JPH09317508A - Controller for stopping/operating multi-cylinder engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate incompatible feeling caused by variations in the number of stopping cylinders by providing a changeover means for changing a low operating state to a high operating state when an engine speed or a throttle opening is above at least one of setting values thereof for changing and for changing the high operating state to the low operating state when the engine speed and the throttle opening are below both of setting values for changing. SOLUTION: An ECU 20 to which the output signals of a crank angle sensor 17, a throttle sensor 18, an air-fuel ratio sensor and the like are input selects suitably a low operation state in which many cylinders are stopped or a high operating state in which few cylinders are stopped. In other words, the high operating state is selected when an engine speed or a throttle opening is above at least one of setting values for changing and the low operating state is selected when the engine speed and the throttle opening are below both of setting values for changing. When the low operating state is changed to the high operating state, the ECU 20 rewrites a correction changing throttle opening for changing the high operating state to the low operating state or for changing low operating state to the high operating state by the throttle opening for changing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylinder deactivation operation control device for a multi-cylinder engine which suspends the operation of a single cylinder or a plurality of cylinders in accordance with the operating state of the engine.

[0002]

2. Description of the Related Art In a two-cycle engine, for example, in a low speed rotation and low load operation range, scavenging is not sufficiently performed, exhaust gas remains in the cylinder, and irregular combustion easily occurs.
Therefore, there are problems such as unstable engine rotation, deterioration of exhaust gas properties, and deterioration of fuel consumption.

As a method for solving the above problem, conventionally, there is a case where a cylinder deactivation operation is performed in which the operation of some cylinders is stopped and the number of operating cylinders is reduced. In order to maintain the same engine speed as when all the cylinders are in operation when the number of operating cylinders is reduced, it is necessary to slightly increase the throttle opening degree because a pseudo heavy load is acting. Therefore, for the operating cylinder, the intake amount increases and scavenging is ensured, and irregular combustion is prevented,
Rotational stability is improved, and the amount of fuel supplied to the idle cylinders is made extremely small, so that blow-through is almost eliminated, and exhaust gas properties and fuel consumption can be improved.

By the way, in the switching control of the number of idle cylinders in the cylinder idle operation, the number of idle cylinders is changed according to the engine operating conditions such as the throttle opening and the engine speed. In this case, in order to change the number of idle cylinders according to the driver's intention, it is considered preferable to perform switching based on the throttle opening information.

[0005]

However, if the number of idle cylinders is switched only by the throttle opening information, a problem occurs when the engine is used for a purpose in which the load condition greatly differs from the design value. For example, in the case of a marine engine, the load becomes lighter when a propeller with a smaller pitch is used, etc., and the engine speed at the idle cylinder number switching throttle opening becomes abnormally high compared to a heavy load, which makes driving uncomfortable. Can be felt.

As described above, the cylinder deactivation operation has the main purpose of preventing irregular combustion. However, when the deceleration cylinder number switching rotation speed increases, the engine rotation speed range in which irregular combustion does not occur originally. However, the cylinder deactivation operation is performed, and the amount of loss such as pumping loss becomes large, which leads to deterioration of fuel efficiency.

Further, in the outboard motor, when the hull gets over the waves, the running resistance fluctuates before and after the hull (large when riding the wave, small when descending the wave), and the engine speed fluctuates. Rotational fluctuations during normal operation are superimposed on this.
If such a state occurs when the vehicle is traveling near the idle cylinder number switching rotation speed, the number of idle cylinders fluctuates in addition to the driver's intention, which causes a feeling of strangeness. In some cases, the number of idle cylinders changes each time the user gets over the wave, resulting in a very jerky behavior, which is unsatisfactory. In order to avoid this, if the hysteresis of the switching engine speed is increased, there is a step in the engine speed, and it is difficult to clearly understand the switching of the number of cylinders.

The present invention has been made in view of the above situation, and when the load condition changes greatly or the hull gets over waves, the number of rotations of the stopped cylinders becomes abnormally high and the number of stopped cylinders changes. An object of the present invention is to provide a cylinder deactivation operation control device for a multi-cylinder engine that does not cause discomfort due to fluctuations or the like.

