TECHNICAL FIELD
[0001] The present invention relates to a control device for an internal combustion engine
supplying a fuel injection amount corresponding to the manifold pressure of the internal
combustion engine.
BACKGROUND ART
[0002] In the past, as a prior art relating to a control device of an internal combustion
engine, there has been known the art disclosed in Japanese Unexamined Patent Publication
(Kokai) No. 2-19626. In this, art is disclosed judging if the amount of increase of
fuel is in the necessary region based on a manifold pressure compensated in accordance
with a change of the atmospheric pressure and increasing the fuel injection amount
in accordance with the result of judgement.
[0003] In general, when a vehicle travels from a low altitude to a high altitude and the
atmospheric pressure falls, if finding the fuel injection amount and controlling the
system to adjust it based on the manifold pressure and the engine speed of the engine
in the same way as above, since the rise in the filling efficiency due to the fall
in the exhaust pipe pressure is not considered, sometimes the air-fuel ratio shifts
to the lean side and the drivability and starting property deteriorate.
[0004] Note that in the above art, the excess or shortage in the fuel injection amount due
to a change in the atmospheric pressure is compensated by finding a compensation coefficient
K from the map shown in FIG. 14 using a one-dimensional function based on the atmospheric
pressure PA detected by an atmospheric pressure sensor etc. and this compensation
coefficient K is multiplied with a basic fuel injection amount TP to calculate a final
fuel injection amount TAU. Here, as shown in FIG. 15, when the atmospheric pressure
PA changes, for example, the compensation amounts Δa, Δb, and Δc of the fuel injection
amounts TAU (A, B, C) with respect to the manifold pressure PM of any three locations
are not uniform (fixed ratios), so it is not possible to deal with them by one-dimensional
compensation of the fuel injection amount TAU for changes in the atmospheric pressure
PA. Therefore, there was the inconvenience that a suitable fuel injection amount TAU
for the manifold pressure PM could not be obtained when the atmospheric pressure PA
changed.
DISCLOSURE OF INVENTION
[0005] Therefore, the present invention was made to eliminate this inconvenience and has
as its object the provision of an engine control device able to reflect changes in
the atmospheric pressure in the manifold pressure of the engine and supply a suitable
fuel injection amount.
[0006] According to the engine control device of one aspect of the present invention, the
difference between a base atmospheric pressure and current atmospheric pressure calculated
by an atmospheric pressure operating means is calculated as a change in atmospheric
pressure by a change operating means based on a manifold pressure detected by a manifold
pressure detecting means, the change in atmospheric pressure and an operation use
manifold pressure for finding the fuel injection amount of the engine calculated by
a manifold pressure operating means based on the manifold pressure detected by the
manifold pressure detecting means are added to find a manifold pressure compensation
value, and a fuel injection amount to be supplied to the engine is calculated by an
injection amount operating means using as parameters the manifold pressure compensation
value and engine speed detected by rotational speed detecting means. By taking into
consideration the change in atmospheric pressure with respect to the manifold pressure
compensation value and reflecting it in the manifold pressure parameter, a suitable
fuel injection amount is supplied regardless of the change in atmospheric pressure,
so the operating state of the engine is maintained well and the drivability is secured.
[0007] According to the engine control device of another aspect of the present invention,
the difference between a base atmospheric pressure and current atmospheric pressure
detected by an atmospheric pressure detecting means is calculated as a change in atmospheric
pressure by a change operating means, the change in atmospheric pressure and an operation
use manifold pressure for finding the fuel injection amount of the engine calculated
by a manifold pressure operating means based on the manifold pressure detected by
the manifold pressure detecting means are added to find a manifold pressure compensation
value, and a fuel injection amount to be supplied to the engine is calculated by an
injection amount operating means using as parameters the manifold pressure compensation
value and engine speed detected by rotational speed detecting means. By taking into
consideration the change in atmospheric pressure with respect to the manifold pressure
compensation value and reflecting it into the manifold pressure parameter, the suitable
fuel injection amount is supplied regardless of the change in atmospheric pressure,
so the operating state of the engine is maintained well and the drivability is secured.
[0008] According to an engine control device of still another aspect of the present invention,
an operation use manifold pressure for finding a fuel injection amount of an engine
calculated by a manifold pressure operating means based on a manifold pressure detected
by the manifold pressure detecting means is compensated by an atmospheric pressure
calculated by an atmospheric pressure operating means and a predetermined atmospheric
pressure and calculated as a manifold pressure compensation value by compensation
value operating means, and a fuel injection amount to be supplied to the engine is
calculated by rotational speed detecting means using as parameters the manifold pressure
compensation value and engine speed detected by the rotational speed detecting means.
By taking into consideration the change in atmospheric pressure with respect to the
manifold pressure compensation value and reflecting it into the manifold pressure
parameter, the suitable fuel injection amount is supplied regardless of the change
in atmospheric pressure, so the operating state of the engine is maintained well and
the drivability is secured.
[0009] Below, the present invention will be more sufficiently understood from the attached
drawings and the description of preferred embodiments of the invention.
BRIEF DESCRIPTION OF DRAWINGS
[0010]
FIG. 1 is a schematic view of the configuration showing an engine to which an engine
control device according to a first embodiment of the present invention is applied
and its peripheral equipment.
FIG. 2 is a flow chart of a processing routine for operating a fuel injection amount
in a CPU in an ECU used in an engine control device according to the first embodiment
of the present invention.
