JPH051383B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a deactivated engine capable of operating all cylinders or some cylinders by controlling the number of active cylinders, and in particular, a method for controlling the engine speed during idle operation. and regarding equipment.

In deactivated engines, in order to improve both starting performance and fuel efficiency during idling operation,
When controlling to operate all cylinders or some cylinders during idling, stable idling can be achieved with a large number of combustion operations per revolution when all cylinders are operating. During partial cylinder operation, the number of combustion operations is small and engine vibration changes.

As a result, vibrations during operation of some cylinders resonate with the natural frequency of the vehicle body, etc., causing unpleasant vibrations in the engine and vehicle body.

In addition, during partial cylinder operation, idling operation is obtained with a lower generated output due to the reduction in pump loss, which may result in an increase in the resistance of the engine itself, such as an increase in lubricating oil resistance or bearing resistance, or an increase in engine auxiliary equipment such as a cooling fan. In response to increased load on generators, etc.
It has become difficult to maintain the idle speed, resulting in problems such as a drop in engine speed, increased vibration, and engine stoppage.

Therefore, it has been considered to solve the above problem by setting the target engine speed when some cylinders are idling higher than the target engine speed when all cylinders are idling, If the engine is switched from all-cylinder operation to partial-cylinder operation, it will not be possible to change the target rotation speed between all-cylinder operation and partial-cylinder operation even though the engine is in partial-cylinder operation. The engine operates at a low target rotation speed for idling operation, which may cause problems such as increased vibration or engine stall during this switching.

The present invention is an attempt to solve these problems.The present invention is aimed at solving these problems. In order to improve fuel efficiency and maintain engine performance such as starting performance under the above operating conditions, when switching between partial cylinder idling operation and all cylinder idling operation in the above operating conditions, By making the idle speed higher than the idle speed when operating all cylinders, we aim to ensure stability during idle operation of some cylinders and improve fuel efficiency when operating all cylinders. When switching to partial cylinder operation, the opening of the intake air amount control valve is set in advance to bring the idle speed close to that for partial cylinder operation, and then by actually switching to partial cylinder operation, all cylinder operation is achieved. It is possible to avoid problems such as vibration and stalling caused by operating some cylinders at the normal idle speed, and it is possible to smoothly switch the engine from operating all cylinders to operating some cylinders. An object of the present invention is to provide a control method and device for a deactivated engine that can ensure stable engine operation. For this reason, the deactivated engine control method of the present invention includes at least a means for controlling the number of activated cylinders that issues a command signal for selectively operating all cylinders or some cylinders during idling operation after completion of warm-up; Equipped with means for switching the number of activated cylinders to switch between all-cylinder operation or partial cylinder operation in response to a command signal, and after warm-up is completed, the idle rotation speed during partial cylinder operation is higher than the idle rotation speed when all cylinders are operated. At the same time, when a command signal to switch from all-cylinder operating operation to partial cylinder operating operation is issued by the operating cylinder number control means during idling operation after completion of warm-up, the idle rotation of the engine is set to After setting the opening of the control valve that adjusts the intake air amount of the engine so that the number approaches the idle speed during partial cylinder operation, the operating cylinder number switching means changes from all cylinder operation to partial cylinder operation. The feature is that it can be switched to driving mode.

The cylinder deactivated engine control device of the present invention also includes an activated cylinder number control unit that issues a command signal for selectively operating all cylinders or some cylinders at least during idling operation after completion of warm-up; a control valve that adjusts the intake air amount of the engine; a control valve that adjusts the amount of intake air of the engine; Thus, the opening degree of the control valve is adjusted based on the output of the operating cylinder number control means so that the rotational speed of the engine becomes a second idle rotational speed higher than the first rotational speed during partial cylinder idle operation. A first engine rotation speed control means for controlling the engine rotation speed, temporarily immediately after a command signal for switching from all cylinder operation to partial cylinder operation is issued by the operating cylinder number control means during idling operation after completion of warm-up; operates in priority over the first engine speed control means, and makes the control valve opening larger than the opening corresponding to the first idle speed when the first engine speed control means operates on all cylinders. a second engine speed control means that sets the engine speed to approach the second idle speed, and switches from all-cylinder operation to partial cylinder operation by the active cylinder number control means during idling operation after completion of warm-up; The present invention is characterized in that it includes a delay means for delaying the start of operation of the operating cylinder number switching means when a command signal is issued.

Hereinafter, a control method and apparatus for a deactivated engine as an embodiment of the present invention will be explained with reference to the drawings. FIG. 1 is a schematic explanatory diagram showing the overall configuration;
Fig. 2 is a control block diagram thereof, and Figs. 3 to 6 are flowcharts for explaining its operation.
Fig. 7 is the target rotation speed-water temperature characteristic diagram, Fig. 8 is the basic target opening-water temperature characteristic diagram, Fig. 9 is the engine output characteristic diagram, and Figs. 10 a to e are the operation of the actuator. Characteristic diagram, Figure 11 a-d
are timing diagrams for explaining the effect, and FIG. 12 is a schematic diagram for explaining the effect.

In this embodiment, the engine E has two deactivated cylinders (in this case, the first and fourth cylinders) that can stop operating and enter a deactivated state depending on the operating state (for example, low-load operating state). and two regular cylinders (in this case, the second,
By providing a third cylinder), the number of operating cylinders can be controlled to either 4-cylinder operation (all cylinder operation) or 2-cylinder operation.
It is configured as an in-line four-cylinder engine with cylinders inactive (partial cylinder operation).

As shown in FIG. 1, an exhaust manifold 4 is attached to one side of a main body 2 of this engine, and an intake manifold 6 is attached to the other side. An intake passage 8, one end of which communicates with the engine combustion chamber via the intake manifold 6, includes a throttle valve 10 interlocked with an accelerator pedal (not shown), a fuel injection device 12, and an air flow meter (Karman vortex flow meter) 14. is interposed, and the other end of this intake passage 8 communicates with the outside air via an air cleaner 16.

