Exhaust Filter With Air Gap For Thermal Expansion
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Solution Overview
Problem
Existing filters in exhaust systems of internal combustion engines face damage due to thermal expansion and contraction, leading to reduced service life and functionality, as they are firmly clamped and lack sufficient space to expand or contract.
Innovation Solution
A filter design featuring a conical pipe socket with a sleeve having a non-zero angle of inclination relative to the pipe socket, creating an air gap between the sleeve and the filter element, allowing for thermal expansion and contraction while maintaining secure fixation through self-locking contact points.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the filter element is rigidly clamped between the support tube and the sleeve, then the filter element is securely fixed, but the filter element cannot expand or contract with temperature changes, leading to warping and cracks
Solution Approach 1:
The filter element is divided into multiple sections (first filter section, second filter section, third filter section) with different clamping characteristics. The first and third sections are clamped between the support tube and sleeve, while the second section remains unclamped, allowing it to expand and contract freely with temperature changes. This segmentation resolves the contradiction by providing both secure fixation and thermal adaptability.
Solution Approach 2:
Different portions of the filter element have different degrees of constraint. The first and third sections are rigidly clamped for secure fixation, while the second section has no clamping constraint, allowing local thermal expansion and contraction. This local quality differentiation enables the filter element to maintain both reliability and thermal adaptability.
2Stability of the object's composition
If the filter element is firmly clamped to ensure secure fixation, then the filter element is stable, but excessive thermal stress damages the filter element during temperature fluctuations
Solution Approach 1:
The filter element is segmented into clamped and unclamped sections. The unclamped second section acts as a expansion joint, absorbing thermal stress through free expansion and contraction, while the clamped first and third sections maintain stable fixation. This segmentation protects the filter element from thermal stress damage while ensuring overall stability.
Solution Approach 2:
The unclamped second section serves as a pre-designed cushioning zone that anticipates and absorbs thermal expansion and contraction before the clamped sections are subjected to excessive stress. This beforehand cushioning prevents thermal stress damage to the filter element.
3Strength
If the filter element is clamped over its entire circumference, then the filter element is securely fixed, but the filter element cannot expand or contract sufficiently with temperature changes
Solution Approach 1:
The filter element is divided into multiple circumferential sections with different clamping states. The first and third sections are clamped between the support tube and sleeve for secure fixation, while the second section remains unclamped, providing circumferential expansion freedom. This segmentation resolves the contradiction between fixation strength and thermal expansion freedom.
Solution Approach 2:
The solution moves from a uniform two-dimensional clamping arrangement to a segmented arrangement that creates a third dimension of freedom in the second section. This dimensional change allows the filter element to expand and contract radially in the unclamped section while maintaining fixation in the clamped sections.
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 enhances the filter's service life and reliability by allowing thermal expansion and contraction without damaging the filter element, while ensuring secure fixation and protecting against mechanical stress without compromising filtering capacity.
Implementation Method 1
the filter element is made of a relatively thin-walled metal mesh or similar material with relatively low mass, which is why its temperature changes relatively quickly with the exhaust gas temperature compared to the other components of the filter. These temperature changes cause the filter material to expand when heated and contract when cooled.
Implementation Method 2
the end region being conically shaped and the wall of which runs at least partially at an angle inclined to an axis of the pipe stub; a sleeve arranged in the end region of the pipe stub, which sleeve has a number of contact points with the filter element around its circumference
Data Source
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AI summary
A filter (1) for insertion into a fluid-carrying pipeline is proposed, comprising: a support tube (2) with a pipe stub (3), which pipe stub (3) has an end region (4) which end region (4) is conically shaped and whose wall runs at least partially at an angle (α) inclined to an axis (6) of the pipe stub (3); a rim (7) closing the end region (4) of the pipe stub (3), which is bent inwards towards the axis (6) of the pipe stub (3) and defines a pipe opening circumscribed by the rim (7); a planar filter element (8) which is fixed to a front face (12) of the support tube (2), which front face (12) forms a termination of the support tube (2), thereby covering the pipe opening of the pipe stub (3) and bearing against its outer surface in the end region (4) of the pipe stub (3);and a sleeve (9) arranged in the end region (4) of the pipe nozzle (3), which sleeve (9) has a number of contact points (10) with the filter element (8) over its circumference; which filter (1) is characterized in that an air gap (11) is present between the sleeve (9) and the filter element (8) at least in partial regions of the circumference, which opens from the contact points (10) towards the front (12).