Patent US4412520A successfully refreshed from Google Patents.
US4412520A
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Fuel injection control apparatus
Assignee: Toyota Motor Corp
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Filing: 1981-07-28
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Granted: 1983-11-01
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Expires: 2001-07-28
Abstract
Abstract A fuel injection control apparatus having a pressure detection device for detecting pneumatic pressure in an intake manifold of an internal combustion engine comprises a pressure transducer and a low-pass filter, electrically connected to the transducer, for transmitting an electrical signal from the transducer below a cutoff frequency which is determined to be a frequency equal to or lower than 40 Hz.
Inventors
- 👤 Masaki Mitsuyasu
- 👤 Keiji Aoki
- 👤 Takayoshi Nakatomi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 23:51
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/30; F02D41/32; G; G01; G01L; G01L23/00; G01L23/24; F02D2200/00; F02D2200/02; F02D2200/04; F02D2200/0406
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
152 words
Fuel injection control apparatus for an internal combustion engine having an intake manifold, comprising: a pressure transducer for converting the pneumatic pressure in the intake manifold to an electrical signal; a low-pass filter electrically connected to said pressure transducer in series for transmitting said electrical signal below a cutoff frequency which is determined to be a frequency equal to or lower than 40 Hz; an analog to digital converter means connected to said low-pass filter in series for converting the output signal from the low-pass filter to a binary number signal; means for calculating the pulse width of fuel injection signals in response to said binary number signal from said analog to digital converter means, said pulse width corresponding to the fuel requirements of the engine during steady state and transient operating condition; and means for adjusting the amount of fuel injected into the engine in response to said fuel injection signals.
Claim 2
Dependent Claim
152 words
Fuel injection control apparatus for an internal combustion engine having an intake manifold, comprising: a pressure transducer for converting the pneumatic pressure in the intake manifold to an electrical signal; a low-pass filter electrically connected to said pressure transducer in series for transmitting said electrical signal below a cutoff frequency which is determined to be a frequency equal to or lower than 40 Hz; an analog to digital converter means connected to said low-pass filter in series for converting the output signal from the low-pass filter to a binary number signal; means for calculating the pulse width of fuel injection signals in response to said binary number signal from said analog to digital converter means, said pulse width corresponding to the fuel requirements of the engine during steady state and transient operating condition; and means for adjusting the amount of fuel injected into the engine in response to said fuel injection signals.
Claim 3
Dependent Claim
35 words
Apparatus as claimed in claim 1, wherein the cutoff frequency of said low-pass filter is determined to be a frequency equal to or lower than 40 Hz and equal to or higher than 0.4 Hz.
Claim 4
Dependent Claim
18 words
Apparatus as claimed in claim 1 or 2, wherein said low-pass filter is composed of a resistance-capacitance filter.
Claim 5
Dependent Claim
18 words
Apparatus as claimed in claim 1 or 2, wherein said low-pass filter is composed of an inductance-resistance-capacitance filter.
References Cited (Backward Citations)
US4010717A
Cited
US4212065A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-10-31 | 1987-05-02 | 1987-11-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-31 | 1991-05-02 | 1991-11-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-31 | 1995-05-02 | 1995-11-01 | $7700.00 | Window Closed / Lapsed |