Flow rate measuring device
AssigneeDenso Corporation
InventorJunzo YAMAGUCHI
Life of this patent
Estimating the term…
Abstract
A sensor SA has a flow sensor that measures a flow rate of intake air in a measurement flow path. The flow sensor has a film-shaped sensor film portion overlapped on a substrate front surface of a sensor substrate. The sensor film portion has a heat generating resistor that heats the sensor film portion and a temperature measuring resistor that measures a temperature of the sensor film portion. The heat generating resistor and the temperature measuring resistor are arranged in a depth direction Z along the substrate front surface of the sensor substrate. A length dimension LM1 of an upstream temperature measuring resistor is equal to or larger than a length dimension LM2 of a downstream temperature measuring resistor.
Claims11
A flow rate measuring device configured to measure a flow rate of fluid, the device comprising:
- a measurement flow path configured to conduct the fluid therethrough;
- and
- a flow sensor configured to measure the flow rate of the fluid in the measurement flow path, wherein
- the flow sensor includes
- a sensor substrate having one surface and
- a film-shaped sensor film portion overlaid on the one surface of the sensor substrate, wherein
- the sensor film portion includes
- a heater portion configured to heat the sensor film portion and
- a temperature measurement portion arranged in the heater portion along the one surface and configured to measure a temperature of the sensor film portion,
- an orthogonal direction is orthogonal to both a thickness direction of the sensor film portion and an arrangement direction of the heater portion and the temperature measurement portion,
- a length dimension of the heater portion in the orthogonal direction is LH,
- a length dimension of an inner edge portion which is an edge portion of the temperature measurement portion on a heater portion side in the orthogonal direction is LM1,
- a length dimension of an outer edge portion which is an edge portion of the temperature measurement portion on a side opposite to the heater portion in the orthogonal direction, is LM2, and
- a thickness dimension of the heater portion in the thickness direction is t1, and
- relationships of Expression 1 and Expression 2 are satisfied,
- 240<LH×t1×(LM1−LM2+1)<2400, and Expression 1:
- LM1≥LM2. Expression 2:
A flow rate measuring device configured to measure a flow rate of fluid, the flow rate measuring device comprising:
- a measurement flow path configured to conduct the fluid therethrough;
- and
- a flow sensor configured to measure the flow rate of the fluid in the measurement flow path, wherein
- the flow sensor includes
- a sensor substrate having one surface;
- and
- a film-shaped sensor film portion overlaid on the one surface of the sensor substrate,
- the sensor film portion includes
- a heater portion configured to heat the sensor film portion;
- and
- a temperature measurement portion arranged in the heater portion along the one surface to measure a temperature of the sensor film portion,
- an orthogonal direction is orthogonal to both a thickness direction of the sensor film portion and an arrangement direction of the heater portion and the temperature measurement portion,
- in the orthogonal direction, a length dimension of an outer edge portion which is an edge portion of the temperature measurement portion on a side opposite to the heater portion is smaller than a length dimension of an inner edge portion which is an edge portion of the temperature measurement portion on a heater portion side, and
- the outer edge portion is at a position spaced inwardly in the orthogonal direction from both end portions of the inner edge portion.
Dependencies are inferred from the claim text.