Patent EP0322459A1 successfully refreshed from Google Patents.
EP0322459A1
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Hot wire type air flow meter
Assignee: Hitachi Ltd
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Filing: 1988-06-15
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Granted: —
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Expires: 2008-06-15
Abstract
Abstract The present invention, the object of which is to provide a hot wire type air flow meter capable of accurately detecting an air suction rate of an internal combustion engine and stabilizing the flow distribution, relates to a hot wire type air flow meter having a main flow passage constituting a suction airflow passage in an internal combustion engine, a hot wire element for measuring the suction air, and an auxiliary flow passage provided therein with the hot wire element and installed in the main flow passage, wherein the auxiliary flow passage has a flow passage member extending in-the axial direction of the main flow passage and a flow passage member extending in the radial direction of the main flow passage, a constriction being provided between the auxiliary flow passage and a throttle valve disposed on the downstream side the reof.
Inventors
- 👤 Yoshito Sekine
- 👤 Nobukatsu Arai
- 👤 Tadao Ohsawa
- 👤 Hiroatsu Tokuda
- 👤 Toshifumi Usui
- 👤 Mitsukuni Tsutsui
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 12:28
CPC Classifications
G; G01; G01F; G01F1/00; G01F1/68; F; F02; F02D; F02D41/00; F02D41/02; F02D41/18; F02D41/187; G01F1/684; G01F1/6842; G01F5/00
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
92 words
A hot-wire air flow meter for internal combustion engines comprising: a main passage forming an air horn for the internal combustion engine; a hot-wire element for measuring the quantity of air drawn in; a bypass passage installed in the main passage and containing the hot-wire element, the bypass passage consisting of a first passage formed along the main passage axis and a second passage formed in the radial direction of the main passage; and a throttled portion formed between the bypass passage and a throttle valve located downstream of the bypass passage.
Claim 2
Dependent Claim
92 words
A hot-wire air flow meter for internal combustion engines comprising: a main passage forming an air horn for the internal combustion engine; a hot-wire element for measuring the quantity of air drawn in; a bypass passage installed in the main passage and containing the hot-wire element, the bypass passage consisting of a first passage formed along the main passage axis and a second passage formed in the radial direction of the main passage; and a throttled portion formed between the bypass passage and a throttle valve located downstream of the bypass passage.
Claim 3
Dependent Claim
36 words
A hot-wire air flow meter as set forth in claim 1, wherein the hot-wire element is installed in the first passage of the bypass passage which is formed in the axial direction of the main passage.
Claim 4
Dependent Claim
36 words
A hot-wire air flow meter as set forth in claim 1, wherein the first passage of the bypass passage running in the axial direction of the main passage is eccentric with respect to the main passage.
Claim 5
Dependent Claim
28 words
A hot-wire air flow meter as set forth in claim 1, wherein a throttle for constricting the air flow is provided at the inlet of the bypass passage.
Claim 6
Dependent Claim
31 words
A hot-wire air flow meter as set forth in claim 1, wherein a member forming the main passage and a member forming the bypass passage are formed integral with each other.
Claim 7
Dependent Claim
94 words
A hot-wire air flow meter as set forth in claim 1, wherein said bypass passage is positioned in such a manner that, when a throttle valve disposed downstream of said main passage is opened with one side directed toward upstream, the inlet thereof is disposed in a region where one part of said throttle valve is disposed in the upper stream passage while the outlet thereof is disposed in a region where the other part thereof is disposed in the lower stream passage, both with respect to the center axis of said main passage.
Claim 8
Dependent Claim
28 words
A hot-wire air flow meter as set forth in claim 1, wherein the outlet of the bypass passage has its upstream side more projecting than the downstream side.
Claim 9
Dependent Claim
104 words
A hot-wire air flow meter for internal combustion engines comprising: a main passage forming an air horn for the internal combustion engine; a hot-wire element for measuring the quantity of air drawn in; a bypass passage installed in the main passage and containing the hot-wire element, the bypass passage consisting of a first passage whose air flow line is in the same direction as that of the main passage and a second passage whose air flow line is perpendicular to that of the first passage; and a throttled portion formed between the bypass passage and a throttle valve located downstream of the bypass passage.
