JPH0338428Y2 - - Google Patents

Description

[Detailed explanation of the invention] [Industrial application field] This invention is a cylinder number control engine that performs partial cylinder operation by suspending the operation of some cylinders depending on the operating conditions such as in the engine light load range. The present invention relates to a switching control device.

[Summary of the idea]

This invention is a cylinder number switching control device for a cylinder number control engine that switches between full cylinder operation and partial cylinder operation depending on operating conditions, by returning to all cylinder operation before stopping the engine and then stopping the engine. This is designed to improve starting performance when restarting.

[Conventional technology]

In general, fuel efficiency tends to improve when an engine is operated under a high load. Therefore, in a multi-cylinder engine, when the engine load is low, the fuel supply to some cylinders is cut off and operation is stopped, and the engine is operated at a low load. An engine with a controlled number of cylinders was devised that relatively increased the load on the remaining active cylinders and improved overall fuel efficiency in the light load range (Japanese Patent Laid-Open Publication No.
No. 51-38639, JP-A-54-33324, JP-A-59-
Publication No. 15648).

[Problem that the invention attempts to solve]

However, in conventional engines with cylinder number control, when the engine is stopped, the engine is stopped with partial cylinder operation, so for example, when restarting at extremely low temperatures, cranking alone is not enough. It was predicted that the engine would not be able to return to cylinder operation and would fail to start, and that starting performance would be poor even at room temperature, so there was room for improvement.

This invention was made by focusing on such conventional problems, and provides a cylinder number switching control device that solves the above problems by returning the engine to all-cylinder operation and stopping when the engine is stopped. The purpose is to

[Means for solving problems]

In order to achieve this object, as shown in FIG. 1, this invention has a cylinder number control engine 100 that switches between all-cylinder operation and partial cylinder operation according to operating conditions, even though the ignition switch 101 is turned off. Command means 102 for causing all cylinders to operate accordingly
and an engine stopping means 103 for stopping the engine after the engine has been brought into full cylinder operation by the command means.

[Example] This invention will be described in detail below with reference to the drawings.

FIG. 2 shows an example of the circuit configuration of this invented device. Here, 1 is a multi-cylinder engine, 2 is a cylinder number control actuator that controls the number of operating cylinders of engine 1 by cutting off the supply of fuel to some cylinders, and 3 is a cylinder number control actuator that controls the number of operating cylinders of engine 1, such as rotation speed and load. This is a device for determining the number of operating cylinders that determines the number of cylinders in operation according to the operating condition detection signal e. The number of operating cylinders determined by the operating cylinder number determining device 3 is output as a cylinder number signal d to the cylinder number control actuator 2, and the actuator 2 causes the engine 1 to operate the number of cylinders corresponding to the cylinder number signal d.

Reference numeral 4 denotes a power cutoff control circuit that controls the cutoff of the power supply E based on the ignition switch signal a, and 5 a power supply relay that opens (OFF) the power supply line f in response to the power relay control signal b from the power cutoff control circuit 4. , 6 is a two-channel ignition switch for opening and closing the current of the primary circuit of the ignition device in the driver's cab. The operating part of the ignition switch 6 is generally a cylinder type key to prevent theft of the automobile.

The above-mentioned ignition switch 6 and power supply relay 5 are connected in parallel to the power supply E, and the engine 1, the cylinder number control actuator 2, the operating cylinder number determining device 3, and the power supply are cut off via the power supply line f. Connect the control circuit 4. The power cutoff control circuit 4 outputs an all-cylinder operation request signal c to the operating cylinder number determining device 3 in response to the ignition switch signal a of the ignition switch 6 changing to L (Low) level. After a certain period of time, the level of the power supply relay control signal b is changed. The operating cylinder number determining device 3 changes the cylinder number signal d into an all cylinder number instruction in response to the all cylinder operation request signal c, and the engine 1 is operated on all cylinders via the cylinder number control actuator 2.

Next, an example of the operation of the device of the present invention with the above configuration will be explained.

When the ignition switch 6 is turned on (closed) by operating a key (engine key) not shown, the power supply line f connects the engine 1, the cylinder number control actuator 2, the operating cylinder number determining device 3, and the power cutoff control circuit 4. Power is supplied to the When power is supplied, the power relay 5 is turned ON by the H (High) level of the power relay control signal b from the power cut-off control circuit 4, and in response to the cylinder number signal from the operating cylinder number determining device 3. The cylinder number control actuator 2 performs normal engine operation in the engine 1 by controlling the number of cylinders.

After that, when the ignition switch 6 is turned OFF (opened) by key operation, the ignition switch signal a becomes L level, but the power relay 5
Since it is in the ON state, the power supply line 5 is maintained at H level. At the same time, in response to the level down of the ignition switch signal a, the power cutoff control circuit 4 outputs an all-cylinder operation request signal c to the operating cylinder number determining device 3. In response to the total cylinder number operation request signal c, the operating cylinder number determining device 3 changes the cylinder number signal d to the total number of cylinders, regardless of the detection signal e.
Engine 1 via cylinder number control actuator 2
Commands all cylinders to operate.

