JPH01167439A - Controller for engine - Google Patents

Abstract

PURPOSE:To secure safety without giving an influence to the ordinary operation by putting an output adjusting device to the state having the min. engine output is realized, by an electric circuit independently of a control means, when an accelerator is put into inoperative state. CONSTITUTION:When the first and/or second brake switch 74 or 75 is turned-ON by the stepping-ON of a brake pedal, the voltage higher than a ground voltage is applied onto the base of a semiconductor switch 71, in a motor control circuit 70. When feet is separated from an accelerating pedal 5 and an accelerator perfect closing switch 72 is turned-ON in this state, no electric current flows in the motor 49 of an electric control mechanism 60, and a throttle valve 6 is compulsorily set into a perfect closed state by a spring 45. In this control disabled state or anomaly, the perfect closed state is generated compulsorily by the operation of a driver, and when the engine revolution speed lowers, a control unit 18 turns OFF an electromagnetic clutch 50, and switching to a mechanical control mechanism 61 is performed. Therefore, safety can be secured without giving an influence to the ordinary operation.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an engine control device, and more specifically,
The present invention relates to an engine control device having an engine output adjusting means for adjusting the output of the engine, an accelerator, and a control means for electrically controlling the engine output adjusting means based on the operation amount of the accelerator.

(Prior Art) In the above-mentioned type of engine control device, the MM of the throttle valve, which is the engine output adjustment means, is performed by a drive motor that operates in response to a command from a microcomputer, which is the control means. It is necessary to install a safety device to prevent the vehicle from running out of control when the drive motor becomes uncontrollable while the vehicle is running.The following are known examples of such safety devices: There is.

(1) A configuration in which the throttle valve shaft is provided with a return spring that returns the throttle valve to the closed state when the control is stopped.

(2) A configuration that includes an electromagnetic clutch that disconnects the throttle valve shaft from the drive motor when control becomes impossible.

(3) The above-mentioned return spring and electromagnetic clutch are combined, and the return spring is activated when the electromagnetic clutch is disengaged.

In the above configuration, to detect loss of control,
For example, as disclosed in Japanese Unexamined Patent Publication No. 59-153945, the control means calculates the difference between the output voltages of the accelerator pedal and the throttle opening sensor, and determines whether this difference is below a predetermined tolerance value. , when this determination is No,
There are known methods that determine if something is out of control or abnormal.

When the control means determines that the control is uncontrollable or abnormal, for example, it issues a signal to release the electromagnetic clutch, disengages the clutch, deactivates the throttle valve, and substantially reduces the engine output. is set to zero.

(Problems to be Solved by the Invention) However, as described above, when determining uncontrollability or abnormality by the control means itself, there is a risk that fail-safe cannot be achieved properly when the control means itself becomes abnormal. There is a problem.

Therefore, the inventors of the present invention conducted a sincere study and found that it is reliable and desirable to detect abnormalities for fail-safe purposes by detecting the driver's natural actions in an emergency. It seems that the most natural action for this driver to take in an emergency is to step on the brakes.

However, if the throttle valve is fully closed simply by stepping on the brake, problems may occur during normal driving, such as starting on a slope, starting from a stall, or driving on a winding road. Therefore, there is a need for a fail-safe system that does not affect the vehicle during normal driving and works safely in an emergency.

(Means for Solving the Problems) The present invention provides an engine output adjustment means for adjusting the output of the engine, an accelerator, and the engine output adjustment means.
In the engine control device having a control means for electrically controlling the accelerator based on the amount of operation of the accelerator, when the accelerator is not operated, the output adjustment means is controlled to control the output of the engine independently of the control means. The device is characterized by comprising an electric circuit that brings the output to zero.

(Operations and Effects of the Invention) As described above, in the engine control device of the present invention, when the accelerator is not operated, the output adjustment means is controlled independently of the control means so that the engine output becomes zero. Since this is done, it is possible to configure a system that operates safely without affecting normal operation.

(Embodiment) Hereinafter, an engine control device according to a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows the overall configuration of an engine control device according to an embodiment of the present invention. In this figure, reference numeral 1 indicates an engine, and reference numeral 5 indicates an accelerator pedal that is depressed and operated in response to an engine output request. . The engine 1 has an intake passage 2, one end of which opens to the atmosphere via an air cleaner 3, and the other end opens to the engine 1 to supply intake air to the engine. The engine 1 also has an exhaust passage 4 which opens into the engine 1 at one end and to the atmosphere at the other end for discharging exhaust gas from the engine. A throttle valve 6 is provided in the intake passage 2 to adjust the amount of intake air. The opening degree of the throttle valve 6 is controlled by pressing the accelerator pedal 5 and via a throttle valve operating device 7, which will be described in detail later.

