Title: Control apparatus and method for variable valve
Abstract: A control apparatus controls an electromagnetically driven valve, which includes at least one of an electromagnetically driven exhaust valve for opening or closing an exhaust valve and an electromagnetically driven intake valve for opening or closing an intake valve in an internal combustion engine. The control apparatus is provided with: a first judging device for judging whether or not the electromagnetically driven valve fails in seating for valve-opening; and a fail-safe device for controlling the electromagnetically driven valve to perform an operation of valve-opening again in a same stroke if it is judged by the first judging device that the electromagnetically driven valve fails in the seating for valve-opening.
Patent Number: 6,994,060 Issued on 02/07/2006 to Yoeda
| Inventors:
|
Yoeda; Keiji (Numazu, JP)
|
| Assignee:
|
Toyota Jidosha Kabushiki Kaisha (Toyota, JP)
|
| Appl. No.:
|
867820 |
| Filed:
|
June 16, 2004 |
Foreign Application Priority Data
| Jun 17, 2003[JP] | 2003-172562 |
| Jun 14, 2004[JP] | 2004-175574 |
| Current U.S. Class: |
123/90.11; 123/90.15; 123/90.24; 251/129.01; 251/129.04; 251/129.07; 251/129.1; 251/129.15; 251/129.18; 251/129.19; 701/107 |
| Current Intern'l Class: |
F01L 9/04 (20060101) |
| Field of Search: |
123/9011,9015-9018
701/107
|
References Cited [Referenced By]
U.S. Patent Documents
| 6044814 | Apr., 2000 | Fuwa.
| |
| 6073596 | Jun., 2000 | Kemper.
| |
| 6390039 | May., 2002 | Fuwa.
| |
| 6422185 | Jul., 2002 | Duesmann et al.
| |
| 6435147 | Aug., 2002 | Eichenseher et al.
| |
| 6619245 | Sep., 2003 | Fujiwara et al.
| |
| 6701887 | Mar., 2004 | Salber et al.
| |
| 2003/0188703 | Oct., 2003 | Vanderpoel.
| |
| Foreign Patent Documents |
| A-11-1320/17 | May., 1999 | JP.
| |
| A-11-2942/09 | Oct., 1999 | JP.
| |
Primary Examiner: Denion; Thomas
Assistant Examiner: Riddle; Kyle M.
Attorney, Agent or Firm: Oliff & Berridge, PLC
Claims
What is claimed is:
1. A control apparatus for controlling an electromagnetically driven valve, which
includes at least one of an electromagnetically driven exhaust valve for opening
or closing an exhaust valve and an electromagnetically driven intake valve for
opening or closing an intake valve in an internal combustion engine,
said control apparatus comprising:
a first judging device for judging whether or not the electromagnetically driven
valve fails in seating for valve-opening; and
a fail-safe device for controlling the electromagnetically driven valve to perform
an operation of valve-opening again in a same stroke of the operation of valve-opening
if it is judged by said first judging device that the electromagnetically driven
valve fails in the seating for valve-opening.
2. The control apparatus for controlling an electromagnetically driven valve
according to claim 1, wherein said fail-safe device controls the electromagnetically
driven valve to perform the operation of valve-opening again in the same stroke
after seating for valve-closing if it is judged that the electromagnetically driven
valve fails in the seating for valve-opening.
3. The control apparatus for controlling an electromagnetically driven valve
according to claim 1, wherein said fail-safe device controls the electromagnetically
driven valve to seat for valve-closing at a same valve-closing timing as in a normal
case, after seating again for valve-opening in the same stroke.
4. The control apparatus for controlling an electromagnetically driven valve
according to claim 1, further comprising: a second judging device for judging whether
or not there is time to perform the operation of valve-opening the electromagnetically
driven valve again in the same stroke,
said fail-safe device controlling the electromagnetically driven valve to perform
the operation of valve-opening again in the same stroke only if it is judged that
there is the time.
5. The control apparatus for controlling an electromagnetically driven valve
according to claim 4, further comprising: an engine-revolutions detecting device
for detecting the number of engine revolutions of the internal combustion engine,
said second judging device judging whether or not there is the time on the basis
of the number of engine revolutions detected by said engine-revolutions detecting device.
6. The control apparatus for controlling an electromagnetically driven valve
according to claim 4, wherein said fail-safe device controls at least one of the
electromagnetically driven valve, a fuel injection valve, and an ignition plug
to prohibit at least one of the operation of valve-opening of the electromagnetically
driven valve, and fuel injection and ignition with respect to the internal combustion
engine, until the same stroke in a next cycle, if it is judged that there is no
time to perform the operation of valve-opening again in the same stroke.
7. The control apparatus for controlling an electromagnetically driven valve
according to claim 1, further comprising:
a measuring device for measuring an actual product of an opening area and time
of the electromagnetically driven valve if it is judged that the electromagnetically
driven valve fails in the seating for valve-opening; and
another judging device for judging whether or not the electromagnetically driven
valve is to be prohibited from performing the operation of valve-opening again
in the same stroke or in the same cycle on the basis of the measured actual product
of the opening area and time,
said fail-safe device controlling the electromagnetically driven valve to prohibit
it from opening in the same stroke or in the same cycle and to prohibit it from
opening until the same stroke in a next cycle, only if it is judged that the electromagnetically
driven valve is to be prohibited.
8. The control apparatus for controlling an electromagnetically driven valve
according to claim 7, further comprising: a calculating device for calculating
a target product of the opening area and time on the basis of required torque of
the internal combustion engine,
said another judging device judging that the electromagnetically driven intake
valve is to be prohibited from performing the operation of valve-opening in the
same cycle, in such a condition that the measured actual product of the opening
area and time of the electromagnetically driven exhaust valve is less than the
calculated target product of the opening area and time.
