JPS6040738A - Fuel controller for cylinder number controlling engine - Google Patents

Abstract

PURPOSE:To make the proper incremental compensation of accelerating fuel in accord with both partial-cylinder and all-cylinder operations attainable, by setting up an incremental rate of the accelerating fuel to be added in time of acceleration so as to make a part of the partial-cylinder operation smaller than that of the all-cylinder one. CONSTITUTION:In case of a control unit 28 inputting output signals out of sensors 3, 29-31 detecting those of throttle opening, cooling water temperature, suction temperature and suction pressure each during engine driving and an ignition coil 32, first of all a fact whether or not a partial-cylinder operated range is the case is discriminated. Likewise, whether it is in a state of acceleration or not is detected on the basis of variations in the opening of a throttle valve 11. And, in time of accelerating state detection, compensation adding accelerating fuel to a fundamental fuel injection quantity to be determined by a fuel injection quantity control device takes place, while an incremental rate of this adding accelerating fuel is set up so as to make a part of the partial-cylinder operation smaller than that of all-cylinder operation. Afterward, this compensated fuel injection quantity is sprayed out of a fuel injection nozzle 10.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is capable of switching between an all-cylinder operation in which output is output from all cylinders and a reduced-cylinder operation in which output is output only from some cylinders, depending on the operating state of the engine. The present invention relates to a fuel control device for an engine that controls the number of cylinders.

(Prior art) In recent years, there has been a desire for a significant improvement in fuel efficiency, especially in automobile engines, and for this reason, for example,
As shown in Japanese Patent Publication No. 338, an engine with cylinder number control has appeared in which the above-mentioned full-cylinder operation and reduced-cylinder operation can be appropriately switched and selected depending on the operating state of the engine. In other words, when the load is high, such as when starting or driving at high speeds, fuel is supplied to all cylinders and output is output from all cylinders, while when the load is low, such as when driving at a constant speed or on a steady road, fuel is supplied to all cylinders. In this type of cylinder number control engine, fuel consumption is reduced by cutting the fuel supply to some cylinders and increasing the filling efficiency to other cylinders. It is equipped with a means for switching the number of cylinders to switch to operation, and detects engine operating conditions such as engine speed, throttle valve opening, intake negative pressure, and engine temperature to determine whether cylinder reduction operation should be performed. , is provided with cylinder reduction determination means for outputting the determination result to the cylinder number switching means.

Incidentally, during acceleration, it is common practice to increase the amount of fuel by a predetermined amount, as shown in Japanese Patent Publication No. 47-38665. In other words, during acceleration, the throttle valve opens rapidly and the amount of intake air increases rapidly, but while this intake air flows relatively quickly into the combustion chamber, fuel, which has a higher specific gravity than air, Due to reasons such as the inability to completely follow the current flow, during acceleration, accelerating fuel is supplied as additional fuel in anticipation of this follow-up delay.

However, in an engine with cylinder number control, the change in intake air amount in response to a change in throttle opening is different between full-cylinder operation and reduced-cylinder operation, and for this reason, there is a Measures are needed.

(Object of the invention) The present invention was made in consideration of the above-mentioned honzuke,
It is an object of the present invention to provide a fuel control device for a cylinder number controlled engine that can obtain an appropriate amount of increased fuel depending on the operating mode of reduced-cylinder operation and full-cylinder operation during acceleration.

(Structure of the Invention) In order to achieve the above-mentioned object, in the present invention, the change in suction chamber %Mj with respect to the change in throttle opening is smaller during reduced-cylinder operation than during full-cylinder operation. Focusing on this, the ring 1i1 ratio of accelerating fuel is set to be smaller during reduced-cylinder operation than during full-cylinder operation.

Specifically, as shown in Fig. 1, as in the past, the engine has a cylinder number control means and a cylinder reduction determination means, and switches between all-cylinder operation and cylinder reduction operation according to the operating state of the engine. ,
For example, a fuel adjustment device such as an electronically controlled fuel injection device is controlled by an acceleration fuel control device that receives output from both an acceleration detection device that detects acceleration based on a change in throttle opening and the cylinder reduction determining device. It's Nishide. That is, while the basic fuel injection amount is determined by the fuel injection amount control means, during acceleration, the acceleration fuel control means makes a correction by adding acceleration fuel to the basic fuel injection amount, and also increases the amount of the added acceleration fuel. )' The L ratio is set to be smaller during reduced-cylinder operation than during full-cylinder operation.

Note that this corrected fuel is injected from the fuel injection valve into the intake passage of the engine.

