Air mass sensors and automobiles

Abstract

The present invention relates to an air mass sensor for determining an air mass flow rate, comprising a housing (4) and sensor electronics (6), the sensor electronics being arranged at least partially in a housing chamber (8) of the housing (4), the housing (4) having a flow passage (14) for guiding an air mass flow rate (L) to be measured through the housing (4), the housing (4) having, in addition to the inlet opening (16) and the outlet opening (18) of the flow passage (14), at least one compensation opening (26) connecting the flow passage (14) to the periphery (U) of the housing (4).

Description

[Technical Field]

[0001] The present invention relates to an air mass sensor for determining an air mass flow rate, the air mass sensor comprising a housing and sensor electronics, the sensor electronics being at least partially arranged in a housing chamber of the housing, the housing having a flow passage for guiding the air mass flow rate to be measured through the housing. Furthermore, the present invention relates to a motor vehicle equipped with such an air mass sensor. [Background technology]

[0002] Air mass sensors of the type mentioned at the outset are known, for example, from US Pat. No. 8,763,452 and DE 10 2018 219 729 A1.

[0003] Such air mass sensors can be used, for example, to determine the air mass flow rate in the intake tract of an internal combustion engine of a motor vehicle. In this case, vibration excitations that impair the measurement results occur in the region of the natural frequencies of the flow path. For example, exhaust gas turbochargers can induce high-frequency pressure pulsations of up to 20 kHz in the air mass flow rate to be measured. Therefore, for a given excitation frequency or excitation frequency range, excessively large deviations occur between the measured air mass flow rate and the actual air mass flow rate. This deviation has a negative effect on engine operation. Summary of the Invention [Problem to be solved by the invention]

[0004] Against this background, the technical problem underlying the present invention is to provide an improved air mass sensor that is more robust, in particular against vibration excitations of exhaust gas turbochargers. Furthermore, it is desired to provide a motor vehicle equipped with such a sensor. [Means for solving the problem]

[0005] According to a first aspect, the present invention relates to an air mass sensor for determining an air mass flow rate, the air mass sensor comprising a housing and sensor electronics, the sensor electronics being at least partially arranged in a housing chamber of the housing, the housing having a flow passage for guiding the air mass flow rate to be measured through the housing. The air mass sensor is characterized in that the housing has, in addition to the inlet and outlet openings of the flow passage, at least one compensation opening connecting the flow passage to the periphery of the housing.

[0006] The compensation opening thus allows a fluid connection between the flow passage and the periphery of the housing, which allows a portion of the air mass flow to be measured to flow from the flow passage to the periphery of the housing and provides additional pressure compensation. This makes it possible to reduce the amplitude of vibration excitations, particularly due to high-frequency pressure pulsations of the turbocharger, thereby enabling reliable measurements even for problematic excitation frequencies. In particular, this makes it possible to eliminate natural frequencies of the flow passage or to reduce the respective vibration response in the region of one or more natural frequencies.

[0007] There may be exactly one compensation aperture or two or more compensation apertures.

[0008] The periphery of the housing may in particular be the interior of a pipe, conduit or the like, inside which an air mass sensor for determining the air mass flow is arranged.

[0009] The compensation opening may be a through opening machined into the wall of the housing, such as a hole or the like.

[0010] Alternatively or additionally, the compensation opening may be formed between the housing components of the housing. For example, if the housing has a first housing component and a second housing component that are combined to form the housing, the compensation opening may be a recess in the area of ​​a seam or abutment edge where the first and second housing components are form-fittingly engaged and / or connected to each other. The first housing component may be, for example, a lid or cover. The second housing component may be a base body of the housing to which the lid is attached.

[0011] The housing components may be bonded together by an adhesive, the compensating opening being at least partially adjacent to the adhesive bonding the housing components together.

[0012] The compensation opening may be specified as a section of an interrupted glue seam or an interrupted glue bead. The compensation opening may therefore be an interruption of the glue seam or glue bead that connects the housing components to one another. In particular, the glue seam or glue bead forms the adhesive bond of the housing components to the periphery and also the seal of the flow passage. This seal is locally interrupted to form the compensation opening.

[0013] Alternatively or additionally, a seal may be provided between the housing components, and the compensation opening may be at least partially adjacent to the seal, which may be machined into the seal or the seal may be at least partially interrupted to form the compensation opening.