The fuel injection device 12 is equipped with a solenoid valve 13 which is a fuel flow rate regulating valve installed in a fuel passage through which low-pressure fuel is supplied from a fuel pump, and the amount of fuel injected into the intake passage 8 is controlled by the solenoid valve 13. It is designed to be set corresponding to the valve opening time of 13.

Further, the intake passage 8 is provided with a bypass passage 18 that bypasses the throttle valve 10, that is, communicates and connects the parts upstream and downstream of the throttle valve disposed part. Bypass valve 2 as a control valve that controls the amount of intake air supplied to the engine combustion chamber by controlling the amount of intake air passing through the passage 18
0 is interposed, and this bypass valve 20 moves from a fully closed position (rightmost position in Figure 1) where it contacts the valve seat and fully closes the bypass passage 18 to a fully open position determined by a stopper (not shown) (Figure 1). It is now possible to move to the leftmost position).

Further, the bypass valve 20 is connected to a diaphragm 24 of a pressure-responsive device 22, which is an actuator. The pressure chamber 26 of the pressure response device 22 is connected via a negative pressure passage 28 to an intake passage downstream of the insertion position of the throttle valve 10, and is connected to the intake passage downstream of the insertion position of the throttle valve 10 via an atmospheric passage 30. The pressure chamber 26 is connected to the intake passage upstream of the position, and intake negative pressure (hereinafter representatively referred to as "manifold negative pressure") is supplied to the pressure chamber 26 via the negative pressure passage 28, and the atmospheric passage 30 Atmospheric pressure is supplied through the

Further, the negative pressure passage 28 is provided with a normally closed first solenoid valve 32 and a check valve 33 between the first solenoid valve 32 and the intake passage 8 side port, which allows fluid to move only from the solenoid valve side to the port side. The first solenoid valve 32 controls the intake negative pressure supplied to the pressure chamber 26.

On the other hand, a normally open second solenoid valve 34 is interposed in the atmospheric passage 30, and this second solenoid valve 34 controls the atmospheric pressure supplied to the pressure chamber 26.

Note that reference numerals 35a and 35b in FIG. 1 indicate orifices for flow rate control.

Furthermore, an auxiliary atmospheric passage 31 having no orifice is provided between a portion of the atmospheric passage 30 upstream of the second solenoid valve 34 and a downstream portion of the orifice 35b. The auxiliary atmosphere passage 31 is connected to the
A third solenoid valve 37 is interposed, and this third solenoid valve 37 applies atmospheric pressure to the pressure chamber 26 in a shorter time than when the second solenoid valve 34 applies atmospheric pressure to the pressure chamber 26. It is something to control.

Further, a spring 36 is disposed within the pressure chamber 26, and this spring 36 biases the bypass valve 20 in the closing direction via the diaphragm 24, making the bypass valve 20 a normally closed valve. That is, when no negative pressure is applied to the pressure chamber 26, the spring 36 holds the bypass valve 20 in the fully closed position, which is the mechanically determined minimum opening position.

Further, a position sensor 38 is provided, and this position sensor 38 uses a variable resistor to detect the actual opening degree of the bypass valve 20 by detecting the position of the diaphragm 24 of the pressure response device 22. The opening position signal of the bypass valve 20 output by the position sensor 38 is input to the computer 40.

Additionally, an idle switch 48 serves as an idle sensor that detects the idle operating state of the engine E.
is provided, and this idle switch 48
is a switch that closes (turns on) when the throttle valve is fully closed and opens (turns off) at other times, and an open/close (on/off) signal from this idle switch 48 is input to the computer 40.

Further, an ignition device 44 is provided as a rotation speed sensor that detects the actual rotation speed of the engine E, and an ignition pulse signal (engine rotation speed signal) from this ignition device 44 is sent to the computer 4.
It is set to be input to 0.

Note that the computer 40 receives an opening position signal,
In addition to the idle switch open/close signal and the ignition pulse signal, the intake air amount signal output from the air flow sensor 42 provided in the air flow meter 14 and the cooling water temperature sensor 46 output from the coolant temperature sensor 46 that detects the coolant temperature of the engine body 2. water temperature signal,
A vehicle speed signal from a vehicle speed sensor 54 that is provided on the output shaft of a transmission (not shown) and detects vehicle speed information from the rotation angle of this output shaft, and a throttle valve 1
An opening signal output from a throttle opening sensor 56 that detects zero opening from fully closed to fully open is input. Additionally, a signal from the boost sensor is also input to the computer 40 as required.

Note that the reference numeral 57 in FIG. 1 indicates a battery.

The computer 40 includes an input waveform shaping circuit 58, a CPU 60, a RAM 62, a ROM 64, and an output waveform shaping circuit that performs waveform shaping of each input signal (including A/D conversion of analog signals such as a cooling water temperature signal and an opening position signal). 66, and this computer 40 forms an output pulse signal for controlling the engine output from each of the above-mentioned input signals and calculation information stored in advance in the ROM 64.

By the way, in this embodiment, the computer 4
The pulse signal output from 0 is a first valve drive signal that opens and closes the first solenoid valve 32, a second valve drive signal that opens and closes the second solenoid valve 34, and a third valve drive signal that opens and closes the third solenoid valve 37. It's summery. The solenoid valves 32, 34, and 37, which are respectively opened and closed by the first valve drive signal, the second valve drive signal, and the third valve drive signal, cooperate to adjust the pressure in the pressure chamber 26 of the pressure response device 22, and act as bypass valves. The amount of intake air is controlled by controlling the opening degree of the valve 20.

In addition, the computer 40 also outputs a cylinder deactivation control signal that turns on and off an oil control valve (hereinafter referred to as "OCV") 51 as a cylinder number switching valve to control the number of activated cylinders, or an injection amount of the fuel injection device 12. Injection signal and ignition device 44
A lead angle amount signal that determines the lead angle amount is output.

