Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
  • G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
  • G01F1/68—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using thermal effects
  • G01F1/684—Structural arrangements; Mounting of elements, e.g. in relation to fluid flow
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
  • G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
  • G01F1/68—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using thermal effects
  • G01F1/684—Structural arrangements; Mounting of elements, e.g. in relation to fluid flow
  • G01F1/688—Structural arrangements; Mounting of elements, e.g. in relation to fluid flow using a particular type of heating, cooling or sensing element
  • G01F1/69—Structural arrangements; Mounting of elements, e.g. in relation to fluid flow using a particular type of heating, cooling or sensing element of resistive type
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
  • G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
  • G01F1/68—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using thermal effects
  • G01F1/684—Structural arrangements; Mounting of elements, e.g. in relation to fluid flow
  • G01F1/6845—Micromachined devices
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
  • G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
  • G01F1/76—Devices for measuring mass flow of a fluid or a fluent solid material
  • G01F1/78—Direct mass flowmeters
  • G01F1/80—Direct mass flowmeters operating by measuring pressure, force, momentum, or frequency of a fluid flow to which a rotational movement has been imparted
  • G01F1/82—Direct mass flowmeters operating by measuring pressure, force, momentum, or frequency of a fluid flow to which a rotational movement has been imparted using a driven wheel as impeller and one or more other wheels or moving elements which are angularly restrained by a resilient member, e.g. spring member as the measuring device

