Cam Angle Sensor Mounting Structure for Engine Cylinder Head

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Solution Overview

Problem

Existing cam angle sensor mounting structures face challenges in achieving a compact and lightweight design while maintaining high precision, particularly due to space constraints in internal combustion engines and concerns about sensor fouling by foreign matter, and they often require rigid metal head covers that increase weight and cost.

Innovation Solution

A cam angle sensor mounting structure featuring a metal sensor bracket rigidly attached to the cylinder head and a lightweight synthetic resin head cover non-rigidly mounted via gaskets, allowing for resilient movement and improved vibration characteristics, with the sensor bracket supporting the cam angle sensor in a manner that faces downward to avoid contamination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the cam angle sensor is mounted on a cylinder head in the lower region, then the mounting space is constrained by the head cover, but the sensor reading precision is maintained

Engineering Contradiction:
Improvesensor reading precisionVSAvoidmounting space
Core Design Contradiction:
Measurement precisionVSArea of stationary object

Solution Approach 1:

The invention divides the mounting structure into separate components: a sensor mounting plate rigidly attached to the cylinder head, and a head cover non-rigidly mounted via vibration isolating members. This segmentation allows the sensor to be mounted in the lower region with precise positioning while the head cover is separated to avoid interference with mounting space.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention introduces vibration isolating members (such as rubber mounts or elastomeric materials) as intermediaries between the head cover and the sensor mounting structure. These intermediaries allow the head cover to be non-rigidly mounted, providing vibration isolation while maintaining the rigid connection needed for sensor precision through the separate sensor mounting plate.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If the cam angle sensor is mounted with upward-facing sensing part, then the mounting flexibility is improved, but the sensing part is fouled by foreign matter such as dust and oil

Engineering Contradiction:
Improvemounting flexibilityVSAvoidsensing part fouling
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The invention inverts the conventional upward-facing sensor orientation by mounting the cam angle sensor with its sensing part facing downward toward the signal plate on the camshaft. This inversion protects the sensing part from fouling by foreign matter while the sensor mounting plate provides the necessary flexible mounting options on the cylinder head.

Inventive Principle:
Principle #13The other way round (Inversion)

3Strength

If the head cover is made of metal to ensure rigidity for supporting the cam angle sensor, then the structural strength is improved, but the weight and cost increase

Engineering Contradiction:
Improvehead cover rigidityVSAvoidhead cover weight
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The invention introduces vibration isolating members as intermediaries between the head cover and the sensor mounting structure. This allows the head cover to be made of lightweight materials such as resin or aluminum alloy while still providing adequate support for the cam angle sensor through the isolated rigid connection at the sensor mounting plate.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention changes the mounting rigidity parameter by using vibration isolating members with specific elastic properties. This allows the head cover to be made of lighter materials while maintaining the necessary structural strength for sensor support through the controlled rigidity of the vibration isolation system.

Inventive Principle:
Principle #35Parameter changes

4Measurement precision

If the head cover is rigidly mounted to the cylinder head, then the sensor reading precision is maintained, but the vibration and noise increase

Engineering Contradiction:
Improvesensor reading precisionVSAvoidvibration and noise
Core Design Contradiction:
Measurement precisionVSObject-generated harmful factors

Solution Approach 1:

The invention uses vibration isolating members (such as rubber mounts, elastomeric materials, or foam) as intermediaries between the head cover and the sensor mounting structure. These intermediaries provide vibration isolation to reduce noise and vibration while maintaining the rigid connection needed for sensor precision through the separate sensor mounting plate rigidly attached to the cylinder head.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention changes the mounting rigidity parameter by using vibration isolating members with specific elastic properties. This allows the head cover to be non-rigidly mounted to reduce vibration and noise, while the sensor mounting plate maintains the necessary rigidity for precise sensor readings through its rigid attachment to the cylinder head.

Inventive Principle:
Principle #35Parameter changes

5Area of stationary object

If the cam angle sensor is mounted on a cam bracket, then the mounting space is utilized, but the reading precision is reduced due to deformation from load

Engineering Contradiction:
Improvemounting space utilizationVSAvoidsensor reading precision
Core Design Contradiction:
Area of stationary objectVSMeasurement precision

Solution Approach 1:

The invention extracts the sensor mounting function from the load-bearing cam bracket by providing a separate sensor mounting plate rigidly attached to the cylinder head. This separation eliminates the deformation issues caused by cam shaft and cover loads on the bracket, while still utilizing the available mounting space on the cylinder head.

Inventive Principle:
Principle #2Taking out (Extraction)

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 enhances detection precision, reduces weight and cost, and minimizes noise by using a full floating soft mounting structure for the head cover, while maintaining sensor rigidity and avoiding contamination of the sensing part.

Implementation Method 1

a head cover non-rigidly mounted on the cylinder head and the sensor bracket via at least one gasket to cover a top opening of the cylinder head with a space being formed around the at least one gasket

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP1748168B1Mounting apparatus for cam angle sensor
Publication Date: 2013.07.17 NISSAN MOTOR CO LTD
  • EP1748168B1 patent drawingFigure 1
  • EP1748168B1 patent drawingFigure 2
  • EP1748168B1 patent drawingFigure 3

AI summary

A cam angle mounting structure includes a cylinder head, a sensor bracket and a head cover. The cylinder head is configured and arranged to rotatably support a camshaft. The sensor bracket is configured and arranged to support a cam angle sensor. The sensor bracket is mounted on the cylinder head with the sensor bracket contacting the cylinder head. The head cover is non-rigidly mounted on the cylinder head and the sensor bracket via at least one gasket to cover a top opening of the cylinder head with a space being formed around the at least one gasket between the head cover and the cylinder head and between the head cover and the sensor bracket.