Internal-combustion engines – Charge forming device – Fuel injection system
Reexamination Certificate
1998-09-16
2002-10-01
Fetsuga, Robert M. (Department: 3751)
Internal-combustion engines
Charge forming device
Fuel injection system
C361S154000
Reexamination Certificate
active
06457457
ABSTRACT:
This invention relates to a method of controlling a drive circuit for use in controlling the operation of a valve actuator. The invention is particularly suitable for use in controlling the operation of an actuator of the two-stage lift type in which, when the actuator is energized to apply a relatively low magnitude force to the armature, the armature thereof moves from a rest position to a first position, the energization of the actuator to apply a higher magnitude force to the armature resulting in the armature moving from the first position to a second position, but is also suitable for use in other applications.
An actuator of the type described hereinbefore could be controlled using a high voltage supply and using an appropriate switching arrangement to turn the current on and off to control the mean applied current.
Where the actuator is used to control a pair of valves, one of which controls communication between the pumping chamber of a fuel injector and a low pressure drain, the other valve controlling the timing of fuel injection, although movement of the said other valve is required to occur rapidly, control of the said one valve need not be as accurate, relatively slow movement of the said one valve being acceptable, and may be preferable as the slow movement of the said one valve reduces the risk of accidental, unwanted early movement of the said other valve.
According to a first aspect of the invention there is provided a method of controlling an electromagnetically operated actuator of the two-stage lift type comprising applying a first, low voltage to the actuator to generate a relatively low magnitude actuator force, and applying a second higher voltage to the actuator to generate a relatively large magnitude actuator force.
Preferably, the relatively low magnitude actuator force is sufficient to move an armature from its rest position to its first position against a first spring loading, the relatively large magnitude actuator force being sufficient to cause movement of the armature to its second position against a second spring loading.
In one mode of operation, the armature is moved to its first position, held in that position and is subsequently moved to its second position.
The use of the low voltage, for example battery voltage, results in a relatively low rate of current increase in the actuator winding, and hence in relatively slow movement of the armature to its first position, but as the rate of movement of the armature during this part of the valve's operating cycle is not critical, the low rate of movement is not of great importance. The use of low voltage during this part of the operating cycle improves the efficiency of the actuator drive circuit.
In an alternative mode of operation, the second voltage is applied to cause the armature to move to its second position, and at a subsequent point in the operation, the second voltage is removed and the first voltage applied, the armature moving to its first position.
There may be occasions in which the battery voltage is insufficient to cause movement of the armature to its first position during the time available, and in these circumstances the application of the first, low voltage may be preceded, interrupted or followed by a period during which high voltage is applied to the actuator to assist in moving the armature to its first position. The application of the higher voltage preferably precedes the application of the low voltage in these circumstances. Movement of the armature to its second position occurs upon the subsequent application of the high voltage as described hereinbefore.
According to another aspect of the invention there is provided a method of controlling an electromagnetic actuator comprising using a low voltage source to energize a winding of the actuator, and using a high voltage source to assist in energization of the actuator in the event that the low voltage source is unable to energize the actuator to a desired extent within a predetermined period.
The voltage of the low voltage source may be monitored and used in determining when to use the high voltage source to assist in energization of the actuator. Alternatively the actuator response time or the time taken for the winding current to rise to a predetermined level may be used to determine whether or not to use the high voltage source.
REFERENCES:
patent: 2934050 (1960-04-01), Pribble
patent: 2970246 (1961-01-01), Gunkel
patent: 3021454 (1962-02-01), Pickens
patent: 3433207 (1969-03-01), Bassot et al.
patent: 3665898 (1972-05-01), Kamazuka
patent: 3682144 (1972-08-01), Suda
patent: 4345564 (1982-08-01), Kawamura et al.
patent: 5267545 (1993-12-01), Kitson
patent: 5694903 (1997-12-01), Ganser
patent: 5717562 (1998-02-01), Antone et al.
patent: 6158419 (2000-12-01), Jett et al
patent: 9701031 (1997-01-01), None
D. Van Nostrand Company Inc., “The International Dictionary of Physics and Electronics”, 2nd Edition, 1961.*
Abstract of JP 4,183,967, Takashi, Jun. 1992.*
Abstract of JP 3,179160, Hiroyuki, Aug. 1991.
Delphi Technologies Inc.
Fetsuga Robert M.
LandOfFree
Control method does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Control method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Control method will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2986114