[0009]

According to a first aspect of the present invention, there is provided a multi-cylinder engine in which a low operating state in which the number of idle cylinders is large and a high operating state in which the number of idle cylinders is small (including zero) are appropriately selected. In the cylinder deactivation operation control device, when the engine speed or the throttle opening exceeds at least one of the switching engine speed and the switching throttle opening, the low operating state is switched to the high operating state, and the switching engine speed and the switching throttle are changed. It is characterized in that it comprises a deactivated cylinder number switching means for shifting from the high operating state to the low operating state when both of the opening degrees are below.

According to a second aspect of the invention, in the first aspect, when the engine operating speed is switched from the low operating state to the high operating state because the engine rotational speed exceeds the switching engine rotational speed, the throttle opening degree at the time of the switching is used to set the above. It is characterized in that a switching throttle opening correction means for rewriting the switching throttle opening is provided.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 12 are views for explaining a cylinder deactivation operation control device for a two-cycle 6-cylinder engine according to an embodiment of the present invention. FIG. 1 is an overall configuration diagram of the cylinder deactivation operation control device, and FIG. Throttle opening for explaining the operation-Engine speed-Character diagram of the number of idle cylinders. Fig. 3 is an engine speed for explaining the starting control-
Time characteristic diagram, FIG. 4 is a fuel supply amount control characteristic diagram of the return cylinder,
FIG. 5 is an ignition timing control characteristic diagram of the return cylinder, FIG. 6 is a schematic diagram showing a fuel injection map, FIG. 7 is a schematic diagram showing an ignition timing map, and FIGS. 8 to 11 are flow chart diagrams for explaining respective control operations. FIG. 12 is an overall configuration diagram of the control flow.

In FIG. 1, reference numeral 1 denotes a water-cooled 2-cycle V-type 6-cylinder crankshaft vertical installation engine for outboard motors. The engine 1 has a crankcase 3 on a front mating surface on the front side in the traveling direction of a cylinder block 2. , The cylinder head 4 is connected to the rear mating surface, and the S side bank of the cylinder block 2 is connected to the P side.
6 cylinders formed in the side bank ~ piston 7 in
Is inserted and each piston 7 is connected to one crankshaft 8 by each connecting rod 7a. It is to be noted that the above items 1 to 3 also indicate the ignition sequence, and the ignition is performed at equal angular intervals of 60 degrees. Reference numeral 15 is a spark plug.

The respective exhaust ports 5a, 5b, 5c of the S-side bank cylinders are connected to the right side collective exhaust passage 5 extending along the arrangement direction of the cylinders, and are connected to the collective exhaust passage 5. The right exhaust pipe 9a is open in the muffler 10. Further, the exhaust ports 6a, 6b, 6c of the P-side bank cylinders are connected to the left-side collective exhaust passage 6 extending along the arrangement direction of the cylinders.
The left exhaust pipe 9b connected to the collective exhaust passage 6 is a muffler 1
It opens inside 0. The exhaust gas discharged into the muffler 10 is discharged into water through the exhaust pipe 10a and around the rotary shaft of the propulsion device.

An intake pipe 11 forming an independent air supply system for each cylinder is connected to the crank chamber for each cylinder of the crankcase 3 so as to communicate therewith. A fuel injection valve 13 and a throttle valve 14 are provided. High-pressure fuel is supplied to the fuel injection valve 13 by a fuel supply system 16. The fuel injection valve may be attached to the cylinder head or the cylinder block to directly inject and supply the fuel into the combustion chamber.

The engine 1 of the present embodiment includes a crank angle sensor 17 for detecting the engine speed and a throttle valve 14.
A throttle sensor 18 for detecting the opening degree (load) of the cylinder and an air-fuel ratio sensor 19 for detecting the oxygen concentration of the cylinder at the upstream end, and thus the air-fuel ratio. The air-fuel ratio sensor 19 is connected to the downstream end of an exhaust extraction passage 19a formed so as to open from the exhaust port 5a of the cylinder to the combustion chamber side, whereby a substantially burnt gas containing almost no blow-through gas is included. It is possible to detect the oxygen concentration of only the air-fuel ratio, and thus to accurately detect the air-fuel ratio of the air-fuel mixture supplied to the cylinder.

Further, the engine 1 of the present embodiment has an ignition timing,
An ECU 20 is provided for performing engine operation control such as fuel injection amount (injection time), injection timing, and cylinder deactivation operation.
FIG. 12 shows the overall configuration of the system control flow. This control flow is based on the main switch OFF and the engine stop state F1 and the entire use state F as all other states.
The entire operating state F2 includes the operating entire state F3 as all engine operating states.