9. The control apparatus for controlling an electromagnetically driven valve
according to claim 7, wherein said fail-safe device controls at least one of the
electromagnetically driven valve, a fuel injection valve, and an ignition plug
to prohibit at least one of the operation of valve-opening of the electromagnetically
driven valve, and fuel injection and ignition with respect to the internal combustion
engine, until the same stroke in a next cycle, if it is judged that the electromagnetically
driven valve is not to be prohibited.
10. The control apparatus for controlling an electromagnetically driven valve
according to claim 1, wherein said fail-safe device further controls at least one
of the electromagnetically driven valve, a fuel injection valve, and an ignition
plug to prohibit at least one of an operation of valve-opening of the electromagnetically
driven valve, and fuel injection and ignition with respect to the internal combustion
engine, until a same stroke in a next cycle of the operation of valve-opening,
if it is judged that the electromagnetically driven valve fails in the seating
for valve-opening.
11. The control apparatus for controlling an electromagnetically driven valve
according to claim 10, wherein said fail-safe device further controls the fuel
injection valve and the ignition plug to allow the fuel injection and prohibit
the ignition in the same cycle, and to prohibit the fuel injection and perform
the ignition in the next cycle, if the fuel injection is started in the same stroke
in which the fail is occurred in the same cycle.
12. A variable valve mechanism for controlling a variable valve, which includes
at least one of a variable exhaust valve for opening or closing an exhaust valve
and a variable intake valve for opening or closing an intake valve in an internal
combustion engine,
said variable valve mechanism comprising:
a first judging device for judging whether or not the variable valve fails in
seating for valve-opening; and
a fail-safe device for controlling the variable valve to perform an operation
of valve-opening again in a same stroke of the operation of valve-opening if it
is judged by said first judging device that the variable valve fails in the seating
for valve-opening.
13. A control method of controlling an electromagnetically driven valve, which
includes at least one of an electromagnetically driven exhaust valve for opening
or closing an exhaust valve and an electromagnetically driven intake valve for
opening or closing an intake valve in an internal combustion engine,
said control method comprising:
a first judging process of judging whether or not the electromagnetically driven
valve fails in seating for valve-opening; and
a fail-safe process of controlling the electromagnetically driven valve to perform
an operation of valve-opening again in a same stroke of the operation of valve-opening
if the electromagnetically driven valve fails in seating for valve-opening.
14. The control method of controlling an electromagnetically driven valve according
to claim 13, wherein said fail-safe process further controls at least one of the
electromagnetically driven valve, a fuel injection valve, and an ignition plug
to prohibit at least one of an operation of valve-opening of the electromagnetically
driven valve, and fuel injection and ignition with respect to the internal combustion
engine, until a same stroke in a next cycle of the operation of valve-opening,
if it is judged that the electromagnetically driven valve fails in the seating
for valve-opening.
15. A control method of controlling a variable valve mechanism for controlling
a variable valve, which includes at least one of a variable exhaust valve for opening
or closing an exhaust valve and a variable intake valve for opening or closing
an intake valve in an internal combustion engine,
said control method comprising:
a first judging process of judging whether or not the variable valve fails in
seating for valve-opening; and
a fail-safe process of controlling the variable valve to perform an operation
of valve-opening again in a same stroke of the operation of valve-opening if the
variable valve fails in seating for valve-opening.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a variable valve which functions as an intake
valve or an exhaust valve of an internal combustion engine mounted on a vehicle
or the like. More specifically, the present invention relates to a control apparatus
for and a control method of controlling an electromagnetically driven valve to
perform fail-safe processing if abnormality occurs in the electromagnetically driven valve.
2. Description of the Related Art
Conventionally, the electromagnetically driven valve is provided
with: a valve body which functions as the intake valve or the exhaust valve of
the internal combustion engine; and a movable needle which is connected to the
valve body and which displaces in the axial direction of the valve body. Hereinafter,
the valve body and the movable needle are referred to as a "movable portion", as
occasion demands. The exhaust valve or the intake valve can be opened and closed
any time (i) by supplying an exciting current to an electromagnetic coil for valve-closing
or an electromagnetic coil for valve-opening at an appropriate timing, thereby
to generate an electromagnetic power, in order to suction the movable needle which
is held at a middle position by the elastic force or applied force of a spring,
and (ii) by displacing the movable portion to the side of the electromagnetic coil
for valve-closing or the side of the electromagnetic coil for valve-opening.
For example, Japanese Patent Application Laying Open NO. 2002-81329 discloses
a technique of controlling the electromagnetically driven valve to supply a proper
exciting current to the electromagnetic coil for valve-closing and the electromagnetic
coil for valve-opening, in order to properly and surely move or displace the valve
body between a fully closed position (i.e., a condition of "seating for valve-closing")
and a fully opened position (i.e., a condition of "seating for valve-opening")
of the electromagnetically driven valve. However, it can be assumed that an operation
of valve-opening or an operation of valve-closing does not succeed completely or
perfectly, (i) from a cause by a change with the passage of time, such as a change
in mass of the movable portion and a change in a friction force by the wear of
the spring, by the accumulation of deposits onto the movable portion, by abrasion,
or the like, and (ii) from an unexpected or sudden cause, such as a reading error
of a lift sensor and a foreign body stuck between the valve body and a valve seat.
For example, Japanese Patent Application Laying Open NO. Hei 11-132017 discloses
a technique of preventing the step-out of the valve body by increasing an electromagnetic
force which suctions the movable portion in the displacement direction by supplying
the exciting current to the electromagnetic coil if a deviation between a detected
displacement amount of the electromagnetically driven valve and a desired displacement
amount is greater than or equal to a threshold value. Here, the "step-out" is such
a phenomenon that the valve body of the electromagnetically driven valve is held
at a neutral position while the valve opening or closing of the electromagnetically
driven valve is driven and that the valve opening or closing cannot be normally driven.
