Gas Sensor Device

Patent metadata

Field	Value
Publication number	US-2016202200-A1
Application number	US-201414914231-A
Country	US
Kind code	A1
Filing date	Feb 3, 2014
Priority date	Aug 27, 2013
Publication date	Jul 14, 2016
Grant date	—

Abstract

A gas sensor device of the present invention, aiming sufficient correction results of an internal combustion engine under different operation conditions, includes a concentration sensor for measuring the concentration of gas and a pressure sensor for measuring the pressure of the gas. The gas sensor device also includes a measuring chamber incorporating the concentration sensor and the pressure sensor, and a processing circuit unit that adjusts a signal of the concentration sensor using a signal of the pressure sensor. The processing circuit unit may preferably be provided with a response speed adjusting unit that brings the response speed of a detected signal of the pressure sensor close to the response speed of a detected signal of the concentration sensor.

First claim

1 . A gas sensor device including a concentration sensor for measuring the concentration of gas and a pressure sensor for measuring the pressure of the gas, the device comprising:
a housing; a measuring chamber provided inside the housing, the measuring chamber being isolated from an air flow; and a processing circuit unit that adjusts a signal of the concentration sensor using a signal of the pressure sensor, wherein the concentration sensor and the pressure sensor are disposed in the measuring chamber.

2 . The gas sensor device according to claim 1 , wherein the processing circuit unit includes a response speed adjusting unit arranged to bring the response speed of a pressure signal of the pressure sensor close to the response speed of a concentration signal of the concentration sensor.

3 . The gas sensor device according to claim 2 ,
wherein the response speed adjusting unit has a function to remove or attenuate a high frequency signal component from a pressure signal sent from the pressure sensor, the high frequency signal component being higher than a frequency corresponding to the response speed of a concentration signal of the concentration sensor, and the concentration signal is corrected by a pressure signal adjusted by the response speed adjusting unit.

4 . The gas sensor device according to claim 3 ,
wherein the processing circuit unit includes a first A/D converter and a second A/D converter, the first A/D converter inputting a concentration signal sent from the concentration sensor and converting the input concentration signal into a digital value, the second A/D converter inputting a pressure signal sent from the pressure sensor and converting the input pressure signal into a digital value, the response speed adjusting unit has a function to remove or attenuate the high frequency signal component from the pressure signal converted into the digital value, and the gas sensor device further comprises a calculation unit, the calculation unit performing a correction calculation of the concentration signal converted into the digital value by the first A/D converter, the correction calculation being performed based on the pressure signal from which the high frequency signal has been removed or attenuated by the response speed adjusting unit.

5 . The gas sensor device according to claim 4 , wherein the measuring chamber includes a communication path communicating the measuring chamber with an external space in which gas to be measured flows, the communication path being provided to a surface of the housing, the surface extending along the flow of the gas.

6 . The gas sensor device according to claim 5 , wherein the concentration sensor measures the concentration of gas by utilizing the event that the amount of heat released from a heat resisting body varies depending on the concentration of the gas.

7 . The gas sensor device according to claim 6 , wherein the heat resisting body of the concentration sensor is provided on a thin part formed in a semiconductor substrate.

8 . The gas sensor device according to claim 1 , wherein the housing integrally includes a flow amount sensor element and a gas intake temperature sensor element, and the humidity signal or the pressure signal is used to correct a flow amount signal of the flow amount sensor element.

Assignees

• Hitachi Automotive Systems Ltd

Inventors

• Nakano Hiroshi
• Matsumoto Masahiro
• Asano Satoshi
• Tashiro Shinobu

Classifications

• G01F1/696 Primary

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

• G01F1/6845

  Micromachined devices · CPC title

• G01N33/0067

  by measuring the rate of variation of the concentration · CPC title

• G01F1/6842

  with means for influencing the fluid flow · CPC title

• G01N27/18 Primary

  caused by changes in the thermal conductivity of a surrounding material to be tested (G01N27/20 takes precedence) · CPC title