JPH0363648B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a method of controlling an internal combustion engine for driving a vehicle.

Prior Art and Problems When shifting the speed of a vehicle driven by an internal combustion engine,
Improper control of the internal combustion engine may result in unpleasant shocks for the driver.

FIG. 1 is a conceptual diagram for explaining the mechanism of the generation of shock due to gear shifting, and illustrates how the rotational speed of the internal combustion engine and the driven shaft change over time using solid lines a and broken lines b, respectively. (A) is an example where no impact is generated;
(B) is an example of generating an impact.

First, in (A), by depressing the clutch and releasing the accelerator at the same time at the beginning of the shift period T, the engine speed N is suddenly reduced as shown by solid line a, and in the latter half of the shift period T, while depressing the accelerator, the clutch is released. Gradually bring it back. In this example, the rotational speed N of the driven shaft increases smoothly as shown by the broken line b, and does not give an unpleasant shock to the driver. However, as illustrated in (B), if the accelerator is depressed too much in the latter half of the gear shift period T, the rotational speed of the internal combustion engine, which is in the no-load state immediately before the clutch is engaged, increases rapidly, causing the clutch to engage. As soon as the load increases, it suddenly decreases. Along with this, a spike as illustrated by the broken line b occurs in the rotational speed of the driven shaft, giving an unpleasant shock to the driver. In addition, in automatic transmission vehicles, the driver does not know when to change gears, so appropriate accelerator operations are not performed, and the rotational speed of the internal combustion engine changes as shown by the dash-dotted line a'. However, there is a disadvantage that a spike occurs in the rotational speed of the driven shaft.

OBJECTS OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and its purpose is to provide a simple method that can effectively reduce the impact caused by shifting.

Structure of the Invention The present invention achieves the above-mentioned object, and when the rotational speed of the internal combustion engine is above a predetermined value and the rotational speed suddenly decreases, it is assumed that the clutch is being engaged, and the intake It is configured to reduce the impact by rapidly reducing the amount of air and rapidly reducing the output of the internal combustion engine.

Hereinafter, further details of the present invention will be explained with reference to Examples.

Embodiment of the Invention FIG. 2 is a configuration block diagram of an internal combustion engine control system to which an embodiment of the present invention is applied, in which 1 is an internal combustion engine, 2 is a throttle opening valve controlled by the driver, and 3 is a control system for an internal combustion engine. 4 is a microprocessor, 4 is a motor drive device, 5 is a motor, 6 is a throttle valve, 7 is an air supply path, and 8 is a rotation sensor of the internal combustion engine.

FIG. 3 is a functional block diagram for explaining the operation of the microprocessor shown in FIG.

To explain the operation of this embodiment with reference to FIGS. 2 and 3, first, the microprocessor 3 receives the crank angle signal CA from the rotation sensor 8 installed in the internal combustion engine 1, and performs the function shown in FIG. As shown in block 10, the rotational speed N of the internal combustion engine 1 is calculated. Next, the microprocessor 3 differentiates the rotation speed N with respect to time, as shown in the function block 11, to obtain a time change rate α of the rotation speed, and calculates this change rate α into the function block 1.
2, it is compared with a predetermined reference value αref. On the other hand, the microprocessor 3 has a function block 13.
As shown in , the rotation speed N and the predetermined reference rotation speed Nref
Make a comparison with The result of comparing the speed and its rate of change is subjected to an AND condition in decision block 14. That is, the process proceeds to the time limit function block 15 only when the rate of change α is greater than the reference value αref and the rotational speed N is greater than the reference value Nref. The timer function block 15 outputs a voltage waveform that falls sharply and gradually recovers over a predetermined period of time as shown in the figure. This voltage waveform drives the motor 5 from the microprocessor 3 via the motor drive device 4.
The throttle valve 6 driven by the motor 5 rapidly reduces the amount of intake air Q flowing through the air supply path 7 and then gradually returns it to its original state.

Therefore, as illustrated in FIG. 1B, when the clutch is engaged with the accelerator pressed too far and the engine speed suddenly drops, the engine output is suddenly reduced as the amount of intake air is suddenly reduced. Therefore, even when the clutch is engaged, a spike as shown in the figure does not occur in the rotational speed of the driven shaft.

Further, since the intake air amount is controlled only when the engine speed is equal to or higher than a predetermined reference value, stall can be effectively prevented.

Specific values of the control parameters such as the reference values αref and Nref and the throttle return time may be set as appropriate values in consideration of various conditions such as the output of the internal combustion engine and the weight of the vehicle. An example of the reference value αref is 2000 rpm/sec,
An example of the reference value Nref is 1000 rpm. Further, an example of the return time of the diaphragm is set to a value approximately equal to the time for completion of engagement of the clutch.

Further, it is also possible to adopt a configuration in which each of the above parameters is dynamically changed in consideration of the temperature of the internal combustion engine.

Furthermore, the degree of restriction of the intake air amount can be set in accordance with the magnitude of the rate of change in the rotational speed, that is, the degree of restriction can be increased as the rate of change is greater.

Effects of the Invention As explained above, in the present invention, when the rotational speed of the internal combustion engine is above a predetermined value and the rotational speed suddenly decreases, it is assumed that the clutch is in the process of being engaged, and Because it is configured to rapidly reduce the amount of intake air and reduce the output of the internal combustion engine,
There is an advantage that the impact caused by shifting can be effectively reduced by a simple method.

[Brief explanation of drawings]

FIG. 1 is a conceptual diagram for explaining the problems of the conventional example, FIG. 2 is a configuration block diagram of an internal combustion engine control system to which an embodiment of the present invention is applied, and FIG. 3 is a microcontroller in FIG. 3 is a functional block diagram for explaining the operation of the processor 3. FIG. 1...Internal combustion engine, 2...Throttle opening valve, 3
... Microprocessor, 4 ... Motor drive device, 5 ... Motor, 6 ... Throttle valve, 7 ... Air supply path, 8 ... Rotation sensor of internal combustion engine.

Claims (1)

[Claims] 1. In a method for controlling an internal combustion engine for driving a vehicle, when the rotational speed of the internal combustion engine is at least a predetermined value and the rate of decrease in the rotational speed is at least a predetermined value, the amount of intake air is suddenly reduced. A method for controlling an internal combustion engine, characterized in that: