Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
  • G01F5/00—Measuring a proportion of the volume flow

Definitions

• the present invention relates to an air mass sensor for determining an air mass flow, having a housing and having sensor electronics, the sensor electronics being arranged at least partially in a housing chamber of the housing and the housing having a flow channel for passing an air mass flow to be measured through the housing.
• the invention further relates to a motor vehicle with such an air mass sensor.
• Such an air mass sensor can be used, for example, to determine an air mass flow in an intake line of an internal combustion engine of a motor vehicle. This can lead to vibration excitations in the range of the natural frequencies of the flow channel, which affect the measurement result.
• an exhaust gas turbocharger can cause high-frequency pressure pulsations of up to 20 kHz in the air mass flow to be measured. For certain excitation frequencies or
• the invention is based on the technical problem of specifying an improved air mass sensor which, in particular, is more robust with regard to vibrational excitations of exhaust gas turbochargers.
• a motor vehicle with such a sensor is also to be specified.
• the invention relates to an air mass sensor for determining an air mass flow, with a housing and with sensor electronics, the sensor electronics being at least partially arranged in a housing chamber of the housing, the housing having a flow channel for passing an air mass flow to be measured through the housing , the flow channel has a measuring channel and a bypass channel, wherein the measuring channel directs part of an air mass flow flowing into the flow channel to a measuring point of the sensor electronics and wherein the bypass channel branches off part of the air mass flow flowing into the flow channel before it reaches the measuring point and discharges it from the housing .
• the air mass sensor is characterized in that a first wall element, which separates the bypass channel and the measuring channel from one another at least in sections, has a wall height that is reduced at least in sections, so that the first wall element can be overflown at least in sections and/or has a through-opening, so that the first Wall element can be flowed through.
• the air mass sensor is alternatively or additionally characterized in that a second wall element, which separates the bypass channel and an inlet of the flow channel from one another at least in sections, has a wall height that is reduced at least in sections, so that the second wall element can be overflown at least in sections and/or has a through-opening , so that the second wall element can be flowed through.
• the reduced wall height and/or the passage opening therefore enable an additional fluid connection within the flow channel in order to create additional pressure equalization for the measuring channel.
• the amplitude of vibration excitations as a result of high-frequency pressure pulsations of turbochargers can be reduced, so that a reliable measurement can also take place for critical excitation frequencies.
• natural frequencies of the flow channel eliminated or a respective vibration response in the range of one or more natural frequencies is reduced or be.
• the first wall element can be arranged between an outlet section of the measuring channel, which is formed downstream of the measuring point, and the bypass channel. Accordingly, the reduced wall height can form a fluid connection between the bypass duct and an outlet section of the measuring duct, so that part of the air mass flow can flow out of the bypass duct into the outlet section of the measuring duct.
• Downstream means that the air mass flow flows over or through a relevant element later in time than an element arranged upstream.
• An inlet opening of the measuring channel is therefore arranged upstream of the measuring point, while an outlet opening of the measuring channel is arranged downstream of the measuring point.
• a gap or a passage opening is formed between the first wall element and a lid or a cover of the housing at least in the region of the reduced wall height in order to create a fluid connection between the bypass channel and the outlet section of the measuring channel. It can be provided that the first wall element can be overflown in sections or along its entire length.
• a wall height of the first wall element in the area of an outlet section of the bypass channel is greater than the reduced wall height in the area over which the wall element can be overflown.
• the reduced wall height can be arranged adjacent to an inlet area of the bypass channel.
• the first wall element can be overflown both in the area of the reduced wall height and in the area of the outlet section.
• a gap or a passage opening is formed between the second wall element and a lid or a cover of the housing in the region of the reduced wall height in order to create a fluid connection between the inlet of the flow channel and the bypass channel.
• the second wall element can be overflowed in sections or along its entire length.
• An inlet of the flow channel can be widened in a funnel shape in order to reduce vibration excitations as a result of high-frequency pressure pulsations.
• the air mass sensor can have additional functions.
• the air mass sensor in addition to measuring an air mass flow, can also be set up to measure one or more of the parameters listed below: pressure of the air mass flow; air mass flow humidity; Air mass flow temperature.
• a 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.
• a hot-film air-mass measuring element can have, for example, at least one heating element and two temperature sensors over which the air-mass flow flows, with the amount of the air-mass flow being able to be derived from the differing measured temperatures or the temperature profiles of the temperature sensors.
• Such a hot-film air-mass measuring element is described in DE 102018219 729 A1, for example.
• the housing in addition to an inlet opening and an outlet opening of the flow channel, has at least one equalizing opening which connects the flow channel to an area surrounding the housing.
• the equalization opening therefore enables a fluid connection between the flow channel and the area surrounding the housing, so that part of the air mass flow to be measured can flow out of the flow channel into the area surrounding the housing in order to create additional pressure equalization.
