Flow velocity detector

• US 6,536,274 B1
• Filed: 04/16/2001
• Issued: 03/25/2003
• Est. Priority Date: 06/14/1999
• Status: Active Grant

• Current Assignee: Yamatake Corporation
• Original Assignee: Yamatake Corporation
• Inventors: Kamiunten, Shoji, Zushi, Nobuhiko
• Primary Examiner(s): Williams, Hezron
• Assistant Examiner(s): THOMPSON, JEWEL VERGIE
• Application Number:
  US09/762,989
• Time in Patent Office: 708 Days
• Field of Search: 732/042.6, 732/042.5, 732/042.3, 732/041.7, 732/041.1
• US Class Current: 73/204.26
• CPC Class Codes: G01F 1/6845 Micromachined devices
• CPC Class Codes: G01F 1/692 Thin-film arrangements

Abstract

A flow velocity detector, wherein an upstream side temperature sensor (3U1) and a downstream side temperature sensor (3D1) are disposed on both sides of a heater (2-1) with the recessed and projected direction of the heater (2-1) in comb tooth-shape positioned approximately in parallel with the flow direction A of a detected fluid, whereby heat from the heater (2-1) first heats the crank-shaped connection parts (J) of the temperature sensors (3U1, 3D1) in comb tooth shape, respectively, and then transfers through straight line parts (S) along the crank-shapes in the direction approximately in parallel with the flow direction of the detected fluid.

Claims

1. A flow velocity detector comprising:

a substrate;

a diaphragm portion provided on said substrate;

a heater provided on said diaphragm portion;

temperature sensors formed on both sides of said heater, wherein said temperature sensors are formed in comb tooth-shape having recessed and projected sections, and said recessed and projected sections of the temperature sensors are positioned approximately in parallel with the flow direction of the detected fluid; and

wherein said comb tooth-shape temperature sensors are positioned a defined distance from said heater such that said temperature sensors and said heater are not superposed on each other.

2. A flow velocity detector according to claim 1,

wherein said heater is formed to be in the comb tooth-shape connecting a plurality of crank shapes,

said heater with the recessed and projected direction of this comb tooth-shape is positioned approximately in parallel with the flow direction of the detected fluid.

3. A flow velocity detector according to claim 2,

wherein at least parts of the respective irregularities of these comb tooth-shapes of said temperature sensor and said heater are positioned in such a way that they cut into each other.

4. A flow velocity detector according to claim 3,

wherein convexed parts cutting into said temperature sensor side of the comb tooth-shapes of said heater are made to be wide in a flow direction of said detected fluid.

5. A flow velocity detector according to claim 1,

wherein said heater is provided extendedly to surround at least part of the periphery of said temperature sensor.

6. A flow velocity detector according to claim 2,

wherein said heater is provided extendedly to surround at least part of the periphery of said temperature sensor.

7. A flow velocity detector according to claim 3,

wherein said heater is provided extendedly to surround at least part of the periphery of said temperature sensor.

8. A flow velocity detector according to claim 4,

wherein said heater is provided extendedly to surround at least part of the periphery of said temperature sensor.

9. A flow velocity detector according to claim 1,

wherein signal derivation parts from said temperature sensor are provided in the position farthest from said heater.

10. A flow velocity detector according to claim 1,

wherein each of said temperature sensor with a crank shape includes a long portion and a short portion, each of the long portion parallel to each other of a crank shape of said temperature sensor has substantially equal length, and the short portion connecting the adjacent long portion crossing at right angles at the edge portion of a long portion is positioned to be even on the same straight line.