JP2011052582A - Engine revolution stabilizing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress fluctuation in engine revolution in travel, while suppressing degradation in startability. <P>SOLUTION: An engine revolution stabilizing device controls an ignition control device 2 depending on statuses in fluctuation of an engine revolution speed occurring in the travel of a vehicle, and makes ignition timing be retarded or advanced to decrease engine output, so as to suppress fluctuation in revolution speed. In the engine revolution stabilizing device, an ECU 1 calculates a traveling speed of the vehicle from transition of crank angles detected by a crank angle sensor 10, and regulates delay or advance of the ignition timing when the traveling speed is lower than a first predetermined value V1. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an engine rotation stabilization device, and more particularly to a technique for suppressing fluctuations in rotational speed when an engine mounted on a vehicle travels.

In order to suppress the rotational fluctuation of the engine mounted on the vehicle, for example, idle stabilization control that suppresses the rotational fluctuation during idling is known. In this idle stabilization control, it is possible to control the fuel injection amount, ignition timing, etc. according to the fluctuation of the engine rotation speed, to keep the engine rotation speed constant, and to reduce the vibration of the vehicle.
In addition to the idling time, a technology for suppressing the vibration of the vehicle due to the engine rotation fluctuation that occurs when the vehicle travels has been developed. As the technology, for example, when the rate of change in the rotational speed is greater than or equal to a predetermined value during acceleration, there is a technology for retarding the engine torque fluctuation by retarding the ignition timing and suppressing the rotational speed fluctuation. Are known. Thereby, the longitudinal vibration which generate | occur | produces at the time of start acceleration can be suppressed (patent document 1).

Japanese Patent No. 3603334

  However, immediately after the start of the vehicle, for example, in a manual transmission vehicle, there is a possibility that the rotational speed of the engine fluctuates in a half-clutch state. Therefore, if the fluctuation of the engine speed is suppressed during traveling as in the above-mentioned Patent Document 1, the engine torque is reduced by ignition timing retard control, the startability of the vehicle is lowered, and the engine is stopped due to insufficient torque. There is a risk that.

  The present invention has been made to solve such problems, and an object of the present invention is to provide an engine rotation stabilization device capable of suppressing engine rotation fluctuation during traveling while suppressing a decrease in vehicle startability. Is to provide.

  In order to achieve the above object, the engine rotation stabilization device according to claim 1 is a fluctuation suppression that changes the output of the engine so as to suppress the fluctuation according to the fluctuation of the rotation speed of the engine that occurs when the vehicle travels. Means, vehicle speed detecting means for detecting the traveling speed of the vehicle, and restricting means for restricting the operation of the fluctuation suppressing means when the traveling speed detected by the vehicle speed detecting means is lower than the first predetermined value. It is characterized by.

According to a second aspect of the present invention, there is provided the engine rotation stabilization device according to the first aspect, wherein the vehicle transmits power from the engine to the drive wheels via a manual transmission.
According to a third aspect of the present invention, there is provided the engine rotation stabilizing device according to the first or second aspect, wherein the fluctuation suppressing means suppresses fluctuations in the rotational speed by correcting the ignition timing of the engine.

  According to the engine rotation stabilization device of the first aspect of the present invention, the fluctuation suppressing means suppresses fluctuations in the engine rotation speed that occur when the vehicle travels. When the travel speed is lower than the first predetermined value, The operation of the fluctuation suppressing means is restricted, and the engine output is prevented from lowering. Accordingly, since the engine output is prevented from decreasing immediately after the start of the vehicle whose rotational speed is likely to fluctuate, it is possible to ensure the startability of the vehicle and to prevent the engine from being stopped due to the output decrease.

According to the engine rotation stabilization device of claim 2 of the present invention, even if a manual transmission vehicle immediately after starting, even if the engine speed changes due to a change in the clutch engagement state, a decrease in engine output is prevented. The startability of the vehicle can be ensured.
According to the engine rotation stabilization device of claim 3 of the present invention, the engine output can be quickly and timely reduced by correcting the ignition timing of the engine, and the fluctuation of the engine rotation speed can be quickly and accurately controlled. Can be suppressed.

It is a schematic block diagram of one Embodiment of the engine rotation stabilization apparatus of this invention. It is a flowchart which shows the correction control point of the ignition timing in ECU. It is a time chart which shows an example of transition of the detected value of each sensor at the time of start of vehicles.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram of an embodiment of an engine rotation stabilization device of the present invention.
The engine rotation stabilization device according to the present embodiment is employed in an engine mounted on a vehicle as a driving power source. In this embodiment, the vehicle is an MT vehicle that transmits power from the engine to the drive wheels via a manual transmission.