That is, the method and apparatus of this embodiment uses the computer 40 to determine the number of operating cylinders and the fuel injection device 12.
The purpose is to perform comprehensive control of the engine by adjusting the amount of injection, the amount of advance of the ignition device 44, and the opening degree of the bypass valve 20, but this control is stored in the ROM 64 in advance. This is done by executing various flows according to instructions from the CPU 60.

Next, we will explain these flows, but here we will mainly focus on bypass valve 2 depending on the number of operating cylinders.
The flow for adjusting the opening degree of 0 will be explained.

Next, we will explain these flows, but here we will mainly focus on bypass valve 2 depending on the number of operating cylinders.
The flow for adjusting the opening degree of 0 will be explained.

That is, the condition determination flow A for identifying the operating state of the engine E as shown in FIG. 3, and the three solenoid valves 32, 34, 37 as shown in FIG.
Valve opening degree control flow B for controlling the opening degree of the bypass valve 20 by driving the valve, rotation speed setting flow C for setting the target rotation speed during idling as shown in FIG. 5, and OCV 51 as shown in FIG. The cylinder number switching timing flow D, which determines the operation timing of the cylinder number changeover timing flow D, will be explained.Selection of each flow is made by an interrupt signal from the CPU 60.

Of these flows, the condition determination flow A is executed in synchronization with the ignition pulse of the ignition device 44, and the valve opening control flow B has a relatively short period t ₁
is executed in synchronization with the interrupt signal of the first timer of
The rotation speed setting flow C is executed in synchronization with the interrupt signal of the second timer with a relatively long period t ₂ (about 4 to 5 times the period of the first timer), and the cylinder number switching timing flow D is executed using the second timer. This is executed in synchronization with the interrupt signal of the third timer, which has approximately the same period _t2 .

In the condition determination flow A shown in FIG. 3, the operating state is read at A-0, and A-1
, the first basic target opening characteristic P ₄ (TW) during 4-cylinder idling operation (see symbol P ₄ (TW) in Fig. 8) and the first target rotation speed characteristic N during 4-cylinder idling operation. ₄ (TW) [See number N ₄ (TW) in Figure 7]
Also, a second basic target opening characteristic P ₂ (θ, N) during two-cylinder idling operation, and a second target rotation speed N ₂ during two-cylinder idling operation are set.

Note that TW is the engine cooling water temperature, θ is the throttle opening, and N is the engine rotational speed.

Then, at A-2, it is determined whether the engine E is starting. Specifically, when the ignition switch is turned on and the engine rotational speed Nr is below the set rotational speed (for example, 200 rpm), it is determined that the engine is starting.

If it is determined that it is time to start, A-3 instructs 4-cylinder operation, and A-4,
Instructs control at startup. At this time, the bypass valve 20 is instructed to be fully open.

If it is determined that it is not the start time, it is determined in A-5 whether or not the idle switch 48 is on, and if it is off, that is, if the throttle opening is not fully closed, then in A-6, It is determined which of the operating states a, b, and c (see FIG. 9) the operating state is.

In addition, if the idle switch is on, that is, if the throttle opening is fully closed, it is determined in A-7 which of the operating states d, e, and f (see Figure 9) is in operation. Ru.

If it is determined that the operating state is a (e.g., corresponding to a low-speed, low-load operating state), it is determined in A-7' whether the cooling water temperature is lower than the temperature in the steady operating state. .

If it is determined that the operating state is b (corresponding to a high-load operating state or a high-speed operating state, for example), in A-8, 4-cylinder operation is instructed, and the
At -9, an instruction is given to fully open the bypass valve.

If the warm-up is almost completed and the cooling water temperature is not low at A-7', two-cylinder operation is instructed at A-10, and bypass valve opening control is instructed at A-11.

In addition, if the operating state is determined to be C (corresponding to an extremely low speed operating state, for example), or if the operating state is a and the cooling water temperature is determined to be low,
At -12, four-cylinder operation is instructed, and at A-13, bypass valve opening control is instructed, similar to A-11.

Furthermore, if it is determined that the operating state is d (for example, a 4-cylinder idling operating state or a 4-cylinder engine braking operating state at low speed corresponds to this), 4-cylinder operation is instructed in A-14. hand,
In A-15, the rotation speed deviation ΔN between the actual engine rotation speed Nr and the first target rotation speed _N4 for 4-cylinder idling operation is calculated, and in A-16, this deviation ΔN is calculated as a predetermined number. compared to n.

If it is determined that the operating state is e (corresponding to, for example, a two-cylinder idling operating state or an engine braking operating state), in A-17, check whether the cooling water temperature is lower than the temperature in a steady operating state. is determined, and if the cooling water temperature is not low, A-
At step 18, it is determined whether the transmission is in a low gear (low or second gear). Then, if the transmission is not in a low gear, two-cylinder operation is instructed at A-19.
After that, at A-20, the actual engine speed
The rotational speed deviation ΔN between Nr and the second target rotational speed _N2 for two-cylinder idle operation is calculated, and A
-16, this deviation ΔN is compared with a predetermined number n.

Even if it is determined that the operating state is e, if the cooling water temperature is low or the transmission is in a low gear, instruct 4-cylinder operation in A-14 and then Take the calculation processing route from A-15 to A-16.

If it is determined that the deviation ΔN is smaller than the predetermined number n, then in A-21, the vehicle speed is 1 km/h.
It is determined whether the vehicle speed is smaller than h, and the vehicle speed is 1.
If it is smaller than Km/h, in A-22,
ISC is instructed, and if the vehicle speed is greater than 1 km/h, bypass valve opening control is instructed at A-23.

If it is determined that the operating state is f (corresponding to the engine brake operating state, for example), A
At -24, a four-cylinder operation is instructed, and at A-25, a deceleration operation is instructed.

Note that if it is determined in A-16 that the deviation ΔN is larger than the predetermined number n, a deceleration operation instruction is given in A-25.

Next, the explanation will move on to the opening degree control flow B shown in FIG.

