JPS5910757A - Cylinder number exchange controller - Google Patents

Abstract

PURPOSE:To prevent contamination of cylinder and to suppress the variation of torque by blocking fuel supply prior to the suction process when the cylinders of a cylinder number control engine are partially stopped while limiting the open operation of a suction/exhaust valve immediately after suction process and supplying fresh air. CONSTITUTION:Stop side cylinder well 2 of a cylinder number control engine is provided with an actuator 15 for changing the operating characteristic of suction/exhaust valves 1, 17, firing plug 24, and fuel injection valve 23 and controlled by a control circuit 29. When transferring from full-cylinder operation to partial-cylinder operation, fuel supply of fuel injection valve 23 at the stop side cylinder is blocked prior to the suction process while an actuator 15 is driven immediately after the suction process to normal open the exhaust valve 17 at the stop side cylinder and to open the suction valve 1 only at the final stage of the suction process thus to enclose only the fresh air in the stop side cylinder and to supply said fresh air. Consequently contamination of the cylinder due to blow-bye can be prevented and variation of torque can be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cylinder number switching control device for a cylinder number controlled engine that performs partial cylinder operation by suspending the operation of some cylinders in a light engine load range or the like.

In general, when an engine is operated under a high load condition, fuel efficiency tends to improve.For this reason, in a high-pressure front engine, the fuel supply to some cylinders is cut to stop operation when the engine load is low. An engine with controlled number of cylinders was devised in which the load on the remaining active cylinders is relatively increased by this amount, thereby improving overall fuel efficiency in the light load range.

As an example of this type of engine, conventionally, when cutting the fuel supply from the fuel injection valve to some cylinders in the light load range or idling range, the relevant cylinder ( Interplant i! of the intake valve 1 and exhaust valve (not shown) of the cylinder on the idle side) There are known substances that regulate l ffi.

In the figure, 2 cylinder heads, 3 rocker arms, 4 rocker shafts, and 5.6 rocker shafts 4.
7 indicates a camshaft.

This camshaft 7 has a valve spring 8 and a cooperating [
2, the first cam 9 has a profile for opening and closing the intake valve 1 via the rocker arm 3 during the intake stroke during operation; The cams 10 are formed in contact with each other.

On the other hand, the rocker arm 3 is swingable with respect to the rocker shaft 7-4 and is not only swingable with respect to the rocker shaft 7-4 (Z) but also the two brackets).
It is supported so that it can also move in the axial direction between 51 and 6.

A switching ring 11 that is slidable in one direction between the rocker arm 3 and one bracket 5 is fitted to the rocker shaft 4, and the rocker arm 3 is interposed between the switching ring 11 and the switching ring 11. The axial positioning is performed according to the tension balance between the spring 12 of the bracket il and the spring 13 of the bracket χ2 interposed between the other bracket 6.

This switching ring 11 is connected via a rod 14 to an actuator 1 composed of a solenoid or a hydraulic cylinder.
51C! The initial position of the rocker arm 3 is set so that the intake valve 1 opens and closes in accordance with the first cam 9 when the actuator 15 is not in operation.

When the actuator 15 is activated, the switching ring 11 moves 80t toward the bracket 6 due to its driving force, causing
2.13 is compressed, the rocker arm 3 is pushed, and its follower part 16 snaps and transfers to the second cam 1° while in the pace circle castle. Since the second cam 1o has a perfect circular shape with the same diameter as the base circle of the first cam 9, the uo rocker arm 3 does not swing in this state, and therefore the intake valve 1 is held closed. It becomes dormant.

Although not shown, the same valve mechanism as above is provided for the exhaust valve, and therefore, by operating the actuator 15 according to the operating conditions of the engine, the intake and exhaust operations of the corresponding cylinder on the idle side are regulated and controlled.

The operation of the actuator 15, that is, the regulation of the opening operation of the intake valve 1 and the exhaust valve, is controlled by a command from a control circuit (not shown), and for example, when the air idling range is reached, the intake and exhaust valves are kept closed. . At this time, the 1% fuel injection valve corresponding to the idle cylinder is kept in the fully closed state, and the ignition current to the spark plug is cut off.