A fuel injection valve 12 is provided downstream of the throttle valve 6 in the intake passage 2 to inject and supply fuel. This fuel injection valve 12 is connected to a fuel pump 13 and a fuel pump 13.
It communicates with a fuel tank 16 through a fuel supply path 15 with a fuel tank 4 interposed therebetween, and receives fuel from the fuel tank 16.

The throttle valve operating device 7 is connected to a control unit 18 composed of a microcomputer. The control unit 18 includes a main accelerator pedal position sensor 19 which is an accelerator detection means for detecting the amount of depression of the accelerator pedal, that is, the amount of accelerator operation, and a main accelerator pedal position sensor 19 that is arranged upstream of the throttle valve 6 in the intake passage 2 and detects the amount of intake air. an air flow meter 20 that detects
A main throttle position sensor 22 that detects the opening of the throttle valve, a water temperature sensor 23 that detects the temperature of engine cooling water, and an air-fuel ratio sensor (lean sensor) 24 that is arranged in the exhaust passage 4 and detects the air-fuel ratio are connected. ing. In the normal operating state, the control unit 18 receives the detection signals from the sensors 19 to 24, performs calculations based on the signals, and sends a control signal to the throttle valve operating device 7 for controlling the opening and closing operation of the throttle valve 6. Output to.

This control unit 18 also controls the fuel injection valve 12.

The control unit 18 further includes an igniter 26
is connected to input a signal indicating the number of ignitions, that is, the engine rotation speed, and output an ignition timing signal set at a predetermined timing to the igniter 26. This control unit 18 is also connected to a distributor 27 and a battery 28, and inputs signals indicating the actual ignition timing and battery voltage. The signal for ignition from the igniter 26 is
The secondary current is output through the distributor 27 to the ignition plug 33 to ignite the ignition plug, and the igniter 26 and distributor 27 constitute ignition control means.

Throttle Valve Actuation Device 7 Next, the throttle valve actuation device 7 will be explained with reference to FIG. FIG. 2 is a diagram schematically showing the throttle valve actuating device 7. As shown in FIG.

The throttle valve actuating device 7 has a base plate 40, and the throttle valve 6 is arranged on one side of the base plate 40.

On the opposite side of the base plate 40 from the throttle valve 6, there are first to third segments 41142 extending perpendicularly to the base plate 40.
．． 43 are provided. The first segment 41 is connected to the throttle valve 6 by a wire 44, and by moving away from the substrate 40, the first segment 41 is connected to the throttle valve 6 by a wire 44.
It operates in the direction of opening. The throttle valve 6 is provided with a spring 45 that biases it in the closing direction, and the first segment 41 is biased toward the substrate 40 by the spring 45. The second and third segments 42.43 are connected by springs 46.4
7 in the direction of the substrate 40.

The second segment 42 is connected to the accelerator pedal 5 via a wire 48 so that it can be moved away from the substrate 40 depending on the amount of operation of the accelerator pedal.

The throttle valve actuating device 7 further includes a throttle motor 49 composed of, for example, a pulse motor. A rotating shaft of the throttle motor 49 is connected to a pulley 51 via a clutch 50. A wire 52 is wound around this pulley 51, and the end of this wire is connected to the third
It is connected to segment 43. When the throttle motor 49 rotates while the clutch 50 is in the engaged state, the third segment 43 moves in a direction toward and away from the base plate 40 .

The first segment 41 has an end portion opposite to the substrate 40;
A mechanical operation protrusion 53 extending toward the second segment 42 is provided, and an electrical operation protrusion 54 extending toward the third segment 43 is provided at a portion closer to the substrate 40 than the second segment 42 . On the other hand, in the center of the second segment 42, the first
A protrusion 55 extending toward the segment 41 is provided at a distance α from the mechanical operation protrusion 53.

At a position of the third segment 43 that substantially corresponds to the electrically actuating protruding part 54, a protruding part 56 extending toward the first segment 41 is in contact with the side wall of the electrically actuating protruding part 54 on the substrate 40 side. It is set up so that

In the above configuration, the control unit 18, throttle motor 49, pulley 51, wire 52, third segment 43, first segment 41, and wire 44,
An electrical control mechanism 60 for the throttle valve 6 is configured, and a mechanical control mechanism 61 for the throttle valve 6 is configured by the wire 48, the second segment 42, the first segment 41, and the wire 44. That is, the throttle valve operating device 7
has an electrical control mechanism 60 and a mechanical control mechanism 61, the electrical control mechanism 60 is in charge of controlling the throttle valve 6 in the normal operating state, while the mechanical control mechanism 61 is, for example, It is in charge of controlling the throttle valve 6 in the event of an abnormality such as a failure of the electrical system. That is, the mechanical control mechanism 61 controls the clutch 50 when the electrical system is abnormal.
The throttle valve 6 is automatically controlled by itself, that is, by the mechanical control mechanism 61.

