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EP-4737865-A1 - SENSOR APPARATUS

EP4737865A1EP 4737865 A1EP4737865 A1EP 4737865A1EP-4737865-A1

Abstract

A sensor apparatus, includes: a casing in which a first opening and a second opening are formed; a first flow channel formed in the casing and that communicates with the first opening and the second opening to form a flow of fluid from the first opening to the second opening; a pressure changer formed in the first flow channel and that is configured to change the pressure of the fluid flowing through the first flow channel; a second flow channel which branches from the first flow channel on an upstream side relative to the pressure changer; and a third flow channel which communicates with the second flow channel and in which a detector of a sensor chip is arranged.

Inventors

  • NIMURA, TOSHIHIKO
  • KAMEI, MAKOTO
  • KUROSE, IZUMI

Assignees

  • MMI Semiconductor Co., Ltd.

Dates

Publication Date
20260506
Application Date
20251028

Claims (10)

  1. A sensor apparatus, comprising: a casing in which a first opening and a second opening are formed; a first flow channel formed in the casing and that communicates with the first opening and the second opening to form a flow of fluid from the first opening to the second opening; a pressure changer formed in the first flow channel and that is configured to change the pressure of the fluid flowing through the first flow channel; a second flow channel which branches from the first flow channel on an upstream side relative to the pressure changer; and a third flow channel which communicates with the second flow channel and in which a detector of a sensor chip is arranged, wherein the first flow channel includes a curved portion forming an arc as viewed in a first direction, the curved portion being formed upstream of the pressure changer, in a cross section crossing the first direction, the curved portion includes a first surface and a second surface which face each other in a direction along a radius of curvature of the curved portion, the second surface is disposed closer to a center of curvature of the curved portion as compared with the first surface, and a third opening is formed in the second surface as a connection portion connecting the first flow channel and the second flow channel.
  2. The sensor apparatus according to claim 1, wherein the pressure changer is formed in a center of the first flow channel in a flow direction and includes a contracted flow channel having a reduced cross-sectional area in a direction crossing the flow direction of the first flow channel.
  3. The sensor apparatus according to claim 1, wherein the second flow channel is formed to bend in a direction opposite to a flow direction of the first flow channel from the third opening as viewed in the first direction.
  4. The sensor apparatus according to claim 1, wherein the second flow channel includes an expanded flow channel whose cross-sectional area in the direction crossing a flow direction of the second flow channel is expanded.
  5. The sensor apparatus according to claim 1, wherein the second flow channel includes a branched flow channel which is formed in a portion connected to the third flow channel, the branched flow channel being configured to include a dead-end structure.
  6. The sensor apparatus according to claim 1, wherein a cross-sectional area in the direction crossing a flow direction of a flow channel in contact with the detector of the sensor chip is smaller as compared with the cross-sectional area of the flow channel upstream or downstream of the flow channel in contact with the detector.
  7. The sensor apparatus according to claim 1, wherein the third opening is disposed on a pressure changer side relative to a position on the first surface where a line connecting the center of curvature and the first surface is the longest.
  8. The sensor apparatus according to claim 3, wherein a corner where the second surface of the first flow channel meets an inner wall surface of the second flow channel forms an acute angle as viewed in the first direction.
  9. The sensor apparatus according to claim 1, further comprising: a fourth flow channel which branches from the first flow channel on a downstream side relative to the pressure changer and communicates with the third flow channel.
  10. The sensor apparatus according to claim 9, wherein the direction connecting the first opening and the second opening is a second direction, and the first flow channel, the second flow channel, the third flow channel, and the fourth flow channel are symmetrically formed as viewed in the first direction with respect to the center of the pressure changer in the second direction.

Description

BACKGROUND 1. Field of the Invention The present disclosure relates to a sensor apparatus. 2. Description of the Related Art For example, there is known a flow rate measuring device including a housing including a bypass channel that takes in a part of the air flowing through a duct, and a flow sensor chip including a detection surface portion arranged in the bypass channel and generating an electric signal that corresponds to the flow rate of the air in the duct by heat transfer with the air flowing through the bypass channel (for example, see Japanese Laid-Open Patent Application No. 2022-153665). For example, there is known a measurement device for measuring a mass flow rate of a flow medium flowing through a piping, in which a measuring element is arranged in a measuring passage including a range having a plurality of different radii of curvature (for example, see Japanese Laid-Open Patent Application No. 2008-197122). SUMMARY In a sensor apparatus in which a sensor chip is disposed inside a flow channel branching from a main flow channel (first flow channel), when it is difficult to cause a fluid flowing through the main flow channel to flow into the flow channel branching from the main flow channel, measurement by the sensor chip may be difficult. Provided is a sensor apparatus in which fluid flowing through the first flow channel can smoothly flow into the flow channel branching from the first flow channel. A sensor apparatus according to one embodiment of the present disclosure includes: a casing in which a first opening and a second opening are formed; a first flow channel formed in the casing and that communicates with the first opening and the second opening to form a flow of fluid from the first opening to the second opening; a pressure changer formed in the first flow channel and that is configured to change the pressure of the fluid flowing through the first flow channel; a second flow channel which branches from the first flow channel on an upstream side relative to the pressure changer; and a third flow channel which communicates with the second flow channel and in which a detector of a sensor chip is arranged, wherein the first flow channel includes a curved portion forming an arc when viewed in a first direction, the curved portion being formed upstream of the pressure changer, wherein, in a cross section crossing the first direction, the curved portion includes a first surface and a second surface which face each other in a direction along a radius of curvature of the curved portion, and wherein the second surface is disposed closer to the center of curvature of the curved portion as compared with the first surface, and a third opening is formed in the second surface as a connection portion connecting the first flow channel and the second flow channel. The present disclosure provides a sensor apparatus capable of smoothly flowing a fluid flowing through a first flow channel into a third flow channel provided with a sensor chip. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view illustrating a sensor apparatus according to an embodiment;FIG. 2 is a plan view illustrating a main flow channel, sub-flow channels, and a sensor chip flow channel formed in a flow channel plate;FIG. 3 is an enlarged plan view illustrating the main flow channel and the sub-flow channel in the vicinity of a first opening;FIG. 4 is an enlarged plan view illustrating the main flow channel and the sub-flow channel in the vicinity of a second opening;FIG. 5 is an enlarged bottom view illustrating an enlarged view of the sensor chip flow channel, the sub-flow channel, and a dead-end structure; andFIG. 6 is a cross-sectional view illustrating the first opening, the main flow channel, the sub-flow channel, and the dead-end structure. DETAILED DESCRIPTION OF THE PRESENT DISCLOSURE The sensor apparatus according to the embodiment will be described in the following with reference to the attached drawings. In the present specification and the drawings, the substantially identical components may be denoted by the same reference numerals, thereby eliminating redundant descriptions. In the present specification, the terms "top" and "bottom" may be used. These are "top" and "bottom" in the state as illustrated in FIG. 1. In a Z-axis direction, the side where a first opening 10a and a second opening 20a are arranged is "top", and the side where a substrate 110 is arranged is "bottom". The actual arrangement of a sensor apparatus 100 is not limited to the above. In the description of the sensor apparatus 100, the term "flow direction" may be used. The "flow direction" is basically a fluid flow direction when the fluid flowing in from the first opening 10a is discharged from the second opening 20a. The fluid flow direction in this case is illustrated by arrows in FIG. 2. The sensor apparatus 100 according to the embodiment can be used by flowing the fluid such that the fluid flowing in from the second opening 20a is