In this way, the supply of fuel and fresh air to the cylinder on the idle side is cut off, and its operation is suspended, and partial cylinder operation is performed by operating only the remaining cylinder on the active side. The intake air trapped in the side cylinders is repeatedly compressed and expanded, which not only improves fuel efficiency, but also has the advantage that increases in torque fluctuations and rotational fluctuations during partial cylinder operation can be kept relatively low.

However, even if the intake air is trapped in the cylinder on the idle side in this way, the compression pressure in the cylinder will gradually decrease due to the blow piping to the crankcase side occurring during repeated compression and expansion. There is a problem in that the effect of suppressing torque fluctuations and the like cannot be achieved to a certain extent, and instead, irregular vibrations increase.

Depending on the timing of the fuel injection valve's fuel cutoff when transitioning to partial cylinder operation, and the timing of regulating the opening operation of the intake and exhaust valves,
The exhaust gas after combustion may become trapped in the cylinder on the idle side, and this becomes blow pie gas, which has a negative impact on the engine oil)! There was a concern that carbon, carbon, etc. would change in quality and stick to the cylinder wall, causing stains.

This invention was made with a focus on these problems, and when transitioning to partial cylinder operation, the fuel supply is completely cut off before the intake stroke, and the opening operation of the intake and exhaust valves is restricted immediately after the intake stroke. The above problem is solved by confining only fresh air (air) in the cylinder on the idle side and replenishing the fresh air in a timely manner to keep the cylinder white compression pressure stable. The purpose of this invention is to provide a cylinder number switching control device.

Hereinafter, the present invention will be explained based on the drawings.

FIG. 3 is a cross-sectional view showing an embodiment of the present invention, in which ≠ 2 is a cylinder on the idle side, 1 and 17 are intake valves and exhaust valves, and 15 is an intake valve and an exhaust valve.
An actuator (
(solenoid).

An air flow sensor 19 that detects the amount of intake air and a throttle valve sensor 21 that detects the opening degree of the throttle valve 20 are connected to the intake passage 18 connected to the idle cylinder #-2 and the active cylinder (not shown). A fuel injection valve 23 as a fuel supply device is provided in the intake boat 22 corresponding to each cylinder.

That's sweet, 24 is the spark plug, 25 is the distributor,
26 is an ignition coil, and a crank sensor 27 is attached to the distributor 25 to detect the crank position. It generates a signal A and is set to produce a medium-wide pulse when a specific cylinder is activated.

In Part 1~, this signal A, the intake air amount signal, the throttle valve opening signal, the rotation speed signal from the rotation sensor (not shown), the water temperature signal from the cooling water temperature sensor 28, etc. are input to the control circuit 29. Based on these signals, the control circuit 29 controls the drive of the fuel injection valve 23f through the injection signal port,
The primary (t) of the ignition coil 26 is activated by the ignition signal C.
The ignition operation is controlled by turning on and off the ill switch 30, and the shear actuator 15 is switched in response to the valve control signal 2 to control the operating state of the intake/exhaust valves 1 and 17 of the cylinder +2 on the inactive side.

This control circuit 29 includes a medium heat processing circuit (CPU) ai,
Read-only memory circuit <ILOM) 32, read at any time,
It is composed of a programmable memory circuit (RAM) 33 and an input/output circuit (Ilo) 34.

Each signal waveform during all-cylinder operation and intake/exhaust valve 1 on the idle side,
17 is shown in FIG. 4. However, in the example applied to a 4-cylinder engine, +1. +4' is the operating cylinder, na2.
+3ffi is set as the cylinder on the idle side.

Based on the pulse signal A from the crank sensor 27 generated at each exhaust top dead center, the operating order of each cylinder +1 to +4 (
According to the ignition order (S1-S3-S4-S2), an injection signal port is sequentially commanded to each fuel injection valve 23 according to the intake air amount, etc. so that the optimum fuel injection timing can be obtained. The fuel injection timing is set at the beginning of each intake stroke.

Similarly, the ignition signal C is sequentially commanded based on the pulse signal A, and the ignition timing is set by the distributor 25 so that optimum ignition is performed near the compression top dead center of each cylinder 1 to 4.

