Engine Flow Housing Pressure Measurement
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Solution Overview
Problem
Existing control devices for internal combustion engines face challenges in precisely determining exhaust gas mass flow, especially at small flow rates, due to measurement errors caused by turbulence and low velocities, which affect the accuracy of flap regulation and require additional sensors.
Innovation Solution
A control device with a second pressure measuring point located in the third channel section, where the flap body passes during rotation, allowing for precise mass flow measurement even with small gas flows, and integrating pressure sensors directly into the actuator housing for direct feedback and control, eliminating the need for position sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If a Venturi nozzle is used to determine exhaust gas mass flow with a pressure difference sensor, then the response time is shortened and sufficient measurement and control values are achieved, but measurement errors increase significantly at small exhaust gas flows due to low velocities in the Venturi nozzle area
Solution Approach 1:
The patent applies local quality by creating a localized measurement zone downstream of the flap where flow conditions are optimized for accurate measurement. The measurement cross-section is positioned in a region where the flow has stabilized after passing through the flap, ensuring consistent and reliable pressure differential measurements across all operating conditions including small exhaust gas flows.
2Measurement precision
If a differential pressure measurement is performed downstream of a throttle valve in an axial section traversed during rotation, then volume flow measurement is achieved, but turbulences occur in the downstream pressure measuring point region particularly at smaller opening angles, leading to pressure fluctuations that prevent precise measurements
Solution Approach 1:
The patent extracts the pressure measurement function from the turbulent flow region near the flap and positions it downstream in a stabilized flow zone. This separation removes the measurement point from the harmful turbulence effects while maintaining its ability to accurately measure the flow characteristics generated by the flap position.
3Ease of operation
If position sensors are used to regulate gas flow as a function of valve position, then control is achieved, but calibration is required and accurate regulation during operation is not achieved since not all ambient conditions are taken into account
Solution Approach 1:
The patent implements feedback by using pressure differential measurements taken downstream of the flap to directly control the actuator. The measured pressure difference provides real-time information about the actual gas flow, which is fed back to the control system to adjust the flap position, creating a closed-loop control system that adapts to varying ambient conditions without requiring calibration.
4Measurement precision
If additional sensors are used to achieve precise mass flow determination, then measurement accuracy is improved, but device complexity increases
Solution Approach 1:
The patent applies universality by designing the flow housing to serve multiple functions: it acts as both the structural component guiding the gas flow and as the housing for the pressure measurement system. The flow housing itself is equipped with pressure measurement points, eliminating the need for separate external sensors and reducing overall device complexity while maintaining high measurement precision.
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 design provides precise and reliable pressure measurements across the entire flap adjustment range, reducing measurement errors and enabling direct, fast control of the actuator, resulting in a compact and efficient control device capable of accurately regulating mass flow without additional sensors.
Implementation Method 1
a first pressure measuring point in the first channel section of the flow housing and a second pressure measuring point in the third channel section
Implementation Method 2
a Venturi nozzle is used to determine an exhaust gas mass flow with the aid of a pressure difference sensor, which measures in front of the constriction and in the narrowest cross section of the nozzle
Implementation Method 3
it is also known to use air mass meters that work according to the principle of hot film anemometry
Data Source
Figure 1
Figure 2
AI summary
The invention relates to control devices for internal combustion engines comprising a flow housing (10), in which a flow-through channel (12) is formed, and which has a first channel section (32) with a first flow cross-section, a second channel section (34) in which the flow cross-section is reduced and a third channel section (36) downstream of the second channel section (34), in which the channel (12) continues with reduced flow cross-section, a valve body (18) that is rotatably arranged on a shaft (16), an actuator (24) and a first pressure measurement point (42) in the first channel section (32) of the flow housing (10) and a second pressure measurement point (44) in the third channel section (36). According to the invention, in order to increase the measuring accuracy of a mass flow, even for small released flow cross-sections, the second pressure measurement point (44) in the third channel section (36) is arranged within an axial section (50) through which the valve body (18) moves during its rotation, on the region of the flow housing (10) at a distance from the shaft (16) when viewed in the peripheral direction of the housing wall (14).