First, when executing opening control flow B,
Initialization of the position sensor 38 is performed. This occurs when the ignition switch is turned on before starting.
This is done immediately after clearing (setting to zero) the values held at each address in the RAM 62, and first, the position sensor corresponding to the opening position (i.e., fully closed position) of the bypass valve 20 before starting 38 output (voltage) is A/D converted and inputted to address A ₀₀ of RAM 62 as initial position information,
Next, from the value φ 0 of A _{00 ,} the movement range information φband giving the permissible movement range of the bypass valve 20 stored in advance in the ROM 64, and the minimum opening degree setting information φ〓 also stored in the ROM 64, the first and the first Calculate the minimum value φmin and maximum value φmax of the setting information that gives the target opening of 2, and store them in the RAM.
62 addresses A ₀₁ and A ₀₂ . That is, A ₀₁ =φ ₀ +φ〓, A ₀₂ =φ ₀ +φ△+φband, but in this case, φ△ is an extremely small value, and φ〓
+φband corresponds to a value slightly smaller than the distance between the mechanically determined fully closed position (position in contact with the valve seat) and fully open position (position determined by a stopper, not shown) of the bypass valve 20, and the bypass valve 20 The relationship between the actual position (opening degree) of 20 and the opening degree information input to the RAM 62 is as shown in FIG. Therefore, the bypass valve 20
The position (opening degree) is the position (opening degree) corresponding to φmin
and the position (opening degree) corresponding to φmax, the opening degree is controlled to reach the first and second target opening degrees as described later. Incidentally, at this time, each target opening degree, which will be described later, is also given between the above-mentioned φmin and φmax.

After the initial setting is performed in this way, the opening control flow B is executed in synchronization with the interrupt signal of the first timer to operate the bypass valve driving means, but in this flow B, at B-0, It is determined whether the control instruction at the time of start-up (processing indicated by A-4 in FIG. An instruction is given to set it to ₀ .

In addition, if there is no control instruction at the time of starting, B-2
, instructions for deceleration operation (A- in Fig. 3) are given.
25) has occurred.
When a deceleration operation instruction is given, an instruction is issued at B-3 to set the bypass valve opening P to fully closed Pc.

Conversely, if there is no instruction for deceleration operation, it is determined in B-4 whether two-cylinder operation is being performed.

If it is determined that it is two-cylinder operation, B-5
At B-6, the second basic target opening _P2 for two-cylinder operation is taken in, and at B-6,
It is determined whether the actual engine rotation speed Nr is larger than a predetermined number N ₀ between the target rotation speeds N ₂ and N ₄ .

And if the rotation speed Nr is greater than N ₀ ,
At B-7, an instruction to set the bypass valve opening P to P ₂ +Δφ is issued, and if the rotational speed Nr is smaller than N ₀ , at B-8, the bypass valve opening P is
An instruction is issued to make P ₂ +Δφ+Δφ ₂ . Here, Δφ is as follows in flow C shown in FIG. 5, which will be described later.
A value that is updated every t ₂ , and Δφ ₂ is a positive correction value for correcting the second target opening degree to the increasing side and opening the bypass valve 20 .

The reason why the bypass valve opening degree P is changed depending on whether the rotational speed Nr is larger than _N0 or smaller is as follows.

That is, the first target rotation speed N ₄ for 4-cylinder idle operation is 2 as shown in FIG. 11a.
Second target rotation speed N ₂ for cylinder idle operation
Therefore, if you immediately switch from 4-cylinder operation to 2-cylinder operation (hereinafter referred to as "4 → 2 switching"), the second target rotation speed will remain in 2-cylinder operation immediately after that. The engine rotates at the first target rotational speed _N4 , which is smaller than _N2 , which causes problems such as increased vibration and engine stall.

Therefore, it is desirable to increase the engine speed in advance to bring it closer to the second target speed N ₂ before the 4→2 changeover is completed. In order to compensate for the transient phenomenon, processes B-6, B-7 and B-8 are performed to function as a second rotational speed control means. This is shown in a timing diagram as follows:
11a to 11d, FIG. 11a is a diagram showing the transient state of the engine speed as described above, FIG. 11b is a diagram showing the transient state of the bypass valve opening P, and FIG. FIG. 11c is a diagram showing the timing of issuing a switching command (4→2 switching command) from the four-cylinder operating state to the two-cylinder operating state, and FIG. 11d is a diagram showing the timing of switching from 4 to 2. As can be seen from these figures, after the switching command is issued until the engine speed reaches N ₀ , the correction value Δφ ₂ is added to P ₂ (processing in B-8), and the engine speed but
When N ₀ is exceeded, addition of the correction value Δφ ₂ is stopped (processing B-7).

Note that the second basic target opening degree P ₂ is the same as the first basic target opening degree P ₄ as shown in FIGS. 8 and 11b.
is set smaller than.

Furthermore, the number of cylinders is switched by switching the OCV 61, and a cylinder number switching timing flow D shown in FIG. 6 is used as a flow for switching the OCV 51.

In this flow D, at D-0, OCV5
It is determined whether or not a switching command of 1 has been received. If there is no switching command, the process returns without any processing. If there is a switching command, 4 → 2 is changed in D-1.
It is determined whether it is a switching command.

If it is a 4→2 switching command, the engine rotation speed Nr is compared with a predetermined number N ₀ in D-2, and Nr>N ₀
If so, 4→2 switching is performed at D-3, and if Nr> _N0 , an instruction to wait until the engine speed Nr reaches _N0 is issued at D-4, When Nr>N ₀ , the process moves to D-3.

In addition, if it is not a 4→2 switching command, at D-5, switching from 2 cylinder operation to 4 cylinder operation (2→
4 switching) is performed.

In addition, in the case of "NO" in the process of D-2, a loop process of returning to the input side of D-2 again may be performed.

Further, instead of the processes D-2 and D-4, a timer process may be performed that delays the process by a certain period of time.