As shown in FIG. 1, the engine rotation stabilization device includes various sensors that detect an operating state of the engine, an ECU 1, and an ignition device 2.
Specifically, the various sensors include a crank angle sensor 10 that detects the transition of the crank angle of the engine, an intake pressure sensor 11 that is provided in the intake manifold and detects the intake pressure, an accelerator position sensor 12 that detects the accelerator opening, A switch that is turned on when idling, an idle switch 13 that detects whether or not the vehicle is in an idle state, and a vehicle speed sensor 14 (vehicle speed detection means) that detects the speed of the vehicle. Instead of the vehicle speed sensor 14, a sensor that detects the wheel speed may be used.

  The ECU 1 includes an input / output device, a storage device (ROM, RAM, non-volatile RAM, etc.), and a central processing unit (CPU), and detects detection signals of the various sensors 10 to 14 and other engine operating states. An ignition signal is output to the ignition device in accordance with signals from various sensors shown. The ignition signal is a reference timing calculated based on the engine rotational speed Ne calculated based on the transition to the crank angle input from the crank angle sensor 10 and the intake pressure Pb input from the intake pressure sensor 11 as the engine load. Output.

The ignition device 2 includes an ignition plug (not shown), and executes ignition in accordance with an ignition signal input from the ECU 1.
The ECU 1 corrects and controls the fuel injection amount and the like according to a deviation ΔNe between the engine rotational speed Ne and the average rotational speed Neo of the rotational speed Ne during a predetermined time during idling. It has an idling stabilization correction control function to make it constant.

Further, as a function of the engine rotation stabilization device, the ECU 1 is configured to retard or advance the ignition timing from the reference timing based on input signals from the various sensors 10 to 14 during traveling. It has an ignition timing correction control function for correcting the output timing of the ignition signal (variation suppression means).
Next, ignition timing correction control in the ECU 1 according to the present embodiment will be described with reference to FIGS.

FIG. 2 is a flowchart showing the ignition timing correction control procedure in the ECU 1. In this flowchart, the operation starts when the key switch is ON.
As shown in FIG. 2, first, in step S10, detection signals are input from the various sensors 10-14. Specifically, the crank angle is input from the crank angle sensor 10, and the engine speed Ne is calculated from the transition. The intake pressure Pb detected by the intake pressure sensor 11 is input. An accelerator opening APS is input from the accelerator position sensor 12. Information on whether or not the idle switch 13 is in an idle state is input. A vehicle speed V is input from the vehicle speed sensor 14. Then, the process proceeds to step S20.

In step S20, based on the various detection signals input in step S10, it is determined whether or not all of the following correction conditions (1) to (5) are satisfied, and all of the conditions (1) to (5) are satisfied. If so, the process proceeds to step S30. If at least one of the conditions (1) to (5) is not satisfied, the process returns to step S10.
(1) Vehicle speed V ≧ first predetermined value V1
(2) Intake pressure Pb ≦ second predetermined value Pb2
(3) Engine actual rotational speed Ne ≦ third predetermined value Ne3
(4) A deviation ΔAPS of the accelerator opening APS every first predetermined time T1 ≦ A fourth predetermined value APS4 is established and a second predetermined time T2 elapses, and ΔNe (= | average rotational speed Neo−engine actual Rotational speed Ne |) ≦ fourth predetermined value Ne4
(5) Idle condition not established (idle switch off)
The first predetermined value V1 may be set to a threshold value that does not include the speed at the time of half-clutch immediately after starting according to the equation (1). The second predetermined value Pb2 and the third predetermined value Ne3 are determined so as not to include a high load or a high speed at which an output should be secured rather than suppression of engine rotation fluctuations according to the expressions (2) and (3). It is good to set to a threshold value. The fourth predetermined value APS4 may be set to a threshold value by which it is possible to determine whether or not there is an intention to suddenly operate the accelerator, that is, sudden acceleration or sudden deceleration, according to the equation (4). You only have to set it. The first predetermined time T1 and the second predetermined time T2 may be set as appropriate so that whether or not the expression (4) is satisfied is not switched in a short time. In addition, the conditions shown in said Formula (1) correspond to the control means in this invention.

  In step S30, the ignition timing correction control is executed. Specifically, the timing of the ignition signal to the ignition device 2 is controlled so that the output of the engine is reduced by retarding or advancing the ignition timing from the reference timing. The retard amount or advance amount (ignition timing correction amount) may be read and set from a previously stored map or the like according to the difference between the average rotational speed Neo and the actual rotational speed Ne. Then, the process proceeds to step S40.

  In step S40, it is determined whether or not a condition for canceling the ignition timing correction control executed in step S30 is satisfied. Specifically, based on the detection signal input in step S10, it is determined whether or not the following correction cancellation conditions (6) to (10) are satisfied, and at least one of the conditions (6) to (10) is determined. If one is established, the process proceeds to step S50. If none of the conditions (6) to (10) is satisfied, the process returns to step S30.

