Title of Invention

IDLE ROTATIONAL SPEED CONTROLLER OF INTERNAL COMBUSTION ENGINE, CONTROL OF INTERNAL COMBUSTION ENGINE AND INTERNAL COMBUSTION ENGINE

Abstract The invention relates to an idle rotational speed controller (50) of an internal combustion engine (1) having an intake path (8) for sucking air to be supplied to a combustion chamber (5) of the internal combustion engine (1), a throttle valve (11) arranged at the intake path (8) for controlling an intake amount, an auxiliary intake path (12) for communicating with the intake path (8) on an upstream side of the throttle valve (11) and on a downstream side of the throttle valve (11), and an opening/closing type control valve (13) arranged at the auxiliary intake path (12) for controlling an idling intake amount, the idle rotational speed controller (50) comprising an intake pressure detecting unit (S1) for detecting an intake pressure of the intake path (8), a fuel supplying unit (17) for controlling a supply amount of a fuel supplied to the combustion chamber (5) based on at least the intake pressure. A controlling unit (15) for synchronizing a drive reference position for driving to open or close the control valve (13) corresponding to a timing of detection of the intake pressure by the intake pressure detecting unit (S1).
Full Text Description
Idle rotational speed controller of internal combustion engine,
controller of internal combustion engine and internal
combustion engine

The present invention relates to an idle rotational speed
controller, a controller of an internal combustion engine and
an internal combustion engine, which enable stable idling
operation.

For example, there is an internal combustion engine
mounted to a vehicle including an auxiliary intake path opened
to a downstream side of a throttle valve of an intake path and
communicating with the atmosphere, a control valve for
controlling an auxiliary air amount (idling intake amount)
supplied to the internal combustion engine via the auxiliary
intake path, and a fuel supplying unit for supplying a
predetermined fuel amount in accordance with a total intake
amount including the auxiliary air amount to a combustion chamber
of the internal combustion engine, in which a predetermined
rotational position of the internal combustion engine is
detected and the control valve is opened in synchronism with
a signal of the predetermined position (refer to, for example.
Patent Reference 1).
(Patent Reference 1) JP-B-63-60219 (pagesl-7. Figs.1-4)
According to a controller of an internal combustion engine
for controlling a fuel supply amount of the fuel supplying unit
by detecting an intake pressure of the intake path by an intake
pressure detecting unit arranged on the downstream side of the
throttle valve of the intake path, when the auxiliary intake
path is connected to the downstream side of the throttle valve
of the intake path and the control valve of an opening/closing
type is used, there is a case in which by a change in the intake
pressure by operating to open and close the control valve,
despite a steady state, the state is erroneously determined
to shift to an accelerating or decelerating state and an idling
rotational sp€;ed becomes unstable.
In addition, when a threshold of the change in the intake
pressure for determining that the state is shifted to the
accelerating or decelerating state in order to avoid the case,
drivability in opening the throttle valve intended by a driver
is deteriorated.
Further, according to a system which is not provided with
a stroke determining sensor for determining a stroke of the
internal combustion engine by detecting the intake pressure
of the intake path, when a condition of a number of times of
establishing stroke determination is increased inorder to avoid
that the stroke of the internal combustion engine cannot be
determined based on a similar cause, starting performance of
the internal combustion engine is deteriorated.
When a ratio of a time period of opening the control valve
withinapredetermined time period is controlled (duty control) ,
in consideration of a fluctuation in rotation of the internal
combustion engine, the control to open and close the control
valve becomes complicated and a calculating load is increased.
When a user changes to set the idling rotational speed
to be low, a fluctuation in rotation of the engine is increased
and there is a case that the idling rotational speed cannot
be controlled stably.
The invention has been carried out in view of such a
situation and it is an object thereof to provide an idle
rotational speed controller, a controller of an internal
combustion engine and an internal combustion engine, which
enable stable Idling operation.