By the way, if it is determined at B-4 in FIG. 4 that the operation is not two-cylinder operation, that is, four-cylinder operation, then it is determined at B-9 whether or not an instruction to fully open the bypass valve has been given.

If there is no such instruction, in D-10,
The basic target opening characteristic P ₄ (TW) is taken in, and in B-11, the bypass valve opening P _is
An instruction to set the value to +Δφ is issued.

Also, if the bypass valve is instructed to fully close,
At B-12, it is determined whether 2→4 switching has occurred, and if not, a command is issued at B-13 to set the bypass valve opening P to fully closed P _c ; If the switching occurs, a flag processing (expressed as K=1 in FIG. 4 for convenience) is performed at B-14 to operate the third solenoid valve 37 and open the auxiliary atmospheric passage 31. After that, the process moves to B-13.

The reason why flag processing is performed at the time of switching from 2 to 4 is as follows. In other words, in this type of deactivated engine, from the viewpoint of fuel efficiency, etc., the cross point (4 cylinder operating output and 2 cylinder operating output at the same throttle valve opening)
The line indicated by the symbol _l1 in FIG. 9 is the line indicating the cross point region at the point where the cylinder operating outputs are the same. ), the 2-cylinder operating range is expanded to a higher engine speed range than the 2-cylinder engine speed range, and for this reason, when switching from 2 to 4 is performed due to acceleration, etc. (indicated by the symbol l ₂ in Figure 9). If the cylinder enters region b even after cutting the line, there is a risk of shock due to the difference between the 4-cylinder operating output and the 2-cylinder operating output at this time, so the bypass passage 18 is opened and the 2→
The 2-cylinder operating output during 4-cylinder switching is increased to match the output during 4-cylinder operation to prevent shock.

However, if the output is increased until after switching to 4-cylinder operation, the 4-cylinder operating output will increase and a shock will occur again, so immediately after switching from 2 to 4, the bypass valve 20 should be fully closed and the engine It is necessary to lower the rotation speed. Then, the third solenoid valve 37 is opened and the auxiliary atmosphere passage 3 without an orifice is opened.
1, a flag is raised for actuation of the third solenoid valve in order to cause atmospheric air to act on the pressure chamber 26 of the pressure response device 22 within a short time.

And B-1, B-3, B-7, B-8, B
-11, B-13, etc. are completed, the actual opening degree Pr of the bypass valve 20 is read in B-15 based on the signal from the position sensor 38, and then the target opening degree P is read in B-16. The opening deviation ΔP from the actual opening Pr is calculated, and at B-17, |ΔP
It is determined whether | is larger than a predetermined number γ (width of dead zone). If ΔP is within the dead zone (|ΔP|≦γ), an instruction is given not to perform opening control.

On the other hand, if |ΔP|>γ, in B-18,
Processing is performed to calculate the solenoid drive time Tr, T ₀ corresponding to |ΔP| and read it into the register.
At B-19, it is determined whether flag processing has been performed (whether K=1).

If K=1, it is determined at B-20 whether the valve opening is to be increased, that is, whether ΔP>0. Then, when increasing the valve opening degree, input Tr to the timer Ta of the solenoid of the first solenoid valve 32 (hereinafter referred to as "first solenoid") in B-21, and
The timer Tb of the solenoid of the solenoid valve 34 (hereinafter referred to as "second solenoid") is set to T ₀ (T ₀ ≦Tr).
If ΔP<0 and the valve opening degree is to be decreased, input Tr to the timer Tb of the second solenoid in B-23, and input T 0 or ₀ to the timer Ta of the first solenoid in B-24. Enter 0. The characteristics of the drive times (opening times) ta and tb of the timers Ta and Tb are shown in FIGS. 10a and 10b, respectively.

In this way, the first solenoid and the second solenoid are driven, but at this time, the first solenoid is energized only for the driving time ta given by the timer Ta, opens the first solenoid valve 32, and operates at other times. is de-energized and closes the first solenoid valve 32, while the second solenoid is de-energized only for the driving time tb given by the timer Tb, opening the second solenoid valve 34, and is energized at other times to close the first solenoid valve 32. 2 solenoid valve 34 is closed. Therefore, when ΔP>0, the opening time of the first solenoid valve 32 is reduced as shown in FIG. 10c.
ta (value of timer Ta) is larger than opening time tb (value of timer Tb) of the second solenoid valve 34, and the pressure inside the pressure chamber 26 is reduced by ΔP according to the difference Δt ₁ = ta−tb between the opening times of the second solenoid valve 34 The bypass valve 20 is driven in the opening direction. On the other hand, when ΔP<0, the opening time tb (value of timer Tb) of the second solenoid valve 34 is greater than the opening time ta (value of timer Ta) of the first solenoid valve 32, as shown in FIG. 10d. , the pressure inside the pressure chamber 26 is increased by ΔP according to the difference Δt ₂ =tb−ta between the two valve opening times, and the bypass valve 20 is driven in the closing direction.

The ΔP characteristic inside the pressure chamber 26 that changes in this way is shown in FIG. 10e.

And after that, in B-25 and B-26,
The first and second solenoids are driven until Ta=0 and Tb=0.

By the way, if it is determined in B-19 that K=1, then in B-27 a process is performed to the effect that the third solenoid valve 37 will not be operated in the next routine (expressed as K=0 for convenience). , then B
At -28, Tr is input to the timer Tc of the solenoid of the third solenoid valve 37 (hereinafter referred to as "third solenoid"), and the third solenoid is driven until Tc=0 at B-29.

Next, the rotation speed setting flow C shown in FIG. 5 will be explained. First, at C-0, it is determined whether ISC has been designated, and if ISC has not been designated, the process returns without doing anything. On the other hand, if ISC is instructed, the actual rotation speed Nr of engine E is read in C-1,
At C-2, it is determined whether a two-cylinder operation instruction has been issued.

