Flow rate measurement device

Patent metadata

Field	Value
Publication number	US-10365142-B2
Application number	US-201615055750-A
Country	US
Kind code	B2
Filing date	Feb 29, 2016
Priority date	Oct 29, 2015
Publication date	Jul 30, 2019
Grant date	Jul 30, 2019

Abstract

An environment sensor arranged in a measuring chamber disposed in a circuit board receiving portion does not affect a flow of air through a bypass passage, and thus does not affect detection accuracy of a flow rate detection element arranged in the bypass passage. A recessed portion is disposed in a side surface of a base parallel to a flow direction A of intake air passing through a main passage and a communication port of the measuring chamber is disposed in the recessed portion, and thus the measuring chamber is unlikely to be infiltrated by fouling substances, water droplets, and the like contained in the intake air. The communication port has a small length dimension L, and thus an environment parameter of the intake air is likely to propagate to the measuring chamber and high levels of detection response, detection accuracy, and reliability are ensured for the environment sensor.

First claim

What is claimed is:

1. A flow rate measurement device that is inserted into a through-hole which is disposed in piping, and measures a flow rate of a fluid to be measured that has a main passage in the piping, the flow rate measurement device comprising:
a connector that includes a connector terminal which transmits and receives a signal to and from an external device;
a flow rate detection element that is arranged in a bypass passage in which a part of the fluid to be measured passing through the main passage is taken;
a circuit board that includes a plurality of wire bonding pads, which are electrically connected to the connector terminal and the flow rate detection element respectively, on one surface;
a circuit board receiving portion that supports and receives the circuit board;
an environment sensor that is mounted on another surface of the circuit board opposite said one surface and measures at least one of temperature, humidity, and pressure of the fluid to be measured; and
a measuring chamber that is disposed in the circuit board receiving portion, the environment sensor being arranged in the measuring chamber,
wherein a recessed portion is disposed in an outer wall surface of the circuit board receiving portion forming the measuring chamber, said outer wall surface facing the fluid to be measured in said main passage and being parallel to a flow direction of said fluid to be measured passing through the main passage, and said recessed portion being a part of said outer wall surface that is recessed relative to other parts of said outer wall surface, and wherein a communication port allowing the main passage and the measuring chamber to communicate with each other is disposed in and surrounded by the recessed portion, and
wherein a raised portion surrounding the communication port is disposed in the recessed portion.

2. The flow rate measurement device according to claim 1 ,
wherein an electronic component other than the environment sensor is mounted on one or both of the one surface and the other surface of the circuit board and the circuit board receiving portion receives the circuit board such that the electronic component other than the environment sensor is not exposed to the fluid to be measured.

3. The flow rate measurement device according to claim 1 ,
wherein a tapered portion is disposed in the recessed portion such that an opening portion of the recessed portion widens toward the main passage side.

4. The flow rate measurement device according to claim 3 ,
wherein the tapered portion is disposed such that the opening portion widens on an upstream side and a downstream side of the flow direction of the fluid to be measured.

5. The flow rate measurement device according to claim 1 ,
wherein a height dimension of the raised portion is smaller than a depth dimension of the recessed portion and said height dimension decreases farther away from the communication port.

6. The flow rate measurement device according to claim 1 ,
wherein a waterproof and moisture-permeable filter is disposed in the communication port.

7. The flow rate measurement device according to claim 6 ,
wherein the filter is fixed from an inside of the measuring chamber.

8. The flow rate measurement device according to claim 1 ,
wherein an output of the environment sensor is superimposed on an output of the flow rate measurement device such that the environment sensor shares the connector terminal.

9. A flow rate measurement device that is inserted into a through-hole which is disposed in piping, and measures a flow rate of a fluid to be measured that has a main passage in the piping, the flow rate measurement device comprising:
a connector that includes a connector terminal which transmits and receives a signal to and from an external device;
a flow rate detection element that is arranged in a bypass passage in which a part of the fluid to be measured passing through the main passage is taken;
a circuit board that includes a plurality of wire bonding pads, which are electrically connected to the connector terminal and the flow rate detection element respectively, on one surface;
a circuit board receiving portion that supports and receives the circuit board;
an environment sensor that is mounted on another surface of the circuit board opposite said one surface and measures at least one of temperature, humidity, and pressure of the fluid to be measured; and
a measuring chamber that is disposed in the circuit board receiving portion, the environment sensor being arranged in the measuring chamber,
wherein a recessed portion is disposed in an outer wall surface of the circuit board receiving portion forming the measuring chamber, said outer wall surface facing the fluid to be measured in said main passage and being parallel to a flow direction of said fluid to be measured passing through the main passage, and said recessed portion being a part of said outer wall surface that is recessed relative to other parts of said outer wall surface, and wherein a communication port allowing the main passage and the measuring chamber to communicate with each other is disposed in and surrounded by the recessed portion, and
wherein a tapered portion is disposed in the recessed portion such that an opening portion of the recessed portion widens toward the main passage side, and
wherein the tapered portion is disposed such that the opening portion widens in a radial shape.

Assignees

• Mitsubishi Electric Corp

Inventors

• Kishikawa Naoyuki
• Ariyoshi Yuji
• Kawai Masahiro
• Hidaka Shinichiro
• Akagi Kazuto

Classifications

• G01F1/005 Primary

  using floats · CPC title

• G01F15/185 Primary

  Connecting means, e.g. bypass conduits · CPC title

• G01F1/684

  Structural arrangements; Mounting of elements, e.g. in relation to fluid flow · CPC title

• G01F1/6842

  with means for influencing the fluid flow · CPC title

• G01F1/696

  Circuits therefor, e.g. constant-current flow meters · CPC title