When the main switch is turned on in the main switch off / engine stop state F1, the main switch on / engine stop state of the entire use state F2 is obtained, and when the starter switch is turned on here, the start control (cranking control) is performed. In the starting control, the fuel injection timing, the injection time, and the ignition timing are controlled to fixed values peculiar to the starting time, and the fuel injection timing is asynchronously controlled. If the starter switch is turned on when the engine stop switch is turned on, a buzzer warning or the like is given.

When the engine speed exceeds the start control end determination speed NEs in the start control, the control is shifted to the post-start control (all cylinder operation). In this post-start control, the fuel injection time and the ignition timing are controlled by the cylinder-by-cylinder map, and the ignition timing lower limit control, the fuel post-start amount increase control, and the like are performed.

In addition, start control and post-start control release conditions,
For example, after the engine temperature exceeds the predetermined value, the cylinder deactivation operation control or the normal all-cylinder operation control is performed under the conditions described later. In the cylinder deactivation operation control and all cylinder operation,
O2 feedback control is performed for the above cylinders, and the fuel injection time and ignition timing for the remaining cylinders are corrected and controlled according to the cylinder-by-cylinder map.

In the cylinder deactivation operation control and the all cylinder operation control, when the throttle is suddenly opened, the control shifts to the rapid acceleration control, and when the throttle is suddenly closed in the all cylinder operation control, the rapid deceleration is performed. Transfer to control. In the sudden acceleration control, the fuel injection amount increase correction during acceleration, the ignition advance correction during ignition timing, and the asynchronous injection control during acceleration are performed. In the rapid deceleration control, the fuel amount increase correction during deceleration is performed.

In the cylinder deactivation operation control, the ECU 20 appropriately sets the low operation state in which the number of idle cylinders is large, that is, the number of operating cylinders is small, and the high operating state in which the number of idle cylinders is small, that is, the number of operating cylinders is large. It is designed to be selected. Specifically, the engine speed and throttle opening are
When at least one of the switching engine speed and the switching throttle opening is exceeded, the low operation state is changed to the high operation status, and when both the switching engine speed and the switching throttle opening are both below, the high operation status is low operation. It functions as a deactivated cylinder number switching unit that shifts to the state.

When the low operating state is switched to the high operating state due to the switching engine speed being exceeded, the ECU 20 changes from the high operating state to the low operating state or vice versa depending on the throttle opening at the time of the switching. Correction switching for shifting Functions as switching throttle opening correction means for rewriting the throttle opening.

Further, when the switching throttle opening is rewritten by the throttle opening when the engine speed is above the upper limit during the starting operation, the ECU 20 writes the switching throttle opening only after the predetermined rewriting prohibition condition is released. It also functions as a switching throttle opening correction limiting means that enables replacement. Specifically, as shown in FIG.
Time point t when the start operation such as turning on the starter motor is performed
1 or the engine speed is the start control release engine speed
From the time t2 when NEs is exceeded, it is judged that the above rewrite prohibition condition has been canceled due to the elapse of a predetermined time T1 'or T1 at which the engine speed is considered to settle near the idle speed, and switching is performed only after canceling the prohibition condition. It is possible to correct the throttle opening.

Since the normal starting operation is performed without opening the throttle valve, it is judged that the rewriting prohibition condition is released when the throttle valve is opened beyond the predetermined opening during the starting operation. You can

Next, the cylinder deactivation operation control in the apparatus of this embodiment will be specifically described. Fig. 2 showing the division of operating areas
In, the load line A and the load line B respectively show the relationship between the throttle opening and the engine speed in the normal load state. In the present embodiment, control in a region (a boat load region shown by hatched lines) surrounded by load lines A ′ and B ′ that is slightly wider than the region surrounded by the load lines A and B is considered.

In the system of this embodiment, in the region D (throttle opening less than Thθnm and engine speed NEnm), the number of deactivated cylinders n (specifically, two cylinder deactivated operation, four cylinder operation), region E
(Throttle opening Thθnm ~ Thθr, engine speed NEnm
(-NEr), the cylinder deactivation operation of the number of deactivated cylinders m (specifically, 1 cylinder deactivation, 5 cylinders operation) is performed, and the region F (throttle opening degree) is performed.
Above Thθr and above engine speed NEr, all cylinders are operated. It should be noted that the throttle opening and engine speed marked with ′ are for when the number of idle cylinders increases, and the difference between when the number of idle cylinders decreases and when the number of idle cylinders increases indicates the hysteresis throttle opening and hysteresis engine speed. ing.