In the case of two-cylinder operation, it is determined in C-3 whether a predetermined time has elapsed after switching from 4 to 2, and if not, in C-4, the control amount Δφn for opening and closing the bypass valve is determined. Set to 0.

On the other hand, if the predetermined time has passed, C-5
At C-6, the second target rotation speed N ₂ for two-cylinder idle operation is read, and at C-6, the actual engine rotation speed Nr and the second target rotation speed N ₂ are read.
The rotational speed deviation ΔN ₂ is calculated.

Then, in C-7, the deviation ΔN ₂ is a predetermined number ε ₂
(width of dead zone) is determined.
If ΔN ₂ is within the dead band (ΔN ₂
≦ε ₂ ), the control amount Δφn is set to 0 in C-8, and if ΔN ₂ is outside the dead zone (ΔN ₂ >
ε ₂ ), a control amount Δφn corresponding to ΔN ₂ is set in C-9.

Also, if it is a 4-cylinder operation, in C-10, 4
First target rotation speed N ₄ for cylinder idle operation
is read, and at C-11, a rotation speed deviation ΔN ₄ between the actual engine rotation speed Nr and the first target rotation speed N ₄ is calculated.

Then, in C-12, the deviation ΔN ₄ is a predetermined number ε ₄
(width of dead zone) is determined,
If ΔN ₄ is within the dead band (ΔN ₄
≦ε ₄ ), the control amount Δφn is set to 0 in C-13, and if ΔN ₄ is outside the dead zone (ΔN ₄ >
ε ₄ ), a control amount Δφn corresponding to ΔN ₄ is set in C-14.

In addition, the control amount Δφn set in C-9
(Now, this is called Δφn _2. ) is the control amount Δφn (now, this is called Δφn ₄ ) set in C-14.
is set to k times.

In other words, if the rotation speed deviation is the same, Δφn ₄ >
Set k so that Δφn ₂ .

And C-4, C-8, C-9, C-13, C
When the processing of -14 etc. is completed, in C-15,
The calculation Δφ=Δφ+Δφn is performed, and this Δφ is used for B-7, B-8, B-11, etc. of the aforementioned flow B.

In this way, the target rotation speed setting means for setting the first target rotation speed N ₄ for the four-cylinder idle operation and the second target rotation speed N ₂ for the two-cylinder idle operation, and the target rotation speed The first or second target rotation speed N ₄ set by the number setting means,
Engine E detected by N ₂ and ignition device 44
The deviation information Δφn 2 , Δφn ₄ related to the rotation speed deviation ΔN ₄ , ΔN ₂ between the actual rotation speed Nr and the first or second target rotation speed N 4 , N ₂ is obtained by comparing the actual rotation speed Nr with the actual rotation speed _{Nr .} A first target opening degree for four-cylinder idle operation or a second target opening degree for two-cylinder idle operation is set based on the deviation information calculation means to be calculated and the calculation result from this deviation information calculation means. A target opening setting means, and a first or second target opening set by the target opening setting means in response to a signal from the operating cylinder number control means during idling, and a bypass valve detected by the position sensor 38. Comparing with the actual opening Pr of 20, this actual opening is the first or second.
The pressure response device 22 is controlled to the target opening degree of
actuator control means for outputting a driving control signal to the first to third solenoids for driving, and switching command detection means for detecting a switching command from four-cylinder operation to two-cylinder operation of the engine; , and correction value setting means for setting a correction value Δφ ₂ for correcting the second target opening to the increasing side in response to the signal from the switching command detection means. The control block diagram is shown in FIG. 2. In this figure 2,
The control period of the part surrounded by the code M is t ₁ , and the control period is the part surrounded by the code N
The control period of the part surrounded by is _t2 .

In this way, this device updates the control amount Δφ according to the engine speed every time _t2 , and also opens the bypass valve every time _t1 , which is 1/5 to _1/4 shorter than time t2. Engine speed control is performed while updating the control amount (valve opening time) t according to the engine speed.

Since the engine speed control device of the present invention is configured as described above, for example, during four-cylinder idling operation, the operating state is determined in flow A shown in FIG. 3, and then as shown in FIGS. ,time
For every t ₂ , the actual rotation speed Nr during 4-cylinder idling operation
A control amount Δφn ₄ is set according to the deviation ΔN ₄ between the target rotation speed N ₄ and the first target rotation speed N ₄ , and as shown in FIGS. Add the basic target opening P ₄ and calculate the deviation ΔP between this addition result and the actual opening Pr of the bypass valve 20 at time t ₁
(This time t ₁ is updated every 1/5 to 1/4 of t ₂ ),
The pressure response device 22 is operated according to the valve opening time t corresponding to this ΔP, and the bypass valve 20 is operated. As a result, engine E is 4
First target rotation speed N ₄ for cylinder idle operation
Rotate with. In this way, since there is a double feedback loop of the feedback of the bypass valve opening and the feedback of the engine speed, and these feedback periods t ₁ and t ₂ are different, the engine E The engine speed can be quickly set to the first target rotational speed, thereby ensuring stable engine operation.

Also, during two-cylinder idling operation, the third
After the operating state is determined in flow A shown in the figure,
As shown in Figs. 2 and 5, at every time t ₂ , the control amount Δφn is determined according to the deviation ΔN ₂ between the actual rotation speed Nr during two-cylinder idling operation and the second target rotation speed N ₂ (>N ₄ ). ₂
(<Δφn ₄ ) is set, and as shown in Figs. 2 and 4, the second basic target opening P ₂ for two-cylinder operation and a correction value Δφ ₂ are added to this control amount Δφn ₂ as necessary. , this addition result and the actual opening degree of the bypass valve 20
The deviation ΔP from Pr is updated every time _t1 , and the pressure response device 22 is operated according to the valve opening time t corresponding to this ΔP, thereby operating the bypass valve 20. As a result, the engine E rotates at the second target rotation speed _N2 for two-cylinder idle operation.

Also in this case, the dual feedback loops with different update periods allow the engine E to quickly settle to the second target rotational speed, thereby ensuring stable engine operation.

