JPS6027740A - Control apparatus for engine capable of changing the number of cylinders to be operated - Google Patents

Abstract

PURPOSE:To prevent fluctuation of torque of an engine designed to be capable of changing the number of cylinders to be operated, by raising the idling speed to the target idling speed at the time of decreasing the number of cylinders to be operated, and then decreasing the number of operated cylinders at the time of decreasing the number of cylinders to be operated. CONSTITUTION:In an engine 1 which is designed to be capable of changing the number of cylinders to be operated and has a cylinder selector 8 for controlling operation of intake and exhaust valves, a throttle valve 12 and a by-pass valve 16 are provided in an intake passage 2, and operation of these valves is controlled by a control circuit 20. The control circuit 20 is furnished with output signals of various sensors 21-23 for detecting the operational conditions of the engine. When a signal for requring to decrease the number of cylinders to be operated in produced, the control circuit 20 at first opens the by-pass valve 16 and raises the engine speed to the target idling speed at the time of cylinder- reduced operation of the engine. Then, the number of operated cylinders is decreased by sending a signal to the clyinder selector 8.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention comprises an operating state detection means for detecting the operating state of an engine, and a switching means for switching the number of cylinders to which fuel is supplied in response to an operating signal. The present invention relates to a cylinder number control engine in which the number of cylinders to which fuel is supplied is controlled according to the operating state of the engine.

(Prior art) Cylinder number control engine For example, in a cylinder number control engine in which the number of operating cylinders can be switched between 2 cylinders and 1 cylinder, 2%
In case of multiple operation, the engine operates intermittently and the torque excitation is large, so in order to improve this, some models set the idle speed during 2-cylinder operation higher than the idle speed during q-cylinder operation (for example, , Patent application filed by the applicant in 1939
7-/132/φ publication).

At the end of the day, when driving normally 2 ki W1 and 4! The idle speed during cylinder rotation is controlled by adjusting the amount of intake air (mixture amount) with a pi-R valve installed in the intake passage bypassing the throttle valve, but conventional cylinder number control In the engine, the output timing of the switching signal for the number of cylinders and the output timing of the bypass valve activation signal are set to be the same.
There has been a problem in that engine vibrations due to torque fluctuations occur during the switching transition period when switching to the cylinder, as will be described later. That is, as shown in FIG. 5, the required number of operating cylinders changes from 1 cylinder to 2 cylinders (IIr!!: 1g) in response to changes in the operating state of the engine. At the same time, a switching signal is output and the number of operating cylinders is switched from Hiro cylinder to 2 cylinders (diagram b), and the bypass valve changes from pulp position P9 during Hiro cylinder operation to valve position 4 during 2 cylinder operation. Even if the engine speed is changed (diagram d), the engine rotational speed will instantly change from a low rotational speed (for example, t j Orpm High rotation speed (e.g. 1
After switching to two cylinders, instead of increasing to A30 rpm), the engine speed increases from A30 rpm to A30 rpm with a certain time difference. Therefore, from l cylinder operation to l
During the transition period when the number of operating cylinders is switched to cylinder operation, there is a period in which the engine is operated at an idle speed of less than lr 00 rpm even though it is in two-cylinder operation, in other words, there is an operation period in which torque fluctuations are large. As a result, engine vibrations due to this torque fluctuation occur during the transition period of switching the number of operating cylinders.

(Object of the Invention) The present invention provides a control device for an engine with several cylinders in order to suppress as much as possible engine vibrations caused by torque fluctuations that occur during the transition period from full-cylinder operation to reduced-cylinder operation. It was made for the purpose of providing.

(Structure of the Invention) As shown in the functional block diagram shown in FIG. 1, the engine control device for controlling the number of cylinders of the present invention includes an operating state detection means A that detects the operating state of the engine, and supplies fuel in response to an operating signal. The cylinder number control engine l is equipped with a switching means for switching the number of cylinders, and the number of cylinders to which fuel is supplied is controlled according to the operating state of the engine. an idle speed adjustment means B that sets the idle speed higher than the engine speed; an intake air increase means E that increases the intake air amount in response to an activation signal; A timing control means C is attached, which outputs an operation signal for activating the intake air increasing means and then outputs an operation signal to the switching means to reduce the number of cylinders, thereby changing from full-cylinder operation to reduced-cylinder operation. When a change in the number of cylinders is requested, the above-mentioned intake air increase means E is activated to reduce the idle speed to 2 while all cylinders are in operation.
After raising the idle speed to a value close to the target idle speed during cylinder operation, switch to reduced-cylinder operation, which is caused by torque fluctuations that occur during the transition period when the number of operating cylinders is switched from all-cylinder operation to reduced-cylinder operation. It is characterized by suppressing engine vibration as much as possible.