• the amplitude of vibration excitations as a result of high-frequency pressure pulsations from turbochargers can be reduced, so that a reliable measurement can also take place for critical excitation frequencies.
• natural frequencies of the flow channel can also be eliminated in this way, or a respective vibration response in the range of one or more natural frequencies can be reduced or reduced.
• the area surrounding the housing can in particular be an interior space of a pipe, a line or the like, within which or within which the air mass sensor for determining the air mass flow is arranged.
• the compensation opening can be a through opening, such as a bore or the like, which is made in a wall of the housing.
• the compensation opening can be formed between housing parts of the housing. If the housing has, for example, a first housing part and a second housing part, which are assembled to form the housing, the compensation opening can be a recess in the area of a seam or joint edge, in the area of which the first and second housing parts engage in one another in a form-fitting manner and/or are connected to one another.
• the first housing part can be a lid or a cover, for example.
• the second housing part can be a base body of the housing to which the cover is attached.
• the housing parts can be connected to one another by means of an adhesive, with the compensation opening at least partially adjoining an adhesive connecting the housing parts.
• the compensation opening can be part of an interrupted adhesive seam or part of an interrupted adhesive bead.
• the compensation opening can therefore be an interruption in a glued seam or bead of glue that connects the housing parts to one another.
• the adhesive seam or bead of adhesive forms an adhesive connection between the housing parts and also seals the flow channel from the environment, with the seal being locally interrupted in order to form the compensation opening.
• the invention relates to a motor vehicle with an air mass sensor according to the invention.
• the motor vehicle can have an internal combustion engine, with the air mass sensor being arranged in an intake line of the internal combustion engine in order to measure an air mass flow within the intake line.
• the internal combustion engine may have one or more turbochargers.
• FIG. 1 shows an air mass sensor according to the invention in a perspective view from above
• FIG. 2 shows the air mass sensor from FIG. 1 without covers or covers
• Figure 3 is an enlarged view of Figure 2;
• FIG. 4 shows a cross section of the air mass sensor from FIG. 1 ;
• Fig. 5 is an enlarged view of Fig. 4;
• FIG. 6 shows a further enlarged view of FIG. 2
• FIG. 8 shows a motor vehicle according to the invention.
• the air mass sensor 2 has a housing 4.
• the air mass sensor 2 has sensor electronics 6, the sensor electronics 6 being arranged in a housing or electronics chamber 8 of the housing 4 (FIG. 2). To illustrate the electronics chamber 8 and the sensor electronics 6, covers 10, 12 or lids 10, 12 of the housing 4 are hidden in FIG.
• the housing 4 has a flow channel 14 for conducting an air mass flow L to be measured through the housing 4 .
• the flow channel 14 has an inlet opening 16 for introducing the air mass flow L into the housing 4.
• the flow channel 14 has an outlet opening 18 for discharging the air mass flow L from the housing 4.
• the inlet opening 16 or the inlet 16 of the flow channel 14 is widened in a funnel shape.
• the flow channel 14 has a measuring channel 20 and a bypass channel 22 .
• Measuring channel 20 directs part of the air mass flow L flowing into flow channel 14 to a measuring point 24 of sensor electronics 6.
• Bypass channel 22 diverts part of air mass flow L flowing into flow channel 14 before it reaches measuring point 24 and guides it out of housing 4 away.
• a measuring element 26 of the sensor electronics 6 is arranged in the area of the measuring point 24 .
• the measuring element 26 is a thermal measuring element 26 - in the present case a hot-film air mass measuring element 26.
• Fig. 3 shows an enlarged detail of Fig. 2.
• the first wall element 28 is arranged between an outlet section 30 of the measuring channel 20 and the bypass channel 22 , the outlet section 30 being formed downstream of the measuring point 24 .
• FIG. 3 shows a cross section of air mass sensor 2 according to FIG. 2.
• a gap 31 or gap 31 can also be formed between cover 12 and first wall element 28 in the region of wall height H2 be so that the first wall element 28 can also be overflown in the region of the wall height H2.
• the cover 12 rests without a gap on the wall element 28 in the area of the wall height H2, so that the wall element 28 can only be overflown in the area of the wall height H1.
• Fig. 6 shows a cross section of air mass sensor 2, which illustrates that a second wall element 33 of housing 4, which separates bypass channel 22 and inlet 16 of flow channel 14 from one another at least in sections, also has a wall height H3 that is reduced at least in sections, so that the second wall element 33 can be overflowed at least in sections.
• a gap 35 is therefore also formed between the cover 12 and the second wall element 33, so that the second wall element 33 can be overflown.
• a through-opening 34 can be made in the first wall element 28, so that the first wall element 28 can be flown through (FIG. 7). This applies equally to the second wall element 33.
• motor vehicle 100 shows a motor vehicle 100 with a turbocharged internal combustion engine 110 and with an air mass sensor 2, with the air mass sensor 2 being arranged in an intake line 120 of the internal combustion engine 110 in order to measure an air mass flow within the intake line 120.
• the intake pipe 120 is connected to an intercooler 130 .
• motor vehicle 100 can be a hybrid vehicle which, in addition to internal combustion engine 110, has at least one electric motor with an associated traction battery.

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• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• General Physics & Mathematics (AREA)
• Measuring Volume Flow (AREA)
• Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

Country Status (4)

Citations (7)

Family Cites Families (3)

• 2021
  • 2021-03-30 DE DE102021203214.1A patent/DE102021203214B3/de active Active
• 2022
  • 2022-03-17 JP JP2023560752A patent/JP2024513415A/ja active Pending
  • 2022-03-17 WO PCT/EP2022/056957 patent/WO2022207334A1/de active Application Filing
  • 2022-03-17 CN CN202280026251.XA patent/CN117203504A/zh active Pending

Patent Citations (7)

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