 5a, 5b, 5c, ... in contact with one electrode portion 4 provided on a rear surface 3r of this pressure-receiving ring block portion 3, given the internal pressure Pc by the pressure-receiving ring block portion 3 and arranged at predetermined positions in a peripheral direction Ff; and a support ring block portion 6 fixed between the outer cylinder portion 2e and the inner cylinder portion 2i, having a front surface 6f as a support surface supporting the pressure detection elements 5a ... and serving also as the other electrode 7.