[0014] The flow path may have a bypass or a bypass passage and a measurement passage, whereby a portion of the air mass flow does not flow through the measurement passage to the measurement point of the air mass sensor, but branches off into the bypass passage upstream of this measurement point and is again led out of the housing.

[0015] The compensation opening may have a predetermined spacing relative to the bypass passage.

[0016] The compensation opening can be arranged in the region of the inlet of the flow path, in particular upstream of the branch point of the flow path where the measuring channel and the bypass channel branch off.

[0017] Alternatively or additionally, at least one compensation opening can be formed in the wall of the housing that defines the bypass passage and / or the measuring passage in addition to the outlet opening of the bypass passage and / or the measuring passage, where the compensation opening is arranged downstream of the branch point of the flow path where the measuring passage and the bypass passage branch off.

[0018] "Downstream" means that the air mass flows past or through the corresponding element later than the element arranged upstream, so that the inlet opening of the measuring passage is arranged upstream of the measuring point, while the outlet opening of the measuring passage is arranged downstream of the measuring point.

[0019] The compensation opening may have a polygonal shape, in particular a rectangular or triangular shape. The compensation opening may have a circular or elliptical shape. The compensation opening may be freely shaped.

[0020] The air mass sensor may have additional functions in addition to measuring the air mass flow rate, for example, the air mass sensor may be configured to measure one or more of the following parameters in addition to measuring the air mass flow rate: the pressure of the air mass flow rate, the humidity of the air mass flow rate, and the temperature of the air mass flow rate.

[0021] The measuring element of the sensor electronics of the air mass sensor can be a thermal measuring element, in particular 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 across which the air mass flow can flow. The amount of air mass flow can then be derived from the different measured temperatures or temperature distributions of the temperature sensors. Such hot-film air mass measuring elements are described, for example, in DE 10 2018 219 729 A1.

[0022] It may be specified that components of the sensor electronics arranged in the housing chamber or electronics chamber of the air mass sensor are at least partially or completely sealed in or surrounded by sealing material, thereby protecting the components of the sensor electronics from environmental influences.

[0023] It may be specified that a first wall element separating the bypass passage and the measurement passage from one another at least partially has an at least partially reduced wall height, whereby air can at least partially flow over the first wall element, and / or has a through opening, whereby air can flow through the first wall element.Alternatively or additionally, the air mass sensor is characterized in that a second wall element separating the bypass passage and the flow passage inlet from one another at least partially has an at least partially reduced wall height, whereby air can at least partially flow over the second wall element, and / or has a through opening, whereby air can flow through the second wall element.

[0024] The reduced wall height and / or through-openings thus allow additional fluid connections within the flow passage, thereby providing additional pressure compensation for the measurement passage. This also makes it possible to reduce the amplitude of vibration excitations, particularly due to high-frequency pressure pulsations in the turbocharger, thereby enabling reliable measurements to be made even for problematic excitation frequencies. In particular, this also makes it possible to eliminate natural frequencies of the flow passage or to reduce the respective vibration response in the region of one or more natural frequencies.

[0025] It may be specified that the flow path and the electronics chamber are connected to one another via an opening, the electronics chamber forming a pressure compensation volume for the flow path.

[0026] The opening thus allows a fluid connection between the flow passage and the electronics compartment, allowing a portion of the air mass flow to be measured to flow from the flow passage into the electronics compartment. This also makes it possible to reduce the amplitude of vibration excitations, particularly due to high-frequency pressure pulsations of the turbocharger, thereby enabling reliable measurements even for problematic excitation frequencies. In particular, this also makes it possible to eliminate natural frequencies of the flow passage or to reduce the respective vibration response in the region of one or more natural frequencies.

[0027] According to a second aspect, the invention relates to a motor vehicle equipped with an air mass sensor according to the invention.

[0028] The vehicle may have an internal combustion engine, and the air mass sensor is disposed in an intake line of the internal combustion engine to measure the air mass flow within the intake line. The internal combustion engine may have one or more turbochargers.

