Cylinder Head Pressure Sensor Flange Segmentation
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Solution Overview
Problem
Existing pressure measurement sensors for motor vehicle engine cylinders face challenges in assembly complexity and cost due to laser welding requirements, and are prone to deformation from temperature and stress, which affects the membrane's ability to accurately transmit mechanical stress to the piezoelectric module.
Innovation Solution
A pressure sensor design with a flange that includes a separation between the connecting zone and fixing portion, incorporating an absorption portion to absorb mechanical deformation, allowing for a single laser weld assembly and reducing the risk of membrane deformation during the welding process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If laser welding is used to assemble the sensor components, then the sensor can be manufactured with precise connections, but the assembly process becomes complex and time-consuming
Solution Approach 1:
The flange is divided into distinct functional zones: a connecting zone for membrane attachment, a separation zone, and a fixing portion for body attachment. This segmentation allows each zone to be optimized independently and simplifies the assembly process by enabling single-pass laser welding of the fixing portion without affecting the membrane connection area.
Solution Approach 2:
The separation zone acts as an intermediary region that isolates the membrane connecting zone from the fixing portion. This intermediary structure prevents heat and deformation from the welding process from affecting the membrane connection, while still maintaining overall structural integrity through the flange.
2Stability of the object's composition
If the membrane is stiffened by mounting it at the level of the shoulder, then the membrane deformation from sensor deformation is limited, but the welding heat deforms the membrane
Solution Approach 1:
The flange is segmented into a connecting zone for membrane attachment and a fixing portion for body attachment, separated by a separation zone. This segmentation allows the membrane to be connected away from the welding area, protecting it from heat-induced deformation while maintaining its structural role.
Solution Approach 2:
The separation zone serves as a protective intermediary that isolates the membrane connecting zone from the heat and mechanical stresses of the welding process. This intermediary structure prevents direct exposure of the membrane to harmful welding effects while maintaining overall flange integrity.
3Strength
If the sensor is force-fitted in the bore, then the sensor is securely mounted, but the skirt and shoulder deform mechanically
Solution Approach 1:
The flange is segmented with the fixing portion located away from the membrane connecting zone, allowing the force-fitting process to affect only the fixing portion and skirt without transmitting deformation to the membrane connection area.
Solution Approach 2:
The separation zone acts as a mechanical intermediary that decouples the force-fitting stresses from the membrane connecting zone. This intermediary structure absorbs and localizes the mechanical stresses during installation, preventing them from propagating to the membrane connection.
4Strength
If multiple welds are performed to assemble the sensor, then all components are securely connected, but the cumulative heat deforms the membrane
Solution Approach 1:
The flange is segmented into distinct zones that allow for single-pass laser welding of the fixing portion without requiring multiple welds. This segmentation enables secure connection while minimizing cumulative heat exposure to the membrane by eliminating the need for repeated welding operations.
Solution Approach 2:
The separation zone serves as a thermal intermediary that protects the membrane connecting zone from heat generated during the welding of the fixing portion. This intermediary structure prevents heat transfer to the membrane while maintaining the structural integrity of the flange assembly.
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 solution simplifies the assembly process, reduces the risk of membrane deformation, and maintains accurate pressure measurement by isolating the membrane from forces and heat-induced deformations, resulting in a more reliable and efficient sensor.
Implementation Method 1
a piezoelectric module 3A for converting a mechanical stress into an electrical voltage
Implementation Method 2
a membrane 3C-2 comprising a circular portion 3C-21 extending transversely in the tubular portion 3C-1 so as to block it
Data Source
AI summary
Disclosed is a sensor for measuring the pressure prevailing in a motor vehicle cylinder head, the sensor including a tubular body and an element sensitive to variations in the pressure, mounted in the tubular body. The sensitive element includes a tether including a fixing portion for fixing the tether to the tubular body, a tubular portion and a membrane fixed to the tubular portion at a connecting zone. The sensor is notable in that the connecting zone and the fixing zone are separated by a non-zero distance along the longitudinal axis and in that the tether includes, between the connecting zone and the fixing portion, a portion for absorbing a mechanical deformation.