FIG. 3 is a map for explaining the calculation of a final fuel injection amount in
the fuel injection amount operation routine of FIG. 2.
FIG. 4 is a schematic view of the configuration showing an engine to which an engine
control device according to a second embodiment of the present invention is applied
and its peripheral equipment.
FIG. 5 is a flow chart of a processing routine for detecting the atmospheric pressure
and manifold pressure in a CPU in an ECU used in an engine control device according
to the second embodiment of the present invention.
FIG. 6 is a flow chart of a processing routine for detecting atmospheric pressure
in FIG. 5.
FIG. 7 is a flow chart of a processing routine for detecting manifold pressure in
FIG. 5.
FIG. 8 is a flow chart of a processing routine for operating a fuel injection amount
in a CPU in an ECU used in an engine control device according to the second embodiment
of the present invention.
FIG. 9 is a flow chart of a first modification of a processing routine for operating
a fuel injection amount in a CPU in an ECU used in an engine control device according
to the second embodiment of the present invention.
FIG. 10 is a flow chart of a second modification of a processing routine for operating
a fuel injection amount in a CPU in an ECU used in an engine control device according
to the second embodiment of the present invention.
FIG. 11 is a flow chart of a third modification of a processing routine for operating
a fuel injection amount in a CPU in an ECU used in an engine control device according
to the second embodiment of the present invention.
FIG. 12 is a flow chart of a fourth modification of a processing routine for operating
a fuel injection amount in a CPU in an ECU used in an engine control device according
to the second embodiment of the present invention.
FIG. 13 is a map for calculating a compensation coefficient in FIG. 12.
FIG. 14 is a conventional map for calculating a compensation coefficient of a fuel
injection amount due to a change in atmospheric pressure.
FIG. 15 is a conventional map showing the difference in compensation amounts of fuel
injection amounts with respect to manifold pressure due to one-dimensional compensation
with respect to a change in atmospheric pressure.
BEST MODE FOR CARRYING OUT THE INVENTION
[0011] Next, the present invention will be explained based on embodiments.
[0012] First, a first embodiment of the present invention will be explained. FIG. 1 is a
schematic view of the configuration showing an engine to which an engine control device
according to a first embodiment of the present invention is applied and its peripheral
equipment.
[0013] In FIG. 1, reference numeral 1 is a single-cylinder water-cooled engine. Air from
an air cleaner 3 is introduced into an intake passage 2 of the engine 1. In the middle
of the intake passage 2 is provided a throttle valve 11 operating linked with operation
of a not shown accelerator pedal etc. By the operation of the throttle valve 11, the
amount of intake to the intake passage 2 (amount of intake air) is adjusted. At the
same time as the amount of intake, fuel is injected and supplied to the engine 1 from
an injector (fuel injector) provided in the intake passage 2 near the intake port
4. Further, an air-fuel mixture comprised of predetermined amounts of fuel and intake
air is sucked into a fuel chamber 7 through an intake valve 6.
[0014] At the downstream side of the throttle valve 11 provided in the middle of the intake
passage 2 is provided a manifold pressure sensor 21 for detecting a manifold pressure
PM in the intake passage 2. A crank shaft 21 of the engine 1 is provided with a crank
angle sensor 22 for detecting a crank angle (°CA) accompanying its rotation. An engine
speed NE of the engine 1 is calculated in accordance with the crank angle detected
by the crank angle sensor 22. An atmospheric pressure sensor 23 is provided for detecting
the atmospheric pressure PA in the ambient environment of the engine 1.
[0015] A spark plug 13 is arranged facing the combustion chamber 7 of the engine 1. This
spark plug 13 is supplied with a high voltage from an ignition coil/ignitor 14 based
on an ignition command signal output from a later explained ECU (electronic control
unit) in synchronization with a crank angle detected by the crank angle sensor 22
and ignites and burns the air-fuel mixture in the combustion chamber 7. In this way,
the air-fuel mixture in the combustion chamber 7 is burned (expanded) and a drive
force obtained. The exhaust gas after the combustion is led through the exhaust valve
8 from the exhaust manifold to the exhaust passage 9 and exhausted to the outside.
[0016] The ECU 30 is comprised as a logical operational circuit consisting of a CPU 31 serving
as the central processing unit for executing various known types of processing, a
ROM 32 for storing a control program, a RAM 33 for storing various data, a B/U (backup)
RAM 34, an input/output circuit 35, a bus line 36 for connecting these, etc. This
ECU 30 receives as input a manifold pressure PM from the manifold pressure sensor
21, the crank angle from the crank angle sensor 22, the atmospheric pressure PA from
the atmospheric pressure sensor 23, etc. Based on the output signals from the ECU
30 based on these various information, the injector 5 is suitably controlled in fuel
injection timing and fuel injection amount and the spark plug 13 and ignition coil/ignitor
14 etc. are suitably controlled in ignition timing.
[0017] Next, the processing routine for operation of the fuel injection amount in the CPU
31 in the ECU 30 used in the engine control device according to the first embodiment
of the present invention will be explained based on the flow chart of FIG. 2. Note
that this fuel injection amount operation routine is repeatedly executed by the CPU
31 every predetermined time interval.