For example, Japanese Patent Application Laying Open NO. 2001-159331 discloses
a fail-safe technique of controlling the electromagnetically driven valve to maintain
it in the fully closed position by increasing an exciting current amount of the
electromagnetic coil for valve-closing, thereby to close the valve, if the electromagnetically
driven valve is opened and fails in seating for valve-opening. There is another
technique disclosed in Japanese Patent Application Laying Open NO. Hei 11-294209.
However, it is impossible to attain such fail-safe processing that a pressure
condition and a combustion condition or the like in a cylinder obtained after the
electromagnetically driven valve is maintained in the fully closed position are
considered, only by controlling the electromagnetically driven valve by the conventional
fail-safe technique for the electromagnetically driven valve, which is disclosed
in the above-described Japanese Patent Application Laying Open NO. 2001-159331
or the like, so as to maintain it again in the fully closed position if the electromagnetically
driven valve fails in the seating for valve-opening. This possibly causes the reduction
of exhaust efficiency, the reduction of filling efficiency for an intake air, the
step-out of the electromagnetically driven valve, or the like, and eventually causes
a decrease in the output of the internal combustion engine, the deterioration of
exhaust emissions, or the like, which is a technical problem.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a control apparatus
for and a control method of controlling a variable valve, by which it is possible
to reduce the influence of failure or abnormality even if the failure or the abnormality
occurs in the operation of valve-opening and the operation of valve-closing of
the electromagnetically driven valve, for example.
The main purpose of the present invention is to inhibit the reduction of the
intake efficiency, in addition to or in place of the exhaust efficiency, by opening
the variable valve again in the same stroke in consideration of, e.g., the number
of engine revolutions in the internal combustion engine, a valve-opening speed
of the variable valve, and further an actual product of the opening area and time
of the variable valve or the like, if the variable valve fails in the seating for
valve-opening in the technique of controlling the variable valve. The failure in
the seating for valve-opening and valve-closing include any situation which causes
abnormal valve-opening and valve-closing operation.
The above object of the present invention can be achieved by a first control
apparatus for controlling an electromagnetically driven valve, which includes at
least one of an electromagnetically driven exhaust valve for opening or closing
an exhaust valve and an electromagnetically driven intake valve for opening or
closing an intake valve in an internal combustion engine, the control apparatus
provided with: a first judging device for judging whether or not the electromagnetically
driven valve fails in seating for valve-opening; and a fail-safe device for controlling
the electromagnetically driven valve to perform an operation of valve-opening again
in a same stroke of the operation of valve-opening if it is judged by the first
judging device that the electromagnetically driven valve fails in the seating for valve-opening.
According to the first control apparatrs for controlling an electromagnetically
driven valve, in the normal operation thereof, specifically, an intake air amount
is adjusted by that at least one of the electromagnetically driven exhaust valve
and the electromagnetically driven intake valve which is opened and closed at a
proper timing according to the number of engine revolutions of the internal combustion
engine. More specifically, the valve-opening of the electromagnetically driven
valve inclides: releasing it from the fully closed position (release for valve-closing);
and seating it to the fully opened position (seating for valve-opening). On the
other hand, the valve-closing of the electromagnetically driven valve includes:
releasing it from the fully opened position (release for valve-opening); and seating
it to the fully closed position (seating for valve-closing).
For example, if the electromagnetically driven valve fails in the seating for
valve-opening, the failure in the seating for valve-opening is judged by the first
judging device. Specifically, the first judging device judges or determines whether
or not the electromagnetically driven valve fails in seating for valve-opening
on the basis of an output of the detection by a lift sensor directly mounted on
the electromagnetically driven valve, for example. Alternatively, it may indirectly
determine whether or not the electromagnetically driven valve fails in seating
for valve-opening, on the basis of an output of the detection by other sensors
for measuring an exciting current amount of the electromagnetically driven valve
or the like.
For example, if the number of engine revolutions is relatively low (low-speed
revolutions), and if it is judged by the first judging device that the electromagnetically
driven valve fails in seating for valve-opening, the electromagnetically driven
valve is controlled to perform the operation of valve-opening again in the same
stroke, under the control of the fail-safe device. Incidentally, the "stroke" associated
with the present invention means each of an exhaust stroke, an intake stroke, a
compression stroke, and a combustion (expansion) stroke in the internal combustion engine.
In the present invention, in an abnormal case, the opening/closing characteristics
of the exhaust valve and the intake valve are controlled, under the control of
the "fail-safe device", the "first judging device", a "second judging device",
a "third judging device", a "measuring device for measuring an actual product of
the opening area and time", a "calculating device for calculating a target product
of the opening area and time", which are described later, for example. In a normal
case, they are controlled under the control of at least one of the "electromagnetically
driven exhaust valve" and the "electromagnetically driven intake valve". These
constituent elements may be constructed from the same controller (e.g. an ECU described
later) or the same control device which is capable of performing both the control
in the abnormal case and the control in the normal case. Alternatively, they may
be constructed from different exclusive controllers or different control devices,
each of which is capable of performing respective one of the control in the abnormal
case and the control in the normal case.