(6) Vehicle speed V <first predetermined value V1
(7) Intake pressure Pb> second predetermined value Pb2
(8) Engine actual rotation speed Ne> third predetermined value Ne3
(9) Accelerator opening APS> fourth predetermined value APS4
(10) Idle condition is established (idle switch on)
In step S50, the ignition timing correction control performed in step S30 is canceled, and the retardation or advance amount is set to zero. Then, this routine is returned.

  By controlling as described above, in the present embodiment, the engine rotational speed Ne is equal to or lower than the third predetermined value Ne3, the intake pressure Pb is equal to or lower than the second predetermined value Pb2, and the idle switch is turned off, that is, idling time. If the engine rotational speed Ne fluctuates with little fluctuation in the accelerator opening APS during low load and low rotation, the engine output is controlled by controlling the ignition timing according to the fluctuation amount. It is possible to suppress the engine rotation fluctuation.

On the other hand, the correction of the ignition timing of the engine is canceled when the condition is opposite, that is, at the time of high load or high rotation or when the accelerator is depressed. Thereby, the output reduction of an engine is suppressed.
In particular, in this embodiment, the vehicle speed is added to the ignition timing correction condition, and the ignition timing correction control is not performed when the vehicle speed V is lower than the first predetermined value V1. The effect obtained by adding the vehicle speed to the ignition timing correction condition will be described below with reference to FIG.

FIG. 3 is a time chart showing an example of transition of detection values of the sensors 10 to 14 when the vehicle starts.
This figure shows an example of the transition of each detected value and the transition of the ignition timing correction amount when starting from an idle state in a manual transmission vehicle. Specifically, it shows a state in which the vehicle starts from the idle state, accelerates to a predetermined speed, and then continues to travel at a constant speed, and shows a case where the engine speed fluctuates during constant speed traveling. In the figure, the large fluctuation portion of the rotational speed at the time of acceleration indicates a state where the gear is shifted from the first speed to the second speed.

As a comparative example, the transition of the ignition timing correction amount is a value in the correction control (A) in which the vehicle speed conditions (1) and (6) are not included in the correction conditions and the value in the correction control (B) of the present embodiment. Is shown.
As shown in FIGS. 4A and 4B, the ignition timing is corrected, so that fluctuations in the rotational speed of the engine during constant speed running are suppressed.
Further, as shown in FIG. 3, immediately after the start, in the MT vehicle, the engine rotational speed fluctuates in the half-clutch state when shifting to the first speed. In the correction control in which the vehicle speed conditions (1) and (6) are not included in the correction conditions, as shown in (A) in FIG. 3, the ignition timing is corrected with respect to the fluctuation immediately after the start. On the other hand, in the present embodiment, since the correction condition includes that the vehicle speed V is equal to or higher than the first predetermined value V1, as shown in FIG. Ignition timing is not corrected. Therefore, in this embodiment, since the output decrease immediately after the start can be suppressed, the startability of the vehicle can be improved and the engine stop due to insufficient torque can be avoided.

In the present embodiment, the ignition timing is corrected as a means for suppressing fluctuations in the rotational speed of the engine. In this embodiment, by suppressing the fluctuation of the rotational speed by correcting the ignition timing in this way, the output of the engine can be quickly and timely reduced, and the fluctuation of the rotational speed of the engine can be suppressed quickly and accurately. Can do.
The present invention is not limited to correcting the ignition timing as a means for suppressing fluctuations in rotational speed. For example, means capable of controlling the rotational speed of the engine, such as fuel injection amount control and intake air amount control, may be used instead.

  In the above embodiment, the present invention is applied to the MT vehicle so that fluctuations in the rotational speed due to the half clutch immediately after starting can be suppressed. However, the present invention may be applied to AT vehicles and CVT vehicles. When the present invention is applied to an AT vehicle or a CVT vehicle, for example, when the vehicle speed does not increase even though the accelerator is stepped on due to an uphill or a step, the output of the engine is reduced to reduce the rotational speed. Since the control for suppressing the fluctuation is restricted, the startability of the vehicle can be improved.

  Further, the present invention relates to the ignition timing correction condition, and other conditions can be appropriately changed as long as at least the vehicle speed condition is provided. For example, an air flow rate detected by an air flow sensor instead of the intake pressure may be used as the engine load.

1 ECU
2 Ignition control device 14 Vehicle speed sensor

Claims (3)

Fluctuation suppression means for changing the output of the engine so as to suppress the fluctuation according to fluctuations in the rotational speed of the engine that occur when the vehicle travels;
Vehicle speed detection means for detecting the traveling speed of the vehicle;
Restriction means for restricting the operation of the fluctuation suppressing means when the travel speed detected by the vehicle speed detection means is lower than a first predetermined value;
An engine rotation stabilization device comprising:   The engine rotation stabilization device according to claim 1, wherein the vehicle transmits power from the engine to a driving wheel via a manual transmission.   3. The engine rotation stabilization device according to claim 1, wherein the fluctuation suppressing unit suppresses fluctuations in the rotation speed by correcting an ignition timing of the engine.

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