[0018] In FIG. 2, first, at step S101, the engine speed NE of the engine 1 is read. Next,
the routine proceeds to step S102, where the atmospheric pressure PA is read. Next,
the routine proceeds to step S103, where the manifold pressure PM is read. Next, the
routine proceeds to step S104, where the manifold pressure PMTP for basic fuel injection
amount operation (hereinafter simply referred to as the "operation use manifold pressure")
is calculated by the following formula (1) based on the manifold pressure PM read
at step S103:
[0019] Next, the routine proceeds to step S105, where the difference between the atmospheric
pressure PAbase at a base location, the atmospheric pressure 760 mmHg at a low altitude
in this embodiment, and the atmospheric pressure PA at the current location read at
step S102, that is, the change in atmospheric pressure PAdev {=(760-PA)}, is added
to the operation use manifold pressure PMTP calculated at step S104 to calculate a
manifold pressure compensation value PMTP' for basic fuel injection amount operation
(hereinafter referred to simply as the "manifold pressure compensation value") by
the following formula (2):
[0020] Next, the routine proceeds to step S106, where the final fuel injection amount TAU
is calculated based on the manifold pressure compensation value PMTP' calculated at
step S105 and the engine speed NE read at step S101, then the routine is ended.
[0021] Next, the calculation of the final fuel injection amount TAU using as parameters
the manifold pressure compensation value PMTP' (mmHg) and engine speed NE (rpm) by
the above fuel injection amount operation routine will be explained concretely with
reference to the map of FIG. 3. Note that the control amount for a middle point in
the map of FIG. 3 is found by interpolation of two points of the engine speed.
[0022] First, the map shown in FIG. 3A is used to calculate the fuel injection amount α
at the time of a low altitude atmospheric pressure of 760 mmHg for when the read value
of the manifold pressure PM is 200 mmHg and the read value of the engine speed NE
is 1000 rpm. When the high altitude atmospheric pressure becomes 660 mmHg in the operating
state of the engine 1, as shown in FIG. 3B, the read value of the manifold pressure
PM ends up becoming 100 mmHg, so the fuel injection amount β is calculated based on
the read value of the manifold pressure PM of 100 mmHg and the read value of the engine
speed NE of 1000 rpm.
[0023] Therefore, at a high altitude atmospheric pressure of 660 mmHg, to maintain the operating
state of the engine 1 of the time of the low altitude atmospheric pressure of 760
mmHg, as shown in FIG. 3C, the fuel injection amount γ is calculated from the manifold
pressure compensation value PMTP' of 200 mmHg, obtained by adding the difference between
the low altitude atmospheric pressure of 760 mmHg and high altitude atmospheric pressure
of 660 mmHg, that is, the change in atmospheric pressure of 100 mmHg, to the high
altitude manifold pressure 100 mmHg, and the engine speed NE of 1000 rpm. That is,
the fuel injection amount γ at the time of the high altitude atmospheric pressure
of 660 mmHg in the present embodiment is set equal to the fuel injection amount α
at the time of the low altitude atmospheric pressure of 760 mmHg.
[0024] Due to this, the change in the manifold pressure PM is suitably compensated, and
the final fuel injection amount TAU at the atmospheric pressure PA at the current
location, that is, the high altitude atmospheric pressure of 660 mmHg, is calculated
based on the atmospheric pressure PAbase at the base location, that is, the low altitude
atmospheric pressure of 760 mmHg. Therefore, even when changing from the low altitude
atmospheric pressure to the high altitude atmospheric pressure, the operating state
of the engine 1 can be maintained well without being influenced by the change in atmospheric
pressure and the drivability can be secured.
[0025] In this way, the engine control device of the present embodiment is provided with
the atmospheric pressure sensor 23 serving as the atmospheric pressure detecting means
for detecting the atmospheric pressure PA; the manifold pressure sensor 21 serving
as the manifold pressure detecting means for detecting the pressure of the intake
air introduced into the intake passage 2 of the engine 1, that is, the manifold pressure
PM; the manifold pressure operating means realized by the ECU 30 for calculating the
operation use manifold pressure PMTP for calculating the fuel injection amount of
the engine 1 based on the manifold pressure PM detected by the manifold pressure detecting
sensor 21; the crank angle sensor 22 serving as the rotational speed detecting means
for detecting the engine speed NE of the engine 1; the change operating means realized
by the ECU 30 for calculating the difference between the atmospheric pressure PAbase
at the base location detected by the atmospheric pressure sensor 23 and the atmospheric
pressure PA at the current location as the change in atmospheric pressure PAdev; and
the injection amount operating means realized by the ECU 30 for calculating the final
fuel injection amount TAU to be supplied to the engine 1 using as parameters the manifold
pressure compensation value PMTP' obtained by adding the change in atmospheric pressure
PAdev calculated by the change operating means to the operation use manifold pressure
PMTP calculated by the manifold pressure operating means and the engine speed NE detected
by the crank angle sensor 22.
[0026] That is, the final fuel injection amount TAU to be supplied to the engine 1 is calculated
using as parameters the manifold pressure compensation value PMTP' found by adding
the difference between the base atmospheric pressure PAbase and the current atmospheric
pressure PA detected by the atmospheric pressure sensor 23, that is, the change in
atmospheric pressure PAdev, and the operation use manifold pressure PMTP for calculating
the fuel injection amount of the engine 1 based on the manifold pressure PM detected
by the manifold pressure sensor 21 and the engine speed NE detected by the crank angle
sensor 22. In this way, by taking into consideration the change in atmospheric pressure
PAdev with respect to the manifold pressure compensation value PMTP' and reflecting
it into the manifold pressure parameter, it is possible to supply a suitable final
fuel injection amount TAU regardless of the change in atmospheric pressure.