First, the control for switching from the low operating state in which the number of idle cylinders is large to the high operating state in which the number of idle cylinders is small (or zero) is performed as follows. When the throttle opening exceeds Thθnm or the engine speed exceeds NEnm in the region D when the two-cylinder deactivation and the four-cylinder operation are performed, the region E is entered and the one-cylinder deactivation and the five-cylinder operation are performed. Becomes In this region E, the throttle opening is Thθ
When the engine speed exceeds r or the engine speed exceeds NEr, the engine moves to the region F and all cylinders are operated.

When the number of idle cylinders is reduced, that is, the number of operating cylinders is increased, the engine speed is increased before the throttle opening reaches the switching opening, for example, when the load is small (see load line A). When the number of vehicles exceeds the NEnm or NEr and is switched to the high operating state, the throttle opening k1 or k2 at that time is stored in the memory,
The stored value is adopted as the correction switching throttle opening,
Switching between a high operating state and a low operating state is performed based on the correction switching throttle opening. The correction switching throttle openings k1 and k2 are used only for switching from the high driving state to the low driving state, and the switching throttle opening before correction is used for switching from the low driving state to the high driving state. You may do it.

The correction switching throttle openings k1 and k2 stored in the memory are rewritten each time the operating state changes due to the engine speed exceeding the switching engine speed. It is also possible to use the first k1 and k2 fixedly until the main switch is turned off. Also, the above k1, k2
Can be erased by performing a throttle operation (rapid acceleration operation) in which the throttle opening speed becomes higher than a predetermined value, and thereafter, the switching throttle opening before correction can be returned to.

Next, the control for switching from the high operating state in which the number of idle cylinders is small (or zero) to the low operating state in which the number of idle cylinders is large is performed as follows. When all cylinders are operating in region F, the throttle opening is Thθr
Below ′ and engine speed below NEr ′,
The operation shifts to the region E, and one cylinder deactivation and five cylinder operation are performed. Then, in this region E, when the throttle opening is below Thθnm 'and the engine speed is below NEnm', the flow shifts to region D and two cylinder deactivation and four cylinder operation are performed.

Here, correction switching throttle opening degrees k1, k
If 2 is stored, the region E is shifted to the region E when the engine speed is below NEr 'and the throttle opening is below k2' when all cylinders are operating in the region F. 1 cylinder is deactivated and 5 cylinders are operated. In this region E, when the engine speed falls below NEnm 'and the throttle opening falls below k1', region D
Then, the operation is switched to 2 cylinder deactivation and 4 cylinder operation.

On the other hand, when the engine start control is being performed, the throttle opening degree k1 or k2 is not stored even when the engine operating speed is switched to the high operating state by the engine speed NEnm or NEr. . Then, when the start control is being performed, the engine speed exceeds the start control release speed NEs, and after a lapse of time T1, it is determined that the prohibition of rewriting the throttle opening at the start has been released, When the engine speed is switched to the high operating state by the NEnm or NEr of the rotation speed, the throttle opening k1,
Alternatively, k2 is stored.

The reason why the memory of the throttle opening degrees k1 and k2 is limited after the prohibition of rewriting at startup is released is as follows. That is, when the engine is started, the amount of fuel that reaches the combustion chamber tends to be insufficient due to reasons such as low engine temperature, poor atomization of fuel, and small amount of fuel adhering to the intake pipe and the inner surface of the crankcase. Therefore, in order to compensate for this, the fuel supply amount at the time of start is set to be larger than that at the time of normal operation. As a result, the engine speed will increase significantly if the first explosion from cranking or continuous explosions can be obtained. However, since the engine temperature is low, the post-start control is performed until the engine temperature reaches the predetermined value, and the cylinder deactivation operation is not performed.

On the other hand, when the engine is restarted after warming up, the engine speed exceeds the switching engine speed. Since the engine temperature is high, the post-start control is not performed and the cylinder deactivation operation is performed. In this case, the throttle opening is substantially fully closed. Therefore, if the above restriction is not applied, a value of substantially fully closed is stored as the throttle opening k1 when restarting after warming up. As a result, the region D is almost nonexistent, so that the 2-cylinder deactivation operation is not performed.