In this manner, when an abnormal situation occurs, the mechanical control mechanism 61 is substantially activated to operate the engine.

In order to disengage the clutch 50 and switch to the operation of the mechanical control mechanism 61 in the abnormal situation, the present throttle valve actuating device 7 uses the control unit 18 and the motor 4.
A motor control circuit 70 is provided which is connected to a line 65 that connects the motor control circuit 9 with the motor control circuit 70 . This motor control circuit 70 is
A line 73 connects the line 65 to ground via the semiconductor switch 71 and the full throttle open switch 72.
have. This semiconductor switch 71 is in a non-conductive state in a normal state. Further, the base of this semiconductor switch 71 is connected to ground via a first brake switch 74 and a second brake switch 75 arranged in parallel.

The first brake switch 74 and the second brake switch 75 are provided on the same brake pedal for backup purposes.

In the motor control circuit 70 configured as described above, when the brake pedal 4 is depressed and the first brake switch 74 or the second brake switch 75 (or both) are turned on, the base of the semiconductor switch 71 has a
Generates a voltage that is sufficiently higher than ground potential. In this state,
When the driver's foot is removed from the accelerator pedal 5 and the accelerator full-open switch 72 is turned on, current flows between the base and emitter of the semiconductor switch 71, and at the same time, the resistance in the collector-emitter direction becomes almost zero. In other words, since the current-carrying terminal of the motor is shorted to ground, the motor 49 has
Current stops flowing. Then, due to the action of the spring 45,
The throttle valve 6 is forced into a fully open state.

As described above, in the event of an uncontrollable state or an abnormality, the throttle valve 6 is forcibly opened fully by the operation of the driver to avoid danger. Furthermore, when the throttle valve 6 is not controlled by the motor 49, that is, the electric control mechanism 60, the control is entrusted to the mechanical control mechanism 61, so there is no possibility that the engine will stop operating at all. .

If the motor control circuit 70 described above is configured with a logic circuit, it will be as shown in FIG. 8.

Purpose of the electrical control mechanism 60 This electrical control mechanism 60 controls the driver's accelerator operation (
The so-called "driving requirements" are improved to match the driver's feeling in the driving characteristics of the vehicle in the practical range, such as acceleration, constant-speed running, deceleration, following of other vehicles, and high-altitude running. The system is designed to perform driving feel control and auto speed control that automatically optimally controls the throttle and gears to maintain the target vehicle speed set by the driver.

Map for driving feel control This driving feeling control basically involves calculating the optimal target throttle opening T v o t in order to obtain engine output according to the various conditions mentioned above. This is done by This target throttle opening degree T v OT is based on the basic throttle opening degree T v OB according to basic required characteristics, such as gear condition, mode switch condition, accelerator release, etc., and based on other required characteristics, such as accelerator pedal release. It is obtained by correcting with correction coefficients depending on the pedal depression speed, vehicle speed, atmospheric pressure, cooling water temperature, etc.

3A, 3B, and 3C in order to calculate the basic throttle opening degree TVOB.
As shown in Fig. 3D, in power mode,
First to fourth maps having control characteristic lines for control during economy mode, hold mode, and during accelerator release are stored in advance. The control unit 18 is also connected to a mode switch 63 for selecting one of the power mode, economy mode, and normal mode, and receives a signal indicating the current driving mode from the mode switch 63. control unit 18
Furthermore, in addition to the maps for accelerator depression speed correction and vehicle speed correction shown in FIGS. 4A and 4B, it also stores maps for other corrections.

Auto Speed Control This auto speed control automatically controls the throttle and gears optimally to maintain the target vehicle speed set by the driver as described above.The above throttle control is the same as the above driving feeling control. The mechanism used in the above is used as is, and the shift control is performed by outputting a 4th speed prohibition signal to the electronic automatic transmission using the control unit 18.

Operation of Mechanical Control Mechanism 61 This mechanical control mechanism 61 is mainly used when the electrical control mechanism 60 breaks down, and controls the minimum opening of the throttle valve 6 to avoid danger. used to secure. This mechanical control mechanism 61 has the above-described distance α between the protrusion 53 of the first segment 41 and the protrusion 55 of the second segment 42 . For this reason,
After the accelerator pedal 5 is depressed to a certain extent and the second segment 42 moves by the distance α, the protrusion 55 comes into contact with the protrusion 53, and after this, the second segment 42 moves the first segment 41 away from the board 40. , and the throttle valve 6 is controlled according to a control characteristic line as shown by line L2 in FIG. In addition, in this FIG. 5, a typical control characteristic line used in the electrical control mechanism 60 is shown as a line L1.

Control by the control unit 18 Control of the throttle valve actuating device 7 by the control unit 18 will be explained with reference to FIG. 6 and subsequent figures.