(Embodiment) FIG. 2 shows an lI-cylinder automobile engine l equipped with a control device according to an embodiment of the present invention. This engine l
is a cylinder number control engine that switches the number of operating cylinders between 1 cylinder and 2 cylinders according to the operating state, and the engine 1 is configured to control the intake valves 1 and exhaust valves of predetermined 2 cylinders among the 1 cylinders. A support member IO is provided at the intermediate portion of the four-wheeled arm 6.6 which is secured to each valve S, and is moved forward and backward in response to a control signal from the mer control circuit 20, and when the support member IO is in the protruding state. 9 is a pair of rocker arm support devices that enable the operation of the rocker arm O and disable the operation of the rocker arm O in the retracted state;
A cylinder selector r consisting of a plurality of cylinders is installed, and the number of operating cylinders of the engine l can be switched between one cylinder and two cylinders by controlling the multi-cylinder selector Ir. In FIG. 2, reference numeral 7 indicates a camshaft for the intake and exhaust valves.

The engine l has an air crevice in its intake passage.
4/, the air flow meter 13, the throttle valve 12, and the fuel injection valve 17 are sequentially installed from the intake upstream side to the intake downstream side, and the bypass passage lS is connected to the bypass passage lS that bypasses the throttle valve /2! A bypass valve 16 is installed which acts to control the idle speed of the engine by regulating the amount of bypass air taken in through the engine. The valve position of this bypass valve L is controlled by an operation signal output from the control circuit 20 depending on the operating state of the engine.
The reference pulp body value P during cylinder operation is set in advance according to the target idle rotation speed during each operation, and is stored in the control circuit 20. That is, lIkiWJ
The standard pulp position limit at the time of arrest is the target idle rotation speed during l-cylinder operation &! ; The amount of bypass air corresponding to Otpm can be obtained at the valve position I, and the standard pulp position P2 during two-cylinder operation can obtain the amount of pipe air equivalent to the target idle rotation speed r 00 rpya during two-cylinder operation. They are set in each category.

Furthermore, a control circuit 20 forming the main body of the control device 2 of the present invention
As a control knob, the current engine speed is detected from a rotation speed sensor 21, and a gear switch 22 outputs an ON signal when the gear shift/chi is in the non-driving position. The current vehicle speed is determined by the vehicle speed sensor 23, the engine cooling water temperature is determined by the water temperature sensor /q attached to the engine L, the current intake air amount is determined by the air flow meter 13, and the throttle valve /2 is in the U5 degree range during idling operation. Whether or not the throttle valve 12 is currently in the idle position is input from the idle switch II which outputs an ON signal when the throttle valve is in the idle position, and based on these input signals, the opening timing and opening of the fuel injection valve 7 are determined. Valve time (
(fuel control), bino f-s valve, /16 position control (adjustment of idle rotation speed), and switching of the number of cylinders by cylinder selector (control of number of operating cylinders), respectively.

This control device 2 is configured to first change the idling speed to 2 cylinders while maintaining 4-cylinder operation when the requested number of operating cylinders changes from t cylinders to 2 cylinders when the engine is in an idling state in 2-cylinder operation. I raised it to near the target idle speed when driving, and when he scolded me, I increased the actual number of operating cylinders to 11gg.
The purpose is to switch from one cylinder to two cylinders, thereby preventing engine vibrations as much as possible when switching between g and number.

The control method by this control device 2 will be explained below based on the control flowchart shown in FIG.

First, when starting the engine, t-cylinder operation is performed from the viewpoint of startability. For this reason, first, in step sI, the correction flag is set to / to initialize the control signal. This correction flag is set during φ cylinder operation, is used when the number of operating cylinders is changed from 1 cylinder to 2 cylinders, and is reset when the number of operating cylinders is completely switched to 2 cylinders.

Next, in step S2, various data indicating the current operating state of the engine l (e.g., engine speed, idle switch state, gear switch state, engine temperature (cooling water temperature), vehicle speed, etc.) are input, and these data are input. Based on the input signal, it is determined in step S1, step S5, and step S whether the engine is currently in an idling operating state or a non-idling operating state (vehicle running state).In other words, the criteria for determining the idling operating state are determined. , the current engine speed n is less than or equal to a preset predetermined speed n, the idle switch/lr is in the ON state, and the gear switch 22 is in the ON state (in the neutral position). When each condition is satisfied, it is determined that the vehicle is in an idling operating state, and if even one of these conditions cannot be satisfied, it is determined that the vehicle is in a non-idling operating state.

