JP2516620Y2 - Engine controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention is designed to electrically drive an engine output increasing / decreasing means such as a throttle valve based on an accelerator operation amount detected by an accelerator operation amount detecting means. The present invention relates to a control device for the engine.

[Prior Art] An accelerator operation amount detecting means for detecting an accelerator operation amount, and an electric step motor (engine output increasing / decreasing means) for opening / closing a throttle valve (engine output increasing / decreasing means) are provided, and detected by an acrylic operation amount detecting means. A so-called drive-by-wire type throttle valve opening / closing mechanism in which the step motor is driven with a predetermined control characteristic based on the accelerator operation amount to perform feedback control of the throttle opening (engine output) is generally known. Further, there has been proposed a throttle valve opening / closing mechanism in which the gain of the throttle opening characteristic with respect to the accelerator operation amount is changed according to the operating state of the engine (for example, see Japanese Patent Laid-Open No. 61-200345).

[Problems to be Solved by the Invention] In a vehicle equipped with a power steering device of a type that power-assists a driver's steering operation, if the power steering device fails, the power assist will not be performed, so the driver's steering・ While the force required to operate the wheels increases, there is a problem that the steering operation is delayed. Therefore, when the power steering device is out of order, for example, when entering the garage,
When the vehicle is running at extremely low speed, the steering operation is delayed even though the engine output is generated in response to the accelerator operation in the same manner as in normal operation.Therefore, the vehicle may behave in a manner that is contrary to the driver's intention. There was a problem of destabilization. Such a problem also occurs in a vehicle with an automatic transmission equipped with the drive-by-wire type throttle valve opening / closing mechanism.

The present invention has been made in view of the above problems of the prior art. Even when the power steering device fails, the vehicle does not behave contrary to the intention of the driver, and the drivability can be stabilized. It is an object of the present invention to provide a control device of.

[Means for Solving the Problems] In order to achieve the above object, the present invention has an accelerator operation amount detecting means for detecting an accelerator operation amount, an engine output increasing / decreasing means for increasing / decreasing an engine output, and the accelerator operation amount detecting means. In an engine control device including an engine output control means for controlling the output of the engine output increasing / decreasing means with a preset control characteristic based on the accelerator operation amount detected by the engine, a power steering assist of a driver is performed. The power steering failure detecting means for detecting a failure of the power steering apparatus and the power steering failure detecting means detect a failure in which power steering by the power steering apparatus is not performed and steering operation is performed by a driver's operating force. Sometimes the engine output with respect to the accelerator operation amount Provided is an engine control device, which is provided with engine output characteristic changing means for changing the control characteristic of the engine output control means so that the output of the increasing / decreasing means becomes smaller than the normal time.

According to the present invention, the power steering device fails,
When the driver has to perform the steering operation by himself / herself without the help of the power steering device, the engine output characteristic changing means reduces the output of the engine output increasing / decreasing means with respect to the accelerator operation amount as compared with the normal time. Since the control characteristic of the engine output control means is changed, the engine output with respect to the accelerator operation amount is reduced as compared with the normal time. For this reason, the movement of the vehicle is slowed down, and even if the steering operation is delayed due to the failure of the power steering, the movement of the vehicle is also delayed correspondingly, and the operation of the steering wheel and the movement of the vehicle are delayed by the driver. The behavior of the vehicle does not occur contrary to the driver's intention, and the drivability of the vehicle can be stabilized.

[Example] Hereinafter, an example of the present invention will be described specifically.

As shown in FIG. 1, a power plant PS of a vehicle with an automatic transmission outputs heat energy obtained by burning intake air (fuel mixture) supplied from the intake passage 1 according to the opening degree of the throttle valve 2. The engine E that converts the rotational energy of the crankshaft 3 and the automatic transmission T that automatically changes the torque of the crankshaft 3 by the torque converter 4 and the gear train 5 and transmits the torque to the output shaft 6 are substantially provided. It is configured.

In the engine E, with respect to the throttle valve 2,
A throttle valve step motor 7 that opens and closes this, and a throttle opening sensor 8 that detects the opening of the throttle valve 2.
And the throttle valve step motor 7 is
Feedback control is performed so that the throttle opening follows the target opening set by the throttle control unit 9. The throttle valve step motor 7 is an ordinary electrically driven step motor. The opening target value of the throttle valve 2 is set by the throttle control unit 9 based on the accelerator opening detected by the accelerator opening sensor 12 provided for the accelerator pedal 11, as described later. It has become.

