Air mass flow sensor and motor vehicle

Abstract

This invention relates to an air mass flow sensor for determining air mass flow rate, the air mass flow sensor having a housing (4) and sensor electronics (6), wherein the sensor electronics are at least partially disposed in a housing chamber (8) of the housing (4), wherein the housing (4) has a flow channel (14) for guiding an air mass flow (L) to be measured through the housing (4), the flow channel (14) having a measuring channel (20) and a bypass channel (22), wherein the measuring channel (20) guides a portion of the air mass flow (L) flowing into the flow channel (14) to a measuring point (24) of the sensor electronics (6), and wherein the bypass channel (22) guides a portion of the air mass flow (L) flowing into the flow channel (14) to a measuring point (24) of the sensor electronics (6) upon reaching the measuring point (24). 24) The first wall element (28) that branches out from the housing (4) at least segmentally separates the bypass channel (22) and the measuring channel (2) from each other has a wall height (H1) that is at least segmentally reduced, such that the first wall element (28) can be overflowed at least segmentally, and / or the first wall element (28) has a through hole (34) that allows flow through the first wall element (28), and the second wall element (33) that branches out from the bypass channel (22) and the inlet (16) of the flow channel (14) at least segmentally separates from each other has a wall height (H3) that is at least segmentally reduced, such that the second wall element (28) can be overflowed at least segmentally, and / or the second wall element (28) has a through hole (34) that allows flow through the second wall element (28).

Description

Technical Field

[0001] This invention relates to an air mass flow sensor for determining air mass flow rate, the air mass flow sensor having a housing and sensor electronics, wherein the sensor electronics are at least partially arranged in a housing chamber of the housing, and wherein the housing has a flow channel for guiding the air mass flow to be measured through the housing. Furthermore, the invention also relates to a motor vehicle having such an air mass flow sensor. Background Technology

[0002] The type of air mass flow sensor mentioned at the beginning is known, for example, from documents US 8,763,425B2 and DE102018219729 A1.

[0003] Such an air mass flow sensor can be used, for example, to determine the air mass flow rate in the intake manifold of an internal combustion engine in a motor vehicle. Here, vibration excitation may occur within the natural frequency range of the flow channel, which can adversely affect the measurement results. For example, an exhaust gas turbocharger may induce high-frequency pressure pulsations up to 20 kHz in the air mass flow to be measured. Therefore, for a specific excitation frequency or range, a significant deviation may occur between the measured air mass flow rate and the actual air mass flow rate. These deviations can adversely affect engine operation. Summary of the Invention

[0004] Against this backdrop, the technical problem upon which this invention is based is to describe an improved air mass flow sensor that is particularly robust to vibration excitation from an exhaust gas turbocharger. Furthermore, a motor vehicle equipped with such a sensor should also be described.

[0005] According to a first aspect, the present invention relates to an air mass flow sensor for determining air mass flow rate, the air mass flow sensor having a housing and sensor electronics, wherein the sensor electronics are at least partially disposed in a housing chamber of the housing, and wherein the housing has a flow channel for guiding an air mass flow to be measured through the housing, the flow channel having a measuring channel and a bypass channel, wherein the measuring channel guides a portion of the air mass flow flowing into the flow channel to a measuring point of the sensor electronics, and wherein the bypass channel branches off a portion of the air mass flow flowing into the flow channel before reaching the measuring point and discharges it from the housing.

[0006] The key feature of the air mass flow sensor is that a first wall element, which at least segmentally separates the bypass channel and the measuring channel, has a wall height that is at least segmentally reduced, allowing the first wall element to overflow at least segmentally, and / or the first wall element has a through-hole, allowing flow through it. Alternatively or supplementarily, the air mass flow sensor is characterized by a second wall element, which at least segmentally separates the bypass channel and the inlet of the flow channel, having a wall height that is at least segmentally reduced, allowing the second wall element to overflow at least segmentally, and / or the second wall element has a through-hole, allowing flow through it.

[0007] The reduced wall height and / or the through-hole thus enables additional fluid connectivity within the flow channel, providing additional pressure compensation for the measurement channel. In this way, the amplitude of vibration excitation caused by the high-frequency pressure pulsations of the turbocharger can be reduced, thereby enabling reliable measurement of critical excitation frequencies. In particular, this method can eliminate the natural frequency of the flow channel or mitigate the corresponding vibration response within one or more natural frequency ranges.