In order to solve the above-described problem and achieve
the object, the invention is constituted as follows.
A first aspect of the invention is an idle rotational
speed controller of an internal combustion engine including
an intake path for sucking air to be supplied to a combustion
chamber of the internal combustion engine, a throttle valve
arranged at the intake path for controlling an intake amount,
an auxiliary intake path for communicating the intake path on
an upstream side of the throttle valve and the intake path on
a downstream side of the throttle valve, and an opening/closing
type control valve arranged at the auxiliary intake path for
controlling an idling intake amount, the idle rotational speed
controller including: an intake pressure detecting unit for
detecting an intake pressure of the intake path; a fuel supplying
unit for controlling a supply amount of a fuel supplied to the
combustion chamber based on at least the intake pressure; and
a controlling unit for synchronizing a drive reference position
for driving to open or close the control valve with a timing
of detecting the intake pressure by the intake pressure detecting
unit.
Incidentally, the controlling unit determines the fuel
supply amount of the fuel supplying unit by predicting a steady
state load from the intake pressure, for example, the intake
pressure at a predetermined position of a crank angle of the
internal combustion engine. Further, the fuel supply amount
determined by the controlling unit is the fuel supply amount
of a successive cycle.
According to the first aspect of the invention, by
synchronizing the drive reference position of driving to open
and close the control valve with the timing for detecting the
intake pressure by the intake pressure detecting unit, it can
be prevented that the intake pressure detecting unit erroneously
detects a pressure fluctuation caused by operating to open and
close the control valve and the supply amount of the fuel cannot
stably be controlled, and stable idling rotation can be carried
out.
A second aspect of the invention is characterized in that
the controlling unit controls a state of closing the control
valve by setting a timing of driving to close the control valve
as the drive reference position in the idle rotational speed
controller of an internal combustion described in the first
aspect.
According to the second aspect of the invention, in
addition to the effect of the first aspect, when an idling
rotational speed is increased, the control valve is controlled
in a direction of restraining an engine rotational speed, and
when the idling rotational speed is reduced, the control valve
is controlled in a direction of increasing the engine rotational
speed, and therefore, the fluctuation in rotation of the internal
combustion engine can be restrained.
A third aspect of the invention is characterized in that
the controlling unit increases the supply amount of the fuel
when a pressure difference between the intake pressure before
one cycle or more and a current one is equal to or larger than
a threshold in accordance with a state of opening or closing
the control valve in the idle rotational speed controller of
an internal combustion engine described in the first aspect.
Incidentally, the controlling unit detects an
accelerating state by comparing, for example, the intake
pressure before one cycle or more and the current intake pressure.
Further, a state of opening or closing the control valve can
be predicted or detected by, for example, an engine rotational
speed, a throttle opening degree, a ratio (duty) of a time period
of opening the control valve in a predetermined time period
or the like.
According to the thirdaspect of the invention, in addition
to the effect of the first aspect, it can be prevented that
even when the state is a steady state, the state is erroneously
determined to shift to the accelerating state by a change in
the intake pressure caused by operating to open or close the
control valve and the supply amount of the fuel is increased,
and the fuel can stably be supplied.
A fourth aspect of the invention is characterized in that
the threshold is set by a two-dimensional table constituting
an axis thereof by an engine rotational speed in the idle
rotational speed controller of an internal combustion engine
described in the third aspect.
According to the fourth aspect of the invention, in
addition to an effect of the third aspect, the threshold is
set by the two-dimensional table constituting the axis thereof
by the engine rotational speed, and therefore, the fuel can
stably be supplied even at a low idling rotational speed at
which the fluctuation in the intake pressure caused by operating
to open or close the control valve is large.
Further, even when a user changes to set the idling
rotational speed to be low, the idling rotational speed can
stably be controlled without being erroneously determined that
the state is not the steady state.
A fifth aspect of the invention is characterized in that
the controlling unit increases the supply amount of the fuel
by asynchronous injection in the idle rotational speed
controller of an internal combustion engine described in the
third aspect.
According to the fifth aspect of the invention, in addition
to the effect of Claim 3, the fuel supply amount is increased
by the asynchronous injection, and therefore, the fuel can be
supplied swiftly and stably.
A sixth aspect of the invention is an idle rotational
speed controller of an internal combustion engine including
an intake path for sucking air to be supplied to a combustion
chamber of the internal combustion engine, a throttle valve
arranged at the intake path for controlling an intake amount,
an auxiliary intake path for communicating the intake path on
an upstream side of the throttle valve and the intake path on
a downstream side of the throttle valve, and an opening/closing
type control valve arranged at the auxiliary intake path for
controlling an idling intake amount, the idle rotational speed
controller including: an intake pressure detecting unit for
detecting an intake pressure of the intake path; a stroke
determining unit for determining a stroke of the internal
combustion engine based on at least the intake pressure; and
a controlling unit for synchronizing a drive reference position
for driving to open or close the control valve with a timing
of detecting the intake pressure by the intake pressure detecting
unit,
Incidentally, the controlling unit determines the stroke
of the internal combustion engine by, for example, a pressure
difference of the intake pressure at a predetermined crank angle
and a change in a speed of rotating a crank.
According to the sixth aspect of the invention, by
synchronizing the drive reference position of driving to open
or close the control valve with the timing of detecting the
intake pressure by the intake pressure detecting unit, it can
be prevented that the intake pressure detecting unit erroneously
detects the fluctuation in the pressure caused by operating
to open and close the control valve and the stroke cannot be
determined, and stable idling rotation can be carried out.
A seventh aspect of the invention is characterized in
that the controlling unit controls a state of closing the control
valve by setting a timing of driving to close the control valve
as the drive reference position
According to the seventh aspect of the invention, in
addition to an effect of the sixth aspect, when the idling
rotational speed is increased, the control valve is controlled
in a direction of restraining the engine rotational speed, and
when the idling rotational speed is reduced, the control valve
is controlled in a direction of increasing the engine rotational
speed, and therefore, the fluctuation in rotationof the internal
combustion engine can be restrained.
An eighth aspect of the invention is an idle rotational
speed controller of an internal combustion engine including
an intake path for sucking air to be supplied to a combustion
chamber of the internal combustion engine, a throttle valve
arranged at the intake path for controlling an intake amount,
an auxiliary intake path for communicating the intake path on
an upstream side of the throttle valve and the intake path on
a downstream side of the throttle valve, and an opening/closing
type control valve arranged at the auxiliary intake path for
controlling an idling intake amount, the idle rotational speed
controller including: an intake pressure detecting unit for
detecting an intake pressure of the intake path; a stroke
determining unit for determining a stroke of the internal
combustion engine based on at least the intake pressure; and
a controlling unit for controlling the control valve by
synchronizing a drive reference position for driving to open
or close the control valve with a timing of detecting the intake
pressure by the intake pressure detecting unit, and changing
the drive reference position with respect to a crank rotation
of the internal combustion engine after finishing to determine
the stroke by the stroke determining unit from that of before
finishing to determine the stroke.
According to the eighth aspect of the invention, the stroke
of the internal combustion engine is determined based on the
intake pressure of the intake path, and therefore, even in a
state in which the stroke of the internal combustion engine
cannot be determined immediately after starting the internal
combustion engine, the intake amount sucked to the combustion
chamber can be controlled by synchronizing the drive reference
position without deviating the intake timing, and excellent
engine starting performance and stable idling rotational speed
control can be realized.
A ninth aspect of the invention is ^harn^t^ri, riPii in thnt
the controlling unit controls to bring about the drive reference
position once for each rotation of a crank before finishing
to determine the stroke by the stroke determining unit and br inj
about the drive reference,posit ion once for each two rotations
of the crank after finishing to determine the stroke in the
idle rotational speed controller of an internal combustion
engine described in the eighth aspect.
According to the ninth aspect of the invention, in addition
to an effect of the eighth aspect, after finishing to determine
the stroke, by completely synchronizing the intake timing and
the drive reference position, an effect as a fast idle device
is further promoted and excellent engine starting performance
and stable idling rotational speed control can be realized.
A tenth aspect of the invention is an idle rotational
speed controller of an internal combustion engine including
an intake path for sucking air to be supplied to a combustion
chamber of the internal combustion engine, a throttle valve
arranged at the intake path for controlling an intake amount,
an auxiliary intake path for communicating the intake path on
an upstream side of the throttle valve and the intake path on
a downstream side of the throttle valve, and an opening/closing
type control valve arranged at the auxiliary intake path for
controlling an idling intake amount, the idle rotational speed
controller including: an intake pressure detecting unit for
detecting an intake pressure of the intake path; a stroke
determining unit for determining a stroke of the internal
combustion engine based on at least the intake pressure; and
a controlling unit for controlling the control valve by
synchronizing a drive reference position for driving to open
or close the control valve with a timing of detecting the intake
pressure by the intake pressure detecting unit, and preventing
the control valve from being driven to open or close before
finishing to determine the stroke by the stroke determining
unit.
According to the tenth aspect of the invention, in a state
in which the stirokeof the internal combustion engine invmediately
after starting the internal combustion engine is difficult to
determine since the stroke of the internal combustion engine
is determined based on the intake pressure of the intake path,
by not driving to open or close the control valve, it can be
prevented that the intake pressure detecting unit cannot
determine the stroke by erroneously detecting the fluctuation
in the pressure caused by operating to open or close the control
valve, and excellent engine starting performance and stable
idling rotational speed control can be realized.
An eleventh aspect of the invention is an idle rotational
speed controller of an internal combustion engine including
an intake path for sucking air to be supplied to a combustion
chamber of the internal combustion engine, a throttle valve
arranged at the intake path for controlling an intake amount,
an auxiliary intake path for communicating the intake path on
an upstream side of the throttle valve and the intake path on
a downstream side of the throttle valve, and an opening/closing
type control valve arranged at the auxiliary intake path for
controlling an idling intake amount, the idle rotational speed
controller including: an intake pressure detecting unit for
detecting an intake pressure of the intake path; a fuel supplying
unit for controlling a supply amount of a fuel supplied to the
combustion chamber based on at least the intake pressure; and
a controlling unit for synchronizing a drive reference position
for driving to open or close the control valve with a timing
of detectingthe intakepressureby the intakepressuredetecting
unit.
According to the eleventh aspect of the invention, by
synchronizing the drive reference position of driving to open
or close the control valve with the timing of detecting the
intake pressure by the intake pressure detecting unit, it can
be preventedthcit the intake pressure detecting unit erroneously
detects the fluctuation in the pressure caused by operating
to open or close the control valve and the supply amount of
the fuel cannot stably be controlled or the stroke cannot be
determined, and stable idling rotation can be carried out.
A twelfth aspect of the invention is characterized in
that the controlling unit controls a state of closing the control
valve by setting a timing of driving to close the control valve
as the drive reference position
According to the twelfth aspect of the invention, in
addition to an effect of the eleventh aspect, when the idling
rotational speed is increased, the control valve is controlled
in a direction of restraining the engine rotational speed, and
when the idling rotational speed is reduced, the control valve
is controlled in a direction of increasing the engine rotational
speed, and therefore, the fluctuationinrotationof the internal
combustion engine can be restrained.
A thirteenth aspect of the invention is an internal
combustion engine including the idle rotational speed
controller of an.internal combustion engine according to any
one of the first to twelfth aspects of the invention.
According to the thirteenth aspect of the invention, there
can be realized an internal combustion engine the rotational
fluctuation of which is restrained and which is provided with
the stable idle rotational speed controller having excellent
engine starting performance.
A fourteenth aspect of the invention is a controller of
an internal combustion engine including an intake path for
sucking air to be supplied to a combustion chamber of the internal
combustion engine, a fuel supplying unit for supplying a fuel
to the combustion chamber, a throttle valve arranged at the
intake path for controlling an intake amount, and intake pressure
detecting unit for detecting an intake pressure of the intake
path; wherein the fuel supplying unit increases a supply amount
of the fuel when a pressure difference of the intake pressure
before one cycle or more and a current one is equal to or larger
than a threshold in accordance with an engine rotational speed
of the internal combustion engine.
According to the fourteenth aspect of the invention, it
can be prevented that despite a steady state, the state is
erroneously determined to shift to accelerating state and the
fuel supply amount is increased, and the fuel can be supplied
stably.
A fifteenth aspect of the invention is characterized in
that the threshold is setby a two-dimensional table constituting
an axis thereof by an engine rotational speed in the internal
combustion engine control apparatus described in the fourteenth
aspect.
According to the fifteenth aspect of the invention, in
addition to an effect of the fourteenth aspect, the threshold
is set by the two-dimensional table constituting the axis thereof
by the engine rotational speed, and therefore, the fuel can
stably be supplied without increasing the fuel supply amount
erroneously by a low idling rotational speed at which the
fluctuation in rotation is large.
Further, even when a user changes to set the idling
rotational speed to be low, stable idling rotational speed
control can be carried out without erroneously determining that
the state is not the steady state.
A sixteenth aspect of the invention is characterized in
that the controlling unit increases the supply amount of the
fuel by asynchronous inj ection in the internal combustion engine
control apparatus described in the fourteenth aspect.
According to the sixteenth aspect of the invention, in
addition to an effect described in the fourteenth aspect, the
supply amount of the fuel is increased by the asynchronous
injection, and therefore, the fuel can be supplied swiftly and
stably.
A seventeenth aspect of the invention is an internal
combustion engine including the controller of an internal
combustion engine according to any one of the fourteenth to
sixteenth aspects.
According to the seventeenth aspect of the invention,
there can be realized an internal combustion engine the
rotational fluctuation of which is restrained and which includes
the controller of the internal combustion engine having
excellent engine starting performance and carrying out stable
idling rotational speed control.