A power steering device S is provided for the front wheels 14 in order to power assist the steering operation of the driver. The power steering device S will be described below.

As shown in FIG. 2, the power steering device S is
A predetermined amount of oil stored in the oil storage tank 15 is passed through an oil supply passage 17 by a hydraulic pump 16 to a power cylinder.
The power cylinder 18 supplies the power to the front wheel 14 (see FIG. 1) via the rod 19 in accordance with the hydraulic pressure introduced into the hydraulic chamber (not shown) therein, that is, the traveling of the vehicle. It is designed to change the direction from side to side. In order to control the hydraulic pressure introduced into the power cylinder 18, the power cylinder step motor is provided in the oil supply passage 17.
21 are installed. The power cylinder step mode 21 controls the hydraulic pressure of oil supplied to the power cylinder 18 in accordance with a signal from the power steering control unit 22 to control the traveling direction of the front wheels 14.

The throttle control unit 9 is a control device for the throttle valve 2, which is composed of a microcomputer and includes the engine output control means and the engine output characteristic changing means described in the claims of the present utility model.
On the other hand, the power steering control unit 22 is a control device for a power steering device including a power steering failure detection means described in the claims of the present utility model, which is composed of a microcomputer. These configurations will be described below. .

As shown in FIG. 3, the throttle control unit 9 is connected to the accelerator opening detected by the accelerator opening sensor 12, the throttle opening detected by the throttle opening sensor 8, and the on / off of the ignition switch 25.
ON / OFF of the accessory main switch 26 that turns ON / OFF the power supply to various accessories such as OFF signal and audio
Controls an off signal, an on / off signal of the clutch switch 27 that detects whether a clutch (not shown) is connected, an on / off signal of the meter reed switch 28, an on / off signal of the starter switch 29, etc. It is designed to be input as information. Then, the throttle control unit 9 sets the opening degree of the throttle valve 2 via the throttle valve switch motor 7 and the throttle opening characteristic value described later as a target value by a predetermined control method based on the control information. In addition to feedback control, it also controls the auto cruiser device 31 (automatic constant-speed traveling device).
Further, when the automatic transmission T is not in the neutral position (N) or the parking position (P) even when the starter switch 29 is turned on, the starter 32 is started to prevent the vehicle from starting against the driver's intention. The inhibitor switch 33 for prohibiting the ON / OFF control is performed.

On the other hand, the steering angle detected by the steering angle sensor 35, the engine speed detected by the rotation speed sensor 36, the on / off signal of the ignition switch 25, etc. are input to the power steering control unit 22 as control information. It has become. Then, the power steering control unit 22 controls the step motor 21 for the power cylinder based on the control information by a normal control method so that the vehicle travels in the direction corresponding to the steering angle, and the power cylinder 18 (first It controls the oil pressure of the oil introduced into (see FIG. 1).

By the way, power steering control unit
A reset signal (fail signal) is transmitted from 22 to the throttle control unit 9 via a fail signal communication line 38 as described later in detail. When the reset signal is received and the failure of the power steering device S is detected based on the reset signal, the throttle control unit 9 indicates the throttle opening characteristic with respect to the accelerator opening as compared with the throttle opening with respect to the accelerator opening. The control characteristic is changed so that the engine E becomes smaller when the accelerator pedal 11 is depressed.
The output of the vehicle is reduced, the movement of the vehicle is slowed in response to the delay in the steering operation by the driver, and the vehicle is controlled not to behave differently from the behavior intended by the driver. The control method will be described below with reference to the flowchart shown in FIG.

When the control is started, in step S1, the elapsed time after receiving the latest reset signal sent from the power steering control unit 22 to the throttle control unit 9 via the fail signal communication line 38 is integrated. The reset signal is a pulse signal that is transmitted each time the control routine of the power steering control unit 22 is executed once when the power steering device S is operating normally. On the other hand, when a failure occurs in the power steering device S, the power steering control unit 22 executes the failure control routine, the reset signal is not transmitted, and the reset signal is not sent to the throttle control unit 9. . Then, the throttle control unit 9 integrates the elapsed time from the latest reset signal reception time, and it is possible to detect the presence or absence of a failure of the power steering device S based on the integrated time. In addition,
The integrated time is cleared each time a new reset signal is received.

In step S2, it is compared whether or not the power steering device S has failed. In the present embodiment, when the elapsed time after receiving the latest reset signal accumulated in step S1 becomes a predetermined time or more, that is, the failure control routine of the power steering control unit 22 continues for the predetermined time or more. When executed, it is determined that the power steering device S has failed.

