Patent US5062294A successfully refreshed from Google Patents.
US5062294A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for detecting pressure in cylinder of internal combustion engine
Assignee: Mitsubishi Electric Corp
•
Filing: 1990-03-29
•
Granted: 1991-11-05
•
Expires: 2010-03-29
Abstract
Abstract An apparatus for detecting the pressure in a cylinder of an internal combustion engine is disclosed which includes a piezoelectric pressure sensor and a current input circuit. The sensor detects the pressure in the cylinder. A current input circuit receives the output signal of the sensor in the form of a current and generates an output corresponding to the value of the current in the form of a voltage or current.
Inventors
- 👤 Toshio Iwata
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 15:25
CPC Classifications
G; G01; G01L; G01L9/00; G01L9/08; F; F02; F02D; F02D41/00; F02D41/24; F02D41/26; F02D41/28; F02D35/00; F02D35/02; F02D35/023; G01L27/00; G01L27/007; F02D2041/281
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
130 words
An apparatus for detecting pressure in a cylinder of an internal combustion engine, comprising: a piezoelectric pressure sensor for detecting pressure in the combustion cylinder of said internal combustion engine and for outputting an electrical output signal according to the pressure; a current input circuit for directly receiving said electrical signal output from said sensor in the form of a current and for generating an output corresponding to the value of the current, wherein said current input circuit consists of an operational amplifier and resistory means connected between input and output terminals of said operational amplifier for converting said current signal output from said sensor to a voltage signal; and wherein said current input circuit outputs said voltage signal which is proportional to dP/dt, where P is said detected pressure.
Claim 2
Independent Claim
130 words
An apparatus for detecting pressure in a cylinder of an internal combustion engine, comprising: a piezoelectric pressure sensor for detecting pressure in the combustion cylinder of said internal combustion engine and for outputting an electrical output signal according to the pressure; a current input circuit for directly receiving said electrical signal output from said sensor in the form of a current and for generating an output corresponding to the value of the current, wherein said current input circuit consists of an operational amplifier and resistory means connected between input and output terminals of said operational amplifier for converting said current signal output from said sensor to a voltage signal; and wherein said current input circuit outputs said voltage signal which is proportional to dP/dt, where P is said detected pressure.
Claim 3
Dependent Claim
19 words
An apparatus according to claim 1, further comprising an integrator for integrating signals output from said current input circuit.
Claim 4
Dependent Claim
38 words
An apparatus according to claim 2, further comprising setting means for setting an output value of said integrator to a predetermined level at a predetermined time in order to obtain signal representing the absolute value of the pressure.
Claim 5
Dependent Claim
18 words
An apparatus according to claim 3, wherein said setting means is a switch adapted to reset said integrator.
Claim 6
Dependent Claim
62 words
An apparatus according to claim 2, further comprising a comparator adapted to compare an output signal from said integrator with a predetermined reference level and a failure detecting circuit adapted to detect an output pulse from said comparator, and wherein when the failure detecting circuit detects no output pulse from the comparator, it is determined that the piezoelectric pressure sensor has failed.
Claim 7
Dependent Claim
24 words
An apparatus according to claim 2, wherein the signals output from said current input circuit are input to said integrator through a coupling capacitor.
Claim 8
Dependent Claim
43 words
An apparatus according to claim 1, further comprising: temperature detecting means for detecting the temperature of said piezoelectric pressure sensor; and temperature correcting means for correcting the output of said current input circuit in accordance with an output of said temperature detecting means.
Claim 9
Dependent Claim
56 words
An apparatus according to claim 7, wherein said temperature detecting means and said temperature correcting means comprise a thermistor which is thermally coupled with said sensor and is connected with said resistor means between said input and output terminals of said operational amplifier, thereby enabling the output of said current input circuit to be temperature corrected.
Claim 10
Dependent Claim
66 words
An apparatus according to claim 7, wherein said resistor between said input and output terminals of said amplifier consists of variable resistor means which is electronically controlled and is constructed so as to variably control a resistance value of said variable resistor means in accordance with the output of said temperature detecting means, thereby enabling the output of said current input circuit to be temperature corrected.
References Cited (Backward Citations)
DE2523694A1
Cited
US4192005A
Cited
DD144606A1
Cited
US4567751A
Cited
US4612895A
Cited
DE3523230A1
Cited
US4750103A
Cited
DE3503489A1
Cited
JPS6291232A
Cited
US4821194A
Cited
DE3704837A1
Cited
JPS62291535A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-11-04 | 1995-05-06 | 1995-11-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-11-04 | 1999-05-06 | 1999-11-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-11-04 | 2003-05-06 | 2003-11-05 | $7700.00 | Window Closed / Lapsed |