Now, if it is determined that the engine l is currently in idle operation, the process proceeds from step Sf to step S7, and in step S&, in the current operating state, 1
It is determined whether cylinder operation or two-cylinder operation is appropriate. In other words, during idling, 2
The conditions for cylinder operation are that the cooling water temperature is above a predetermined value (engine warm-up complete state) and the transmission gear is not in the running position.If these conditions are not met, two-cylinder operation is performed and other In all cases, full-speed fiB operation shall be performed. Immediately after starting the engine, the engine temperature is generally low, so it must be operated on one cylinder, so #
The control steps proceed from step s6 to step S via step S7.

In step S1, the target idle rotation speed mv (= f 00 rp weight) in I1% 1 cylinder operation is calculated, and further in step s1, from the current rotation speed and the target idle rotation speed n - deviation, the bypass valve l Calculate the correction amount. A final correction amount Pvo for the bypass valve/≦ is calculated from this second correction amount Δ- and the reference valve position value for the Hiro cylinder operation (step 5Ho), and further this final correction amount P. The bypass valve 16 is controlled based on k (step S//), and the engine l is operated for one cylinder (step 5th). ≠ After controlling the cylinder operation, the process returns to step S again, and the above control operation is repeated until the operating state shifts to non-idling operation or the conditions for performing two-cylinder operation in idling operation are satisfied. .

Changes in the rotational speed, etc., and the state in this case are shown in control mode I in FIG. 1I.

If the engine temperature rises while idling in 1-cylinder operation and the conditions for 2-cylinder operation are met, the process advances from step Sj to step StS, and furthermore, 1-cylinder operation is still being continued and correction is required. Flag =
Since it is l, the process advances from step SIJ to step S/final side. Below is Step S〆! Until then, change the current idle speed (=GS ORP) while maintaining the 1-cylinder operation to the target idle speed (=r 00
The valve position value of the bypass valve/g is calculated when the bypass valve/g is increased to a value close to the rpm fis' (here, the target idle speed is set), and a predetermined control signal is output to the bypass valve/6. That is, first, in step S2, a provisional target idle speed n9' is calculated when switching the number of operating cylinders from t cylinder to 2 cylinders, and then in step Sσ, this target, target idle speed n-', and current The bypass valve/≦primary correction amount △& necessary to raise the current idle rotation speed nle to the target idle rotation speed nq' from the deviation of the idle rotation speed n of Calculate the final correction jlP of the bypass valve/B from the reference valve position P and the reference valve body position P at the time of air pressure (step s/6). Based on this final correction amount P/17, calculate the spinal signal to the bypass valve/≦. is output (step s/2). After the control signal is output, the process returns to step S and 2 via step Sat, and the above control operation is repeated until the current idle speed n reaches the target idle speed n.

If n≧nJ after repeating the control operation several times, the conditions for switching the number of operating cylinders from 1-cylinder operation to 2-cylinder operation have been met, so step S/g to Step S Proceed to step Szo through /F and set the engine l to two-cylinder operation. That is, first, in step 5xr, the target idle rotation speed n2 (=1r00
rpm), and from this target idle rotation speed Tit and the current idle rotation speed n, calculate the primary correction amount of the bypass valve lB necessary to bring the idle rotation speed to the target idle rotation speed nχ in a two-stroke rotation. Calculate P2 (step Si
t), and calculate the final correction amount pxo of the bypass valve /6 from this -order correction amount ΔP2 and the above-mentioned 2-11 operation base valve position change Pg.Step 5z2)
Based on this final correction amount P2σ, a control signal for bypass valve B is output (step 523), and the engine is operated with two cylinders (step S2g). Now from 1 cylinder operation to 2
Switching to cylinder operation is completed. 2 from this l cylinder operation
The state of change in the rotational speed, etc. at the time of switching to cylinder operation is shown as control type Ml in Fig. ; O
Since the number of operating cylinders changes from t cylinders to λ cylinders after increasing the rpm from r 00 rpm, the number of operating cylinders changes from t cylinders to λ cylinders.
There is no region where the engine rotates at idle below r 00 rpm (in other words, a region where torque decrease occurs), so there is little torque fluctuation, and it is possible to prevent the occurrence of engine vibration caused by the torque fluctuation as much as possible. .