(Example) In Fig. 2, l is the main body of the engine, and the intake air is
The air is supplied to the combustion chamber 7 via the air cleaner 2, throttle chamber 4, intake manifold 5, and intake boat 6, and the path from the air cleaner 2 to the intake boat 6 constitutes an intake passage 8. The amount of fuel from the fuel injection valve 10 is mixed into the intake air flowing through the intake passage 8, and the amount of intake air is controlled by the throttle valve 11. Furthermore, the exhaust gas from the fuel chamber 7 is discharged into the atmosphere from the tI (gas) 12 through the tJI manifold 13 and the like.

The intake valve 14 that opens and closes the intake boat 6 and the exhaust valve 15 that opens and closes the exhaust boat 12 are opened and closed at predetermined timing by a valve operating mechanism. In this embodiment, this valve mechanism includes a turn spring 16.17 that biases the intake valve 14.15 in the direction of closing the valve, a camshaft 18 rotationally driven by a crankshaft (not shown), A cam 19 and rocker arms 2o and 21 provided on the camshaft.
．． It is generally composed of tappets 22 and 23 that constitute the rocking fulcrum of the rocker arms 2o and 21. In the embodiment, the engine main body 1 is a 4-cylinder engine, and the ignition order is 1-3 to 4-2, and the ignition order is 1-3 to 4-2.
Cylinder No. 1 and cylinder No. 4 are the cylinders that are inactive, that is, the fuel supply is cut off. Therefore, the valve drive control device 2
4.25 is installed in A'-1.

The valve drive control devices 24 and 25 each have a solenoid 1.
It is FA exchanged and driven by Mi 26.27, and if solenoid 26.27 is in one position, tapeft 22.
23, the rocker arm 20.21 is at a position displaced downward in the figure, and the rocker arm 20.21 swings in response to the rotation of the camshaft 18, thereby controlling the intake and exhaust gases 4114.23 of all cylinders. 15 is opened and closed, resulting in an all-cylinder operation. Conversely, when the solenoids 26 and 27 are energized, the pivot point can be displaced in the upward direction in the figure, and the interlocking relationship between the camshaft 18 and the suction valves 14 and 15 is interrupted. When cylinder reduction operation is performed with the intake and exhaust valves 14.15 of the No. 1 and No. 4 cylinders maintained in the closed state, the above-mentioned valve drive control device 24.25 itself is
For example, it is already well known as shown in No. 4, No. 52-56212, so a detailed explanation thereof will be omitted.

In FIG. 2, 28 is a control unit consisting of a microcomputer, which not only controls the solenoids 26 and 27 to perform one of the cylinder reduction operation, but also controls the fuel injection amount, ignition timing, etc. It is also controlled,
In the following description, description of parts not directly related to the ignition timing Kasagi invention will be omitted.

” The control unit 28 receives the following information: the opening degree of the throttle valve 11 from the throttle sensor 3, the engine cooling water temperature as the engine temperature from the cooling water temperature sensor 29, and the intake air from the intake air temperature sensor 30 provided in the intake passage 8. While the temperature, the intake negative pressure detected by the intake negative pressure sensor 31, and the engine rotation speed from the ignition coil 32 are inputted, C. 6
ij Both solenoids 26 and 27 and fuel injection brake r1
Output for 0.

In FIG. 2, numeral 33 is a destroyer, numeral 34 is a spark plug, and numeral 35 is a battery.

Next, the content of control by the control unit 28 will be explained based on the flowchart 1 shown in FIGS. This shows the case where no acceleration fuel is supplied (during sudden acceleration that requires acceleration fuel, the engine shifts to all-cylinder operation). In addition, the above flowchart.

It is roughly divided into a routine for cylinder discrimination, a routine for fuel calculation, and a routine for acceleration detection.
In the following explanation, each of these routines will be explained separately.

I cylinder discrimination routine (steps 36 to 47) First, the routine is initialized in step 36, where the cylinder number flag is set to 1, the accelerator flag is set to O, and the read value of the throttle opening is cleared. When this cylinder number flag is "L", it means all-cylinder operation, and when it is "O", it means reduced-cylinder operation, and the accelerator flag means "
1” is when accelerating (during sudden acceleration when transitioning to all-cylinder operation)
When it is "0", it indicates that it is not accelerating.

Next, in step 37, each data of intake air temperature, engine cooling water temperature, intake negative pressure, engine speed, and throttle valve opening is input.

Thereafter, based on the data input manually in step 37, it is determined in steps 38 to 4o whether or not the engine operating state satisfies the conditions for reduced-cylinder operation. That is,
The cooling water temperature is higher than the set value To (for example, 60°C) (step 38), and the engine speed is higher than the set value To (for example, 60°C).
o (for example 2.