In general, the exhaust efficiency by the exhaust valve and the intake efficiency
by the intake valve, i.e., charging efficiency is influenced by three factors,
which are the valve-opening timing, the valve-closing timing, and the actual product
of the opening area and time of the exhaust valve and the intake valve. Here, the
"actual product of the opening area and time" is a measured quantity calculated
by multiplying a time length in which the electromagnetically driven valve is actually
open and a valve lift amount. Qualitatively, in the case of the actual product
of the opening area and time of the exhaust valve, it means the degree of completion
of the exhaust stroke and is substantially in inverse proportion to the amount
of burned gas remained in the cylinder. Specifically, if the actual product of
the opening area and time of the electromagnetically driven exhaust valve is large,
the exhaust efficiency increases, and the amount of burned gas remained in the
cylinder decreases. On the other hand, if the actual product of the opening area
and time of the electromagnetically driven exhaust valve is small, the exhaust
efficiency decreases, and the amount of burned gas remained in the cylinder increases.
Moreover, qualitatively, in the case of the actual product of the opening area
and time of the intake valve, it means the degree of completion of the intake stroke
and is substantially proportional to the amount of burned gas remained in the cylinder.
Specifically, if the actual product of the opening area and time of the electromagnetically
driven intake valve is large, the intake efficiency increases, and the amount of
air inhaled into the cylinder increases. On the other hand, if the actual product
of the opening area and time of the electromagnetically driven intake valve is
small, the intake efficiency decreases, and the amount of air inhaled into the
cylinder decreases. Particularly, for example, if the number of engine revolutions
is relatively low (low-speed revolutions), the actual product of the opening area
and time is sufficiently secured, so that the exhaust efficiency and the intake
efficiency are influenced the most by the valve-closing timing of the exhaust valve
and the intake valve.
Particularly in the present invention, in order to match the valve-closing
timing of the exhaust valve and the intake valve with the valve-closing timing
in the normal case, if the electromagnetically driven valve fails in the seating
for valve-opening, the electromagnetically driven valve is opened again in the
same stroke, thereby to seat it for valve-opening, under the control of the fail-safe
device. By this, it is possible to reduce a bad influence on a next stroke by the
failure in the seating for valve-opening of the electromagnetically driven valve,
and it is possible to inhibit the reduction the intake efficiency in addition to
or in place of the exhaust efficiency.
Thus, it is possible to inhibit a cylinder pressure from increasing and being
a higher pressure than an intake-port pressure by inhibiting the increase in the
amount of burned gas remained in the cylinder, which is caused by the reduction
of the exhaust efficiency. Therefore, in the next intake stroke, it is possible
to prevent the elctromagnetically driven intake valve from receiving a pressure
from the inside of the cylinder in the direction against the valve-opening of the
electromagnetically driven intake valve and from failing in the seating for valve-opening
or from stepping out. Moreover, it is possible to prevent the burned gas from back-flowing
to an intake system when the electromagnetically driven intake valve is opened
in the intake stroke, and it is possible to inhibit the reduction of the intake
efficiency, by inhibiting the increase in the amount of burned gas remained in
the cylinder, which is caused by the reduction of the exhaust efficiency.
On the other hand, with respect to the intake efficiency, it is possible to inhibit
the decrease in the output of the internal combustion engine, which is caused by
that the air/fuel mixture of an appropriate amount of new air and fuel is not taken
in the cylinder, thereby causing improper combustion, because of the reduction
of the intake efficiency. In addition, it is possible to inhibit the increase in
an intake pump loss. Moreover, it is possible to prevent the intake air amount
from being insufficient, the air/fuel ratio from decreasing, and the inside of
the cylinder from being in an excessive rich condition, because of the reduction
intake efficiency. Therefore, it is possible to prevent the occurrence of an accidental
fire in the cylinder, and it is possible to prevent the air/fuel mixture including
a large amount of unburned fuel, in other words, raw gas, from being exhausted
without sufficient purification by a catalyst or the like. Thus, it is possible
to inhibit deterioration of the exhaust emissions.
As described above, according to the first control apparatus for controlling
an
electromagnetically driven valve, it is possible to inhibit the reduction of the
intake efficiency, in addition to or in place of the exhaust efficiency, by opening
the electromagnetically driven valve again in the same stroke if the electromagnetically
driven valve fails in the seating for valve-opening.
In one aspect of the first control apparatus for controlling an electromagnetically
driven valve of the present invention, the fail-safe device controls the electromagnetically
driven valve to perform the operation of valve-opening again in the same stroke
after seating for valve-closing if it is judged that the electromagnetically driven
valve fails in the seating for valve-opening.
According to this aspect, the electromagnetically driven exhaust valve
and the electromagnetically driven intake valve are opened again and seated for
valve opening after they are seated for valve-closing in the same stroke in order
to substantially match the valve-closing timing, which influences the exhaust efficiency
and the intake efficiency the most, with the valve-closing timing in the normal
case, under the control of the fail-safe device. Therefore, it is possible to inhibit
the reduction of the intake efficiency, in addition to or in place of the exhaust efficiency.
In another aspect of the first control apparatus for controlling an electromagnetically
driven valve of the present invention, the fail-safe device controls the electromagnetically
driven valve to seat for valve-closing at a same valve-closing timing as in a normal
case, after seating again for valve-opening in the same stroke.
According to this aspect, the valve-closing timing of the electromagnetically
driven exhaust valve and the electromagnetically driven intake valve, which influences
the exhaust efficiency and the intake efficiency the most, is brought close to
the valve-closing timing in the normal case, under the control of the fail-safe
device. Therefore, it is possible to inhibit the reduction of the intake efficiency,
in addition to or in place of the exhaust efficiency.
In another aspect of the first control apparatus for controlling an electromagnetically
driven valve of the present invention, it is further provided with: a second judging
device for judging whether or not there is time to perform the operation of valve-opening
the electromagnetically driven valve again in the same stroke, the fail-safe device
controlling the electromagnetically driven valve to perform the operation of valve-opening
again in the same stroke only if it is judged that there is the time.
