US 4,058,100 AGranted

Intake air flow rate measuring device for internal combustion engine

AssigneeNippon Soken, Inc.

InventorsEizi Tanaka, Hiroshi Mochizuki

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Abstract

A flow rate measuring device for an internal combustion engine with an unbalanced sensing vane pivotably disposed in an intake pipe upstream of a throttle valve, an actuating device having a pressure chamber and a movable diaphragm coupled to the sensing vane for actuating the same in response to a pressure applied to the pressure chamber, and a conduit communicating the pressure chamber with the intake pipe between the sensing vane and the throttle valve. The flow rate measuring device further has a pressure difference responsive valve responsive to a pressure difference across the sensing vane to compensate the pressure applied to the pressure chamber, whereby the pressure difference across the sensing vane can be kept constant irrespective of changes in the amount of intake air.

Claims15

Dependent claims

A flow rate measuring device for intake air into internal combustion engines of the type provided with an air intake pipe (1) and a throttle valve (3) disposed within said air intake pipe (1) for controlling the flow rate of intake air flowing into the engine, said device comprising:

a. an unbalanced sensing vane (60 pivoted to said air intake pipe (1) at the upstream of said throttle valve (3), said sensing vane being opened or closed in response to the flow rate of intake air flowing into said air intake pipe (1),
b. a shaft (5) operatively coupled to and rotated by said sensing vane (6), the angular displacement of said shaft representing the flow rate of intake air,
c. a pressure-difference-responsive valve (15) comprising:
a housing (32),
a flexible member (16) extended through said housing (32) to define therein a first pressure chamber (17) and a second pressure chamber (18),
said first and second pressure chambers being so communicated with said air intake pipe that the air pressures at the upstream and downstream of said sensing vane (6) may be transmitted to said first and second pressure chambers, respectively,
valve means (19, 20, 23) attached to said flexible member (16), and communicated with both the atmosphere and said intake pipe (1) between said sensing vane and said throttle valve, and
spring means (26) so loaded as to normally bias said flexible member (16) toward said first pressure chamber,
whereby in response to both the pressure produced in said intake pipe between said sensing vane and throttle valve and the pressure difference between a pressure in said intake pipe upstream of said sensing vane and a pressure in said intake pipe downstream of said sensing vane, said pressure-difference-responsive valve producing a pressure signal, and
d. pressure-responsive actuating means (9) comprising:
a housing (9A),
a flexible member (12) extended through said housing to define in said housing a pressure chamber (9B) into which is transmitted said pressure signal from said pressure-difference-responsive valve (15), and
connecting means (7, 8) for operatively interconnecting between said flexible member (12) and said sensing vane (6),
whereby in response to said pressure signal said flexible member being deflected and the deflection thereof being transmitted through said connecting means to said sensing vane (6), thereby controlling said pressure difference at a constant value.

11 more elements

A flow rate measuring device for intake air into internal combustion engines of the type having an intake pipe through which air is introduced into an engine, and a throttle valve disposed in said intake pipe for controlling the flow rate of intake air flowing therethrough, said flow rate measuring device comprising:

a. an unbalanced sensing vane pivotally disposed in said intake pipe upstream of said throttle valve;
b. pressure responsive actuating means having a pressure chamber, a movable member operable in response to a pressure introduced into said pressure chamber, and connecting means for operatively interconnecting said movable member with said sensing vane, said actuating means actuating said sensing vane to open and close in response to the pressure introduced into said pressure chamber;
c. conduit means communicating said pressure chamber with said intake pipe between said sensing vane and said throttle valve to thereby introduce a pressure produced in said intake pipe between said sensing vane and said throttle valve into said pressure chamber;
and
d. pressure difference responsive means for supplying air into said pressure chamber in response to a pressure difference between a pressure in said intake pipe upstream of said sensing vane and a pressure in said intake pipe downstream of said sensing vane so as to actuate said sensing vane so that said pressure difference is kept constant.

2 more elements

Dependencies are inferred from the claim text.