[0027] Note that in the above embodiment, the difference between the base atmospheric pressure
PAbase and the current atmospheric pressure PA is used as it is as the change in atmospheric
pressure PAdev for calculation of the fuel injection amount, but it is also possible
to multiply for example 0.8 as a predetermined compensation coefficient based on compliance
with the difference between the base atmospheric pressure PAbase and atmospheric pressure
PA at the current location to obtain the change in atmospheric pressure PAdev.
[0028] The change operating means realized by the ECU 30 of the engine control device multiplies
a predetermined compensation coefficient with the difference to calculate the change
in atmospheric pressure PAdev and can expect actions and effects similar to the above
embodiment.
[0029] Further, in the above embodiment, the difference between the base atmospheric pressure
PAbase and the current atmospheric pressure PA is used as it is as the change in atmospheric
pressure PAdev for calculation of the fuel injection amount, but it is also possible
to multiply a predetermined compensation coefficient (1.0, 0.9, 0.8, ...) having as
a parameter the manifold pressure PM (100, 200, 300,...) as the one-dimensional map
based on compliance with the difference between the base atmospheric pressure PAbase
and atmospheric pressure PA at the current location to obtain the change in atmospheric
pressure PAdev.
[0030] The change operating means realized by the ECU 30 of the engine control device multiplies
a predetermined compensation coefficient having the manifold pressure PM as a parameter
with the difference to calculate the change in atmospheric pressure PAdev and can
expect actions and effects similar to the above embodiment.
[0031] Further, the above embodiment is configured provided with the atmospheric sensor
23 to detect the atmospheric pressure PA in the ambient environment of the engine
1, but it is also possible to calculate the atmospheric pressure PA based on the manifold
pressure PM detected by the manifold pressure sensor 21 at a predetermined timing.
In this case, the atmospheric pressure sensor 23 is not required.
[0032] This engine control device is provided with the manifold pressure sensor 21 serving
as the manifold pressure detecting means for detecting the pressure of the intake
air introduced into the intake passage 2 of the engine 1, that is, the manifold pressure
PM; the manifold pressure operating means realized by the ECU 30 for calculating the
operation use manifold pressure PMTP for calculating the fuel injection amount of
the engine 1 based on the manifold pressure PM detected by the manifold pressure sensor
21; the atmospheric pressure operating means realized by the ECU 30 for calculating
the atmospheric pressure PA based on the manifold pressure PM detected by the manifold
pressure sensor 21; the crank angle sensor 22 serving as the rotational speed detecting
means for detecting the engine speed NE of the engine 1; the change operating means
realized by the ECU 30 for calculating the difference between the base atmospheric
pressure PAbase and the atmospheric pressure PA at the current location calculated
by the atmospheric pressure operating means as the change in atmospheric pressure
PAdev; and the injection amount operating means realized by the ECU 30 for calculating
the final fuel injection amount TAU to be supplied to the engine 1 using as parameters
the manifold pressure compensation value PMTP' obtained by adding the change in atmospheric
pressure PAdev calculated by the change operating means to the operation use manifold
pressure PMTP calculated by the manifold pressure operating means and the engine speed
NE detected by the rotational speed detecting means. Similar actions and effects as
the above embodiment can be expected.
[0033] In the above embodiment, the explanation was made of the case of a change from the
low altitude atmospheric pressure to the high altitude atmospheric pressure when using
a low altitude as the reference, but when working the present invention, the change
is not limited to this. A similar explanation may also be applied to a change from
a high altitude atmospheric pressure to low altitude atmospheric pressure when using
the high altitude as a reference. Note that in this case, the positive/negative sign
of the difference between the base atmospheric pressure and atmospheric pressure at
the current location merely becomes opposite.
[0034] Next, a second embodiment of the present invention will be explained. FIG. 4 is a
schematic view of the configuration showing an engine to which an engine control device
according to the second embodiment of the present invention is applied and its peripheral
equipment. Only the atmospheric pressure sensor 23 for detecting the atmospheric pressure
PA in the ambient environment of the engine 1 in FIG. 1 showing a schematic view of
the configuration of the above first embodiment is removed. A detailed explanation
will therefore be omitted.
[0035] Next, the processing routine for detecting the atmospheric pressure and manifold
pressure in the CPU 31 in the ECU 30 used in the second embodiment of the present
invention will be explained based on the flow charts of FIG. 5, FIG. 6, and FIG. 7.
Note that the atmospheric pressure and manifold pressure detection routine is repeatedly
executed by the CPU 31 every predetermined time interval.
[0036] In FIG. 5, first, at step S201, it is judged if there an N signal interruption. This
"N signal" is a signal output every 30° CA by the crank angle sensor 22 of the crank
shaft 12 of the engine 1. When the judgement condition of step S201 does not stand,
that is, there is no N signal interruption, the routine waits until there is an N
signal interruption at step S201. It then proceeds to step S202, where "1" is added
to the interruption number NNUM0 of the previous N signal, that is, the N signal interruption
number NNUM is incremented by "+1". This N signal interruption number NNUM is a signal
expressing crank angle positions "0" to "23" given for every 30°CA interval of the
range of crank angle 720°CA comprised of four cycles (suction stroke → compression
stroke → expansion (explosion) stroke → exhaust stroke) starting with the base crank
angle position detected by the crank angle sensor 22 provided at the crank shaft 12
of the engine 1 as "0 (zero").
[0037] Next, the routine proceeds to step S203, where it is judged if Na≤NNUM≤Nb. When the
judgement condition of step S203 stands, that is, the N signal interruption number
NNUM is between the preset constant Na and constant Nb, the routine proceeds to step
S204, where it is judged that the timing is the atmospheric pressure detection timing
and the later explained atmospheric pressure detection processing is executed. On
the other hand, when the judgement condition of step S203 does not stand, that is,
the N signal interruption number NNUM is not between the preset constant Na and constant
Nb, the routine proceeds to step S205, where it is judged if Nc≤NNUM≤Nd. When the
judgement condition of step S205 stands, that is, the N signal interruption number
NNUM is between a preset constant Nc and constant Nd, the routine proceeds to step
S206, where it is judged that the timing is the manifold pressure detection timing
and the later explained manifold pressure detection processing is executed.
[0038] When the atmospheric pressure detection processing at step S204, the manifold pressure
detection processing at step S206, or the judgement condition of step S205 does not
stand, that is, the N signal interruption number NNUM is not between the preset constant
Nc and constant Nd, the routine proceeds to step S207, where it is judged if the N
signal interruption number NNUM is a preset constant Ne (="23"). When the judgement
condition of step S207 does not stand, that is, the N signal interruption number NNUM
is not equal to a preset constant Ne, the routine returns to the above step S201,
where similar processing is repeatedly executed. When the judgement condition of step
S207 stands, that is, the N signal interruption number NNUM becomes equal to a preset
constant Ne, the routine proceeds to step S208, where the N signal interruption number
NNUM is cleared to "0", then the routine proceeds to the above step S201, where the
same processing is repeatedly executed.
[0039] Next, the processing routine for detection of the atmospheric pressure will be explained
with reference to FIG. 6.
[0040] In FIG. 6, first, at step S301, the manifold pressure PM is read. Next, the routine
proceeds to step S302, where the manifold pressure PM read at step S301 is made the
atmospheric pressure detection value PAi. That is, in the present embodiment, the
pressure value based on the manifold pressure PM detected by the manifold pressure
sensor 21 is used as the atmospheric pressure PA. Note that "i" is a number matching
with the N signal interruption number NNUM. Next, the routine proceeds to step S303,
where it is judged if "i" is equal to Nb. When the judgement condition of step S303
does not stand, that is, "i" is not equal to Nb, the atmospheric pressure detection
value PAi from step S302 is stored, then the routine is ended.
[0041] On the other hand, when the judgement condition at step S303 stands, that is, "i"
becomes equal to Nb, the routine proceeds to step S304, where the average value obtained
by dividing the total ∑PAi of the atmospheric pressure detection values PAi stored
at step S302 by the number NPA is made the atmospheric pressure PA. Next, the routine
proceeds to step S305, where all of the manifold pressure detection values PMi are
cleared to "0", then the routine is ended.
[0042] Next, the processing routine for detection of the manifold pressure will be explained
with reference to FIG. 7.
[0043] In FIG. 7, first, at step S401, the manifold pressure PM is read. Next, the routine
proceeds to step S402, where the manifold pressure PM read at step S401 is made the
manifold pressure detection value PMi. Note that "i" is a number matching with the
N signal interruption number NNUM. Next, the routine proceeds to step S403, where
it is judged if "i" is equal to Nd. When the judgement condition of step S403 does
not stand, that is, "i" is not equal to Nd, the manifold pressure detection value
PMi from step S402 is stored, then the routine is ended.
[0044] On the other hand, when the judgement condition at step S403 stands, that is, "i"
becomes equal to Nd, the routine proceeds to step S404, where the value according
to the manifold pressure calculation function f(PMi) in which the manifold pressure
detection value PMi stored at step S402 is entered is made the manifold pressure calculation
value PML. Note that the manifold pressure calculation value PML is treated simply
as the "manifold pressure PM" in the subsequent flow charts. Next, the routine proceeds
to step S405, where all of the manifold pressure detection values PMi are cleared
to "0", then the routine is ended.
[0045] Next, a processing routine for operation of the fuel injection amount in the CPU
31 in the ECU 30 used in the engine control device according to the second embodiment
of the present invention will be explained based on the flow chart of FIG. 8. Note
that this fuel injection amount operation routine is repeatedly executed by the CPU
31 every predetermined time interval.
[0046] In FIG. 8, first, at step S501, the engine speed NE of the engine 1 is read. Next,
the routine proceeds to step S502, where the atmospheric pressure PA found by the
above-mentioned atmospheric pressure detection routine is read. Next, the routine
proceeds to step S503, where the manifold pressure PM found by the above manifold
pressure detection routine is read. Next, the routine proceeds to step S504, where
the operation use manifold pressure PMTP is calculated by the above formula (1) based
on the manifold pressure PM read at step S503.