00 rpm) (step 39), and is not in an acceleration state but in steady state or deceleration running (step 4).
0), the process moves to step 41. Note that whether or not the vehicle is in the acceleration state is determined by determining whether the accelerator flag is 1 or 0, and this accelerator flag is changed in the flowchart of FIG. 4, which will be described later.

From step 41 above, since the generous number flag is initialized to 1 in step 37, the process first moves to step 42, where it is determined whether the intake negative pressure is equal to or higher than the set value 24. be done. If the intake negative pressure is a low load equal to or less than the set value P, the process moves to step 43, where the cylinder number flag is set to O.

” The transition to step 43 is when all the conditions for cylinder reduction operation are satisfied, so step 44 outputs an output to the effect that cylinder reduction operation (in the embodiment, 2 cylinder operation) is to be performed, i.e. The solenoids 26 and 27 are energized, resulting in reduced-cylinder operation in which the intake and exhaust valves 14 and 15 of the first and fourth cylinders are maintained in the closed state.

After this, fuel calculation processing is performed in steps 48' to 52, which will be described later, and the process returns to step 37. However, if the engine operating condition is the same as described above, Similarly, the process moves to step 41. Then, in step 41, as a result of the cylinder number flag being set to O as described above in step 43, the step 4
Since the cylinder number flag of 1 has been converted to 0, the process moves to step 45, where the intake negative pressure is set to the set value P.
It is determined whether or not the value is greater than 2. In other words, the intake negative pressure is different during reduced-cylinder operation and during full-cylinder operation, even if the engine speed is the same, and therefore, the conditions for switching to full-cylinder operation during reduced-cylinder operation are different. The intake negative pressure P
2 is used during reduced-cylinder operation, and intake negative pressure P4, which is a condition for switching to reduced-cylinder operation during full-cylinder operation, is used during full-cylinder operation (P 2 > P 4 ). This prevents frequent switching between reduced-cylinder operation and full-cylinder operation in a short period of time depending on the negative or positive intake air (
Hunting prevention).

Here, when the cooling water temperature is lower than the set value TO, the engine speed is the set value N. or when accelerating (when the accelerator flag in step 40 is 1), or when the intake negative pressure is greater than the set value P2 (during reduced-cylinder operation) or P4 (during full-cylinder operation). If the conditions are met, the process moves to step 46, where the cylinder number flag is set to 1, and then, in step 47, an output indicating that all-cylinder operation is to be performed is made. That is, the solenoids 26 and 27 are demagnetized and the intake and exhaust valves 14 and 15 of all cylinders are opened and closed, resulting in all-cylinder operation.

II Fuel calculation routine (steps 48 to 52) First,
In step 48, the basic fuel injection amount τ is calculated from the engine speed and intake negative pressure. Of course, in this step 48, depending on the output from the step 44.47 for cylinder reduction operation or all-cylinder operation, the map for cylinder reduction operation or the map for all cylinder detour is selected. , which calculates the basic fuel injection amount τ.

Next, in step 49, the correction coefficient C3 based on the cooling water temperature is multiplied by the basic fuel injection acid τ to correct the fuel injection amount (corrected fuel injection amount I). The corrected fuel injection amount of 1 obtained by this correction is multiplied by a correction coefficient C2 based on the intake air temperature in step 50 to obtain a corrected fuel injection amount τ2.

Thereafter, the process moves to step 51, and when accelerating when the accelerator flag is 1, the process moves to step 52, where the corrected fuel injection amount τ2 is multiplied by a correction coefficient 03 based on acceleration, and the corrected fuel injection amount is τ3 is calculated. Then, in step 53, a signal based on the corrected fuel injection amount of 2 is output to the fuel injection valve 10. Further, if it is determined in step 51 that the current time is not acceleration (the accelerator flag is O), the process proceeds to step 53 without performing the fuel injection amount correction based on the acceleration in step 52, and the corrected fuel injection amount in step 50. A signal based on 2 is output to the fuel injection valve 10.

As mentioned above, the accelerator fuel is not increased during cylinder reduction operation, so as is clear from the explanation of the flowchart in Fig. 4, which will be described later, the accelerator flag is not always set to O during cylinder reduction operation. Therefore, the step 52 of performing correction for acceleration is performed only when the engine is in full-cylinder operation and at the time of acceleration.

■Acceleration detection routine (Fig. 4) The flowchart shown in Fig. 4 interrupts the flowchart shown in Fig. 3 at predetermined time intervals. First, in step 54, the throttle valve opening degree is Data is input at each predetermined time, and a predetermined number n of throttle valve opening degrees inputted at step 5 are sequentially stored as values at each predetermined time.