Fig.l is a constitution view substantially showing the
whole of an idle rotational speed controller of an internal
combustion engine;
Fig. 2 is a diagram showing a relationship between a crank
angle and an intake pressure;
Fig. 3 is a diagram showing a relationship between a crank
angle and an intake pressure when a throttle opening degree
is changed;
Fig.4 is a diagram showing a state of driving to open
and close a control valve;
Fig. 5 is a diagram showing a crank pulse and a stroke;
Fig. 6 is a diagram showing timings of a crank pulse.
determination of a stroke, detection of an intake pressure,
and a state of driving a control valve;
Fig.7 is a diagram showing timings of a crank pulse,
determination of a stroke, detection of an intake pressure,
and a state of driving a control valve according to a first
embodiment;
Fig. 8 is a diagram showing a timing of a reference position
of driving a control valve according to a second embodiment;
Fig. 9 is a diagram showing a timing of a reference position
of driving a control valve according to a third embodiment;
Fig.10 is a diagram showing a threshold of a pressure
difference between an intake pressure before one cycle and a
current intake pressure by a two-dimensional table constituting
an axis thereof by an engine rotational speed according to a
fourth embodiment;
Fig. 11 is a diagram showing a flow of a crank pulse
interruption;
Fig. 12 is a diagram showing a flow of a timer interruption;
and
Fig. 13 is a timing chart of a control in an idle rotational
speed controller of an internal combustion engine.
Incidentally, in the drawings, numeral 1 designates an
internal combustion engine, numeral 2 designates a crank,
numeral 8 designates an intake path, numeral 11 designates a
throttle valve, numeral 12 designates an auxiliary intake path.
numeral 13 designates a control valve, numeral 15 designates
controlling unit, numeral 17 designates a fuel supplying unit,
numeral 30 designates crank angle detecting unit, numeral 31
designates engine rotational speed detecting unit, numeral 33
designates stroke determining unit, notation SI designates an
intake pressure detecting unit, notation S2 designates an engine
temperature detecting unit, notation S3 designates a crank pulse
output detecting unit, and numeral 50 designates a control
apparatus unit.