[0047] Next, the routine proceeds to step S505, where the value of the atmospheric pressure
calculation function f(PA) in which the atmospheric pressure PA read at step S502
is entered and the value of the atmospheric pressure calculation function f(PA0) in
which the predetermined atmospheric pressure PAO is entered are multiplied with the
operation use manifold pressure PMTP calculated at step S504 to calculate the manifold
pressure compensation value PMTP' by the following formula (3):
[0048] Next, the routine proceeds to step S506, where the final fuel injection amount TAU
is calculated based on the manifold pressure compensation value PMTP' calculated at
step S505 and the engine speed NE read at step S501 and the routine is ended. Note
that the calculation of the final fuel injection amount TAU using as parameters the
manifold pressure compensation value PMTP' (mmHg) and the engine speed NE (rpm) by
the fuel injection amount operation routine is similar to that of the above embodiment,
so the explanation will be omitted.
[0049] In this way, the engine control device of the present embodiment is provided with
the manifold pressure sensor 21 serving as the manifold pressure detecting means for
detecting the pressure of the intake air introduced into the intake passage 2 of the
engine 1, that is, the manifold pressure PM; the manifold pressure operating means
realized by the ECU 30 for calculating the operation use manifold pressure PMTP for
calculating the fuel injection amount of the engine 1 based on the manifold pressure
PM detected by the manifold pressure sensor 21; the atmospheric pressure operating
means realized by the ECU 30 for calculating the atmospheric pressure PA based on
the manifold pressure PM detected by the manifold pressure sensor 21; the crank angle
sensor 22 serving as the rotational speed detecting means for detecting the engine
speed NE of the engine 1; the compensation value operating means realized by the ECU
30 for compensating the operation use manifold pressure PMTP calculated by the manifold
pressure operating means by the atmospheric pressure PA calculated by the atmospheric
pressure operating means and the predetermined atmospheric pressure PAO and calculating
the result as the manifold pressure compensation value PMTP'; and the injection amount
operating means realized by the ECU 30 for calculating the final fuel injection amount
TAU to be supplied to the engine 1 using as parameters the manifold pressure compensation
value PMTP' obtained by the compensation value operating means and the engine speed
NE detected by the crank angle sensor 22. Further, the manifold pressure compensation
value PMTP' in the compensation value operating means realized by the ECU 30 of the
engine control device of the present embodiment is calculated by multiplying the atmospheric
pressure PA and predetermined atmospheric pressure PA0 with the operation use manifold
pressure PMTP.
[0050] That is, the operation use manifold pressure value PMTP for calculating the fuel
injection amount of the engine 1 based on the manifold pressure PM detected by the
manifold pressure sensor 21 is compensated by the atmospheric pressure PA calculated
based on the manifold pressure PM and the predetermined atmospheric pressure PAO,
and the final fuel injection amount TAU to be supplied to the engine 1 is calculated
using as parameters the manifold pressure compensation value PMTP' and the engine
speed NE detected by the crank angle sensor 22. By taking into consideration the change
in atmospheric pressure with respect to the manifold pressure compensation value PMTP'
and reflecting this into the manifold pressure parameter, it is possible to calculate
the optimal manifold pressure compensation value regardless of the change in atmospheric
pressure and supply a suitable final fuel injection amount TAU by this manifold pressure
compensation value.
[0051] Next, a first modification of the processing routine for operation of the fuel injection
amount in the CPU 31 in the ECU 30 used in the engine control device according to
the second embodiment of the present invention will be explained based on the flow
chart of FIG. 9. Note that this fuel injection amount operation routine is repeatedly
executed by the CPU 31 every predetermined time interval.
[0052] In FIG. 9, step S601 to step S604 correspond to step S501 to step S504 in the above
embodiment, so a detailed description will be omitted. Here, at step S605, the value
obtained by dividing the predetermined atmospheric pressure PAO by the atmospheric
pressure PA read at step S602 is multiplied with the operation use manifold pressure
PMTP calculated at step S604 to calculate the manifold pressure compensation value
PMTP' by the following formula (4):
[0053] Next, the routine proceeds to step S606, where the final fuel injection amount TAU
is calculated based on the manifold pressure compensation value PMTP' calculated at
step S605 and the engine speed NE read at step S601 and the routine is ended. Note
that the calculation of the final fuel injection amount TAU using as parameters the
manifold pressure compensation value PMTP' (mmHg) and the engine speed NE (rpm) by
the fuel injection amount operation routine is similar to that of the above embodiment,
so the explanation will be omitted.
[0054] In this way, the operation use manifold pressure compensation value PMTP' in the
compensation value operating means realized by the ECU 30 of the engine control device
of the present modification is calculated by multiplying a value obtained by dividing
a predetermined atmospheric pressure PA0 by the atmospheric pressure PA with the operation
use manifold pressure PMTP. That is, by taking into consideration the change in atmospheric
pressure with respect to the manifold pressure compensation value PMTP' and reflecting
this into the manifold pressure parameter, it is possible to calculate the optimal
manifold pressure compensation value PMTP' for setting the final fuel injection amount
TAU regardless of the change in atmospheric pressure.
[0055] Next, a second modification of the processing routine for operation of the fuel injection
amount in the CPU 31 in the ECU 30 used in the engine control device according to
the second embodiment of the present invention will be explained based on the flow
chart of FIG. 10. Note that this fuel injection amount operation routine is repeatedly
executed by the CPU 31 every predetermined time interval.