- After cylinder operation @ switching 191T, return from step 5r-1 to step 32K, then proceed to step Sho via step Sl and step Sη, and from then on, the required number of operating cylinders of the engine changes from 2 cylinders to 5 cylinders. Alternatively, the above control operation can be repeated until the state changes from idle M rotation to non-idle operation. In this case, the state of change in the rotational speed, etc., is shown in Fig. 1.
I'm playing as N.

If the required operating percentage of the engine changes from 2 cylinders to 2 cylinders while performing idle link in 2-cylinder operation (for example, due to a request for better starting performance, the clutch should be depressed. , when the gear is shifted to the driving position, etc.), the two-cylinder operating condition is not satisfied, so from step S7 to step S? Then, the same control operation as that during operation of the Il cylinder described above is performed. When switching the operating mode from 2-cylinder operation to t-cylinder operation, the cylinder number switching signal and the bypass valve l O operation signal are output at the same timing. Even if the activation signals are output at the same timing, the t r o o rpm is
There is no operating region in which idle rotation occurs below that level, and therefore torque fluctuations hardly occur. Incidentally, the state of change in the number of revolutions and the like in this case is shown by control mode (2) in FIG.

On the other hand, when the vehicle is not idling (when the vehicle is running), step SI,
Step S from either step SP or step S5
Proceed to step ar, and if the required number of operating cylinders of engine l is λ cylinders, the valve body of bypass valve l is set to 2 above.
While the reference valve position is fixed at P2 during cylinder operation,
In addition, when the required number of operating cylinders is ψ cylinders, each operation is performed with the pulp position of the bypass valve L being fixed at the reference pulp position P during operation of the G cylinder.

(Effects of the Invention) The ftR control device for the air pressure control engine of the present invention switches the number of operating cylinders between the ψ cylinder and the 2-cylinder according to the engine operating state, and also controls the idle speed during the 2-cylinder operation. t
In an engine that controls the number of cylinders so that the engine speed is set higher than the idle speed during cylinder operation, if the number of cylinders required to operate the engine changes from ≠ cylinders to 2 cylinders, first ψ
The idle speed is raised to near the target idle speed for two-cylinder operation while cylinder operation is continued, and then the number of operating cylinders is actually switched from ≠ cylinders to two cylinders, so it is two-cylinder operation. While! There is no operating region in which the engine is operated at a rotational speed lower than the target idle rotational speed during cylinder operation, and therefore, torque fluctuations during the transition period when switching from single-cylinder operation to two-cylinder operation are suppressed. This has the effect of preventing the occurrence of engine vibration as much as possible.

Outside drawing fl! Fig. 1 is a functional block diagram of a control device for an engine with controlled number of cylinders according to the present invention, Fig. 2 is a system diagram of a control device according to an embodiment of the present invention installed in an engine with controlled number of cylinders, and Fig. 3 is a control flowchart of the control device in Fig. 2, and Fig. 1I is a control flow chart of the control device in Fig. 2.
FIG. 5 is a control characteristic diagram of the conventional control device.

/...Engine...Intake passage L...Intake valve 2...Exhaust valve 2...Rocker arm R...・Cylinder selector...Rocker arm support device 10...
Support member/2・e...Throttle valve 13...Air flow meter/l...Air cleaner 13...Bypass passage 16...Bypass valve 17...Fuel Embroidery injection valve/r...Idle switch/q...Water temperature sensor 20...Control circuit 21...Rotation speed sensor, 2.2...Gear switch 23 ...Vehicle speed sensor A...Engine rotation speed detection means B--...
Control signal output means C...Intake air ffl adjustment means D...
Load operation timing correction means

Claims (1)

[Claims] l- Equipped with operating state detection means for detecting the operating state of the engine and switching means for switching the number of cylinders to which fuel is supplied in response to an operating signal, and the number of cylinders to which fuel is supplied is controlled according to the operating state of the engine. The number of cylinders is controlled by the engine.
an idle rotation speed iim means for setting the idle rotation speed during reduced cylinder operation to be higher than the idle rotation speed during full cylinder operation; an intake air increase means for increasing the amount of intake air in response to an activation signal; timing control means configured to reduce the number of cylinders by outputting an actuation signal to the switching means at the same time that the actuation signal for actuating the intake air increasing means is outputted when switching from all-cylinder operation to reduced-cylinder operation; A control device for an engine that controls the number of cylinders.