Although a detailed explanation will be given of an
embodiment of an idle rotational speed controller of an internal
combustion engine according to the invention in reference to
the drawings as follows, the invention is not limited to the
embodiment. Further, the embodiment of the invention shows
the most preferred mode of the invention, and technical terms
of the invention are not limited thereto.
Fig.l is a constitution view substantially showing the
whole of an idle rotational speed controller of an internal
combustion engine. Fig.2 is a diagram showing a relationship
between a crank angle and an intake pressure. Fig. 3 is a diagram
showing a relationship between the crank angle and the intake
pressure when a throttle opening degree is changed. Fig.4 is
a diagram showing a state of driving to open and close a control
valve. Fig.5 is a diagram showing a crank pulse and a stroke,
and Fig.6 is a diagram showing the crank pulse, determination
of the stroke, detection of the intake pressure, and a state
of driving the control valve.
Although the internal combustion engine 1 of the
embodiment shows an internal combustion engine of a single
cylinder, the embodiment is applicable also to an internal
combustion engine of multi cylinders. According to the
internal combustion engine 1, the crank 2 is connected to a
piston 4 via a connecting rod 3, and the crank is rotated in
an arrow mark direction by reciprocating the piton 4. The
internal combustion engine 1 is provided with an ignition plug
6 that faces to a combustion chamber 5, and the combustion chamber
5 is opened with an exhaust path 7 and the intake path 8. An
opening of the exhaust path 7 is opened and closed by an exhaust
valve 9, an opening of the intake path 8 is opened and closed
by an intake valve 10, and the exhaust valve 9 and the intake
valve 10 are opened and closed in synchronism with rotation
of the crank 2,
The throttle valve 11 is arranged at a middle of the intake
path 8 and the throttle valve 11 controls an intake amount for
sucking air to be supplied to the combustion chamber 5. The
intake path 8 is provided with the auxiliary intake path 12
for communicating an upstream side and a downstream side by
bypassing the throttle valve 11, and the auxiliary intake path
12 is provided with the control valve 13 of an opening/closing
type for controlling an idling intake amount.
As shown in Fig. 2, the intake pressure immediately after
opening the intake valve 10 is high. When the piston 4 is moved
down, the intake pressure is reduced and when the intake valve
10 is closed, the intake pressure is increased. A crank number
of "0" designates a compression upper dead center.
As shown in Fig.3, the intake pressure is changed by a
throttle opening degree. That is, as the throttle opening
degree is increased, a reduction in the intake pressure when
the intake valve 10 is opened is reduced. The crank angle of
"0" designates the compression upper dead center.
The control valve 13 of the embodiment is constituted
by a solenoid valve and opens/closes the auxiliary intake path
12 by being controlled by a controlling unit 15 provided at
a control apparatus unit 50.
The controlling unit 15 is constituted by CPU, RAM, ROM
and the like. As shown in Fig.4, a drive reference position
is constituted by a timing of driving to close the control valve
13 and by controlling a time period of closing the control valve
13, a ratio of a time period of opening the control valve 13
within a predetermined time period is controlled (duty control)
to thereby drive to open and close the control valve 13 . Further,
an idle intake amount is controlled by setting the drive
reference position and the time period of closing the control
valve.
The intake path 8 is provided with a fuel injection valve
16 on a downstream side of aportion of communicating the throttle
valve 11 and the auxiliary intake path 12. The fuel injection
valve 16 constitutes fuel supplying unit along with the fuel
pump 17 and the like and a fuel injection amount is controlled
by the controlling unit 15 electrically connected thereto.
Further, the intake path 8 is provided with an intake
pressure detecting unit SI on the downstream side of the portion
of communicating the throttle valve 11 and the auxiliary intake
path 12. The intake pressure detecting unit SI detects the
intake pressure of the intake path 8 on the downstream side
of the auxiliary intake path 12 and transmits information of
the detected intake pressure to the controlling unit 15.
The controlling unit 15 predicts a steady state load by
the intake pressure at a predetermined position of a crank angle
of the internal combustion engine 1 and determines a fuel supply
amount of the fuel supplying unit, and therefore, the fuel can
be supplied with high accuracy based on the intake pressure.
The fuel supply amount determined by the controlling unit 15
is a fuel supply amount for a next cycle.
The fuel can be supplied with high accuracy by making
the intake path 8 and the auxiliary intake path 12 merge to
communicate with the single combustion chamber 5 of the internal
combustion engine 1. The fuel can be supplied with high accuracy
based on the intake pressure by arranging the intake pressure
detecting unit SI on a downstream side of a merging portion
8a at which the intake path 8 and the auxiliary intake path
12 merge and detecting the intake pressure.
Further, the internal combustion engine 1 is provided
with an engine temperature detecting unit S2. The engine
temperature detecting unit S2 detects an engine temperature
and transmits information of the detected engine temperature
to the controlling unit 15. Further, the internal combustion
engine 1 is provided with a crank pulse outputting unit S3.
The crank pulse outputting unit S3 outputs a crank pulse produced
by a projection 2a of the rotating crank 2 and transmits the
crank pulse to the controlling unit 15.
Further, the control apparatus unit 50 is provided with
a crank angle detecting unit 30, an engine rotational speed
detecting unit 31, a stroke determining unit 33 and the like
other than the controlling unit 15. The crank angle detecting
unit 30 detects a crank angle of the crank 2 by the crank pulse
produced by the crank pulse outputting unit S3. The engine
rotational speed detecting unit 31 detects an engine rotational
speed by the crank pulse produced by the crank pulse outputting
unit S3 . The controlling unit 15 controls the fuel supply amount
by driving the fuel injection valve 16 and the fuel pump 17
in the fuel supplying unit based on the intake pressure and
the engine rotational speed.
In determining the stroke by the stroke determining unit
33, as shown in Fig.5, when 11 pieces of the projections 2a
are provided at equal intervals except a position of one portion
at positions constituted by dividing 360 degrees of the crank
2 by 12, a crankpulse number is attached to a crankpulse produced
by the projection 2a. A crank pulse number at a compression
dead center is designated by '*'0". It is determined that the
crank pulse numlDers of "0" through "6" designate an expansion
stroke, the crank pulse numbers of "6" through ^'12" designate
an exhaust stroke, the crank pulse numbers of "12" through "18"
designate an intake stroke, and the crank pulse numbers of "18"
through "0" designate a compression stroke.
As shown in Fig.6, when cranking is stated by starting
the internal combustion engine 1, the crankpulse is outputted,
and the intake pressure is increased. The intake pressure is
reduced when the crank pulse is not outputted, and the upper
dead center is finished to be determined by a timing at which
the crank pulse is not outputted.
Further, the intake pressure is increased, combustion
is carried out and combustion is finished to be determined by
the timingatwhich the crankpulse is not outputted. The strokes
are finished to be determined by repeating these twice. Until
finishing to determine the strokes, the drive reference position
is controlled to constitute the timing for each one rotation,
and after finishing to determine the strokes, the drive reference
position is controlled to constitute the timing once for each
two rotations of the crank.
A first 6;inbodiment of the invention is constituted as
shown in Fig.7.
The first embodiment includes the crank angle detecting
unit 30 for detecting the crank angle of the crank 2 by the
crank pulse piroduced by the crank 2, the intake pressure
detecting unit SI for detecting the intake pressure of the intake
path 8 on the downstream side of the auxiliary intake path 12,
the stroke determining unit 33 for determining the stroke of
the internal combustion engine 1 based on the crank pulse and
a change in the intake pressure, and the controlling unit 15
for controlling the control valve 13 by controlling a state
of closing the control valve 13 by setting the drive reference
position as the timing of driving to close the throttle valve
13. The controlling unit 15 synchronizes the timing of driving
the control valve 13 based on the crank angle with the timing
of detecting the intake pressure.
That is, in Fig. 7, when cranking is started by starting
the internal combustion engine 1, the crank pulse is outputted,
the intake pressure is increased, and the controlling unit 15
drives to open and close the control valve 13 by controlling
a ratio of a time period of closing the control valve 13 to
a time period of opening the control valve in a predetermined
time period to open the auxiliary intake path 12. The intake
pressure is reduced by rotating the crank 2 by the cranking,
the upper dead center is finished to be determined at the timing
at which the crankpulse is not outputted, and the intake pressure
at this occasion is designated by notation PO. The intake
pressure is then increased, combustion is carried out, and the
combustion is finished to be determined by the timing at which
the crank pulse is not outputted. The intake pressure at this
occasion is designated by notation PI. The timing of driving
to close the control valve 13, which is set as the drive reference
position, is synchronized with the timing for detecting the
intake pressure, and the control valve 13 closes the auxiliary
intake path 12,
Further, the crank pulse is outputted after finishing
to determine the combustion, andwhen a predetermined time period
of closing the control valve has elapsed, the state of driving
the control valve 13 is made to be opened to open the auxiliary
intake path 12. The intake pressure at the timing at which the
crank pulse is not outputted is designated by notation P2, and
the state of driving the control valve 13 synchronized with
the timing of detecting the intake pressure is closed to close
the auxiliary intake path 12.
Subseguently, as the crankpulse is outputted, the intake
pressure is increased and combustion is carried out. When a
predetermined time period of closing the control valve has
elapsed, the state of driving the control valve 13 is opened
to open the auxiliary path 12, the intake pressure at a timing
at which the crank pulse is not outputted is designated by
notation P3, and the state of driving the control valve 13
synchronized v/ith the timing of detecting the intake pressure
is closed to close the auxiliary intake path 12.
Further, the upper dead center is finished to be determined
at a timing at v^hich the crank pulse is not outputted, the intake
pressure at this occasion is designated by notation P4 and the
stroke is finished to be determined.
Until finishing to determine the strokes, the drive
reference position for driving to close the control valve 13
is controlled to be once for each rotation of the crank and
when combustion is finished to be determined and the intake
pressure is at PI, the control valve 13 driven to close in
synchronism with the timing of detecting the intake pressure
closes the auxiliary intake path 12. When combustion is
finished to be determined and the intake pressure is at PI,
the state of driving the control valve is controlled to be once
for each rotation of the crank by setting the drive reference
position as a time point of closing the state of closing the
control valve. Thereafter, until finishing to determine the
strokes, the intake pressures P2, P3 constitute the drive
reference positions.
When the stroke is finished to be determined, the drive
reference position of driving to close the control valve 13
thereafter is controlled to be once for each two rotations (1
cycle) of the crank to constitute the drive reference position
in synchronism with the intake pressures P4, P5....
When compared with Fig. 6, in Fig. 7, the timing of driving
to close the control valve 13 based on the crank angle is
synchronized with the timing of detecting the intake pressure.
By synchronizing the timing of driving to open or close the
control valve 13 in this way with the timing of detecting the
intake pressure, a fluctuation in the intake pressure at a crank
pulse the same as a crank pulse one cycle before can be restrained
to be small, a fluctuation in the intake pressure caused by
opening or closing the control valve 13 is prevented from being
detected erroneously, and the steady state load can be detected
further accurately.
In this way, the idling rotational speed of the internal
combustion engine 1 is controlled by controlling the intake
air amount immediately after starting. At this occasion, the
idling rotational speed can stably be controlled without
determining that the state is not brought into the steady state
by a change in the intake pressure caused by opening or closing
the control valve 13, and the stroke can be determined without
fail even in a system which is not provided with the stroke
determining sensor by determining the stroke of the internal
combustion engine 1 by detecting the intake pressure of the
intake path 8.
A second embodiment of the invention is constituted as
shown in Fig.8.
The embodiment includes the crank angle detecting unit