[0056] In FIG. 10, step S701 to step S704 correspond to step S501 to step S504 in the above
embodiment, so a detailed description will be omitted. Here, at step S705, the value
obtained by dividing the predetermined atmospheric pressure PAO multiplied with a
predetermined compensation coefficient δ by the atmospheric pressure PA read at step
S702 is multiplied with the operation use manifold pressure PMTP calculated at step
S704 to calculate the manifold pressure compensation value PMTP' by the following
formula (5):
[0057] Next, the routine proceeds to step S706, where the final fuel injection amount TAU
is calculated based on the manifold pressure compensation value PMTP' calculated at
step S705 and the engine speed NE read at step S701 and the routine is ended. Note
that the calculation of the final fuel injection amount TAU using as parameters the
manifold pressure compensation value PMTP' (mmHg) and the engine speed NE (rpm) by
the fuel injection amount operation routine is similar to that of the above embodiment,
so the explanation will be omitted.
[0058] In this way, the manifold pressure compensation value PMTP' in the compensation value
operating means realized by the ECU 30 of the engine control device of the present
modification is calculated by multiplying a value obtained by dividing a predetermined
atmospheric pressure PA0 multiplied with a predetermined compensation coefficient
δ by the atmospheric pressure PA with the operation use manifold pressure PMTP. That
is, by taking into consideration the change in atmospheric pressure with respect to
the manifold pressure compensation value PMTP' and reflecting this into the manifold
pressure parameter, it is possible to calculate the optimal manifold pressure compensation
value PMTP' for setting the final fuel injection amount TAU regardless of the change
in atmospheric pressure.
[0059] Next, a third modification of the processing routine for operation of the fuel injection
amount in the CPU 31 in the ECU 30 used in the engine control device according to
the second embodiment of the present invention will be explained based on the flow
chart of FIG. 11. Note that this fuel injection amount operation routine is repeatedly
executed by the CPU 31 every predetermined time interval.
[0060] In FIG. 11, step S801 to step S804 correspond to step S501 to step S504 in the above
embodiment, so a detailed description will be omitted. Here, at step S805, the value
obtained by multiplying a predetermined compensation coefficient ε with the difference
between the predetermined atmospheric pressure PAO and the atmospheric pressure PA
read at step S802 is added to the operation use manifold pressure PMTP calculated
at step S804 to calculate the manifold pressure compensation value PMTP' by the following
formula (6):
[0061] Next, the routine proceeds to step S806, where the final fuel injection amount TAU
is calculated based on the manifold pressure compensation value PMTP' calculated at
step S805 and the engine speed NE read at step S801 and the routine is ended. Note
that the calculation of the final fuel injection amount TAU using as parameters the
manifold pressure compensation value PMTP' (mmHg) and the engine speed NE (rpm) by
the fuel injection amount operation routine is similar to that of the above embodiment,
so the explanation will be omitted.
[0062] In this way, the manifold pressure compensation value PMTP' in the compensation value
operating means realized by the ECU 30 of the engine control device of the present
modification is calculated by adding a value obtained by multiplying a predetermined
compensation coefficient ε with the difference between the predetermined atmospheric
pressure PAO and atmospheric pressure PA to the operation use manifold pressure PMTP.
That is, by taking into consideration the change in atmospheric pressure with respect
to the manifold pressure compensation value PMTP' and reflecting this into the manifold
pressure parameter, it is possible to calculate the optimal manifold pressure compensation
value PMTP' for setting the final fuel injection amount TAU regardless of the change
in atmospheric pressure.
[0063] Next, a fourth modification of the processing routine for operation of the fuel injection
amount in the CPU 31 in the ECU 30 used in the engine control device according to
the second embodiment of the present invention will be explained with reference to
FIG. 13 based on the flow chart of FIG. 12. Here, FIG. 13 is a map for calculating
by interpolation the predetermined compensation coefficient ζ from the operation use
manifold pressure PMTP and engine speed NE. Note that this fuel injection amount operation
routine is repeatedly executed by the CPU 31 every predetermined time interval.
[0064] In FIG. 12, step S901 to step S904 correspond to step S501 to step S504 in the above
embodiment, so a detailed description will be omitted. Here, at step S905, the map
shown in FIG. 13 is used for calculation of a predetermined compensation coefficient
ζ from the operation use manifold pressure PMTP and engine speed NE by known four-point
interpolation. Next, the routine proceeds to step S906, where the value obtained by
multiplying a predetermined compensation coefficient ζ calculated at step S905 with
the difference between the predetermined atmospheric pressure PAO and the atmospheric
pressure PA read at step S902 is added to the operation use manifold pressure PMTP
calculated at step S904 to calculate the manifold pressure compensation value PMTP'
by the following formula (7):
[0065] Next, the routine proceeds to step S907, where the final fuel injection amount TAU
is calculated based on the manifold pressure compensating value PMTP' calculated at
step S906 and the engine speed NE read at step S901 and the routine is ended. Note
that the calculation of the final fuel injection amount TAU using as parameters the
manifold pressure compensation value PMTP' (mmHg) and the engine speed NE (rpm) by
the fuel injection amount operation routine is similar to that of the above embodiment,
so the explanation will be omitted.
[0066] In this way, the manifold pressure compensation value PMTP' in the compensation value
operating means realized by the ECU 30 of the engine control device of the present
modification is calculated by adding a value obtained by multiplying a predetermined
compensation coefficient ζ with the difference between the predetermined atmospheric
pressure PAO and atmospheric pressure PA to the operation use manifold pressure PMTP.