Definitions

• the adhesive area does not extend over the entire sensor element, but the sensor element is only glued into the recess of the sensor carrier on one side and the area of the sensor element which has the electrical membrane is located self-supporting in the recess.
• a flow channel is provided which is formed in the sensor carrier as a groove-shaped depression and extends around the sensor element.
• the sensor carrier has at least one adhesive displacement space, in which excess adhesive used to form the adhesive seam can be displaced when the sensor element is inserted into the recess of the sensor carrier. In this way, an accumulation of adhesive at unfavorable points, in particular in the cavity of the sensor element formed below the membrane, is prevented.
• an elastic silicone adhesive By using an elastic silicone adhesive, the mechanical tensioning of the sensor element is minimized even with different thermal expansion coefficients between the material of the sensor element and the material of the sensor carrier.
• Fig. 3 is a plan view of a measuring device according to a second embodiment of the invention and 4 shows a section along the line IV-IV in FIG. 3.
• the sensor carrier 1 is preferably made of metal and can be produced by folding a thin metal strip, for which stamping, bending, folding, deep-drawing and embossing processes are suitable. In the final state of the bent metal strip, approximately two elements 14 and 15 of equal size lie against one another.
• the non-curved element 14 surrounding the sensor element 2 is referred to as a frame element 14 and the element 15 bent below it is referred to as a holding element 15.
• the holding element 15 covers in the finished bent state of approximately 180 degrees an opening 16 of the non-bent frame element 14 in order to limit a recess 17 for receiving the sensor element 2 together with the frame element 14.
• the frame element 14 or the recess 17 has a cross section which corresponds approximately to the rectangular shape of the sensor element 2, for example.
• the sensor element 2 is accommodated in the recess 17 with its surface 8 approximately flush with a surface 18 of the frame element 14.
• the holding element 15 Before the metal strip is folded, the holding element 15 can be deformed by means of a tool acting on the outer surface 22 of the holding element 15, for example an embossing tool, in such a way that two elevations 20, 21 are formed in cross section in the exemplary embodiment.
• the elevations 20, 21 are each delimited in the cross section shown in FIG. 1 by adhesive displacement spaces 23, 24 and 25 to be described in more detail.
• the sensor carrier 1 has a flattened portion 49 on its end face facing the flow direction 9 in order to improve the inflow behavior and to counteract the deposition of dirt particles.
• the plate-shaped sensor element 2 is glued into the recess 17 of the sensor carrier 1 by means of an adhesive applied along adhesive seams 26, 27 in the form of beads of adhesive. As can be seen better from FIG.
• a first adhesive seam 26 is cruciform and is used for gluing the sensor element 2 onto the plateau-shaped elevation 20.
• Pads formed connecting elements 28 are provided, which are used for the electrical connection of conductor tracks of the sensor element 2 with connecting lines 10.
• the first adhesive seam 26 serves to fix the sensor element 2 in the area of the connection elements 28 in order to achieve a secure bond connection.
• the second adhesive seam 27 is, as can be seen from FIG. 2, U-shaped in the embodiment shown in Figures 1 and 2.
• the second adhesive seam 27 is used to glue the sensor element 2 in the region of the plateau-shaped elevation 21.
• the two adhesive seams 26 and 27 are each formed between the bottom surface 29 of the sensor element 2 and the surface 31 or 30 of the elevations 20 and 21 of the holding element 15.
• the opening cross section of the recess 40 defines a throttle point.
• This opening cross-section is expediently determined such that there is a sufficiently rapid pressure compensation, preventing destruction of the membrane 4, between the front of the membrane 4 facing the flowing medium and the back 44 of the membrane 4 facing away from the flowing medium and facing the cavity 5.
• the opening cross section of the cutout 40 is to be dimensioned so small that a flow of the medium in the cavity 5 is prevented or at least sufficiently suppressed.
• the opening cross section of the cutout 40 is determined on the one hand by the width b of the cutout 40 shown in FIG. 2 and on the other hand by the thickness d of the adhesive seam 27 shown in FIG. 1.
• the thickness of the adhesive seam d can, for. B.
• spacers 43a - 43i can be adjusted by spacers 43a - 43i.
• the spacers 43a-43i can e.g. B. by an embossing process using a z. B. needle-shaped embossing tool which engages the holding element 15 on the outer surface 22 are formed.
• the adhesive seams 26 and 27 can be applied as fine beads of adhesive using a conventional metering method.
• a suitable adhesive is preferably an adhesive that remains elastic after curing, in particular an elastic silicone adhesive. Mechanical stresses between the sensor element 2 and the sensor carrier 1 are thereby minimized. Mechanical stresses occur in particular as a result of the different thermal expansion coefficients of the sensor carrier 1, which is preferably made of a metal sheet, and of the sensor element 2, which is preferably made of a semiconductor material.
• FIG. 3 and 4 show a second exemplary embodiment of the measuring device according to the invention.
• 3 shows a plan view of the measuring device according to the invention
• FIG. 4 shows a section along the line IV-IV in FIG. 3.
• Elements already described are labeled with the same reference numerals, so that a repetitive description is not necessary.
• the adhesive seam 60 can extend into the edge region of the recess 17 formed in the frame element 14.
• a recess 66 is formed in the holding element 15 of the sensor carrier 1. B. introduced by means of a deep embossing process.
• the recess 66 serves as an adhesive displacement space and receives excess adhesive.
• the depression 66 also serves to vent the cavity 5 of the sensor element 2.
• the depression 66 is essentially L-shaped and extends through the cutout 40 of the adhesive seam 60 to an extended section 67.
• the extended section 67 is therefore not covered by the sensor element 2 and is with the flowing medium to be measured for pressure equalization z. B. connected via holes, not shown, in the holding element 15.

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• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• General Physics & Mathematics (AREA)
• Measuring Volume Flow (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=7844293

Family Applications (1)

Country Status (8)

Families Citing this family (27)

Family Cites Families (6)

• 1997
  • 1997-10-01 DE DE19743409A patent/DE19743409A1/de not_active Withdrawn
• 1998
  • 1998-08-21 US US09/319,149 patent/US6318170B1/en not_active Expired - Fee Related
  • 1998-08-21 WO PCT/DE1998/002441 patent/WO1999018415A1/de not_active Application Discontinuation
  • 1998-08-21 JP JP52074199A patent/JP3784420B2/ja not_active Expired - Fee Related
  • 1998-08-21 KR KR1019997004781A patent/KR100579429B1/ko not_active IP Right Cessation
  • 1998-08-21 RU RU99114597/28A patent/RU2196965C2/ru not_active IP Right Cessation
  • 1998-08-21 EP EP98951183A patent/EP0941456A1/de not_active Withdrawn
  • 1998-08-21 CN CN98801457A patent/CN1109879C/zh not_active Expired - Fee Related

Non-Patent Citations (1)

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