As described above, according to this embodiment, the position sensor 38 is provided to detect the opening degree of the bypass valve 20, and the position sensor 38 is set based on the actual opening degree Pr detected by the sensor during idling operation of the engine and the rotation speed deviation. The opening degree of the bypass valve 20 is controlled by the opening deviation ΔP from the first and second target opening degrees so that the engine rotation speed Nr becomes the first and second target rotation speeds N ₄ and N ₂ . Since it is configured as 4
Rotational speed control suitable for each of cylinder idling operation and two-cylinder idling operation can be performed extremely quickly, and problems such as engine stalling during idling operation can be reliably prevented.

By the way, when switching from 4 to 2, the engine speed is brought close to the second target speed N ₂ during two-cylinder idling operation before the switch is completed, so engine vibration is reduced and the engine It is possible to prevent stalls.

Furthermore, when the rotation speed deviation is the same, the values of Δφn ₄ and Δφn ₂ are set as different values (specifically, Δφn ₄ > Δφn ₂ ), so they are optimal for 4-cylinder or 2-cylinder operation. The engine speed can be controlled under the following conditions.

Furthermore, in the above embodiment, when a sudden change in engine speed occurs during ISC, a larger correction opening is set according to the amount of change and the opening of the bypass valve 20 is controlled, thereby quickly resolving the sudden change. Then, when the above-mentioned sudden change condition is resolved, the corrected opening degree is set to a small value and opening control is performed, and then target opening control is performed based on the normal rotation speed deviation, so that the idle rotation This has the effect that fluctuations in the number of rotations can be quickly removed and the idle speed can be stabilized extremely quickly.

Furthermore, according to the above embodiment, the bypass valve 20
A means is provided for A/D converting the output of the position sensor 38 corresponding to the initial opening position (fully closed position) of the bypass valve 20 and reading it into the computer 40 as initial position information of the bypass valve 20. Since the opening degree of the valve 20 is controlled, there is no need to input the initial position information of the bypass valve into a computer for each engine during engine manufacture, as is the case with conventional methods, and the work required during engine assembly is reduced. This results in a significant improvement.

Further, according to the above embodiment, the initial position information input to the address A ₀₀ of the RAM 62 and the ROM 6
4, set φmin and φmax based on the information φband and φ〓 stored in 4, and set the mechanically set minimum opening of the bypass valve 20 (fully closed state).
It is configured to be controlled within the range from φmin, which is slightly more open, to φmax, which is slightly closed than the mechanically set maximum opening (fully open state), and the opening of the bypass valve 20 is controlled in response to pressure. device 22
This is uniquely set at the equilibrium point between the magnitude of the negative pressure in the pressure chamber 26 and the biasing force of the spring 36, so that when the bypass valve 20 is displaced from any opening position to another opening position. Even if it is, the displacement is quickly performed by controlling the pressure in the pressure chamber 26 based on the drive of the solenoid valves 32, 34, and 37, and there is an effect that delays in opening degree control are prevented.

Furthermore, in the above embodiment, a check valve 33 is disposed in the negative pressure passage 28 to allow fluid to move only from the first solenoid valve 32 side to the intake passage 8 side, so that the manifold negative pressure is small and fluctuates. Even during a large startup cranking, when the absolute value of the negative pressure is relatively large, the gas in the pressure chamber 26 is sucked into the intake passage 8 side via the first solenoid valve 32, and this state is maintained by the check valve 33. Therefore, a relatively large negative pressure is applied in the pressure chamber 26 even during starting cranking, and it is possible to improve the startability of the engine.

Furthermore, in the above embodiment, the manifold negative pressure conducted to the pressure chamber 26 is applied to the first solenoid valve 32.
The atmosphere communicated to the pressure chamber 26 is controlled by the second solenoid valve 34, and the pressure in the pressure chamber 26 according to the opening degree of the bypass valve 20 is controlled by the operating time of both solenoid valves 32, 34. This eliminates the limit on the minimum drive time, which was a problem when operating with a single solenoid valve, and allows The pressure inside the pressure chamber 26, that is, the bypass valve 20, can be adjusted accurately in response to minute deviations.
The opening degree of the bypass valve 20 can be controlled, and in ISC, the rotation speed can be quickly stabilized, and on the other hand, in opening control, the opening degree of the bypass valve 20 can be quickly optimized. .

Further, a third solenoid valve 37 is interposed in the auxiliary atmospheric passage 31 without an orifice, and this third solenoid valve 37
Since the solenoid valve 37 opens the auxiliary atmosphere passage 31 when switching from 2 to 4 and causes the atmosphere to suddenly act on the pressure chamber 26, a shock-free operation can be performed when switching from 2 to 4.

Furthermore, in the above embodiment, the idle switch 48
Based on the output of the vehicle speed sensor 54, the idling operating state of the engine is detected when the vehicle is stopped, and the idle switch 48 and the vehicle speed sensor 54
The system is configured to detect the idling operating state of the engine when the vehicle is running based on the output of the It is possible to stabilize the idling rotation speed when the vehicle is running, and it is possible to prevent engine stall when the vehicle is running.

Note that when the atmosphere acts on the pressure chamber, the bypass valve 2
When a pressure-responsive device that drives 0 toward the open side is used as an actuator, the auxiliary atmospheric passage 3
1, an auxiliary negative pressure passage without an orifice is provided alongside the negative pressure passage in the same manner as in the previous embodiment,
A third solenoid valve is interposed in this auxiliary negative pressure passage.

Further, in the above embodiment, the pressure responsive device 22, that is, the negative pressure motor, which operates the intake negative pressure based on the pressure difference between the atmospheric pressure and the atmospheric pressure, was used as the actuator.
A DC motor may be used as the actuator, and the rotational force of the DC motor generated by electric power may be transmitted to the bypass valve 20 via a reduction gear device to drive the bypass valve 20.

