EP0025149A2
Expired / Lapsed
EP
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Gas flow measuring apparatus
Assignee: Hitachi Ltd
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Filing: 1980-08-20
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Granted: —
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Expires: 2000-08-20
Abstract
Abstract An intake barrel (10) connected to an intake pipe of an internal combustion engine is provided therein with a venturi member (12). Openings (22,16) are formed in the wall of the intake barrel (10) at the upstream and donwstream sides of the venturi member (12). A bypass passage forming member (28) provided with a groove (26) of a length greater than the distance between said openings (22,16) is fixed to the outside of the intake barrel (10). A bypass passage (34) is formed by these openings (22, 16) and the groove (26). A spacer (32) is interposed between the intake barrel (10) and the bypass passage forming member (28). The cross-sectional area of the bypass passage (34) can be varied by varying the thickness of the spacer (32).
Inventors
- 👤 Kanemasa Sato
- 👤 Sadayasu Ueno
- 👤 Kazuhiko Miya
- 👤 Yoshishige Oyama
- 👤 Yutaka Nishimura
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 17:26
CPC Classifications
G; G01; G01F; G01F1/00; G01F1/68; G01F1/684; G01F1/6842; G01F5/00
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
194 words
An apparatus for measuring the flow rate of a gas comprising: a main supply path (10) through which said gas flows, said main supply path (10) having a first and a second openings (22, 16) formed in the wall thereof and spaced by a predetermined distance in the direction of flow of said gas; a restrictive element disposed in said main supply path between said first and second openings and adapted to maintain a higher pressure at said first opening than at said second opening; a bypass member (28) fixed to the outside of said main supply path and provided with an elongated groove of a length greater than the length of said first and second openings, said elongated groove being communicated at its one side with said first opening (22) and at its other end with said second opening (16); a spacer (32) interposed between said main supply path (1) and said bypass passage and provided with an opening corresponding to said groove of said bypass member; and a gas flow meter including a pair of resistance members (44, 46) exposed to the inside of said groove (26) of said bypass member (28).
Claim 2
Independent Claim
194 words
An apparatus for measuring the flow rate of a gas comprising: a main supply path (10) through which said gas flows, said main supply path (10) having a first and a second openings (22, 16) formed in the wall thereof and spaced by a predetermined distance in the direction of flow of said gas; a restrictive element disposed in said main supply path between said first and second openings and adapted to maintain a higher pressure at said first opening than at said second opening; a bypass member (28) fixed to the outside of said main supply path and provided with an elongated groove of a length greater than the length of said first and second openings, said elongated groove being communicated at its one side with said first opening (22) and at its other end with said second opening (16); a spacer (32) interposed between said main supply path (1) and said bypass passage and provided with an opening corresponding to said groove of said bypass member; and a gas flow meter including a pair of resistance members (44, 46) exposed to the inside of said groove (26) of said bypass member (28).
Claim 3
Dependent Claim
34 words
An apparatus for measuring the flow rate of a gas as claimed in claim 1, characterized by further comprising a filter (24) disposed in said first opening (22) of said main supply path (10).
Claim 4
Dependent Claim
28 words
An apparatus for measuring the flow rate of a gas as claimed in claim 1, wherein said bypass member (28) and said spacer are made of synthetic resins.
Claim 5
Dependent Claim
63 words
An apparatus for measuring the flow rate of a gas as claimed in claim 1, wherein said gas flow meter includes a flow rate sensor resistance and a temperature compensation resistance exposed to the inside of said groove of said bypass member, and a bridge circuit two sides of which being constituted by said flow rate sensor resistance and said temperature compensation resistance.
Claim 6
Independent Claim
245 words
An apparatus for measuring the flow rate of a gas comprising: a main supply path defined by a cylindrical member (10) having a greater inside diameter at the upstream side than at the downstream side thereof and through which said gas is made to flow, the small diameter portion of said main supply path being provided with a first and a second openings formed in the wall thereof, said first and second openings being spaced from each other by a predetermined distance in the direction of flow of said gas; a venturi member (12) fitted in the small diameter portion of said main supply path (10) and provided at its throat portion with a third opening (20) communicated with said second opening (16); a bypass passage forming member (28) fixed to the outside of said main supply path (10) and provided with an elongated groove (21) of a length greater than the distance between said first and second openings (22, 11), said groove (21) being communicated at its one end with said first opening (2) and at its other end with said second opening (16); a spacer (32) interposed between said main supply path (10) and said bypass member (25) and provided with a fourth opening corresponding to said groove (26) of said bypass member (29); and a hot wire sensor including a first and a second resistances (44. 46) exposed to the inside of the groove (21) of said bypays passage forming member (28).
Claim 7
Independent Claim
245 words
An apparatus for measuring the flow rate of a gas comprising: a main supply path defined by a cylindrical member (10) having a greater inside diameter at the upstream side than at the downstream side thereof and through which said gas is made to flow, the small diameter portion of said main supply path being provided with a first and a second openings formed in the wall thereof, said first and second openings being spaced from each other by a predetermined distance in the direction of flow of said gas; a venturi member (12) fitted in the small diameter portion of said main supply path (10) and provided at its throat portion with a third opening (20) communicated with said second opening (16); a bypass passage forming member (28) fixed to the outside of said main supply path (10) and provided with an elongated groove (21) of a length greater than the distance between said first and second openings (22, 11), said groove (21) being communicated at its one end with said first opening (2) and at its other end with said second opening (16); a spacer (32) interposed between said main supply path (10) and said bypass member (25) and provided with a fourth opening corresponding to said groove (26) of said bypass member (29); and a hot wire sensor including a first and a second resistances (44. 46) exposed to the inside of the groove (21) of said bypays passage forming member (28).
Claim 8
Dependent Claim
47 words
An apparatus for measuring the flow rate of a gas as claimed in claim 4, wherein said bridge circuit is formed on a circuit board (38), which is accomodated by a recess (36) formed in the bypass member (28) so as to oppose to the groove (26).
Claim 9
Dependent Claim
47 words
An apparatus for measuring the flow rate of a gas as claimed in claim 6, wherein said circuit board (38) is coated with an anti-humidity insulating material (52), and said recess (36) is filled with an insulating filler (54) and sealed by means of a cover (55).
Claim 10
Dependent Claim
58 words
An apparatus for measuring the flow rate of a gas as claimed in claim 1 or claim 5, wherein said spacer (32) is replaceable with another spacer (32) of different thickness, and/or said venturi member (12) is replaceable with another venturi member (12) of different cross-sectional area to control the gas flowing velocity through the bypass passage (34).
Claim 11
Dependent Claim
67 words
An apparatus for measuring the flow rate of a gas as claimed in claim 1 or claim 5, wherein said main supply path (10) is communicated at its downstream side end with the combustion chamber of an engine through the throttle valve chamber and the intake pipe, and a fuel injection valve is disposed at a portion of the throttle valve chamber downstream from the throttle valve.
References Cited (Backward Citations)
No citation records indexed.
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