Claim 10
Dependent Claim
104 words
A hot-wire air flow meter for internal combustion engines comprising: a main passage forming an air horn for the internal combustion engine; a hot-wire element for measuring the quantity of air drawn in; a bypass passage installed in the main passage and containing the hot-wire element, the bypass passage consisting of a first passage whose air flow line is in the same direction as that of the main passage and a second passage whose air flow line is perpendicular to that of the first passage; and a throttled portion formed between the bypass passage and a throttle valve located downstream of the bypass passage.
Claim 11
Dependent Claim
40 words
A hot-wire air flow meter as set forth in claim 8, wherein the hot-wire element is installed in the first passage of the bypass passage whose air flow line is in the same direction as that of the main passage.
Claim 12
Dependent Claim
43 words
A hot-wire air flow meter as set forth in claim 8, wherein the first passage of the bypass passage whose air flow line is in the same direction as that of the main passage is installed eccentric with respect to the main passage.
Claim 13
Dependent Claim
101 words
A hot-wire air flow meter for internal combustion engines comprising: a main passage forming an air horn for the internal combustion engine, the main passage being formed as a cylindrical structure; a hot-wire element for measuring the quantity of air drawn in; a bypass passage installed in the main passage and containing the hot-wire element, the bypass passage consisting of a first passage formed along the main passage axis and a second passage formed in the circumferential direction of the main passage; and a throttled portion formed between the bypass passage and a throttle valve located downstream of the bypass passage.
Claim 14
Dependent Claim
101 words
A hot-wire air flow meter for internal combustion engines comprising: a main passage forming an air horn for the internal combustion engine, the main passage being formed as a cylindrical structure; a hot-wire element for measuring the quantity of air drawn in; a bypass passage installed in the main passage and containing the hot-wire element, the bypass passage consisting of a first passage formed along the main passage axis and a second passage formed in the circumferential direction of the main passage; and a throttled portion formed between the bypass passage and a throttle valve located downstream of the bypass passage.
Claim 15
Dependent Claim
85 words
A hot-wire air flow meter for internal combustion engines comprising: a main passage forming an air horn for the internal combustion engine; a hot-wire element for measuring the quantity of air drawn in; a bypass passage installed in the main passage and containing the hot-wire element, the bypass passage being formed along the main passage axis, the bypass passage having a check valve at the outlet; and a throttled portion formed between the bypass passage and a throttle valve located downstream of the bypass passage.
Claim 16
Dependent Claim
85 words
A hot-wire air flow meter for internal combustion engines comprising: a main passage forming an air horn for the internal combustion engine; a hot-wire element for measuring the quantity of air drawn in; a bypass passage installed in the main passage and containing the hot-wire element, the bypass passage being formed along the main passage axis, the bypass passage having a check valve at the outlet; and a throttled portion formed between the bypass passage and a throttle valve located downstream of the bypass passage.
Claim 17
Dependent Claim
93 words
An internal combustion engine comprising: a hot-wire air flow meter claimed in any one of the claims 1 through 11; a speed sensor to detect the revolution speed of the engine; fuel injectors to inject fuel into air drawn in; and a controller to determine the amount of fuel to be injected according to the quantity of air intake detected by the hot-wire air flow meter and the revolution speed detected by the revolution speed sensor and then output to the fuel injectors signals representing the calculated amount of fuel to be injected.
Claim 18
Dependent Claim
63 words
A method of manufacturing a hot-wire air flow meter claimed in claim 1, comprising the step of die-casting the hot-wire air flow meter by using inner molds, the inner molds consisting of: an inner mold having an abutting surface and an overlapping surface, the inner mold being adapted to form the throttled portion; and two divisible inner molds to form the bypass passage.
References Cited (Backward Citations)
No citation records indexed.
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