[0008] The first wall element can be arranged between the discharge section formed downstream of the measurement point in the measurement channel and the bypass channel. Therefore, the reduced wall height forms a fluid connection between the bypass channel and the discharge section of the measurement channel, allowing a portion of the air mass flow to flow from the bypass channel into the discharge section of the measurement channel.

[0009] "Downstream" means that the air mass flow overflows or flows through the relevant element later in time than the element arranged upstream. Therefore, the inlet opening of the measurement channel is arranged upstream of the measurement point, while the outlet opening of the measurement channel is arranged downstream of the measurement point.

[0010] Specifically, it can be specified that a gap or through-hole is formed between the first wall element and the cover or cover of the housing, at least in the region of the reduced wall height, to establish a fluid connection between the discharge section of the bypass channel and the measuring channel. It can also be specified that the first wall element can overflow segmentally or along its entire length.

[0011] It can be specified that the wall height of the first wall element in the discharge section of the bypass channel is greater than the reduced wall height, and the wall element can overflow in the area of ​​the reduced wall height. In particular, the reduced wall height can be arranged adjacent to the inlet area of ​​the bypass channel. It can be specified that the first wall element can overflow not only in the area of ​​the reduced wall height but also in the area of ​​the discharge section.

[0012] Specifically, it can be specified that a gap or through-hole is formed in the region of reduced wall height between the second wall element and the cover or cover of the housing to establish a fluid connection between the inlet of the flow channel and the bypass channel. It can also be specified that the second wall element can be overflowed segmentally or along its entire length.

[0013] The inlet of the flow channel can be widened in a funnel shape to reduce vibration excitation caused by high-frequency pressure pulsations.

[0014] In addition to measuring air mass flow rate, the air mass flow sensor can have supplementary functions. For example, besides measuring air mass flow rate, the air mass flow sensor can be configured to measure one or more of the following parameters: air mass flow pressure; air mass flow humidity; and air mass flow temperature.

[0015] The measuring element of the sensor electronics of the air mass flow sensor can be a thermal measuring element, particularly a hot-film air mass measuring element. Such a hot-film air mass measuring element can, for example, have at least one heating element and two temperature sensors overflowing with air mass flow, wherein the magnitude of the air mass flow can be derived from the different temperatures or temperature distributions measured by the temperature sensors. Such a hot-film air mass measuring element is described, for example, in DE 102018219729 A1.

[0016] It can be specified that the components of the sensor electronics arranged in the housing or electronic chamber of the air mass flow sensor are at least partially or completely encased in or wrapped in a casting material in order to protect the components of the sensor electronics from the influence of the surrounding environment.

[0017] It can be specified that the flow channel and the electronic chamber are interconnected through an opening, wherein the electronic chamber forms a pressure compensation space for the flow channel. Therefore, the opening enables fluid connection between the flow channel and the electronic chamber, allowing a portion of the air mass flow to be measured to flow from the flow channel into the electronic chamber. In this way, the amplitude of vibration excitation caused by high-frequency pressure pulsations in the turbocharger can be reduced, thereby enabling reliable measurement of the critical excitation frequency. In particular, this method can also eliminate the natural frequency of the flow channel or mitigate the corresponding vibration response within one or more natural frequency ranges.

[0018] It can be specified that the housing, in addition to the inlet and outlet openings of the flow channel, has at least one compensation opening that connects the flow channel to the surrounding environment of the housing. Therefore, the compensation opening enables fluid connection between the flow channel and the surrounding environment of the housing, allowing a portion of the air mass flow to be measured to flow from the flow channel to the surrounding environment of the housing, thus providing additional pressure compensation. In this way, the amplitude of vibration excitation caused by the high-frequency pressure pulsations of the turbocharger can also be reduced, thereby enabling reliable measurement of the critical excitation frequency. In particular, this method can also eliminate the natural frequency of the flow channel or mitigate the corresponding vibration response within one or more natural frequency ranges.

[0019] It can set exactly one compensation opening or two or more compensation openings.

[0020] The surrounding environment of the housing can be, in particular, the internal space of a pipe, pipeline, etc., in which the air mass flow sensor for determining the air mass flow rate is arranged.

[0021] The compensation opening can be a through hole cut into the wall of the shell, such as a drilled hole.