30 for detecting the crank angle of the crank 2 by the crank
pulse produced by the crank 2 and the control valve 13.
As shown in Fig. 8 (a) , the controlling unit 15 constitutes
the drive reference position by the timing of driving to close
the control valve 13 and the time period of closing the control
valve constituting the state of closing the control valve 13
is controlled by a timer 40 provided to the controlling unit
15.
That is, the control is executed by the time period of
closing the control valve. As shown in Fig. 8 (b) , when the engine
rotation is increased, the control valve opening time period
of the control valve 13 is shortened in accordance with an
increase in the number of the crank pulses in the control valve
closing time period of the control valve 13. Meanwhile, as
shown in Fig.8(c), when the engine rotation is reduced, the
time period of opening the control valve 13 is made to be long
in accordance with a reduction in the number of crank pulses
in the control valve closing time period of the control valve
13.
In this way, by making the time period of opening the
control valve short in accordance with the increase in the number
of crank pulses in the control valve closing time period of
the control valve 13 and making the time period of opening the
control valve long in accordance with the reduction in the number
of crank pulses, when the idling rotational speed is increased,
the control valve is controlled in a direction of restraining
the engine rotational speed, and when the idling rotational
speed is reduced, the control valve is controlled in a direction
of increasing the engine rotational speed. Therefore, the
fluctuation in rotation of the internal combustion engine can
be restrained.
Although according to the second embodiment of the
invention, the control valve closing time period is controlled
by the timer 40, for example, the control valve closing time
period can also be controlled with respect to a position by
the crank angle of the crank 2.
A third embodiment of the invention is constituted as
shown in Fig.9,
The third embodiment includes the crank angle detecting
unit 30 for detecting the crank angle of the crank by the crank
pulse produced by the crank, the intake pressure detecting unit
SI for detecting the intake pressure of the intake path 8 on
the downstream side of the auxiliary path 12, the stroke
determining unit 33 for determining the stroke of the internal
combustion engine 1 by the crank pulse and a change in the intake
pressure, and the controlling unit 15 for controlling the state
of closing the control valve 13 by constituting the drive
reference position by the timing of driving to close the control
valve 13.
The controlling unit 15 synchronizes the timing of driving
to close the control valve 13 based on the crank angle with
a stroke determination finish timing as the drive reference
position, and the drive reference position with respect to a
crank rotation of the internal combustion engine 1 is changed
before and after finishing to determine the stroke.
That is, in pattern 1 and pattern A, after finishing to
determine the stroke, even when the drive reference position
of driving to close the control valve 13 is changed, two rotations
of the crank are controlled by constituting the drive reference
position, in which the control valve 13 is closed in the crank
numbers of "18" through "0" and opened in crank numbers "1"
through "18".
Meanwhile, in pattern 2 and pattern 3, after finishing
to determine the stroke, when the drive reference position of
driving to close the control valve 13 is changed, the crank
numbers of "6" through "18" constitute the time period of
controlling the control valve 13 . After finishing to determine
the stroke, when the crank 2 is rotated by one rotation or more
until reaching the initial crank angle of detecting the intake
pressure, the control valve 13 is closed at the crank numbers
of "6" through "9", and the control valve 13 is opened at the
crank numbers of "10" through "18". A time period of not driving
the control valve 13 is eliminated, from the crank number "18",
the control valve 13 is driven to open and close similar to
pattern 1 and pattern 4, and stable idling rotational speed
control can be realized by eliminating the time period of not
driving the control valve 13 in changing the drive reference
position.
According to the third embodiment, the drive reference
position is varied before and after finishing to determine the
stroke, and after finishing to determine the stroke, the drive
reference position is controlled to be synchronized with an
initial predetermined crank angle.
That is, although in pattern 1 and pattern 2, the control
valve 13 is closed at the crank number of "6" of the drive reference
position of driving to close the control valve 13 before
finishing to determine the stroke, in pattern 3 and pattern
4, the control valve 13 is closed at the crank number of "18"
of the drive reference position of driving to close the control
valve 13, and the control is executed by constituting the
reference by the crank number of "6" or "18", after finishing
to determine the stroke, in any of pattern 1 through pattern
4, for example, the control valve 13 is closed at the crank
number of "18" and the control is executed by constituting the
reference by the crank number of "18". In this way, the drive
reference position is varied before and after finishing to
determine the stroke, after finishing to determine the stroke.
the control is executed by synchronizing the drive reference
position of driving to close the control valve 13 with the initial
predetermined crank angle, or the crank number of "18" according
to the embodiment and the idling rotational speed control which
is stable with a small variation in rotation can be realized.
Further, according to the third embodiment of the
invention, the drive reference position is varied before and
after finishing to determine the stroke, before finishing to
determine the stroke, the control valve 13 is controlled to
open fully and after finishing to determine the stroke, the
control valve 13 is controlled in accordance with a state of
operating the internal combustion engine. That is, before
finishing to determine the stroke, the control valve 13 is
controlled to open fully, as shown in Fig. 8 (b) , when the engine
rotation is increased, the time period of opening the control
valve 13 is shortened in accordance with the increase in the
number of crank pulses in the time period of closing the control
valve 13. On the other hand, as shown in Fig.8(c), when the
engine rotation is reduced, the time period of opening the
control valve 13 is made to be long in accordance with the
reduction in the number of crank pulses in the time period of
closing the control valve 13, and the idling rotational speed
can be realized to control stably with a smaller fluctuation
in rotation by driving to open or close the control valve 13
in accordance with the state of the internal combustion engine.
Further, according to the third embodiment of the
invention, the drive reference position is varied before and
after finishing to determine the stroke, before finishing to
determine the stroke, as shown in Fig.6, the drive reference
position is controlled once for each rotation of the crank 2,
after finishing to determine the stroke, the drive reference
position is controlled once for two rotations of the crank angle
2, thereby, the idling rotational speed can be realized to
control stably with smaller fluctuation in rotation.
After finishing to determine the stroke, by completely
synchronizing the intake timing and the drive reference position,
an effect as a fast idle device is further promoted, and excellent
engine starting performance and stable idling rotational speed
control can be realized.
A fourth embodiment of the invention is constituted as
shown in Fig.10.
The fourth embodiment includes the engine rotational
speed detecting unit 31 for detecting the engine rotational
speed by the crank pulse produced by the crank 2, the intake
pressure detecting unit SI for detecting the intake pressure
of the intake path 8 on the downstream side of the auxiliary
intake path 12, and fuel supplying unit for supplying fuel to
the combustion chamber 5. The fuel supplying unit delivers
fuel from the fuel pump 17 to the fuel injection valve 16 and
fuel is supplied to the combustion chamber 5 by the fuel injection
valve 16. Although fuel is supplied from the fuel injection
valve 16 to the combustion chamber 5 via the intake path 8,
the invention is not limited thereto, and the fuel maybe supplied
from the fuel injection valve 16 directly to the combustion
chamber 5. Further, the fuel supplying unit can also be
constituted by an electronically controlled carburetor and the
fuel pump.
The controlling unit 15 controls the fuel supply amount
supplied to the combustion chamber 5 based on the intake pressure
and the engine rotational speed, and the controlling unit 15
is provided with a threshold of a pressure difference between
the intake pressure before one cycle which is required for
determining an accelerating or decelerating state of the engine
rotational speed and the current intake pressure. The
threshold of the pressure difference between the intake pressure
before one cycle which is required for determining the
accelerating or decelerating state of the engine rotational
speed and the current intake pressure is set by a two-dimensional
table constituting an axis thereof by the engine rotational
speed as shown in Fig.10.
When the engine rotational speed is small, the threshold
of the pressure difference between the intake pressure before
one cycle and the current intake pressure is increased, and
when the engine rotational number is increased, the threshold
is successively reduced and when a predetermined engine
rotational speed is reached, the threshold is made to be constant
at a small value.
In this way, by setting the threshold of the pressure
difference between the intake pressure before one cycle which
is required for determining the accelerating or decelerating
state when the engine rotational speed is small and the current
intake pressure by the two-dimensional table constituting the
axis thereof by the engine rotational speed, the fuel can be
supplied stably without increasing the fuel supply amount
erroneously by a low idling rotational speed having a large
fluctuation in rotation.
Further, even when a user sets the idling rotational speed
to be low, the idling rotational speed can stably be maintained
without being erroneously determined not to be in the steady
state.
Further, when a change in the pressure difference between
the intake pressure before one cycle and the current intake
pressure is equal to or larger than the threshold in accordance
with the engine rotational number, the fuel supply amount is
increased and fuel can be supplied stably. Further, fuel can
be supplied stably by increasing the fuel supply amount by
asynchronous injection.
Next, an explanation will be given of a control of an
idle rotational speed controller of an internal combustion
engine in reference to flowcharts of Fig.11 and Fig.12 and a
timing chart of Fig.13.
Fig.11 shows a crank pulse interruption flow. When
cranking is started by starting the internal combustion engine
1, the intake pressure is increased and the intake pressure
is converted by AD conversion to input (Sa 1).
The control valve (solenoid valve) 13 is started to be
controlled to close (Sa 2), and it is determined whether the
timing is before determining the stroke (Sa 3).
In the case of before determining the stroke, at a timing
of closing the control valve 13 (Sa 4) , a time period of closing
the control valve 13 at the drive reference position of once
for each rotation is calculated from the engine rotational speed
and the engine temperature (Sa 5) , and the timer 40 is started
to output the close signal to the control valve 13 (Sa 6).
Meanwhile, in the case of after determining the stroke,
it is determined whether the drive reference position is
determined once for each rotation (Sa 7), and at a timing of
closing the control valve 13 (Sa 8) , the time period of closing
the control valve 13 at the drive reference position is
determined once for two rotations from the engine rotational
speed and the engine temperature (Sa 9) . The timer 40 is started
and the close signal is outputted to the control valve 13 (Sa
6) .
Fig.12 shows a timer interruption flow. When the control
of opening the control valve 13 is started (Sb 1), and when
the timer is stopped, the open signal is outputted to the control
valve 13 (Sb 2).
According to the timing chart of Fig.13, cranking is
started and the engine rotation is detected. When the cranking
is started, the control valve 13 is closed and is opened at
the upper dead center and is continued to open until finishing
to determine combustion, and the ratio (duty) of the time period
of opening the control valve 13 in the predetermined time period
is set to 100,
When combustion is finished to be determined, the control
valve 13 is duty controlled by FID initial duty searched by
mapping of the engine temperature. The control valve 13 is duty
controlled while attenuating the duty by each FID duty
attenuating amount/2 by mapping of the engine temperature and
is duty controlled by the FID duty attenuating amount searched
by mapping by the engine temperature.
When the attenuated duty becomes smaller than FID target
duty, the control valve 13 is duty controlled by the FID target
duty by the engine temperature mapping, the control valve 13
is controlled by the constant duty control from the FID drive
duty control value (close side), and when the duty in calculation
becomes "0", duty control of the control value 13 is stopped.
The first embodiment to the fourth embodiment are
applicable to the internal combustion control apparatus or the
internal combustion respectively by themselves or applicable
by combinations of any of them.