[0029] The invention will be explained in more detail below on the basis of the drawings which show several exemplary embodiments. [Brief explanation of the drawings]

[0030] [Figure 1]1 is a schematic perspective view of an air mass sensor according to the present invention, seen from above; [Figure 2] 2 is a schematic diagram of the air mass sensor shown in FIG. 1 without the cover or lid. FIG. [Figure 3] FIG. 10 is a diagram schematically illustrating another configuration of an air mass sensor according to the present invention. [Figure 4] FIG. 10 is a diagram schematically illustrating another configuration of an air mass sensor according to the present invention. [Figure 5] FIG. 10 is a diagram schematically illustrating another configuration of an air mass sensor according to the present invention. [Figure 6] FIG. 10 is a diagram schematically illustrating another configuration of an air mass sensor according to the present invention. [Figure 7] FIG. 10 is a diagram schematically illustrating another configuration of an air mass sensor according to the present invention. [Figure 8] FIG. 10 is a diagram schematically illustrating another configuration of an air mass sensor according to the present invention. [Figure 9] 2 is a schematic diagram of another configuration of an air mass sensor according to the present invention without a cover or lid. FIG. [Figure 10] FIG. 10 is a schematic enlarged view of the air mass sensor shown in FIG. [Figure 11] 1 is a diagram showing a schematic view of a motor vehicle according to the present invention, which is equipped with an air mass sensor according to the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0031] FIG. 1 shows an air mass sensor 2 for determining the air mass flow rate.

[0032] The air mass sensor 2 has a housing 4. The air mass sensor 2 has sensor electronics 6. The sensor electronics 6 is arranged in a housing chamber or electronics chamber 8 of the housing 4 (FIG. 2). In order to illustrate the electronics chamber 8 and the sensor electronics 6, the covers 10, 12 or lids 10, 12 of the housing 4 have been omitted from FIG. 2.

[0033] The housing 4 has a flow passage 14 for guiding the air mass flow L to be measured through the housing 4 .

[0034] The flow passage 14 has an inlet opening 16 for introducing the air mass flow L into the housing 4. The flow passage 14 has an outlet opening 18 for leading the air mass flow L out of the housing 4.

[0035] The flow path 14 has a bypass 20 or bypass passage 20, which causes a portion of the air mass flow L not to flow to the measuring point 22 of the air mass sensor 2, but to branch off upstream of this measuring point 22 and be led out of the housing 4 again.

[0036] A measuring element 24 of the sensor electronics 6 is arranged in the region of the measuring point 22. This measuring element 24 is a thermal measuring element 24, and in the illustrated configuration is a hot-film air mass measuring element 24.

[0037] In addition to the inlet openings 16 and outlet openings 18 of the flow passages 14, the housing 4 has compensation openings 26 connecting the flow passages 14 to the periphery U of the housing 4. In other words, there is a fluid connection between the periphery U and the flow passages 14, so that air with an air mass flow rate L can flow from the flow passages 14 to the periphery U and from the periphery U into the flow passages 14.

[0038] In the illustrated configuration, the compensation opening 26 is a cylindrical through-opening 26. The through-opening 26 is machined in a wall 28 of a base 29 of the housing 4.

[0039] In the illustrated configuration, the compensation opening 26 is arranged in the region of the inlet 16 of the flow path 14, and is therefore arranged upstream of the branching point of the flow path 14 where the flow path branches into the measurement path 30 and the bypass path 20. The compensation opening 26 is therefore arranged at a distance from the bypass path 20.

[0040] Furthermore, the lid 12 of the housing 4 is provided with another additional compensation opening 32 which connects the flow passage 14 to the periphery U of the housing 4 .

[0041] Herein, the lid 12 is the first housing component 12 of the housing, the base 29 is the second housing component 29 of the housing 4, and the lid 10 is the third housing component 10 of the housing 4.

[0042] FIG. 3 is a partially enlarged plan view of the air mass sensor 2 shown in FIG.

[0043] The air mass flow rate L flowing into the inlet 16 can partly escape through the compensation opening 26. This also applies to the compensation opening 32 (not shown) in the lid 12.

[0044] The flow path 14 then branches into a measuring passage 30 which leads to the measuring point 22 and into a bypass passage 20 which bypasses the measuring point 22 and leads a portion of the air mass flow L out of the housing 4 without supplying it to the measuring point 22. The air mass flow L which is supplied to the measuring point 22 via the measuring passage 30 and measured by the measuring element 24 is led out of the housing 4 via the outlet opening 18 of the measuring passage 30.

[0045] 4 to 8 show alternative embodiments of the air mass sensor 2 which differ from one another only in the configuration of the shape of the compensation opening 26. In FIG.

[0046] 4 shows an air mass sensor 2 having a narrow, rectangular compensation opening 26. In this case, the width B1 of the compensation opening 26 corresponds to less than one-third of the smallest width B2 of the flow passage 14 upstream of the branching of the flow passage 14 into the measurement passage 30 and the bypass passage 20.