In order to prevent the approximately fully closed value as the throttle opening k1 from being stored, the switching engine speed may be set higher than the maximum engine speed due to excess fuel at the time of restart. However, in such a case, particularly during light load operation such as when using a propeller having a small pitch, the number of rotations for switching to a high operating state becomes unnecessarily high and the driving feeling deteriorates.

Note that another method can be adopted as the method of determining that the prohibition of rewriting at the start has been released. For example, after the engine speed exceeds the starting control release speed NEs,
This is the case where the throttle opening exceeds a predetermined value and is opened.

Here, it is also possible to switch from a low operating state (a 4-cylinder operating state in which cylinders are deactivated) to an all-cylinder operating state without passing through a 5-cylinder operating state. The ignition timing control will be described. The amount of fuel supplied to the cylinders that continue to operate, and the ignition timing are controlled as usual, but the control shown in FIGS. 4 and 5 is added when the deactivated cylinders return to the operating state. During sudden acceleration, the cylinder deactivation operation is switched to the all cylinder operation without performing connection control.

Injection width (fuel injection amount) to the cylinder
4, FD6 and FD4 indicate the injection widths (map values) of the cylinders in the all cylinder operation and the four cylinder operation, respectively. In this example, fuel supply is continued even during the idle period from the viewpoint of ensuring the cooling performance of the idle cylinder and improving the connection when returning from the idle cylinder state to the operating state. Driving and rest are performed.

When the cylinder deactivation operation is switched to the all-cylinder operation, the injection width is not immediately increased to the reference value FD6, but to the reference value (FD-S46).
It is reduced only by (FD-KCYCL) after that (FD
-KSTR) is gradually changed to the injection width FD6 during all cylinder operation.

Here, the fuel injection map has the form shown in FIG. 6. First, in all cylinder operation, the fuel injection width (amount) to the cylinder is the value (total) of the basic injection width map of the cylinder. (Cylinder operating basic injection width), and the fuel injection width to the cylinders is obtained by adding the correction map value (correction injection width) for each cylinder to the all cylinder operating basic injection width.
That is, the fuel injection width in the O2 feedback control to the cylinder is used as a basic value, and this is corrected according to the intake amount characteristic, temperature characteristic, etc. of each cylinder.
It is the fuel injection width for each.

In the cylinder deactivation operation, the fuel injection width to the cylinder is obtained by multiplying the basic injection width during all cylinder operation by the correction coefficient of the basic injection width correction coefficient map of the cylinder (the basic injection width during cylinder deactivation operation). ), The fuel injection width to the cylinders is obtained by adding the corrected injection width of the injection width correction map for each cylinder to the basic injection width during the cylinder deactivation operation. Note that the two-cylinder deactivated operation and the one-cylinder deactivated operation have different maps.

As described above, at the time of switching from the four-cylinder operation to the all-cylinder operation, the fuel supply amount to the returning cylinder is gradually decreased from the reference value and then gradually increased. It is possible to avoid excessively strong combustion and smooth the connection.

In FIG. 5, which shows the amount of ignition timing advance to the cylinders, SA6 and SA4 are all cylinder operation,
The ignition advance amounts (map values) of the cylinders in the 4-cylinder operation are shown.

When the cylinder deactivation operation is switched to the all-cylinder operation, the ignition advance amount is not immediately corrected to the reference value SA6, but is retarded from the reference value by (SA-S46), and thereafter ( SA-KCYCL) (SA-
KSTR) is gradually advanced to the ignition advance amount SA6 at the time of all cylinder operation.

Here, the ignition timing map has a form shown in FIG. 7. First, in the all cylinder operation, the ignition timing of the cylinder is the value of the basic ignition timing map of the cylinder (the basic ignition timing during all cylinder operation). ), The ignition timing of each cylinder is obtained by adding a correction map value (correction ignition timing) for each cylinder to the basic ignition timing during all cylinder operation.

In the cylinder deactivation operation, the cylinder ignition timing is the basic ignition timing for all cylinders operation multiplied by the correction coefficient of the basic ignition timing correction map for the cylinder (basic ignition timing for cylinder deactivation operation), The ignition timings to the cylinders are obtained by adding the corrected ignition timing of the ignition timing correction map for each cylinder to the basic ignition timing during the cylinder deactivation operation. Note that the two-cylinder deactivated operation and the one-cylinder deactivated operation have different maps.

