US3828247A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Testing a fuel injection valve
Assignee: Volkswagen AG
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Filing: 1973-06-25
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Granted: 1974-08-06
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Expires: 1993-06-25
Abstract
Abstract An electromagnetic device such as a fuel-injection valve is tested by monitoring the variation in the impedance of the electric coil of the device as it operates. The change in impedance of a properly-operating device can be converted into a generally decaying voltage signal with a series of small voltages peaks. An inoperative device will not produce these voltage peaks. The voltage peaks are converted into pulses and then counted. If more than two pulses are detected the device is operating properly.
Inventors
- 👤 K Kirsch
- 👤 W Grotewold
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:02
CPC Classifications
F; F02; F02M; F02M65/00; F02M65/005; F02M51/00; F02M51/06; F02M51/061; F02M51/0625; F02M51/0664; F02M51/0671; F02M51/0675; F02M51/08; F02D; F02D41/00; F02D41/22; F02D41/221; F02M2200/00; F02M2200/50; F02M2200/507
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
123 words
A method for the functional testing of an electromagnetic device comprising a magnetic coil, an armature mounted for relative movement with respect to the coil, and a stop for limiting the relative movement, the relative movement being effected by a current flowing through the magnetic coil to produce a magnetic flux coupled to the armature, comprising the steps of: applying across the coil a substantially constant voltage electrical pulse of such a magnitude that the resulting magnetic flux is capable of effecting said relative movement until limited by said stop; monitoring the current through the coil to detect the presence of peaks therein; and generating a control signal in response to said monitoring, which is indicative of the functional state of the device.
Claim 2
Independent Claim
123 words
A method for the functional testing of an electromagnetic device comprising a magnetic coil, an armature mounted for relative movement with respect to the coil, and a stop for limiting the relative movement, the relative movement being effected by a current flowing through the magnetic coil to produce a magnetic flux coupled to the armature, comprising the steps of: applying across the coil a substantially constant voltage electrical pulse of such a magnitude that the resulting magnetic flux is capable of effecting said relative movement until limited by said stop; monitoring the current through the coil to detect the presence of peaks therein; and generating a control signal in response to said monitoring, which is indicative of the functional state of the device.
Claim 3
Dependent Claim
27 words
A method according to claim 1 wherein the monitoring begins after a period of time sufficient to allow the limiting of the relative movement by the stop.
Claim 4
Dependent Claim
18 words
A method according to claim 1 wherein the electromagnetic device is a fuel-injection valve for an internal-combustion engine.
Claim 5
Dependent Claim
20 words
A method according to claim 3 wherein the flow of fluid through the valve is interrupted during the functional testing.
Claim 6
Independent Claim
116 words
A device for the functional testing of an electromagnetic device comprising a magnetic coil, an armature mounted for relative movement with respect to the coil, and a stop for limiting the relative movement, the relative movement being effected by a current flowing through the magnetic coil to produce a magnetic flux coupled to the armature, comprising: means for deriving a signal from said coil while a current is passing through it; signal-processing means for converting peaks in the voltage signal due to the limiting of said relative movement by the mechanical stop into voltage pulses; and digital evaluating means for counting the voltage pulses and generating a control signal whenever there are more than two pulses.
Claim 7
Independent Claim
116 words
A device for the functional testing of an electromagnetic device comprising a magnetic coil, an armature mounted for relative movement with respect to the coil, and a stop for limiting the relative movement, the relative movement being effected by a current flowing through the magnetic coil to produce a magnetic flux coupled to the armature, comprising: means for deriving a signal from said coil while a current is passing through it; signal-processing means for converting peaks in the voltage signal due to the limiting of said relative movement by the mechanical stop into voltage pulses; and digital evaluating means for counting the voltage pulses and generating a control signal whenever there are more than two pulses.
Claim 8
Dependent Claim
45 words
A device according to claiM 5 wherein said means for deriving said signal comprises: means for maintaining the current through the magnetic coil substantially constant; and means for coupling a voltage produced across the coil by the current passing through it to the signal-processing means.
Claim 9
Dependent Claim
47 words
A device according to claim 5 wherein said means for deriving said signal comprises: means for maintaining the voltage across the magnetic coil substantially constant; means for converting the current into a derived voltage signal; and means for coupling the derived voltage signal to the signal-processing means.
Claim 10
Dependent Claim
78 words
A device as claimed in claim 5 wherein said signal-processing means comprises: filter means for filtering out the d.c. component of the signal to form a filtered signal; amplifier means for amplifying the filtered signal to form an amplified signal; limiter means for suppressing the portions of the amplified signal having polarity opposite from the polarity of the peaks in the amplified signal; and gating means for converting the peaks in the amplified and limited signal into pulses.
Claim 11
Dependent Claim
68 words
A device according to claim 5 in which said digital evaluating means comprises: a first bistable multivibrator responsive to the pulses from the signal-processing means; and a second bistable multivibrator responsive to the output of the first bistable multivibrator, the output of the second bistable multivibrator being the control signal, whereby the control signal is generated only when at least two pulses are received from the signal-processing means.
Claim 12
Dependent Claim
125 words
A device according to claim 9 further comprising: a NAND circuit that receives the pulses from the signal-processing means on one of its inputs; a first monostable multivibrator responsive to the signal from said means for deriving a signal from said coil; and a second monostable multivibrator responsive to the output of the first monostable multivibrator, the output of the second monostable multivibrator being applied to the other input of the NAND circuit, the form of the outputs from the monostable multivibrators being such that the pulses from the signal-processing means are inhibited from passing through the NAND circuit for the period from just after the voltage signal is present until a time sufficient for the movable body to reach the mechanical stop has elapsed.
Claim 13
Dependent Claim
18 words
A device according to claim 10 wherein the output of the first monostable multivibrator resets the bistable multivibrators.
Claim 14
Independent Claim
122 words
A method for the functional testing of an electromagnetic device comprising a magnetic coil, an armature mounted for relative movement with respect to the coil, and a stop for limiting the relative movement, the relative movement being effected by a current flowing through the magnetic coil to produce the magnetic flux coupled to the armature, comprising the steps of: applying to the coil a substantially constant current electrical pulse of such a magnitude that the resulting magnetic flux is capable of effecting said relative movement until limited by said stop; monitoring the voltage across the coil to detect the presence of peaks therein; and generating a control signal in response to said monitoring, which is indicative of the functioning of the device.
Claim 15
Independent Claim
122 words
A method for the functional testing of an electromagnetic device comprising a magnetic coil, an armature mounted for relative movement with respect to the coil, and a stop for limiting the relative movement, the relative movement being effected by a current flowing through the magnetic coil to produce the magnetic flux coupled to the armature, comprising the steps of: applying to the coil a substantially constant current electrical pulse of such a magnitude that the resulting magnetic flux is capable of effecting said relative movement until limited by said stop; monitoring the voltage across the coil to detect the presence of peaks therein; and generating a control signal in response to said monitoring, which is indicative of the functioning of the device.
Claim 16
Dependent Claim
27 words
A method according to claim 12 wherein the monitoring begins after a period of time sufficient to allow the limiting of the relative movement by the stop.
Claim 17
Dependent Claim
18 words
A method according to claim 12, wherein the electromagnetic device is a fuel-injection valve for an internal-combustion engine.
Claim 18
Dependent Claim
20 words
A method according to claim 14, wherein the flow of fuel through the valve is interrupted during the functional testing.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-08-05 | 1978-02-04 | 1978-08-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-05 | 1982-02-04 | 1982-08-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-05 | 1986-02-04 | 1986-08-06 | $7700.00 | Window Closed / Lapsed |