Thereafter, after a predetermined period of time has elapsed, the power cutoff control circuit 4 outputs the power relay control signal b at L level and turns the power relay 5 OFF (open). As a result, the power supply to engines 1 to 4 is cut off,
All systems stop. Thus, in this example,
All cylinders are operated until a predetermined time has elapsed from when the ignition switch 6 is turned off, and then the power is cut off to stop the engine.

It should be noted that, instead of waiting for a predetermined time to elapse, it would be more reliable to stop the engine after knowing that all-cylinder operation has been executed based on a discrimination signal detected by a sensor (not shown) from engine 1. However, if the power supply relay control signal b is kept at the H level by the internal timer of the power cutoff judgment circuit 4 for a sufficiently longer time than the time required to switch from partial cylinder operation to full cylinder operation, this operation can be stopped. No switching problems arise. Also, the cylinder number signal d
When indicates an all-cylinder operation, the power supply relay 5 may be opened immediately in response to a drop in the level of the ignition switch signal a.

FIG. 3 shows another embodiment of this invention. Here, 8 is a single control unit consisting of a microcomputer, etc., and has the functions of the operating cylinder number determining device 3 and the power cutoff control circuit 4 described above. The engine 1 includes the above-mentioned cylinder number control actuator 2, and the engine 1 outputs a full cylinder/partial cylinder discrimination signal g to the control unit 8. This discrimination signal g is obtained by a switch that detects the movement of the rocker arm, as disclosed in, for example, Japanese Patent Laid-Open No. 59-15648.

The ignition switch 6 of this example is a single channel, and this terminal is connected to the contacts of the power supply relay 5 and the engine 1 through a diode 9. Therefore, even if the ignition switch 6 is turned on by key operation, power does not flow to the engine 1 side, only the control unit 1 is operated, and after the power relay 5 is turned on by the power relay control signal b, Engine 1 starts operating. Therefore, the diode 9 does not require a large capacity.

FIG. 4 shows an example of a control procedure stored in advance in the internal memory of the control unit 8 mentioned above. Next, the control operation of the control unit 8 will be explained with reference to the flowchart shown in FIG.

First, when driving, check the ignition switch signal a.
When the signal becomes L level, this flowchart is activated by an interrupt. Then, it is determined whether the signal a is truly at the L level (step S1), and if the determination is affirmative, after waiting for a predetermined time to prevent chattering (step S2), it is again determined whether the signal a is at the L level ( Step S3). If the determination is affirmative, the cylinder number signal d is set to "all cylinders" and output to the engine 1 regardless of the detection signal e (step S).
4). As a result, the engine 1 changes from partial cylinder operation to full cylinder operation.

Next, it is determined based on the determination signal g whether or not all-cylinder operation has started, and the system waits until an affirmative determination is made (step S5). If the discrimination signal g indicates that all cylinders are in operation, the determination is affirmative, so the process moves to the next step, and the power relay control signal b is turned OFF and output to the power relay 5 (step S6). This results in
The power relay 5 is opened and the power supply is cut off.

Note that if a negative determination is made in the above-mentioned steps S1 and S3, it is assumed that a malfunction has occurred and the operation returns to normal operation.

In this example, since the discrimination signal g is fed back,
The switching operation is more reliable than the first embodiment in which the switching operation is delayed by a predetermined period of time, and the engine key is not pressed for an unnecessarily long period of time.
It can also prevent the engine from continuing to run after being turned off. Furthermore, in this example, by using the diode 9, the ignition switch 6 can be made into a single channel, resulting in a simple configuration.

[Effect of idea]

As explained above, according to this invention, a power relay is connected in parallel with the ignition switch, and when the ignition switch is turned off, all cylinders are operated before the power relay is opened. Therefore, when restarting, all cylinders are always operated, and good startability is obtained, and even if the engine temperature becomes extremely low while the engine is stopped, startability equivalent to that of a normal engine can be ensured.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the overall configuration of this invention, FIG. 2 is a block diagram showing an example of the basic circuit configuration of the device of this invention, and FIG. 3 is a block diagram showing the circuit configuration of another embodiment of this invention. FIG. 4 is a flowchart showing an example of the operation of the control unit shown in FIG. 1...Multi-cylinder engine, 2...Cylinder number control actuator, 3...Device for determining the number of operating cylinders, 4...
Power cutoff control circuit, 5...Power relay, 6...Ignition switch, 8...Control unit, 9...Diode, a...Ignition switch signal, b...Power relay control signal, c...
...All cylinder operation request signal, d...Cylinder number signal, e...
...Detection signals for rotation speed, load, etc., g...All cylinder/partial cylinder discrimination signal, f...Power line.

Claims (1)

[Scope of Claim for Utility Model Registration] a. In a cylinder number control engine that switches between full-cylinder operation and partial-cylinder operation according to operating conditions, b. A command to perform all-cylinder operation when the ignition switch is turned off. A cylinder number switching control device comprising: (c) engine stopping means for stopping the engine after all cylinders are operated by the commanding means.