As described above, at the time of switching from the four-cylinder operation to the all-cylinder operation, the ignition timing of the returning cylinder is once retarded and gradually advanced. Therefore, the ignition advance amount of the returning cylinder is also determined from this ignition advance amount. It is possible to avoid excessively strong combustion at the time of return and smooth the connection.

Next, the cylinder deactivation control in this embodiment will be described in more detail with reference to the flowchart. As shown in FIG. 8, when the control for determining the cylinder deactivation is started, a pulser failure, acceleration / deceleration control, start control, start mode, over-revolution (over-rotation), or oil empty ( It is judged whether or not it is in the condition of insufficient lubricating oil) or in the case of overheating (steps S1 to 7), and if any of them is satisfied, operation of all cylinders is instructed, and an ignition permission signal is output to all cylinders (step S8, 9), the cylinder deactivation operation is not performed.
On the other hand, if none of the above applies, the cylinder deactivated state is determined (step S10).

As shown in FIG. 9, in the cylinder deactivation state determination, when the cylinder deactivation operation is not being performed (step S11), the throttle opening Thθ is smaller than Thθr and Thθnm, and the engine speed NE is NEr and NEr. When it is smaller, that is, in the operating range D (steps S12 to S15), the number of cylinder deactivations n (2)
Is instructed (step S16), and 4-cylinder operation is performed. When the throttle opening Thθ and the engine NE are larger than Thθr and NEr, respectively, in steps S12 and S13, that is, in the operating range F, all cylinders are operated.

Further, in steps S14 and S15, the throttle opening is not smaller than the switching throttle opening Thθnm, that is, Thθr to Thθnm, or the engine speed is not smaller than the switching engine speed NEnm, that is, NEr to NEr. In the case of NEnm, that is, in the case of the operating region E, the cylinder deactivation number m (1) is instructed (step S17), and the 5-cylinder operation is performed.

Furthermore, in step S11, it is determined that the cylinder deactivation operation is in progress, and the number of cylinder deactivation is n, that is, two cylinder deactivation 4
When it is determined that the cylinder is in operation (step S18)
In addition, the throttle opening is smaller than the switching throttle opening Thθnm, and the engine speed is the start control release speed NEs.
If it is larger and smaller than the switching engine speed NEnm,
That is, in the operating region D, a four-cylinder operation with the cylinder deactivation number n = 2 is instructed (step S16). On the other hand, step S2
When the engine speed exceeds NEnm in 1 and the engine is not started immediately after the start control is performed, the throttle opening at that time is stored as the correction switching throttle opening k1 (steps S21 ', 22).

Then, in step S18, the number of cylinders to be stopped is n.
If it is not (2), that is, if it is determined to be m (1), if the throttle opening is larger than Thθnm in step S19, if it is immediately after the start control is performed in step S21 ′, and if step S22 is passed. Step S23
, And the throttle opening is switched Throttle opening Thθ
If it is smaller than r and larger than Thθnm and the engine speed is smaller than the switching engine speed NEr and larger than NEnm, that is, in the operating region E (steps S23 to 26), the process proceeds to step S17 and the cylinder deactivation number m ( 1) is instructed. At this time, if the previous operating state is n-cylinder deactivation, the presence or absence of a returning cylinder is determined, and if it is present, connection control is executed (steps S54, 55). If no, the process proceeds from step S54 to S17.

When the throttle opening is smaller than the switching throttle opening Thθnm or the engine speed is smaller than the switching engine speed NEnm in steps S25 and S26, the cylinder deactivation number n (2) is instructed (step S16). ) Shift from 5-cylinder operation to 4-cylinder operation.

In steps S23 and S24,
If the throttle opening is larger than the switching throttle opening Thθr, or if it is smaller than Thθr and the engine speed is larger than the switching engine speed NEr, and if it is not immediately after starting when the start control is performed, the throttle at that time The opening is stored as the correction switching throttle opening k2, and the cylinder deactivation control is canceled through the connection control (step S2).
3 ', 28-30), and shifts from 5-cylinder operation to 6-cylinder operation. It should be noted that, in step S20, if the engine speed is lower than the start control release speed NEs, the process proceeds to step S30 and the cylinder deactivation operation is not performed.

