JP2516630Y2 - Engine controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention relates to an engine control device in which the number of operating cylinders is changed according to a predetermined condition.

(Prior Art and Problems Thereof) There are some engines in which the number of operating cylinders is changed according to a predetermined condition, as called by the name of a cylinder number control engine. This cylinder number control engine generally reduces the number of operating cylinders in an operating region where output is not particularly required from the viewpoint of improving fuel efficiency.

Recently, controlling the number of cylinders has been considered from the viewpoint of exhaust gas purification. That is, in a predetermined operating region where the unburned components are large, the fuel supply to some of the cylinders is stopped or greatly reduced, so that the amount of air (oxygen) in the gas discharged from some of the cylinders is reduced. It has been considered to increase the number of cylinders so as to function as a pump for supplying secondary air to the exhaust path.

Further, it is not preferable to uniformly set the deactivated cylinder in which the operation is deactivated as a specific cylinder such as the third cylinder, because only the deactivated cylinder is cooled. Therefore, Japanese Patent Laid-Open No. 58-124030 discloses appropriately changing the idle cylinders.

By the way, in a vehicle equipped with an automatic transmission,
In order to prevent gear shift shock, there is one in which fuel is suppressed, that is, reduced during gear shift (prevention of gear shift shock due to engine output reduction). Thus, it is conceivable to apply the suppression of fuel at the time of shifting to a cylinder number control engine.

However, in this case, when the fuel control for preventing the shift shock and the fuel control for performing the cut-off cylinder operation are performed in close proximity to each other, that is, at substantially the same time, the engine output excessively decreases. It turned out to occur.

(Purpose of Invention) The present invention has been made in consideration of the above circumstances, and the purpose thereof is to perform reduced cylinder operation by stopping fuel supply to some cylinders, that is, a first predetermined number of cylinders. At the same time, when the fuel supply to some of the cylinders, that is, the second predetermined number of cylinders is stopped during the shift of the automatic transmission, the engine output can be prevented from excessively decreasing. It is to provide a control device.

(Structure of the Invention) In order to achieve the above object, the present invention has the following structure. That is, based on a predetermined condition, the fuel supply to the first predetermined number of cylinders smaller than the total number of cylinders is stopped to stop the first predetermined number of cylinders; A second fuel stop means for stopping the fuel supply to a second predetermined number of cylinders smaller than the total number of cylinders and suspending the second predetermined number of cylinders when shifting the machine; When the condition that the two fuel stopping means operate at the same time is satisfied, the stop of the fuel supply by the second fuel stopping means is limited so that the number of cylinders in which the fuel supply is stopped is the first predetermined number and the first predetermined number. And a limiting unit that limits the number to a number smaller than the total number of the two predetermined numbers.

(Effect of the Invention) According to the present invention, the operation of the first fuel stopping means causes
When a shift of the automatic transmission occurs in a reduced-cylinder operating state in which a predetermined number of cylinders are deactivated, the number of deactivated cylinders in which the fuel supply is stopped by limiting the fuel stop by the second fuel stopping means becomes too large. Since this is not done, it is possible to prevent excessive reduction in engine output while ensuring reduced cylinder operation and preventing shift shock.

With the configuration as described in claim 2, the engine output adjustment is delicately adjusted to the limit of the engine output adjustment by the second fuel stopping means that can adjust the engine output only in the number of cylinders. It is possible to compensate for the shift shock and the excessive reduction of the engine output at a higher level by compensating by utilizing the retarded ignition timing.

(Embodiment) An embodiment of the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, reference numeral 1 denotes an engine main body.
It is a type 6 cylinder. That is, it has a left bank 1L and a right bank 1R that form a V shape with each other.
No. 3, No. 3 and No. 5 cylinders C1, C3 and C5 are formed, and three cylinders C2, C4 and C6 No. 2, No. 4 and No. 6 are provided in the right bank 1R.
Are formed.

Each cylinder C (when it is not particularly necessary to distinguish C1 to C6, the symbol of C is simply used) has an intake port 2 and an exhaust port 3, and a spark plug 4 is arranged. Of course, the intake / exhaust ports 2 and 3 are opened and closed at well-known timing by intake valves or exhaust valves (not shown) in synchronization with rotation of the crankshaft. In the example,
The intake / exhaust valves of the cylinder to be deactivated are continuously opened and closed at a predetermined timing, so that the deactivated cylinder functions as a pump for supplying secondary air.