The invention is applicable to an idle rotational speed
controller and an internal combustion control apparatus of an
internal combustion as well as an internal combustion engine
including an intake path for sucking air to be supplied to a
combustion chamber of the internal combustion engine, and an
auxiliary intake path communicating with a downstream side of
a throttle valve arranged at the intake path for controlling
an intake amount, and a control valve arranged at the auxiliary
intake path for controlling an idling intake amount.
We Claim:
1. An idle rotational speed controller (50) of an internal combustion engine
(1) having an intake path (8) for sucking air to be supplied to a
combustion chamber (5) of the internal combustion engine (1), a throttle
valve (11) arranged at the intake path (8) for controlling an intake
amount, an auxiliary intake path (12) for communicating with the intake
path (8) on an upstream side of the throttle valve (11) and on a
downstream side of the throttle valve (11), and an opening/closing type
control valve (13) arranged at the auxiliary intake path (12) for controlling
an idling intake amount, the idle rotational speed controller (50)
comprising:
an intake pressure detecting unit (Si) for detecting an intake pressure
of the intake path (8);
a fuel supplying unit (17) for controlling a supply amount of a fuel
supplied to the combustion chamber (5) based on at least the intake
pressure; characterized by comprising:
a controlling unit (15) for synchronizing a drive reference position for
driving to open or close the control valve (13) corresponding to a timing
of detection of the intake pressure by the intake pressure detecting unit
(Si).
2. The idle rotational speed controller as claimed in claim 1, wherein the
controlling unit (15) controls a state of closing the control valve (13) by
setting a timing of driving to close the control valve (13) as the drive
reference position.