Further, in the above embodiment, a bypass passage 18 is provided to bypass the throttle valve 10 that is manually operated, and a bypass valve 20 installed in the passage 18 is driven to perform comprehensive output control of the automobile engine including the ISC. However, when only idling is considered as engine output control, as in this device, an actuator that changes the minimum opening position of the throttle valve, which is manually operated, is provided, and the throttle valve is controlled during idling. The engine speed may be adjusted by controlling the minimum opening degree.

Furthermore, in the above embodiment, the rotation speed control is performed when the automobile engine is idling, but in the engine rotation speed control device of the present invention, a plurality of target rotation speeds are set according to the load condition, The present invention can also be applied to, for example, a cylinder-stopped engine for agricultural machinery, etc., in which control is performed so that the actual engine speed approaches the target engine speed. In this case, since the throttle valve is usually not operated manually, the throttle valve can be used as an intake flow rate control valve.

As described in detail above, according to the method and apparatus for controlling a cylinder deactivated engine of the present invention, the following effects and advantages can be obtained.

(1) After warming up, the engine can be rotated at the first and second target rotation speeds suitable for all-cylinder idling operation and partial cylinder idling operation, and the setting to each target rotation speed is quick. This has the advantage of ensuring stable engine operation.

(2) In a deactivated engine, improvements in fuel efficiency and engine starting performance in the operating state where the operating time is the longest among all engine operating times (i.e., the operating state where the engine temperature is steady, which is typical after warm-up is completed) In order to ensure performance at the same time, when switching between partial cylinder idle operation and all cylinder idle operation in the above operating conditions, the idle rotation speed during partial cylinder operation is set to be lower than the idle rotation speed during all cylinder operation. By increasing the idle speed, we aim to ensure stability during partial cylinder idling operation and improve fuel efficiency during all cylinder operation.In addition, when switching from all cylinder operation to partial cylinder operation, it is possible to partially reduce the idle speed in advance. After setting the opening of the intake air control valve to be close to that for cylinder operation,
By actually switching to partial cylinder operation, it is possible to avoid problems such as vibration and stalling that occur when partial cylinder operation is performed at the idle speed for all cylinder operation. This has the advantage that stable engine operation can be ensured by smoothly switching from to partial cylinder operation.

[Brief explanation of the drawing]

The figures show a control method and apparatus for a deactivated engine as an embodiment of the present invention, in which Fig. 1 is a schematic explanatory diagram showing the overall configuration, Fig. 2 is a control block diagram thereof, and Figs. 3 to 6. are flowcharts to explain their actions, Fig. 7 is the target rotation speed vs. water temperature characteristic diagram, and Fig. 8 is the basic target opening degree.
Water temperature characteristic diagram, Figure 9 is the engine output characteristic diagram,
Figures 10a to 10e are all operational characteristic diagrams of the actuator, Figures 11a to d are timing diagrams to explain the action, and Figure 12 is a schematic diagram to explain the action. . 2...Engine body, 4...Exhaust manifold, 6...
Intake manifold, 8... Intake passage, 10... Throttle valve, 12... Fuel injection device, 13... Solenoid valve, 14
...Air flow meter, 16...Air cleaner, 18
...Bypass passage, 20...Bypass valve as a control valve, 22...Pressure response device as an actuator, 24...Diaphragm, 26...Pressure chamber, 28...
Negative pressure passage, 30... Atmospheric passage, 31... Auxiliary atmospheric passage, 32... First solenoid valve, 33... Check valve, 3
4... Second solenoid valve, 35a, 35b... Orifice, 36... Spring, 37... Third solenoid valve, 38... Position sensor, 40... Computer, 42... Air flow sensor, 44... Ignition device as rotation speed sensor, 46 ...Cooling water temperature sensor, 4
8...Idle switch as an idle sensor,
51... Oil control valve, 54... Vehicle speed sensor, 56... Throttle opening sensor, 57... Battery, 58... Input waveform shaping circuit, 60... CPU,
62...RAM, 64...ROM, 66...output waveform shaping circuit, E...engine.

Claims (1)

[Scope of Claims] 1. A means for controlling the number of activated cylinders that issues a command signal for selectively operating all cylinders or some cylinders during idle operation after completion of warm-up; Equipped with means for switching the number of activated cylinders to switch between cylinder operation or partial cylinder operation, and setting the idle rotation speed during partial cylinder operation to be higher than the idle rotation speed when all cylinders are operated after completion of warm-up. , when the operating cylinder number control means issues a command signal to switch from all cylinder operating operation to partial cylinder operating operation during idling operation after completion of warm-up, the idle speed of the engine changes to partial cylinder operating operation. The operating cylinder number switching means switches from full cylinder operation to partial cylinder operation after setting the opening of the control valve that adjusts the intake air amount of the engine so that it approaches the idle speed of the engine. A control method for a deactivated engine. 2. Operating cylinder number control means for issuing a command signal to selectively perform all-cylinder operation or partial cylinder operation at least during idling operation after completion of warm-up;
A control valve that adjusts the intake air amount of the engine; a control valve that adjusts the intake air amount of the engine; The control valve opening degree is adjusted based on the output of the operating cylinder number control means so that the engine rotation speed becomes a second idle rotation speed higher than the first rotation speed during partial cylinder idle operation. a first engine rotation speed control means for controlling the rotation speed of the engine, and a command signal for switching from all-cylinder operation to partial cylinder operation is issued by the active cylinder number control means during idling operation after completion of warm-up; Immediately after, it temporarily operates with priority over the first engine speed control means, and controls the control valve opening to an opening corresponding to the first idle speed when all cylinders are operated by the first engine speed control means. a second engine rotation speed control means for setting the engine rotation speed to be larger than the second idle rotation speed, and controlling the number of activated cylinders from full cylinder operation to partial cylinder operation during idling operation after completion of warm-up; A control device for a cylinder-deactivated engine, comprising a delay means for delaying the start of operation of the operating cylinder number switching means when a command signal for switching to operation is issued.