Fuel Injector Sensor Mounting for Pressure Detection Accuracy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing fuel injectors face challenges in maintaining a reliable connection between the sensor element and the deformation area due to environmental influences and temperature variations, which can affect the accuracy and durability of pressure detection.
Innovation Solution
A support device is used to apply a force perpendicular to the sensor element, connected via an elastic intermediate element, ensuring a secure and accurate detection of deformation even if the adhesive connection weakens, and is integrated with a rigid metal housing for enhanced reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the sensor element is connected to the deformation area by means of an adhesive connection, then the sensor element can detect expansions or tensile stresses occurring in the contact area, but the bonded joint is exposed to negative effects from environmental influences such as dirt or gases, which can reduce the fatigue strength of the bonded joint
Solution Approach 1:
The patent introduces a support device that applies a prestressing force to the sensor element beforehand, creating a safety reserve that compensates for potential adhesive connection failures. This prestressing ensures that even if the adhesive bond deteriorates due to environmental influences, the sensor element remains in contact with the deformation area and continues to function reliably.
Solution Approach 2:
The support device acts as an intermediary between the sensor element and the deformation area, providing an additional mechanical connection path. This intermediary structure ensures continuous contact and force transmission, reducing dependency on the adhesive connection alone and protecting against its potential failure.
2Reliability
If the sensor element is subjected to a force in the direction of the deformation region by means of a support device, then contact is maintained even if the adhesive connection weakens, but the sensor element may be exposed to mechanical damage
Solution Approach 1:
The elastic intermediate element is pre-configured to provide a cushioning effect that absorbs and distributes mechanical forces. This beforehand cushioning protects the sensor element from sudden or excessive forces that could cause mechanical damage, while still maintaining the necessary prestressing force for reliable contact.
Solution Approach 2:
The elastic intermediate element changes its mechanical parameters (force, displacement) dynamically in response to external conditions. It provides sufficient prestressing force under normal conditions while automatically reducing force transmission when excessive loads are detected, thus protecting the sensor element from mechanical damage.
3Reliability
If an elastic intermediate element is used between the support device and the sensor element, then mechanical relief and elastic prestressing force are provided, but the structure becomes more complex
Solution Approach 1:
The elastic intermediate element is implemented as a flexible component (such as an elastic membrane or thin-walled structure) that provides the necessary mechanical functions with minimal added complexity. This flexible element can be integrated into the existing support device structure, achieving both protection and prestressing without significantly increasing overall device complexity.
4Force
If the support device is rigidly connected to the injector housing, then a supporting force is generated, but the structure becomes less adaptable to deformation
Solution Approach 1:
The support device is segmented into distinct functional components: a rigid connection element for generating supporting force, an elastic intermediate element for adapting to deformation, and a sensor element for detection. This segmentation allows each component to perform its specific function optimally - the rigid part provides force while the elastic part provides adaptability.
Solution Approach 2:
The support device incorporates dynamic characteristics through the elastic intermediate element, which allows the structure to adapt its stiffness and geometry in response to deformation. This dynamic behavior enables the rigidly connected support device to maintain supporting force while accommodating the deformation of the injector housing.
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 improves the resolution and accuracy of pressure detection, reduces mechanical damage, and maintains sensor element reliability over the fuel injector's lifespan by providing mechanical relief and elastic prestressing.
Implementation Method 1
the support device is supported on the side of the sensor element facing away from the adhesive connection via an elastic intermediate element on the sensor element. The elastic intermediate element causes, on the one hand, a mechanical relief of the sensor element or the avoidance of mechanical damage to the sensor element, and on the other hand, the application of an elastic prestressing force to the sensor element
Implementation Method 2
the injector housing has a deformation area in the area of the measuring device, which is designed to be elastically deformable as a function of the fuel pressure in the supply bore. When the pressure in the supply hole increases, the deformation area bulges outwards, which can be detected by the sensor element
Data Source
Figure 1
Figure 2~3
AI summary
The invention relates to a fuel injector (10), in particular a common-rail injector, with an injector housing (11) in which a high-pressure chamber (15) is formed, which can be supplied with pressurized fuel via a supply bore (19) arranged in the injector housing (11), with at least one injection opening (12) formed in the injector housing (11) and connected at least indirectly to the high-pressure chamber (15) for injecting fuel into the combustion chamber of an internal combustion engine, with an injection element (16) that releases or closes the at least one injection opening (12), and with a measuring device (30) for at least indirectly detecting the pressure in the high-pressure chamber (15) or the supply bore (19), wherein the measuring device (30) is configured to detect an elastic deformation of a deformation area (27) arranged in operative connection at least indirectly with the supply bore (19) or the high-pressure chamber (15).and wherein the measuring device (30) comprises a sensor element (32) which is connected to the surface of the deformation area (27) via an adhesive bond (34). According to the invention, it is provided that the sensor element (32) is subjected to force in the direction of the deformation area (27) by means of a support device (35; 40).