3. The idle rotational speed controller as claimed in claim 1, wherein the
controlling unit (15) increases the supply amount of the fuel when a
pressure difference between the intake pressure before at least one cycle
and a current one is equal to or larger than a threshold value in
accordance with a state of opening or closing the control valve (13).
4. The idle rotational speed controller as claimed in claim 3, wherein the
threshold value is set by a two-dimensional table constituting an axis
thereon by an engine rotational speed.
5. The idle rotational speed controller as claimed in claim 3, wherein the
controlling unit (15) increases the supply amount of the fuel by a
synchronous injection,
6. An idle rotational speed controller as claimed in claim 1, comprising a
stroke determining unit (33) for determining a stroke of the internal
combustion engine (1) based on at least the intake pressure.
7. An idle rotational speed controller as claimed in claim 1, wherein the
controlling unit (15) controls the control valve (13) by synchronizing a
drive reference position for driving to open or close the control valve (13)
corresponding to the detection pressure of the intake pressure by the
intake pressure detecting unit (Si), and changing the drive reference
position with respect to a crank rotation of the internal combustion engine
(1) after completion of the stroke determination by the stroke determining
unit (33) from that of before completion of the stroke determination.

8. The idle rotational speed controller as claimed in claim 7, wherein the
controlling unit (15) controls to bring about the drive reference position
once for each rotation of a crank (2) before completion of the
determination by the stroke determining unit (33) and bring about the
drive reference position once for each two rotations of the crank (2) after
completion of the stroke determination.
9. An idle rotational speed controller as claimed in claim 1, wherein the
controlling unit (15) controls the control valve (13) by synchronizing a
drive reference position for driving to open or close the control valve (13)
corresponding to a detection of the intake pressure by the intake pressure
detecting unit (S1), and preventing the control valve (13) from being
driven to open or close before completion of stroke determination by the
stroke determining unit (33).
10. An internal combustion engine comprising an idle rotational speed
controller of an internal combustion engine as claimed in any one of
claims 1 to 9.


