초록 ▼

A flow sensor functions as a flow meter, for measuring the flow rate of a measurement objective fluid. The flow sensor comprises a flow passage, through which the measurement objective fluid flows, a sensor arranged so as to face the flow passage from a top wall that defines the flow passage, a thro

A flow sensor functions as a flow meter, for measuring the flow rate of a measurement objective fluid. The flow sensor comprises a flow passage, through which the measurement objective fluid flows, a sensor arranged so as to face the flow passage from a top wall that defines the flow passage, a throttle surface opposed to the top wall where the sensor is arranged, and an inclined surface provided on an upstream side of the throttle surface. The inclined surface is disposed such that the flow passage widens toward the inlet side of the flow passage. The inclined surface has an angle such that an extension line thereof passes through a position that is offset toward the upstream side, as compared to the detecting section of the sensor.

대표청구항 ▼

What is claimed is: 1. A flow sensor comprising: a main body including a flow passage formed at least by a top wall and a bottom wall, wherein a measurement objective fluid flows through said flow passage; and a sensor arranged along said top wall forming said flow passage so as to face said flow p

What is claimed is: 1. A flow sensor comprising: a main body including a flow passage formed at least by a top wall and a bottom wall, wherein a measurement objective fluid flows through said flow passage; and a sensor arranged along said top wall forming said flow passage so as to face said flow passage, wherein said flow passage includes a throttle surface opposed to said sensor, and a first inclined surface formed continuously and with a constant angle on an upstream side of said throttle surface, said first inclined surface being disposed such that said flow passage, which is formed between said top wall and said first inclined surface, widens toward said upstream side, and wherein said constant angle of said first inclined surface is formed such that an extension line of said first inclined surface, which is directed toward a downstream side, passes through a position offset toward said upstream side, as compared with a detecting section that is provided on a detection surface of said sensor. 2. The flow sensor according to claim 1, further comprising: a second inclined surface formed continuously and with a constant angle on said downstream side of said throttle surface, said second inclined surface being provided such that said flow passage, which is formed between said top wall and said second inclined surface, widens toward said downstream side, wherein said constant angle of said second inclined surface is formed such that an extension line of said second inclined surface passes through a position offset toward said downstream side, as compared with said detecting section that is provided on said detection surface of said sensor. 3. The flow sensor according to claim 2, wherein an angle formed by a first inclined surface and said bottom wall that continues on said upstream side of said first inclined surface, and/or an angle formed by said second inclined surface and said bottom wall that continues on said downstream side of said second inclined surface, is not more than 150°. 4. The flow sensor according to claim 1, wherein an angle formed by said first inclined surface and said bottom wall that continues on said upstream side of said first inclined surface is not more than 150°. 5. The flow sensor according to claim 1, wherein a length of said throttle surface in a flow direction of said measurement objective fluid is larger than a length of said sensor in said flow direction. 6. The flow sensor according to claim 1, wherein a mesh member is disposed on an inlet side and/or an outlet side of said flow passage. 7. The flow sensor according to claim 6, wherein said mesh member is attached by means of a fixing screw, thereby allowing said measurement objective fluid to flow through said mesh member. 8. The flow sensor according to claim 1, wherein a projection, having a trapezoidal cross-sectional shape formed in a flow direction of said measurement objective fluid, is disposed on said bottom wall opposed to said top wall of said flow passage, and wherein said throttle surface, which is opposed to said sensor and disposed in parallel to said top wall, is formed on said projection.