According to this aspect, it is possible to perform the control by the
fail-safe device more accurately by opening again the electromagnetically driven
exhaust valve and the electromagnetically driven intake valve with time as a reference.
Therefore, it is possible to inhibit the reduction of the intake efficiency, in
addition to or in place of the exhaust efficiency.
In an aspect associated with the second judging device, the first control apparatus
may be further provided with: an engine-revolutions detecting device for detecting
the number of engine revolutions of the internal combustion engine, the second
judging device judging whether or not there is the time on the basis of the number
of engine revolutions detected by the engine-revolutions detecting device.
By constituting in this manner, the second judging device is relatively easily
capable of judging whether or not there is time to seat the electromagnetically
driven valve for valve-opening again in the same stroke. For example, the second
judging device may be constructed to directly compare the number of engine revolutions
with the number of engine revolutions set in advance as being a predetermined threshold
value. Alternatively, it may be constructed to calculate the remaining time in
the same stroke from the number of engine revolutions or from both the number of
engine revolutions and a time point of the failure in the seating for valve-opening,
and to compare the remaining time with a time length for valve opening or closing
set in advance as being a predetermined threshold value. The "number of engine
revolutions set in advance as being a predetermined threshold value" is calculated
by using a time length required for the valve-opening and valve-closing of the
electromagnetically driven valve which is the performance of the electromagnetically
driven valve, and an operating angle, as parameters.
In an aspect of the fail-safe device, the fail-safe device controls at least
one
of the electromagnetically driven valve, a fuel injection valve, and an ignition
plug to prohibit at least one of the operation of valve-opening of the electromagnetically
driven valve, and fuel injection and ignition with respect to the internal combustion
engine, until the same stroke in a next cycle, if it is judged that there is no
time to perform the operation of valve-opening again in the same stroke.
By constituting in this manner, it is possible to omit the ineffective operation
of valve-opening of the electromagnetically driven valve, and the excessive fuel
injection and the ineffective ignition in the cylinder which is inappropriate condition
for combustion. Thus, it is possible to suppress the influence of the failure in
the seating for valve-opening on the next cycle, and it is possible to perform
the operation of valve-opening of the electromagnetically driven valve, the fuel
injection, and the ignition, in the next cycle in the same manner as in the normal case.
In another aspect of the first control apparatus for controlling an electromagnetically
driven valve of the present invention, it is further provided with: a measuring
device for measuring an actual product of an opening area and time of the electromagnetically
driven valve if it is judged that the electromagnetically driven valve fails in
the seating for valve-opening; and a third judging device for judging whether or
not the electromagnetically driven valve is to be prohibited from perform the operation
of valve-opening again in the same stroke or in the same cycle on the basis of
the measured actual product of the opening area and time, the fail-safe device
controlling the electromagnetically driven valve to prohibit it from opening in
the same stroke or in the same cycle and to prohibit it from opening until the
same stroke in a next cycle, only if it is judged that the electromagnetically
driven valve is to be prohibited.
According to this aspect, for example, even if the number of engine revolution
is relatively high (high-speed revolutions), it is judged by the third judging
device how considerably the amount of burned gas remained in the cylinder influences
the operation of valve-opening of the electromagnetically driven valve, after the
exhaust stroke, on the basis of the directly measured actual product of the opening
area and time of the electromagnetically driven valve. Only if the influence is
considerable, it is possible to prohibit the electromagnetically driven valve from
opening again in the same stroke and to prohibit it from opening in the same cycle,
i.e. until the exhaust stroke in the next cycle. Thus, it is possible to realize
the control by the fail-safe device more appropriately.
In an aspect associated with the third judging device, the first control apparatus
may be further provided with: a calculating device for calculating a target product
of the opening area and time on the basis of required torque of the internal combustion
engine, the third judging device judging that the electromagnetically driven intake
valve is to be prohibited from perform the operation of valve-opening in the same
cycle, in such a condition that the measured actual product of the opening area
and time of the electromagnetically driven exhaust valve is less than the calculated
target product of the opening area and time.
By constituting in this manner, it is possible to calculate the target product
of the opening area and time relatively easily and quickly by the calculating device
for calculating a target product of the opening area and time. If the actual product
of the opening area and time of the electromagnetically driven exhaust valve is
less than the target product of the opening area and time, the pressure in the
cylinder is high and the electromagnetically driven intake valve highly possibly
fails in the seating for valve-opening even if opened. Thus, the electromagnetically
driven valve is controlled so as to prohibit the valve-opening of the electromagnetically
driven intake valve in the same cycle.
Here, the "target product of the opening area and time" is, in the case of
the electromagnetically driven exhaust valve, an actual product of the opening
area and time of the electromagnetically driven exhaust valve minimally required
for the valve-opening against the cylinder pressure, which is proportional to the
amount of burned gas remained in the cylinder without being exhausted. On the other
hand, in the case of the electromagnetically driven intake valve, it is an actual
product of the opening area and time of the electromagnetically driven intake valve
minimally required to allow the ignition and combustion of the air/fuel mixture
of fuel and new air inhaled into the cylinder by the electromagnetically driven
intake valve. In any case, the target product of the opening area and time is a
reference value determined with both the number of engine revolutions and an engine
load for indicating the torque to the internal combustion engine, as parameters.
Incidentally, the engine load is proportional to an initial amount of the burned gas.
In an aspect associated with the fail-safe device, the fail-safe device may controls
at least one of the electromagnetically driven valve, a fuel injection valve, and
an ignition plug to prohibit at least one of the operation of valve-opening of
the electromagnetically driven valve, and fuel injection and ignition with respect
to the internal combustion engine, until the same stroke in a next cycle, if it
is judged that the electromagnetically driven valve is not to be prohibited.