The invention relates to an idle rotational speed controller (50) of an internal combustion engine (1) having an intake path (8) for sucking air to be supplied to a combustion chamber (5) of the internal combustion engine (1), a throttle valve (11) arranged at the intake path (8) for controlling an intake amount, an
auxiliary intake path (12) for communicating with the intake path (8) on an upstream side of the throttle valve (11) and on a downstream side of the throttle valve (11), and an opening/closing type control valve (13) arranged at the auxiliary intake path (12) for controlling an idling intake amount, the idle
rotational speed controller (50) comprising an intake pressure detecting unit (S1) for detecting an intake pressure of the intake path (8), a fuel supplying unit (17) for controlling a supply amount of a fuel supplied to the combustion chamber (5) based on at least the intake pressure. A controlling unit (15) for synchronizing a drive reference position for driving to open or close the control valve (13)
corresponding to a timing of detection of the intake pressure by the intake pressure detecting unit (S1).

Documents:

00313-kolnp-2005-abstract.pdf

00313-kolnp-2005-claims.pdf

00313-kolnp-2005-correspondence-1.1.pdf

00313-kolnp-2005-correspondence-1.2.pdf

00313-kolnp-2005-correspondence-1.3.pdf

00313-kolnp-2005-correspondence.pdf

00313-kolnp-2005-description (complete).pdf

00313-kolnp-2005-drawings.pdf

00313-kolnp-2005-form-1.pdf

00313-kolnp-2005-form-18.pdf

00313-kolnp-2005-form-2.pdf

00313-kolnp-2005-form-3.pdf

00313-kolnp-2005-form-5.pdf

00313-kolnp-2005-international search authority report.pdf

00313-kolnp-2005-pa.pdf

00313-kolnp-2005-pct request form.pdf

00313-kolnp-2005-priority document.pdf

313-KOLNP-2005-(27-01-2012)-CORRESPONDENCE.pdf

313-KOLNP-2005-(27-01-2012)-FORM 27.pdf

313-KOLNP-2005-(27-01-2012)-PA.pdf

313-KOLNP-2005-FOR ALTERATION OF ENTRY.pdf

313-kolnp-2005-granted-abstract.pdf

313-kolnp-2005-granted-claims.pdf

313-kolnp-2005-granted-correspondence.pdf

313-kolnp-2005-granted-description (complete).pdf

313-kolnp-2005-granted-drawings.pdf

313-kolnp-2005-granted-examination report.pdf

313-kolnp-2005-granted-form 1.pdf

313-kolnp-2005-granted-form 18.pdf

313-kolnp-2005-granted-form 2.pdf

313-kolnp-2005-granted-form 3.pdf

313-kolnp-2005-granted-form 5.pdf

313-kolnp-2005-granted-pa.pdf

313-kolnp-2005-granted-reply to examination report.pdf

313-kolnp-2005-granted-specification.pdf

313-kolnp-2005-granted-translated copy of priority document.pdf


Patent Number 237800
Indian Patent Application Number 313/KOLNP/2005
PG Journal Number 02/2010
Publication Date 08-Jan-2010
Grant Date 07-Jan-2010
Date of Filing 02-Mar-2005
Name of Patentee YAMAHA HATSUDOKI KABUSHIKI KAISHA
Applicant Address 2500 SHINGAI,IWATA-SHI,SHIZUOKA-KEN
Inventors:
# Inventor's Name Inventor's Address
1 YASUTAKA MINE C/O YAMAHA HATSUDOKI KABUSHIKI KAISHA 2500 SHINGAI, IWATA-SHI, SHIZUOKA-KEN 438-8501
PCT International Classification Number F02D 41/08
PCT International Application Number PCT/JP2004/004429
PCT International Filing date 2004-03-29
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 2003-092447 2003-03-28 Japan