In the above connection control, as shown in FIG. 10, the gradual change is started when the gradual change control of the fuel supply amount as shown in FIG. 4 is started or being executed, not during acceleration. Then (steps S31 to 33), the gradual change execution flag is set, the start flag is cleared, the gradual change counter is reset, and the reduction correction amount initial value is set (steps S34 to 36).

If the gradual change is not started in step S33, the gradual change counter is reset after a lapse of a predetermined time, and the reduction correction amount is calculated (step S37).
~ 39). And the correction amount calculation value is positive (no correction is required)
In this case, the reduction correction amount is set to 0 and the gradual change execution flag is cleared (steps S40 to S42).

When the gradual change execution flag is cleared and when the correction amount is determined to be negative in step S40, the fuel reduction amount is FD-S2 and FD-S2 respectively when all cylinders are operating. FD-S1 is reached, and the reduction correction amount is stored in the memory (steps S43-4).
6).

In step S31, if the vehicle is accelerating, the amount of reduction correction is set to 0 and each flag is cleared (steps S47, 48). That is, the weight reduction correction is not performed.

When an instruction to cancel the number of cylinders or cancel the cylinders is issued in steps S16, 17, 30 and the like, as shown in FIG.
When the cylinder deactivation operation is not instructed, the ignition permission signal is output to all the cylinders (step S50), and when the cylinder deactivation and the four cylinder operation are performed, the ignition permission signal is output. Is output to four cylinders, and is output to five cylinders when not operating in four cylinders (steps S51 to S5).
3), all-cylinder operation, two-cylinder deactivated four-cylinder operation, one-cylinder deactivated five-cylinder operation, respectively.

As described above in detail, in this embodiment, when either the throttle opening or the engine speed exceeds the predetermined switching throttle opening or the switching engine speed, the low operating state in which the number of idle cylinders is large To a high operating state, that is, from a 4-cylinder operation to a 5-cylinder operation, and then to a 6-cylinder operation. It is switched to a high operation state based on the number.

Therefore, it is possible to switch the number of idle cylinders according to the driver's intention such that the number of operating cylinders increases based on the throttle opening when, for example, the throttle is opened widely due to a large load. . In addition, when used for applications with a small load, the number of operating cylinders increases based on the engine speed, which causes a problem that the operating cylinder number is not switched until the engine speed becomes abnormally high. Can be prevented.

Further, when both the throttle opening and the engine speed are below the predetermined switching throttle opening and the switching engine speed, the high operating state in which the number of idle cylinders is small is switched to the low operating state in which many cylinders are inactive. Switching When traveling near the engine speed, the number of idle cylinders does not increase immediately unless the throttle opening decreases even if the resistance increases due to overcoming the wave and the engine speed decreases, and the overrun of the wave It is possible to prevent jerky operation such that the number of idle cylinders fluctuates each time.

Further, when the increase in the number of operating cylinders is switched over a predetermined value of the engine speed such as when the load is small, the throttle opening at the time of switching is adopted as the correction switching throttle opening. Therefore, even if the engine speed decreases, if the throttle opening is larger than the correction switching throttle opening, the number of idle cylinders does not immediately increase. It is possible to prevent fluctuations in the number of cylinders and prevent jerky operation. By the way, when the switching throttle opening is fixed, the number of operating cylinders immediately fluctuates if the engine speed fluctuates while the engine is running near the switching engine speed, and the operation tends to be jerky.

On the other hand, when the engine is started, the throttle opening at that time is corrected until the start control is released. Since the correction of the switching throttle opening is limited so that it is not adopted as the opening, it is possible to avoid the inconvenience that the 2-cylinder deactivation operation is not performed especially in the case of a light load application. It is not necessary to set the rotation speed higher than the maximum speed at the start, and the driving feeling can be improved.

That is, especially when restarting after the completion of warming up, it is general that the above switching engine speed is exceeded even when the throttle is fully closed. The closed throttle opening is stored as the correction switching throttle opening. As a result, there is a concern that switching from the 1-cylinder deactivated operation (region E) to the 2-cylinder deactivated operation (region D) becomes impossible. In the present embodiment, the storage of the switching throttle opening is limited until the start control is released. Therefore, the substantially fully closed opening is not stored as the switching throttle opening k1. The two-cylinder idle operation is performed without any trouble.