By constituting in this manner, it is possible to omit the ineffective operation
of valve-opening of the electromagnetically driven valve, and the excessive fuel
injection and the ineffective ignition in the cylinder which is inappropriate condition
for combustion. Thus, it is possible to perform the operation of valve-opening
of the electromagnetically driven valve, the fuel injection, and the ignition,
in the next cycle in the same manner as in the normal case almost without having
almost any influence of the failure in the seating for valve-opening on the next cycle.
The above object of the present invention can be achieved by a second control
apparatus for controlling an electromagnetically driven valve, which includes at
least one of an electromagnetically driven exhaust valve for opening or closing
an exhaust valve and an electromagnetically driven intake valve for opening or
closing an intake valve in an internal combustion engine, the control apparatus
provided with: a first judging device for judging whether or not the electromagnetically
driven valve fails in seating for valve-opening; and a fail-safe device for controlling
at least one of the electromagnetically driven valve, a fuel injection valve, and
an ignition plug to prohibit at least one of an operation of valve-opening of the
electromagnetically driven valve, and fuel injection and ignition with respect
to the internal combustion engine, until a same stroke in a next cycle of the operation
of valve-opening, if it is judged that the electromagnetically driven valve fails
in the seating for valve-opening.
According to the second control apparatus for controlling an electromagnetically
driven valve of the present invention, it operates as with the above-described
first control apparatus for controlling an electromagnetically driven valve, in
the normal operation thereof.
For example, if the electromagnetically driven exhaust valve fails in the seating
for valve-opening, at least one of the operation of valve-opening of the electromagnetically
driven intake valve, and the fuel injection and the ignition with respect to the
internal combustion engine, is prohibit until the same stroke in the next cycle,
under the control of the fail-safe device.
For example, if fuel is not injected yet in the intake port in the same cycle
upon the judgment by the first judging device, the fuel injection and the ignition
are prohibited in the same cycle in advance, under the control of the fail-safe
device. In the next cycle, the operation of valve-opening of the electromagnetically
driven exhaust valve, the fuel injection, and the ignition are performed in the
same manner as in the normal case. On the other hand, if the fuel is already injected
in the same cycle upon the judgment by the first judging device, the fuel injection
is continued and is not stopped halfway, under the control of the fail-safe device.
Since the fuel for burning one time drifts in the intake port, the fuel injection
in the next cycle is prohibited.
As described above, according to the second control apparatus for controlling
an electromagnetically driven valve of the present invention, if the electromagnetically
driven valve fails in the seating for valve-opening, it is possible to omit the
ineffective operation of valve-opening of the electromagnetically driven valve,
and the excessive fuel injection and the ineffective ignition in the cylinder which
is inappropriate condition for combustion. Thus, it is possible to suppress the
influence of the failure in the seating for valve-opening on the next cycle, and
it is possible to perform the operation of valve-opening of the electromagnetically
driven valve, the fuel injection, and the ignition, in the next cycle in the same
manner as in the normal case. Thus, it is possible to inhibit the reduction the
intake efficiency in addition to or in place of the exhaust efficiency.
In one aspect of the second control apparatus for controlling an electromagnetically
driven valve of the present invention, the fail-safe device controls the fuel injection
valve and the ignition plug to allow the fuel injection and prohibit the ignition
in the same cycle, and to prohibit the fuel injection and perform the ignition
in the next cycle, if the fuel injection is started in the same stroke in the same cycle.
According to this aspect, if fuel is already injected in the same cycle
upon the judgment by the first judging device, the fuel injection is continued
and is not stopped halfway, and the ignition is prohibited, under the control of
the fail-safe device. Since the fuel for burning one time drifts in the intake
port, the fuel injection in the next cycle is prohibited and the ignition is performed.
In this case, since the fuel injection is already started, the fuel injection valve
are controlled so as not to prohibit the fuel injection without exception, regardless
of whether the fuel injection is completed or halfway. Namely, the fuel injected
by the fuel injection is used in the next cycle. Thus, the failure in the seating
for valve-opening of the electromagnetically driven valve hardly or does not influence
the next cycle at all.
The above object of the present invention can be achieved by a variable valve
mechanism for controlling a variable valve, which includes at least one of a variable
exhaust valve for opening or closing an exhaust valve and a variable intake valve
for opening or closing an intake valve in an internal combustion engine, the variable
valve mechanism provided with: a first judging device for judging whether or not
the variable valve fails in seating for valve-opening; and a fail-safe device for
controlling the variable valve to perform an operation of valve-opening again in
a same stroke of the operation of valve-opening if it is judged by said first judging
device that the variable valve fails in the seating for valve-opening.
According to the variable valve mechanism for controlling a variable valve,
in the normal operation thereof, specifically, an intake air amount is adjusted
by that at least one of the variable exhaust valve and the variable intake valve
which is opened and closed at a proper timing according to the number of engine
revolutions of the internal combustion engine. More specifically, the variable
valve mechanism can change a correlation of a phase of the cam and at least one
of a lift amount and an operating angle of the valve.
As described above, according to the variable valve mechanism for controlling
a variable valve, as with the above-described first control device for controlling
an electromagnetically driven valve of the present invention, it is possible to
inhibit the reduction of the intake efficiency, in addition to or in place of the
exhaust efficiency, by opening the variable valve again in the same stroke if the
variable valve fails in the seating for valve-opening.
The above object of the present invention can be achieved by a first control
method of controlling an electromagnetically driven valve, which includes at least
one of an electromagnetically driven exhaust valve for opening or closing an exhaust
valve and an electromagnetically driven intake valve for opening or closing an
intake valve in an internal combustion engine, the control method provided with:
a first judging process of judging whether or not the electromagnetically driven
valve fails in seating for valve-opening; and a fail-safe process of controlling
the electromagnetically driven valve to perform an operation of valve-opening again
in a same stroke of the operation of valve-opening if the electromagnetically driven
valve fails in seating for valve-opening.