As a result of the comparison, if the power steering device S is not in failure (NO), the control proceeds to step S3, and the throttle valve opening / closing control for normal traveling is performed. During normal running, the throttle opening characteristic value with respect to the depression amount of the accelerator pedal 11 (accelerator operation amount) is as shown in the curve G ₁ in FIG. It has the characteristic that it gradually increases to the maximum opening. In this case, an engine output similar to that of a normal engine is obtained with respect to the accelerator operation amount, and normal operation is performed.

Next, in step S5, it is compared whether or not the ignition switch 25 is turned on, and the ignition switch 25 is turned on.
If 25 is on (YES), the operation of engine E is continued, so control returns to step S1 and continues, while if ignition switch 25 is off (NO), engine E is Since the operation of is stopped, the control ends.

On the other hand, as a result of the comparison in step S2, if the power steering device S is out of order (YES), the control is step S4.
Then, the opening / closing control of the throttle valve 2 for the power steering failure is performed. When the power steering device S fails, the throttle opening characteristic value with respect to the accelerator operation amount is such that the throttle opening is a predetermined value θ with respect to an increase in the accelerator operation amount, as shown by a curve G ₂ in FIG.
_It has a characteristic that the upper limit is ₁ . in this case,
Even if the accelerator pedal 11 is depressed, the throttle valve 2 is not opened beyond the predetermined value θ _1, so the output of the engine E is suppressed. When the power steering device S is out of order, a large amount of force is required for the steering operation by the driver as described above, and therefore, the steering operation is slightly delayed. However, since the output of the engine E is suppressed, the movement of the vehicle is slowed down, and the movement of the vehicle matches the steering operation with some delay, which causes the vehicle to match the driver's intention. Proceed in the direction you want to. Therefore, it is possible to prevent the vehicle from traveling contrary to the driver's intention, and to stabilize the drivability even when the power steering device S fails. After this, step S5
Then, depending on whether the ignition switch 25 is turned on or off, the control returns to step S1 and continues or ends.

As described above, according to the present invention, it is possible to prevent the occurrence of behavior contrary to the intention of the driver of the vehicle due to the steering operation delay when the power steering device fails, and to stabilize the drivability.

It should be noted that the present invention is not limited to vehicles using a throttle valve as engine output increasing / decreasing means, but also vehicles equipped with means for increasing / decreasing engine output in accordance with other accelerator operations, for example,
It can also be applied to a vehicle equipped with a diesel engine using a fuel injection valve as an engine output increasing / decreasing means.

[Brief description of drawings]

FIG. 1 shows an engine control device according to the present invention,
It is a system configuration diagram of a power plant and front wheels of a vehicle with an automatic transmission. FIG. 2 is a schematic diagram showing the configuration of the power steering device shown in FIG. FIG. 3 is a diagram showing an input / output system for the throttle control unit and the power steering control unit. FIG. 4 is a flowchart showing a control method of throttle valve opening / closing control by the throttle control unit and the power steering control unit. Fig. 5 shows the power steering device when normal and when it fails.
It is a figure which shows the throttle opening characteristic with respect to the accelerator operation amount. PS ... Power plant, E ... Engine, S ... Power steering device, T ... Automatic transmission, 1 ... Intake passage, 2 ... Throttle valve, 3 ... Crankshaft, 7 ... Throttle valve step Motor, 8 ... Throttle opening sensor, 9 ... Throttle control unit, 11 ...
Accelerator pedal, 12 …… accelerator opening sensor, 14 …… front wheel, 15 …… power cylinder, 22 …… power steering control unit, 35 …… steering angle sensor.

Claims (1)

(57) [Scope of utility model registration request] 1. An accelerator operation amount detecting means for detecting an accelerator operation amount, an engine output increasing / decreasing means for increasing / decreasing an engine output, and a preset control based on an accelerator operation amount detected by the accelerator operation amount detecting means. In an engine control device comprising an engine output control means for controlling the output of the engine output increasing / decreasing means by characteristics, a power steering failure detecting means for detecting a failure of a power steering apparatus for power assisting a steering operation of a driver, When the power steering failure detection means detects a failure in which power steering by the power steering device is not performed and steering operation is performed by the driver's operating force, the output of the engine output increasing / decreasing means with respect to the accelerator operation amount is normally set. Engineer to be smaller Engine control apparatus is characterized by providing an engine output characteristic changing means for changing a control characteristic of the output control means.