[0022] As an alternative or supplementary solution, the compensation opening can be formed between the housing components. As long as the housing has, for example, a first housing component and a second housing component assembled into a housing, the compensation opening can be a gap in a region of a seam or joint edge where the first and second housing components are form-fitted into and / or connected to each other. The first housing component can be, for example, a cover or shield. The second housing component can be the base of the housing, to which the cover is fixed.

[0023] The housing components can be connected to each other by means of an adhesive, wherein the compensation opening is at least partially adjacent to the adhesive that connects the housing components.

[0024] It can be specified that the compensation opening is part of an interrupted adhesive seam or an interrupted adhesive strip. Therefore, the compensation opening can be an interruption in an adhesive seam or adhesive strip that connects the housing components to each other. In particular, the adhesive seam or adhesive strip forms an adhesive connection of the housing components and further forms a seal for flow channels relative to the surrounding environment, wherein the seal is partially interrupted to construct the compensation opening.

[0025] According to a second aspect, the present invention relates to a motor vehicle having an air mass flow sensor according to the invention.

[0026] The motor vehicle may have an internal combustion engine, wherein the air mass flow sensor is arranged in the intake manifold of the internal combustion engine to measure the air mass flow rate inside the intake manifold. The internal combustion engine may have one or more turbochargers. Attached Figure Description

[0027] The invention will now be described in detail with the aid of the accompanying drawings, which illustrate embodiments. The drawings are shown schematically as follows:

[0028] Figure 1 An air mass flow sensor according to the invention is shown in a perspective view from above;

[0029] Figure 2 Shown without any cover or cover Figure 1 Air mass flow sensor in the middle;

[0030] Figure 3 It shows Figure 2 Enlarged image;

[0031] Figure 4 It shows Figure 1 The cross-section of the air mass flow sensor in the image;

[0032] Figure 5 It shows Figure 4 Enlarged image;

[0033] Figure 6 It shows Figure 2 Another enlarged view;

[0034] Figure 7 A cross-section of an air mass flow sensor is shown.

[0035] Figure 8 A motor vehicle according to the invention is shown. Detailed Implementation

[0036] The air mass flow sensor 2 has a housing 4. The air mass flow sensor 2 has sensor electronics 6, wherein the sensor electronics 6 is arranged in the housing chamber or electronics chamber 8 of the housing 4. Figure 2 To illustrate the electronics chamber 8 and the sensor electronics 6, in Figure 2 The cover 10, 12 or cover 10, 12 of the housing 4 are hidden.

[0037] The housing 4 has a flow channel 14 for guiding the air mass flow L to be measured through the housing 4.

[0038] The flow channel 14 has an inlet opening 16 for introducing an air mass flow L into the housing 4. The flow channel 14 has an outlet opening 18 for discharging the air mass flow L out of the housing 4. The inlet opening 16 or inlet 16 of the flow channel 14 is widened in a funnel shape.

[0039] The flow channel 14 has a measurement channel 20 and a bypass channel 22. The measurement channel 20 guides a portion of the air mass flow L flowing into the flow channel 14 to the measurement point 24 of the sensor electronics 6. The bypass channel 22 branches off a portion of the air mass flow L flowing into the flow channel 14 before reaching the measurement point 24 and discharges it from the housing 4.

[0040] The measuring element 24 of the sensor electronics 6 is arranged in the area of ​​measuring point 24. The measuring element 26 is a thermal measuring element 26, and more precisely, a thermal film air quality measuring element 26.

[0041] Figure 3 It shows Figure 2 Enlarged view of the cropped portion.

[0042] The first wall element 28 of the housing 4, which at least sectionally separates the bypass channel 22 from the measuring channel 20, has a wall height H1 that is at least sectionally reduced, such that the first wall element 28 can be overflowed at least sectionally. The first wall element 28 is arranged between the discharge section 30 of the measuring channel 20 and the bypass channel 22, wherein the discharge section 30 is formed downstream of the measuring point 24.

[0043] As in Figure 3 As shown, a portion of the air mass flow L overflows from the bypass channel 22 into the discharge section 30 of the measurement channel 20 through the wall 28. Therefore, a through-hole 32 exists between the cover 12 and the wall 28 to establish a fluid connection between the bypass channel 22 and the discharge section 30 of the measurement channel 20.