In this control, first, a main routine is performed according to the flowchart shown in FIG.

First, in this control, initialization, that is, software reset is performed in step S1, and then step S1 is performed.
At step 2, the clutch 50 is disengaged, the electrical control mechanism 60 is temporarily inactivated, and the mechanical control mechanism 61 controls the throttle. Next, in step S3, a battery check is performed.

This battery check shows that the battery voltage is 8V.
This is done by determining whether there are more than When the determination in step S3 is No, it is unstable, and the control returns to the beginning.

On the other hand, when the determination in step S3 is YES, in step S4, including determining whether the engine is not starting,
It is determined whether the engine rotation speed is greater than 5oorpm. When this determination is YES, the engine is in a stable state and the engine is not starting, so in step S5, the clutch 50 is engaged and the electrical control system is put into operation. After that, in step S6, it is determined whether the conditions for automatic speed control (ASC) are satisfied, and if this determination is YES, automatic speed control is performed (step S7), and if NO, the electric control mechanism 60, a target throttle opening TVOT is calculated based on the maps shown in FIGS. 3A to 4B (step S8). This throttle control will be explained in detail later.

If the determination in step S4 is NO, it means that the engine condition is unstable, including when starting the engine, so in step S9, the clutch 50 is disengaged and the electric control mechanism 6
0 is inactive. This improves the startability of the engine, as described above. After the above steps are completed, the clock output A for the watchdog timer is inverted in step S9, used as the clock output A, and outputted from the port in step S10, thereby completing one cycle of control.

Next, with reference to the flowchart of FIG. 7, the calculation of the basic throttle opening when calculating the target throttle opening in the throttle control in step S9 of the main routine will be described.

In this calculation, first, in step S1, it is determined whether the mode switch is 1, that is, whether the driving mode is the economy mode. When this determination is YES, it is determined in step S2 whether a flag AF indicating that the accelerator pedal is being returned is 1 or not. If this determination is NO, a map for economy mode driving shown in FIG. 3B is read out in step S3. On the other hand, if the determination in step S1 is NO, then in step S4 the mode switch is set to 3.
In other words, it is determined whether the driving mode is the power mode. When this determination is YES, it is determined in step S5 whether the flag AF is 1 or not. If this determination is No, the map for power mode driving shown in FIG. 3A is read out in step S6.

On the other hand, when the determination in step S4 is NO, it indicates that the mode switch is set to the normal mode, and in this case as well, the flag AF is set to the normal mode.
It is determined whether or not is 1 (step S7). If this determination is NO, a map for normal mode driving shown in FIG. 3C is read out in step S8. Then, step S2, step S5, step S7
When the determination is YES, that is, when the accelerator is being released, a map for driving while the accelerator is being released, shown in FIG. 3D, is read out in step S9.

When the reading of the necessary map is completed, step S
With IO, the detected accelerator pedal depression amount α1 is shown on the control characteristic line of the map, and the basic throttle opening T
Find 1. Note that the basic throttle opening degree T corresponds to the above-mentioned basic throttle opening degree TVOB. When step 310 is completed, the basic throttle opening degree calculation routine is completed, and the above steps are repeated.

The calculated basic throttle opening degree is corrected by the accelerator depression speed, etc., and the target throttle opening degree T v ot in step S9 in FIG. 6 is calculated.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the overall configuration of an engine control device according to an embodiment of the present invention, FIG. 2 is a schematic diagram of a throttle valve actuation device used in the engine control device, FIG. 3A, FIG. 3B, Figures 3C and 3D are maps for calculating the basic throttle opening stored in the control unit, Figures 4A and 4B are maps showing correction coefficients, and Figure 5 is a control characteristic map. FIG. 6 is a flowchart showing the control of the throttle valve operating device by the control unit, and FIG. 7 is a flowchart for basic throttle opening calculation. FIG. 8 is a circuit diagram in which the motor control circuit is constructed of logic circuits. 1 Engine 5 - Accelerator pedal 6 - Throttle valve 7 - Throttle valve operating device 18 -, control unit 60 - Electrical control mechanism 61 - Mechanical control mechanism 70 - Motor control circuit third eight-pronged puff mode Figure 3B: VOB during economy mode Figure 3C: vo B during normal mode Figure 3D: While releasing the accelerator Figure 4A: Accelerator pedal chain correction Figure 4B: Vehicle speed correction V 5 Figure throttle Figure 8: 7゜

Claims (1)

[Claims] An engine control device comprising an engine output adjustment means for adjusting the output of the engine, an accelerator, and a control means for electrically controlling the engine output adjustment means based on an operation amount of the accelerator, wherein the accelerator is in a non-operated state. 1. An engine control device comprising: an electric circuit that sets the output adjustment means to a state where the output of the engine is minimized, independently of the control means, when the engine output reaches a minimum.