Next, in step 56, it is determined whether the cylinder number flag is 0 or 1, and if it is 1, which is during all-cylinder operation, the process moves to step 57. In this step 57, a comparison level A of acceleration during all-cylinder operation is set. In addition, during cylinder reduction operation where the cylinder number flag in step 56 is O, the process moves from step 56 to step 58, and in step 58, a comparison level A of acceleration during cylinder reduction operation is set. .

The process in steps 57 and 58 above is performed because the level of acceleration is greater during all-cylinder operation than during reduced-cylinder operation, even when the rotational throttle opening is changed. This is to make the comparison level of acceleration, which is a set value for this determination, correspond to reduced-cylinder operation or full-cylinder operation. For the reasons mentioned above, the comparison level during reduced-cylinder operation is greater than the comparison level during full-cylinder operation, and as a result,
- In order to obtain acceleration at the predetermined acceleration level, which is the above-mentioned set value, a larger change in throttle opening is required during reduced-cylinder operation than during full-cylinder operation.

From step 57 or 58, the process moves to step 59, where the change in throttle opening per predetermined time, that is, the acceleration level (TVl-TVn), is calculated, and this calculated acceleration level B is used in step 60. It is determined whether or not the comparison level is greater than the comparison level A. Then, when acceleration level B is larger than comparison level A,
That is, if it is determined that the acceleration state is in progress, the process moves to step 61 and the accelerator flag is set to 1, and if it is determined that the acceleration level B is in a steady state where it is smaller than the comparison level A or in a slow deceleration state, the step - Move to pump 62 and set the accelerator flag to O. Of course, this step 6
The accelerator flag at 1 or 62 will be used for the determination at step 40 or step 51 described above, respectively.

Thereafter, the process moves to step 63, where the oldest throttle opening degree i1ri stored in step 55 is changed to the newest throttle opening degree 6ei, and the data is rearranged.

Although the embodiments have been described above, the present invention is not limited thereto, and includes, for example, the following cases.

(It can be applied not only to the 4-cylinder engine but also to other multi-cylinder engines such as 6-cylinder engines, and the number of cylinders to be deactivated is not necessarily half of the total number of cylinders, but can be adjusted as appropriate. l
a (for example, stopping two or four cylinders in a six-cylinder engine).

(In order to configure a dynamic cylinder, a valve drive control device 24, 25 is provided in the valve mechanism, and the camshaft 18 and intake/bleed valve 1 are
4.15, and for example, a shutter valve may be provided in the intake passage corresponding to the cylinder to be deactivated to cut off the supply of air-fuel mixture to the cylinder to be deactivated. In addition, in the case where a fuel supply device such as a fuel injection valve is provided individually for each cylinder,
The fuel supply from the fuel injection valve to the cylinder to be deactivated may be cut, and in this case, intake air may be supplied to the cylinder to be deactivated, or intake air may also be supplied to the cylinder to be deactivated. You can also choose not to. However, the intake air supply to the cylinders that should be stopped should also be
) is preferable in terms of reducing so-called pumping loss and further improving fuel efficiency.

(2) The control unit 28 can be configured by either an analog or digital computer.

(2) A carburetor may be used as the fuel adjustment device, and in this case, the amount of acceleration fuel can be increased by changing the diameter of the main jet or main air jet, for example.

(ΦDuring cylinder reduction operation, the acceleration fuel may be increased instead of being reduced to zero.

(Effects of the Invention) As is clear from the above description, the present invention is capable of appropriately increasing the amount of acceleration fuel in accordance with reduced-cylinder operation and full-cylinder operation, and as a result, smooth acceleration is always achieved. becomes possible.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of the present invention. FIG. 2 is an overall system diagram showing one embodiment of the present invention. FIG. 3 and FIG. 4 are flowcharts showing an example of control contents of the present invention. 1-...Engine body 8...Intake passage 10...Fuel injection valve 11...Fuel e-throttle valve 14...Middle intake valve 15... ...Exhaust valves 24, 25...Valve drive control device

Claims (1)

[Claims] (1) A cylinder reduction determination means for determining whether or not a cylinder reduction operation region is in which fuel supply to some cylinders is cut in accordance with the engine motion state, and receiving an output from the cylinder reduction determination means; cylinder number control means that is activated to cut fuel supply to some of the cylinders; a fuel control device for supplying fuel to an intake passage of the engine; an acceleration detecting means for detecting acceleration based on a change in throttle opening; and an output from the acceleration detecting means and the cylinder reduction determining means, and adjusting the fuel. 1. A fuel control device for an engine with a controlled number of cylinders, comprising: an acceleration fuel control means that controls the device to make the rate of increase in acceleration fuel smaller during reduced-cylinder operation than during full-cylinder operation.