Further, the predetermined compensation coefficient ζ of the present modification
is calculated using as parameters the operation use manifold pressure PMTP and engine
speed NE. That is, by calculating the optimal compensation coefficient ζ regardless
of the change in atmospheric pressure, taking into consideration the change in atmospheric
pressure with respect to the manifold pressure compensation value PMTP', and reflecting
this into the manifold pressure parameter, it is possible to calculate the optimal
manifold pressure compensation value PMTP' for setting the final fuel injection amount
TAU regardless of the change in atmospheric pressure.
[0067] Note that while the present invention has been described in detail based on specific
embodiments, a person skilled in the art could make various modifications, changes,
etc. within the claims and idea of the present invention.
1. An engine control device provided with:
manifold pressure detecting means for detecting pressure of intake air introduced
into an intake passage of an engine, that is, manifold pressure;
manifold pressure operating means for calculating operation use manifold pressure
for calculating a fuel injection amount of an engine based on manifold pressure detected
by said manifold pressure detecting means;
atmospheric pressure operating means for calculating an atmospheric pressure based
on a manifold pressure detected by said manifold pressure detecting means;
rotational speed detecting means for detecting an engine speed of said engine;
change operating means for calculating the difference between a base atmospheric pressure
and a current atmospheric pressure calculated by said atmospheric pressure operating
means as the change in atmospheric pressure; and
injection amount operating means for calculating a fuel injection amount to be supplied
to said engine using as parameters a manifold pressure compensation value obtained
by adding the change in atmospheric pressure calculated by said change operating means
to said operation use manifold pressure calculated by said manifold pressure operating
means and the engine speed detected by said rotational speed detecting means.
2. An engine control device provided with:
atmospheric pressure detecting means for detecting an atmospheric pressure;
manifold pressure detecting means for detecting pressure of intake air introduced
into an intake passage of an engine, that is, manifold pressure;
manifold pressure operating means for calculating an operation use manifold pressure
for calculating a fuel injection amount of said engine based on a manifold pressure
detected by said manifold pressure detecting means;
rotational speed detecting means for detecting an engine speed of said engine;
change operating means for calculating the difference between a base atmospheric pressure
and a current atmospheric pressure detected by said atmospheric pressure detecting
means as the change in atmospheric pressure; and
injection amount operating means for calculating a fuel injection amount to be supplied
to said engine using as parameters a manifold pressure compensation value obtained
by adding the change in atmospheric pressure calculated by said change operating means
to said operation use manifold pressure calculated by said manifold pressure operating
means and the engine speed detected by said rotational speed detecting means.
3. An engine control device as set forth in claim 1 or 2, wherein said change operating
means multiplies a predetermined compensation coefficient with said difference to
calculate said change in atmospheric pressure
4. An engine control device as set forth in claim 1 or 2, wherein said change operating
means multiplies a predetermined compensation coefficient using a manifold pressure
as a parameter with said difference to calculate said change in atmospheric pressure.
5. An engine control device provided with:
manifold pressure detecting means for detecting a pressure of intake air introduced
into an intake passage of an engine, that is, a manifold pressure;
manifold pressure operating means for calculating an operation use manifold pressure
for calculating a fuel injection amount of an engine based on a manifold pressure
detected by said manifold pressure detecting means;
atmospheric pressure operating means for calculating an atmospheric pressure based
on a manifold pressure detected by said manifold pressure detecting means;
rotational speed detecting means for detecting an engine speed of said engine;
compensation value operating means for compensating the operation use manifold pressure
calculated by said manifold pressure operating means by the atmospheric pressure calculated
by said atmospheric pressure operating means and a predetermined atmospheric pressure
to calculate a manifold pressure compensation value; and
injection amount operating means for calculating a fuel injection amount to be supplied
to said engine using as parameters the manifold pressure compensation value calculated
by said compensation value operating means and the engine speed detected by said rotational
speed detecting means.
6. An engine control device as set forth in claim 5, wherein said manifold pressure compensation
value in said compensation value operating means is calculated by multiplying the
compensation value using as a parameter the atmospheric pressure calculated by said
atmospheric pressure operating means and said compensation value based on a predetermined
atmospheric pressure with said operation use manifold pressure.
7. An engine control device as set forth in claim 5, wherein said manifold pressure compensation
value in said compensation value operating means is calculated by multiplying a value
obtained by dividing said predetermined atmospheric pressure by an atmospheric pressure
calculated by said atmospheric pressure operating means with said operation use manifold
pressure.
8. An engine control device as set forth in claim 5, wherein said manifold pressure compensation
value in said compensation value operating means is calculated by multiplying a value
obtained by dividing said predetermined atmospheric pressure multiplied with a predetermined
compensation coefficient by the atmospheric pressure calculated by said atmospheric
pressure operating means with said operation use manifold pressure.
9. An engine control device as set forth in claim 5, wherein said manifold pressure compensation
value in said compensation value operating means is calculated by adding a value obtained
by multiplying a predetermined compensation coefficient with a difference between
said predetermined atmospheric pressure and the atmospheric pressure calculated by
said atmospheric pressure operating means to said operation use manifold pressure.
10. An engine control device as set forth in claim 8 or 9, wherein said predetermined
compensation coefficient is calculated using as parameters said operation use manifold
pressure and said engine speed.