In addition, valve control signal 2 is OFF, and each actuator 15
are kept at the initial position, and therefore the idle side cylinders +2. 3
Intake/exhaust valve 1. , 17f-1 respectively perform normal opening and closing operations.

On the other hand, FIG. 5 shows signal waveforms during partial cylinder operation in which the operations of cylinders 2 and 4 are completely stopped, and the operating states of the intake and exhaust valves 1 and 17.

Based on the intake air amount signal and rotation speed signal, the injection signal to the fuel injection valve 2; 3 corresponding to the cylinder +2° is cut off in the engine's light load range or idling range, resulting in a fully closed state. At the same time, the corresponding ignition signal C is also cut.

Then, the valve control signal 2 turns ON and each actuator 15 operates, and the cylinders on the idle side +2. +3 intake/exhaust valve 1,
170 opening operation is regulated.

At this time, the exhaust valve 17ii is kept closed, but the intake valve 1 is configured to open somewhat at the end of its intake stroke, as shown. That is, as shown in FIG.
At the predetermined position of the second cam 1o corresponding to the lift part 9a of the first cam 9, a lift part Oa which is considerably smaller in both overall height and operating angle is provided, and the lift part Oa is considerably smaller in both the overall height and the operating angle. +3
A means of supplying fresh air is formed. 1 As a result, full cylinder operation and partial cylinder operation are performed, and when transitioning from this full cylinder operation to partial cylinder operation,
Fuel injection valve 2 on the corresponding idle side cylinder + 2゜ bone 3 before the intake stroke
1. Specifically, a control means (control 1 circuit 29) is provided which cuts off the supply of fuel It and controls the opening operation of the intake and exhaust valves 1 and 17 immediately after the intake stroke. Based on the pulse signal A from the crank sensor 27 that is input to
．． The injection signal port and ignition signal C for +3 are cut off, and the valve control signal 2 is switched ON.

FIG. 7 shows each timing chart at this time. Based on the intake air amount signal from the air flow sensor 19 and the rotational speed signal from the rotation sensor, for example, if a light load region is determined at point A, during the exhaust stroke of cylinder +2 near point A,
In response to the pulse signal A of the crank sensor 27 output at the P cylinder + 40 exhaust top dead center, the corresponding injection (i port is cut and the fuel supply is cut off before the intake stroke of 1 cylinder divided by 2 Similarly, in response to pulse signal A, t
.

Immediately after the suction stroke, the corresponding ignition signal C is cut off and the valve control signal II is switched ON.

In cylinder 3, the injection signal port is cut off before the intake stroke (during the exhaust stroke) in response to the pulse signal A output at the exhaust top dead center of cylinder ÷ 1, which is delayed from this, and the injection signal port is cut off immediately after the intake stroke. The ignition signal C is cut off and the valve control signal 2 is turned on.
can be switched to

Furthermore, when the point A is close to the exhaust stroke of cylinder +3, the above-described control is performed for cylinder +3 earlier than for cylinder +2.

In other words, when switching to partial cylinder operation, the operation 1 to
The cylinder on the idle side that appeared was 4!2. Exhaust valve 1
At the same time, the fuel supply is cut off in the next intake stroke.
Lead to within +3. Then, in this state, stop the ignition, and
The opening operation of the exhaust valves 1,170 is regulated, and partial cylinder operation is entered while supplying fresh air to the cylinders on the inactive side +2°+3 as described above.

Incidentally, FIG. 8 shows each timing chart when returning from partial cylinder operation to full cylinder operation. For example, when entering a high load area from a light load area etc. at point B, the cylinders near this point B +
In response to the pulse signal A corresponding to the end of the intake stroke of 2 (or +3), the supply of the corresponding ignition signal to the injection signal port is restarted immediately after the intake stroke of the cylinder = #2, and the valve control signal is 2 is switched OFF. Then, the supply of the ignition signal and the injection signal port to the cylinder +3 (or +2) is resumed, and the valve control signal 2 is switched OFF.

When returning to this all-cylinder operation, ignition is performed in advance, so the cylinders on the idle side +2. If the fresh air trapped inside the +3 contains residual gasoline or oil mist in the cylinder, this will be burned and have an adverse effect on the exhaust composition W'
This can be avoided.