The intake passage for each cylinder C has a surge tank 5 in the middle, and an air cleaner 7, an air flow meter 8, and a throttle valve 9 are arranged in order from the upstream side in a common intake passage 6 for supplying intake air to the surge tank 5. Has been established. The surge tank 5 and each of the intake ports C1 to C6 are independently connected to each other via an independent intake passage 10, and a fuel injection valve 11 is disposed in each of the independent intake passages 10.

On the other hand, the independent exhaust passages 12L, each of which is independently connected to the exhaust port 3 of the left bank 1L, are joined by the left collective exhaust passage 13L,
Further, the independent exhaust passages 12R, which are individually connected to the exhaust ports 3 of the right bank 1R, are joined by the right collective exhaust passage 13R. The left and right collective exhaust passages 13L and 13R are finally connected to one common exhaust passage 14.

U in FIG. 1 is a control unit configured using a microcomputer. In the embodiment, the control unit U performs the fuel injection amount from each fuel injection valve 11, the ignition timing control of each spark plug 4, and the shift control of the automatic transmission AT. For this reason, the control unit U is provided with the intake air amount signal from the air flow meter 8 and the sensor 21.
And the engine speed signal from. Further, the control unit U outputs the fuel to each fuel injection valve 11, the automatic transmission AT (shift solenoid of the automatic transmission AT), and the igniter 22. Of course, when a predetermined ignition timing signal is output from the control unit U to the igniter 22, the temporary current of the ignition coil 23 is cut off at the timing of the predetermined ignition timing, and the predetermined current is supplied via the distributor 24. The spark plug 4 is ignited. In FIG. 1, the output signal from the control unit U to the fuel injection valve 11 and the signal path from the distributor 24 to the spark plug are shown only for the fourth cylinder C4 for simplification. The other cylinders are not shown.

Next, the control content of the control unit U will be described in detail with reference to the flowcharts of FIGS. 2 and 3, and P in the following description indicates a step. Here, in the embodiment, the idle timer is changed by using the soft timer. In addition, the fuel stop to prevent shift shock is 1
This is done by stopping the fuel supplied to one cylinder. Then, when the fuel stop for deactivating the cylinder and the fuel stop for the shift shock prevention are almost at the same timing, one fuel stop is completely stopped. Further, during shifting, the ignition timing is retarded (the degree of reduction in engine output due to retardation is set to be smaller than the amount of engine output reduction due to fuel stop). The gear shift control is performed based on a predetermined gear shift characteristic that is set using, for example, the engine speed and the intake air amount (engine load) as parameters. A shift signal is output from U to the automatic transmission AT.

On the premise of the above, a description will first be given of the fuel injection amount control shown in FIG.

After the engine speed and the intake air amount are read in P1, the basic fuel injection amount TB is determined in P2 based on both of them. Thereafter, in P3, the basic fuel injection amount TB is corrected based on the water temperature, the intake air temperature, the acceleration, the battery voltage, and the like, and the corrected fuel injection amount TF is determined. Note that the data for this correction is also read in P1, but the sensors and the like for this are omitted in FIG.

When it is confirmed in P4 that the fuel injection timing has come, the shift timer is counted down in P5. This shift timer is set when the fuel is stopped for a certain cylinder, and as will be described later, until the shift timer reaches 0, stopping the fuel to prevent shift shock is prohibited. After that, in P6, it is determined whether or not a shift is in progress. When the determination in P6 is NO, in P7, it is the operating range of whether or not the thinning injection is prohibited, that is, the operating range of prohibiting the reduced cylinder operation in which the fuel supply to some cylinders is stopped. It is determined whether or not. More specifically, in the embodiment, the reduced-cylinder operation is performed when all of the following conditions 1 to 4 are satisfied.

The engine water temperature is 20 to 80 ° C, it is not in idle operation, it is not in high load, it is not in acceleration, it is not in starting, and it is not in returning fuel from fuel cut during deceleration.

If YES in the determination in P7 above, that is, in the operating region in which thinning injection (reduced cylinder operation) is prohibited, P3 in P8
The fuel injection amount TF at is directly injected.