[0044] Figure 4 It shows according to Figure 2 The cross-section of the air mass flow sensor 2. As can be made according to... Figure 5 As can be seen from the enlarged view, a gap 31 or slit 31 can also be formed between the cover 12 and the first wall element 28 in the region of wall height H2, so that the first wall element 28 can also overflow in the region of wall height H2. According to an alternative design of the present invention, the cover 12 can be specified to abut against the wall element 28 without gap in the region of wall height H2, so that the wall element 28 can only overflow in the region of wall height H1.

[0045] Figure 6A cross-section of the air mass flow sensor 2 is shown, illustrating that the second wall element 33 of the housing 4, which at least sectionally separates the bypass channel 22 of the flow channel 14 from the inlet 16, has a wall height H3 that is at least sectionally reduced, allowing the second wall element 33 to be at least sectionally overflowed. Figure 5 As shown in the diagram, a gap 35 is thus formed between the cover 12 and the second wall element 33, allowing the second wall element 33 to overflow.

[0046] As an alternative or supplementary solution, the through-hole 34 can be formed into the first wall element 28, allowing flow through the first wall element 28. Figure 7 This also applies to the second wall element 33.

[0047] Figure 8 A motor vehicle 100 is shown, which has a turbocharged internal combustion engine 110 and an air mass flow sensor 2, wherein the air mass flow sensor 2 is arranged in the intake manifold 120 of the internal combustion engine 110 to measure the air mass flow rate inside the intake manifold 120. The intake manifold 120 is connected to a turbocharged air cooler 130.

[0048] According to an alternative design of the present invention, the motor vehicle 100 can be a hybrid vehicle having at least one electric motor to supplement the internal combustion engine 110, the electric motor having a allocated traction battery.

Claims

1. An air mass flow sensor used to determine air mass flow rate. -Has a housing (4), and - Equipped with sensor electronics (6). -The sensor electronics (6) are at least partially arranged in the housing chamber (8) of the housing (4), -The housing (4) therein has a flow channel (14) for guiding the air mass flow (L) to be measured through the housing (4). - The flow channel (14) has a measurement channel (20) and a bypass channel (22). - wherein the measurement channel (20) guides a portion of the air mass flow (L) flowing into the flow channel (14) to the measurement point (24) of the sensor electronics (6), and -The bypass channel (22) therein branches off a portion of the air mass flow (L) flowing into the flow channel (14) before reaching the measuring point (24) and discharges it from the housing (4). Its features are, - A first wall element (28) that separates the bypass channel (22) and the measuring channel (20) from each other at least segmentally has a wall height (H1) that is at least segmentally reduced, such that the first wall element (28) can be overflowed at least segmentally, and / or the first wall element (28) has a through hole (34) that allows flow through the first wall element (28), and / or The second wall element (33), which at least segmentally separates the bypass channel (22) and the inlet (16) of the flow channel (14), has a wall height (H3) that is at least segmentally reduced, such that the second wall element (33) can be overflowed at least segmentally, and / or the second wall element (33) has a through hole (34) such that the second wall element (33) can be through-flowed. The outlet of the bypass channel and the outlet of the measurement channel are arranged adjacent to each other and separated by the first wall element (28).

2. The air mass flow sensor according to claim 1, Its features are, - The first wall element (28) is arranged between the discharge section (30) formed downstream of the measurement point (24) of the measurement channel (20) and the bypass channel (22).

3. The air mass flow sensor according to claim 2, Its features are, - The wall height (H2) of the first wall element (28) in the discharge section of the bypass channel (22) is greater than the reduced wall height (H1), in which the first wall element (28) can be overflowed. -The first wall element (28) can also be overflowed in the region of the wall height (H2) or can only be overflowed in the region of the reduced wall height (H1).

4. The air mass flow sensor according to claim 1, Its features are, - The inlet of the flow channel is widened in a funnel shape.

5. The air mass flow sensor according to claim 1, Its features are, - A gap (31, 32, 35) is formed between the cover (12) of the housing (4) and the first wall element (28) and / or the second wall element (33) of the housing (4), in which the first wall element (28) and / or the second wall element (33) can be overflowed.

6. Motor vehicles, Its features - Air mass flow sensor (2) according to any one of claims 1-5.

7. The motor vehicle according to claim 6, - Equipped with an internal combustion engine (110). Its features are, - The air mass flow sensor (2) is arranged in the intake manifold (120) of the internal combustion engine (110) to measure the air mass flow (L) inside the intake manifold (120).

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