In the above embodiment, the case where the 5-cylinder operation and the 4-cylinder operation are performed in the 6-cylinder engine has been described, but the number of engine cylinders and the number of idle cylinders are of course an example. Further, in the above-mentioned embodiment, the case of the engine for the outboard motor has been described, but the present invention can of course be applied to an engine for a land-based vehicle, for example, an automobile or a motorcycle.

[0067]

As described above, according to the cylinder deactivation operation control device for a multi-cylinder engine according to the invention of claim 1, a low operation state is obtained when at least one of the switching engine speed and the switching throttle opening is exceeded. Therefore, when the throttle opening is widened for a high load application, for example, the throttle opening is switched to the high operating state according to the driver's will. There is an effect that the number of idle cylinders can be switched.

Further, at the time of low load operation such as the case of being used for a light load application, the operating state is switched to the high operating state based on the engine speed and the operating cylinder number is switched until the engine speed becomes abnormally high. This has the effect of preventing problems such as not being performed.

Further, when both the switching throttle opening and the switching engine speed are below both, the high operating state in which the number of idle cylinders is small is switched to the low operating state in which the number of idle cylinders is large, so that the vehicle is traveling near the switching engine rotational speed. In case,
Even if the engine speed decreases due to overcoming waves, the number of idle cylinders does not immediately increase unless the throttle opening degree decreases, and it is possible to prevent jerky operation in which the number of idle cylinders fluctuates.

According to the second aspect of the present invention, when the low operating state is switched to the high operating state due to an increase in the switching engine speed, the throttle opening at the time of switching is adopted as the correction switching throttle opening. Therefore, the switching throttle opening is corrected to an appropriate opening according to the load condition, and even if the engine speed decreases, the number of idle cylinders increases immediately as long as the throttle opening is larger than the correction switching throttle opening. Therefore, there is an effect that it is possible to prevent the occurrence of jerky operation in which the number of operating cylinders changes due to the change in engine speed.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram for explaining a cylinder deactivation operation control device for a multi-cylinder engine according to an embodiment of the present invention.

FIG. 2 is a characteristic diagram of throttle opening-engine speed-control region for explaining the control operation of the above-described embodiment device.

FIG. 3 is an engine speed-time characteristic diagram for explaining a starting control of the above-described embodiment device.

FIG. 4 is a fuel control characteristic diagram of a return cylinder of the apparatus of the above embodiment.

FIG. 5 is an ignition timing control characteristic diagram of a return cylinder of the apparatus of the above embodiment.

FIG. 6 is a schematic diagram showing a fuel injection width (amount) map of the apparatus of the above embodiment.

FIG. 7 is a schematic diagram showing an ignition timing map of the above-described embodiment device.

FIG. 8 is a flow chart for explaining the control operation of the apparatus of the above embodiment.

FIG. 9 is a flow chart for explaining the control operation of the apparatus of the above embodiment.

FIG. 10 is a flow chart for explaining a control operation of the apparatus of the above embodiment.

FIG. 11 is a flow chart for explaining a control operation of the apparatus of the above embodiment.

FIG. 12 is an overall configuration diagram of a control flow of the apparatus of the above embodiment.

[Explanation of symbols]

1 multi-cylinder engine, deactivated cylinder 20 ECU (deactivated cylinder number switching means, switching throttle opening correction means) NEnm, NEr switching engine speed Thθnm, Th θr switching throttle opening D, E low operating state, high operating state E, F Low operating state, high operating state k1, k2 correction switching throttle opening

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical display location F02D 45/00364 F02D 45 / 00364G

Claims (2)

[Claims] 1. A cylinder deactivation operation control apparatus for a multi-cylinder engine, wherein a low operation state with a large number of deactivated cylinders and a high operation state with a small number of deactivated cylinders (including zero) are appropriately selected. When the throttle opening exceeds at least one of the switching engine speed and the switching throttle opening, the above low operating state shifts to a high operating state,
A cylinder deactivation operation control device for a multi-cylinder engine, comprising a deactivated cylinder number switching means for shifting from the high operating state to the low operating state when both the switching engine rotational speed and the switching throttle opening are below both. 2. The switching throttle opening according to claim 1, wherein when the engine speed exceeds the switching engine speed and thereby the low operating state is switched to the high operating state, the switching throttle opening is controlled by the throttle opening at the time of switching. A cylinder deactivation operation control device for a multi-cylinder engine, comprising a switching throttle opening correction means for rewriting.