According to the first control method of controlling an electromagnetically
driven valve, as with the above-described first control device for controlling
an electromagnetically driven valve of the present invention, for example, it is
possible to reduce a bad influence on the next stroke by the failure in the seating
for valve-opening of the electromagnetically driven valve and it is possible to
inhibit the reduction of the intake efficiency, in addition to or in place of the
exhaust efficiency, by opening the electromagnetically driven valve again in the
same stroke if the electromagnetically driven valve fails in the seating for valve-opening.
The above object of the present invention can be achieved by a second control
method of controlling an electromagnetically driven valve, which includes at least
one of an electromagnetically driven exhaust valve for opening or closing an exhaust
valve and an electromagnetically driven intake valve for opening or closing an
intake valve in an internal combustion engine, the control method provided with:
a first judging process of judging whether or not the electromagnetically driven
valve fails in seating for valve-opening; and a fail-safe process of controlling
at least one of the electromagnetically driven valve, a fuel injection valve, and
an ignition plug to prohibit at least one of an operation of valve-opening of the
electromagnetically driven valve, and fuel injection and ignition with respect
to the internal combustion engine, until a same stroke in a next cycle of the operation
of valve-opening, if the electromagnetically driven valve fails in seating for valve-opening.
According to the second control method of controlling an electromagnetically
driven valve, as with the above-described second control device for controlling
an electromagnetically driven valve of the present invention, if the electromagnetically
driven valve fails in the seating for valve-opening, it is possible to omit the
ineffective operation of valve-opening of the electromagnetically driven valve,
and the excessive fuel injection and the ineffective ignition in the cylinder which
is inappropriate condition for combustion. Thus, it is possible to suppress the
influence of the failure in the seating for valve-opening on the next cycle, and
it is possible to perform the operation of valve-opening of the electromagnetically
driven valve, the fuel injection, and the ignition, in the next cycle in the same
manner as in the normal case. Thus, it is possible to inhibit the reduction the
intake efficiency in addition to or in place of the exhaust efficiency.
The above object of the present invention can be achieved by a control method
of controlling a variable valve mechanism for controlling a variable valve, which
includes at least one of a variable exhaust valve for opening or closing an exhaust
valve and a variable intake valve for opening or closing an intake valve in an
internal combustion engine, the control method provided with: a first judging process
of judging whether or not the variable valve fails in seating for valve-opening;
and a fail-safe process of controlling the variable valve to perform an operation
of valve-opening again in a same stroke of the operation of valve-opening if the
variable valve fails in seating for valve-opening.
According to the control method of controlling a variable valve, as with
the above-described variable valve mechanism for controlling a variable valve of
the present invention, for example, it is possible to reduce a bad influence on
the next stroke by the failure in the seating for valve-opening of the variable
valve and it is possible to inhibit the reduction of the intake efficiency, in
addition to or in place of the exhaust efficiency, by opening the variable valve
again in the same stroke if the variable valve fails in the seating for valve-opening.
The nature, utility, and further features of this invention will be more clearly
apparent from the following detailed description with reference to preferred embodiments
of the invention when read in conjunction with the accompanying drawings briefly
described below.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross sectional view schematically showing a control apparatus for
controlling an electromagnetically driven valve and an internal combustion engine
in an embodiment.
FIG. 2 is a cross sectional view schematically showing the electromagnetically
driven valve associated with the embodiment and an Electronic Control Unit (ECU)
for controlling the electromagnetically driven valve;
FIG. 3 is a conceptual diagram showing (i) the ECU for controlling the electromagnetically
driven valves associated with the embodiment, (ii) various sensors for inputting
various detection signals and parameters to the ECU, and (iii) various valves controlled
by the ECU or the like;
FIG. 4A to FIG. 4C are characteristic diagrams showing a valve lift amount and
an operating angle with respect to a crank angle, in the normal case or the like
of the electromagnetically driven valves of first fail-safe processing associated
with the embodiment;
FIG. 5 is a flowchart showing a first fail-safe processing routine associated
with the embodiment;
FIG. 6A to FIG. 6C are characteristic diagrams showing a cylinder pressure with
respect to the crank angle, in the normal case or the like associated with the embodiment;
FIG. 7 is a parameter table for determining a target product "A2" of the opening
area and time, which is a criterion for judgment or determination in second fail-safe
processing associated with the embodiment;
FIG. 8 is a flowchart showing a second fail-safe processing routine associated
with the embodiment;
FIG. 9A to FIG. 9C are characteristic diagrams showing the valve lift amount
and the operating angle with respect to the crank angle, in the normal case or
the like of the electromagnetically driven valves associated with the embodiment;
FIG. 10 is a flowchart showing a third fail-safe processing routine associated
with the embodiment;
FIG. 11A and FIG. 11B are characteristic diagrams showing the valve lift amount
and the operating angle with respect to the crank angle, in the normal case or
the like of the electromagnetically driven valves associated with the embodiment;
FIG. 12 is a flowchart showing a fourth fail-safe processing routine associated
with the embodiment;
FIG. 13 is a schematic diagram showing the structure and operation of one specific
example of a variable valve mechanism of the present invention;
FIG. 14 is a schematic diagram showing the structure and operation of a valve-characteristics
adjusting mechanism of another specific example of a variable valve mechanism of
the present invention as viewed from further another direction;
FIG. 15 is a schematic diagram showing the structure and operation of a valve-characteristics
adjusting mechanism of another specific example of a variable valve mechanism of
the present invention; and
FIG. 16 is a partially cut-away schematic diagram showing the structure and
operation of a valve-characteristics adjusting mechanism of another specific example
of a variable valve mechanism of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The specific embodiment of the control apparatus for controlling an electromagnetically
driven valve associated with the present invention will be explained below with
reference to the drawings.
