Prime-mover dynamo plants – Electric control – Engine control
Reexamination Certificate
2001-07-17
2004-03-16
Mullins, Burton S. (Department: 2834)
Prime-mover dynamo plants
Electric control
Engine control
C290S04000F, C290S04000F, C290S04000F, C290S041000
Reexamination Certificate
active
06707169
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an engine generator for driving a generator with an engine, a controller for the engine generator, an inverter-type engine generator arranged for converting the main output of a generator to an alternating current voltage by an inverter circuit, an engine starter apparatus arranged for protecting a starter motor from being excessively loaded at the start-up of an engine, and a remote-control system for the engine generator arranged for receiving and transmitting remote-control signals over an output line of the engine generator.
2. Description of the Related Art
(1) A modern engine generator is designed in which the on-timing for starting the supply of power from an igniter to the primary side of an ignition coil and the off-timing for canceling the supply of power from the igniter to generate a high voltage at the secondary side of the ignition coil are controlled by a microcomputer (a CPU).
More specifically, upon detecting the output signal of a pulser coil indicating that the engine rotating angle reaches a predetermined degree, the microcomputer calculates the on-timing and the off-timing on the basis of the engine speed and actuates the igniter from the on-timing to the off-timing to energize the primary side of the ignition coil.
In an engine generator having the engine started by a starter motor, the starter motor when energized for starting the engine draws a rush current and sharply increases the consumption of power instantly thus declining the battery voltage temporarily. When the microcomputer in the generating system is energized by a battery, its action may be unstable at the start-up of the engine or it may be reset.
For eliminating the above drawback, the conventional engine generator has an exciter winding provided on the generator in addition to the main windings for energizing the microcomputer.
The driving duration of the igniter depends on the source voltage. If the source voltage is low, the driving duration of the igniter or an interval between the on-timing and the off-timing is increased thus decreasing the operable period of the CPU. As a result, the CPU may fail to calculate the timing and the power generation will hardly be improved in the efficiency.
When the microcomputer is energized directly from the exciter winding, its source voltage will not be declined at the start-up of the engine. It is however necessary for feeding the microcomputer with an operable level of voltage at a minimum or cranking speed of the engine at the start-up to increase the size of the exciter winding. This may develop an excessively large level of voltage when the engine runs at a high speed.
(2)
FIG. 22
is a block diagram showing a primary part of a conventional inverter type engine generator. A three-phase alternating current generator G is driven by an engine E. An AC output of the generator G is smoothed and converted to a DC form by a rectifying-smoothing circuit
61
. A DC output of the rectifying-smoothing circuit
61
is then converted by an inverter circuit
62
to an AC output at a specific frequency.
The generator G has three-phase main windings C wound on a number (e.g. twenty one poles) of magnetic poles as some of full (e.g. twenty four) magnetic poles for generating a main output. Wound on the remaining (or three) of the magnetic poles are an inverter source coil
82
, a battery charging coil
83
, and an external DC source coil
84
.
In the prior art shown in
FIG. 22
, each of the inverter source oil
82
, the battery charging coil
83
, and the other sub coil
84
holds one magnetic pole. Accordingly, when the total number of magnetic poles is 24 in the generator, only twenty one poles are assigned to the main output. Assuming that the main output is 4200 W, each of 21 magnetic poles undertakes 200 W. Consequently, each of the sub coils
82
,
83
, and
84
shares 200 W.
As the output of each of the sub coils
82
,
83
, and
84
is drawn only 10 to 15 W, 200 W is too large. On the other hand, the output of the main windings C may be too small for the size of the generator G.
(3) A conventional engine starter apparatus using a starter motor is provided for switching its ignition switch on to start an engine igniter. Then, when a starter switch is switched on, the start motor starts rotating. When the starter switch is turned off, the starter motor stops its action. More specifically, a driver presses the starter switch to actuate the starter motor and when the engine is started, releases the starter switch to stop the starter motor.
The starter motor consists mainly of a drive motor and a starter pinion gear. As the drive motor is rotated, the pinion gear is driven by its inertia to move into and engage with a ring gear mounted on the outer rim of a flywheel and the engine is cranked.
FIGS. 23 and 24
are timing charts showing the actions of relevant components at the start and stop of the engine in the prior art.
While the engine is being driven, the ignition switch is shifted at t
1
from the on state to the off state. This cancels the action of the engine igniter thus gradually decreasing the engine speed. When the ignition switch is turned on just before the engine stops at t
2
, the action of the engine igniter is returned. If the engine is ignited again before the piston reaches the upper dead point for a compression process, it may rotate in a reverse direction thus exerting an excessive load to the starter motor. This phenomenon is known as “back kicking”.
When the piston fails to complete the compression process before the engine stops and the engine rotates in a reverse direction, the switching on of the starter switch at t
3
starts the starter motor and throws its pinion gear into the ring gear which rotates in the reverse direction. This is also known as “reverse re-throwing” and may exert an excessive load on the starter motor.
Also, once the starter motor is started, it continues to rotate even if the engine speed exceeds its complete combustion speed until it is switched off.
As shown in
FIG. 24
, when the engine fails to be started, the ignition switch remains turned on. Accordingly, when the piston fails to complete the compression process, the engine is ignited prior to the upper dead point thus developing an event of back kicking.
The prior art is only implemented by a rigid structure capable of bearing the excessive load generated in the back kicking or reverse re-throwing of the starter motor which is thus increased in the overall dimensions.
(4) The conventional engine generator having a power generator driven by an engine is connected from its body to a remote controller box by a remote control cable of substantially 10 meters. The remote controller box includes an engine switch for connecting the engine with a main source, a start switch for driving a starter motor to crank the engine, a pilot lamp for indicating that the engine generator is in action, and soon. The engine generator can thus be controlled from a remote location with the remote controller box.
The engine generator may of ten be sited close to an electric apparatuses to be energized. As the remote control cable connects between the engine generator and the remote controller box, it will interrupt the engine generator from being moved to a desired location.
Also, the engine generator has a receptacle provided on the main body thereof for directly accepting a plug from the electric apparatus to be energized and may allow its receptacle to be joined with the plug of an extension cable from the electric apparatus. As the electric apparatus is energized via the extension cable from the engine generator which is spaced significantly from the electric apparatus, the remote controller cable has to be extended for remote controlling the electric apparatus.
In the prior art, any error developed on the engine generator can hardly be notified by the remote controller box. In case that the operator of the remote controller box works out of sight of the engine generator, it may fail to
Asai Kouichi
Nakamura Masashi
Shimizu Motohiro
Cuevas Pedro J.
Honda Giken Kogyo Kabushiki Kaisha
Mullins Burton S.
Westerman Hattori Daniels & Adrian LLP
LandOfFree
Engine generator, controller, starter apparatus, and remote... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Engine generator, controller, starter apparatus, and remote..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Engine generator, controller, starter apparatus, and remote... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3220517