[0047] FIG. 5 shows an air mass sensor 2 having two narrow rectangular compensation openings 26 .

[0048] 6 shows an air mass sensor 2 having a wide, rectangular compensation opening 26. In this case, the width B3 of the compensation opening 26 corresponds to a width greater than one-third of the smallest width B2 of the flow passage 14 upstream of the branching of the flow passage 14 into the measurement passage 30 and the bypass passage 20.

[0049] FIG. 7 shows an air mass sensor 2 having a triangular compensation opening 26 .

[0050] FIG. 8 shows an air mass sensor 2 with a freely shaped compensation opening 26 .

[0051] The selected shape of the compensation opening 26 may be determined by tests and / or simulations and can be adapted to the installation situation and excitation in the fully assembled state, thereby providing a reliable measure against problematic excitation frequencies. In particular, natural frequencies of the flow path can thus be reduced or eliminated.

[0052] It may be specified that the lid 12 is machined with compensation openings 32 formed in correspondence with the compensation openings 26 shown in FIGS.

[0053] 9 and 10 show another configuration of the air mass sensor 2 which differs from the variant shown in FIG. 1 in that no bypass is provided and the compensation opening 26 is formed as an interruption in the glued seam 34.

[0054] FIG. 10 is an enlarged view of FIG.

[0055] The glued seam 34 serves to connect the lid 12 to the housing 4 and to seal the flow passage 14 in the glued area against the surroundings U. In the area of ​​the compensation opening 26, the glued seam 34 shown on the left side in the drawing is interrupted so that part of the air mass flow L can escape through the compensation opening 26 between the lid 12 and the base 29 of the housing 4 when the lid 12 is assembled.

[0056] 11 shows an automobile 100. The automobile 100 is equipped with a turbocharged internal combustion engine 110 and an air mass sensor 2. The air mass sensor 2 is disposed in an intake pipe 120 of the internal combustion engine 110 and measures the air mass flow rate inside the intake pipe 120. The intake pipe 120 is connected to an intercooler 130.

[0057] According to an alternative configuration of the invention, the motor vehicle 100 may be a hybrid vehicle having at least one electric motor, complementary to the internal combustion engine 110, with an associated traction battery.

Claims

1. An air mass sensor for determining an air mass flow rate, a housing (4); Sensor electronics (6), It is equipped with the sensor electronics (6) comprises a measuring element (24) for measuring the air mass flow (L), The housing (4) has a flow path (14) for guiding the air mass flow (L) to be measured through the housing (4), the flow path (14) has a branch downstream of the inlet opening (16) that branches into a measuring passage (30) and a bypass passage (20), the measuring passage (30) having an outlet opening (18), and the measuring element (24) is arranged in the measuring passage (30); the housing (4) has, in addition to the inlet opening (16) and the outlet opening (18) of the flow passage (14), at least one compensating opening (26, 32) connecting the flow passage (14) to the periphery (U) of the housing (4); In the air mass sensor, the compensation opening (26) is arranged in the region of the inlet opening (16) of the flow path (14) and upstream of the branching point, Air mass sensor.

2. 2. The air mass sensor according to claim 1, wherein the compensation opening (26) is formed between the housing components (12, 29) of the housing (4).

3. 3. The air mass sensor according to claim 2, wherein the housing components are bonded to one another by an adhesive, and the compensation opening is at least partially adjacent to the adhesive that bonds the housing components to one another.

4. 4. The air mass sensor according to claim 3, wherein the compensation opening (26) is part of an interrupted glue seam (34) or part of an interrupted glue bead.

5. 5. The air mass sensor according to claim 2, wherein a seal (34) is provided between the housing components (12, 29), and the compensation opening (26) is at least partially adjacent to the seal (34).

6. 6. The air mass sensor according to claim 5, wherein the compensation opening is machined into the seal or the seal is at least partially interrupted to form the compensation opening.

7. 7. The air mass sensor according to claim 1, wherein the compensation opening (26) has a polygonal shape, or the compensation opening (26) has a circular or elliptical shape, or two or more compensation openings (26) are provided.

8. A motor vehicle comprising an air mass sensor (2) according to any one of claims 1 to 7.

9. 9. The vehicle of claim 8, comprising an internal combustion engine (110), 9. The motor vehicle according to claim 8, wherein the air mass sensor (2) is arranged in an intake duct (120) of the internal combustion engine (110) and measures the air mass flow rate inside the intake duct (120).

Images