Firstly, the structures and the operations of the internal combustion engine
and the control apparatus for controlling the electromagnetically driven valve
in the embodiment will be explained with reference to FIG. 1 to FIG. 3. FIG. 1
schematically shows the control apparatus for controlling the electromagnetically
driven valve and the internal combustion engine.
An internal combustion engine
100 associated with the embodiment shown
in FIG. 1 is a gasoline internal combustion engine of a water-cooled type of the
four-stroke-cycles which is fueled by gasoline and which is mounted on a vehicle,
such as an automobile, and is a port-injection-type internal combustion engine
for injecting fuel into a cylinder
110 from an intake port
140. Moreover,
the internal combustion engine
100 associated with the embodiment has a
layout having a plurality of cylinders
110. Each of the cylinders
110
is provided with: a fuel injection valve
145; an ignition plug
165;
or the like, which will be described later. Incidentally, FIG. 1 shows one cylinder
out of the plurality of cylinders, for convenience of explanation.
Particularly, in the internal combustion engine
100 provided
with the electromagnetically driven valves, an intake air amount is continuously
adjusted, from low-speed revolutions to high-speed revolutions, according to the
individual number of revolutions, and a fuel injection amount is controlled according
to the adjusted intake air amount and the detected number of engine revolutions.
As described above, the intake air amount is adjusted or controlled by optimally
adjusting the opening/closing characteristics of the electromagnetically driven
valves according to operational conditions, such as the number of engine revolutions,
the desired torque or the load, for example, and the normal operation of the internal
combustion engine is performed. Here, the "opening/closing characteristics" are
the operation of valve-opening and the operation of valve-closing of the electromagnetically
driven valves, the valve opening or closing timing, the valve lift amount, or the
valve lift amount and the valve lift period (the operating angle).
In FIG. 1, the internal combustion engine
100 is provided with: an Electronic
Control Unit (ECU)
10; a crank angle sensor
125; the ignition plug
165; a lift sensor
202; a lift sensor
212; and elements in
the intake system and elements in the exhaust system, which will be described later.
In FIG. 1, the intake system of the internal combustion engine
100 is
constructed
such that the air inhaled from a not-illustrated air duct for taking in the outside
air, through an airflow meter
220 and an electronic control throttle valve
240 with a throttle position sensor
230, flows from an intake tube
250 to a surge tank
260, which has a function of preventing an intake
pulse, and further flows through an intake port
140, which is provided with
the fuel injection valve
145, to a combustion chamber
160, which
is constructed from a bottom surface of a cylinder head
130, a top surface
of a piston
120, and side walls of the cylinder
110. Incidentally,
a valve body
201a and a valve seat (for intake)
170 of an
electromagnetically driven intake valve
200, which function as an intake
valve
201 for opening or closing the intake port
140, are disposed
at an opening end portion on the combustion chamber
160 side of the intake
port
140.
On the other hand, the exhaust system of the internal combustion engine
100
is constructed such that exhaust gases are emitted from the combustion chamber
160 in the cylinder
110 through an exhaust port
150, an exhaust
tube, an exhaust gas purification catalyst, and a muffler, which are not illustrated,
to the air. A valve body
211a and a valve seat (for exhaust)
180
of an electromagnetically driven exhaust valve
210, which function as an
exhaust valve
211 for opening or closing the exhaust port
150, are
disposed at an opening end portion on the combustion chamber
160 side of
the exhaust port
150
The up-and-down sliding of the piston
120 inside the cylinder
110
formed for the internal combustion engine
100 in the embodiment is converted
into a rotational motion of a not-illustrated crankshaft. The rotation angle of
the crankshaft and the number of engine revolutions are measured with the crank
angle sensor
125.
The combustion chamber
160 is provided with the ignition plug
165.
The internal combustion engine
100 in the embodiment is provided with
two intake valves
201 and two exhaust valves
211 for each cylinder
110. Therefore, two electromagnetically driven intake valves
200
and two electromagnetically driven exhaust valves
210, which are incorporated
in the cylinder head
130, are provided for each cylinder
110. The
electromagnetically driven intake valve
200 and the electromagnetically
driven exhaust valves
210 have the same structure.
Next, with reference to FIG. 2, the structures and the operations of the electromagnetically
driven intake valve
200, the electromagnetically driven exhaust valves
210,
and the ECU for controlling the electromagnetically driven valves will be explained.
FIG. 2 schematically shows the electromagnetically driven valve and the ECU for
controlling the electromagnetically driven valve.
As shown in FIG. 2, with respect to the electromagnetically driven intake valve
200 (the electromagnetically driven exhaust valves
210), a plate-like
movable needle
205 (
215) made from a soft magnetic material is mounted
on a valve shaft
203 (
213) of the valve body
201a (
211a).
Elastic forces by a lower spring
206 (
216) and an upper spring
207
(
217) are applied to the movable needle
205 (
215) to be at
the neutral position. An electromagnetic coil
208 (
218) for valve-opening
is placed on the lower side of the movable needle
205 (
215), and
an electromagnetic coil
209 (
219) for valve-closing is placed on
the upper side.
Upon the valve-opening, after electricity to the electromagnetic coil
209
(
219) for valve-closing on the upper side is stopped under the control of
the ECU
10, electricity is turned on to the electromagnetic coil
208
(
218) for valve-opening on the lower side. Then, the movable needle
205
(
215) is adsorbed to the lower side by the generation of an electromagnetic