On the other hand, if NO in the determination of P7, after counting down the thinning-out timer in P9, it is determined in P10 whether or not the thinning-out timer value becomes 0 (the fuel injection timing of the cylinder to be stopped. Confirm whether or not). If the determination in P10 is YES, the coefficient α (α
= 0) is injected (the fuel injection is stopped). After that, in P12, the thinning timer is set to an initial value (5 in the embodiment), and then in P13, the shift timer is initialized. Set to the value. In addition, N is determined by P10
When O, shift to P8.

When the determination in P6 is YES, it is determined in P14 whether the shift timer is 0 or not. YES in the determination of P14
In the case of, the process proceeds to P11 and the above-mentioned fuel stop is performed. When the determination in P14 is NO, the process proceeds to P8 and the fuel stop is not performed.

Next, the ignition timing control will be described with reference to the flowchart shown in FIG. The flowchart of FIG. 3 is executed by interrupt processing with respect to the flowchart of FIG. 2 at a predetermined ignition timing determination timing.

First, at P21, the engine speed and the intake air amount (engine load) are read, and then the basic ignition timing θB is determined at P22 based on both of them. Next, in P23, as is known, the corrected ignition timing θC is determined by correcting the basic ignition timing θB according to the water temperature, acceleration, and the like. Note that the data for this correction is also read in P1, but the sensors and the like for this are omitted in FIG.

In P24, it is determined whether or not to retard the gearshift shock. The execution of retarding at the time of shifting is performed by checking whether the engine cooling water temperature is equal to or higher than a predetermined value (for example, 40 ° C.) and the shifting is started. When the determination in P24 is YES, the retard amount θS is set to the initial value in P25. Then, at P26, the value obtained by subtracting θS from θC at P23 is set as the final ignition timing θF (θ
Ignition is executed at timing F).

If NO in the above P24, in P27, the previous θ
A value obtained by subtracting the predetermined decrease Δθ from S is newly updated as θS (θS is subjected to limit processing so as not to be less than 0), and the process proceeds to P26.

The above-mentioned control contents are shown in FIG. This fourth
In the figure, among the three lines showing the engine torque, the solid line shows the present embodiment, the α line shows that the ignition timing retardation is removed from that of the present embodiment, and the β line shows for the reduced cylinder operation. The case where both the fuel stop and the fuel stop for gear shift shock prevention are performed is shown.

[Brief description of drawings]

FIG. 1 is an overall system diagram showing an embodiment of the present invention. 2 and 3 are flowcharts showing a control example of the present invention. FIG. 4 is a time chart schematically showing a control example of the present invention. U …… Control unit AT …… Automatic transmission C1 to C6 …… Cylinder 1 …… Engine body 2 …… Intake port 4 …… Ignition plug 8 …… Air flow meter 10 …… Independent intake passage 11 …… Fuel injection valve 21 …… Sensor (engine speed) 22 …… Ignator 23 …… Ignition coil 24 …… Distributor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-64-16446 (JP, A) JP-A-2-45626 (JP, A) JP-A-62-216840 (JP, A)

Claims (2)

(57) [Scope of utility model registration request] 1. A first fuel stop means for stopping fuel supply to a first predetermined number of cylinders smaller than the total number of cylinders and suspending the first predetermined number of cylinders based on a predetermined condition. A second fuel stop means for stopping the fuel supply to a second predetermined number of cylinders smaller than the total number of cylinders and stopping the second predetermined number of cylinders when shifting the automatic transmission; When the condition that the means and the second fuel stopping means operate at the same time is satisfied, by restricting the stop of the fuel supply by the second fuel stopping means, the number of cylinders in which the fuel supply is stopped is determined by the first predetermined A control device for an engine, comprising: a limiting unit configured to limit the number to a number smaller than the total number of the second predetermined number. 2. The invention according to claim 1, further comprising retarding means for retarding the ignition timing during shifting of the automatic transmission, wherein the limiting means is characterized in that the number of cylinders for which fuel supply is stopped is the first cylinder. 1 is configured to limit the fuel stop by the second fuel stop means so as not to exceed a predetermined number, and even when the fuel stop by the second fuel stop means is limited by the limit means, An engine control device, characterized in that the ignition timing is retarded by a retarding means.