With this configuration, when transitioning from full cylinder operation to partial cylinder operation, the idle cylinders +2. ≠ 3. It is possible to trap fresh air without fail, and even if it occurs, it will not deteriorate the engine oil, or prevent unburned gas, gasoline in the combustion exhaust, tar, etc. from adhering to the cylinder wall and staining it. things are prevented.

During partial cylinder operation, the idle side cylinder +2. +3 is replenished with fresh air at the end of each suction stroke, so even if it decreases during repeated compression and expansion, it can be filled and a stable high compression pressure can be maintained at all times. As a result, torque fluctuations and rotational fluctuations during partial cylinder operation can be sufficiently reduced, and good drivability can be obtained.

Note that the control of each signal is commanded based on the pulse signal A of the crank sensor 27, but the control of each signal is
70 response time is taken into account. For example, if the exhaust valve 17 cannot be switched in time, separate intake/exhaust valve 1 and 170 operation switching actuators 15 should be provided to set the exhaust valve 17 to switch earlier. Good.

Next, FIGS. 1 and 9 show another embodiment of the present invention, in which the fuel injection valve 23 is injected into the rest side in accordance with the intake valve 1 which is opened at the end of the intake stroke, just before returning from partial cylinder operation to full cylinder operation. Cylinder +2. A predetermined amount of fuel is injected into the +3.

This fuel injection responds to the crank signal A of the crank sensor 27 when the decision to switch the number of cylinders is made at 13 points.
It is performed only once prior to each control operation. Therefore, the cylinder on the idle side +2. The +3 mixture is ignited near the next compression top dead center, combusts and completely explodes, and the cylinder 4F2, +
3 will be restarted.

According to this, when returning to all-cylinder operation, the idle cylinder ÷
2, n) The responsive and smooth operability of 3 can be obtained, and acceleration performance etc. can be improved. Since the fresh air in the cylinders 42 and 43 on the idle side is not directly discharged to the exhaust system upon return, the purifying function can be maintained well when a three-way catalyst or the like is used.

As explained above, according to the present invention, the opening operations of the intake and exhaust valves of some cylinders are fully regulated to perform partial cylinder operation.1. In a cylinder number controlled engine, only fresh air (rush air) is trapped in the cylinders that are inactive during partial cylinder operation, and the fresh air is replenished. This prevents contamination of the cylinders and other parts due to blow-by. This has the effect that torque fluctuations and the like during partial cylinder operation can be sufficiently suppressed, and engine performance and driving performance can be significantly improved.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an example of a valve device CN that regulates the opening operation of an intake valve or an exhaust valve, FIG. 2 is a schematic front view thereof, and FIG. 3 is a cross-sectional view showing a configuration of an embodiment of the present invention. Figures 4 and 5
Figures 7 and 8 are timing charts showing the signal waveforms and operating states of the intake and exhaust valves of the present invention, respectively.
This figure is a partial perspective view of an intake valve cam, and FIG. 9 is a timing chart diagram of another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Intake valve, 3... Rocker arm, 9... First cam, 10... Second cam, 11... Switching ring, 15... Actuator, 17... Exhaust valve, 1
9...airf C-de/break, -20...throttle valve, 21...
・Haigobensenri, 23...ro;norifu ``1 benten, 2
4...Spark plug, 25...Distributor, 2
7...Crank-b y 4J-129...City control circuit, 30...Switch.

Claims (1)

[Claims] When the fuel supply from the fuel injection valve is cut off due to light load, etc., the opening operation of the intake valve and exhaust valve is restricted and the operation is suspended, and the cylinder is equipped with an inactive cylinder, which continues to operate at all times. In a cylinder number controlled engine, there is a means for supplying fresh air to the cylinder on the idle side when the operating body is stopped, and a means for supplying fresh air to the cylinder on the idle side when the operation is stopped, and a means for cutting off the fuel supply of the fuel injection valve of the corresponding cylinder on the idle side before the intake stroke, 1. A cylinder number switching control device comprising a control means for regulating the opening operation of the intake and exhaust valves immediately after the stroke.