JPS58144651A - Engine controlling apparatus - Google Patents

Abstract

PURPOSE:To ensure safe operation when a computor for controlling fuel supply to an engine has caused uncontrolled operation, by actuating a circuit for controlling the fuel supply rate on the basis of the opening of an accelerator pedal and the engine speed when the uncontrolled operation of the computor is detected. CONSTITUTION:In operation of an engine, an accelerator opening signal PPS and an engine-speed signal RS are subjected to AD conversion and then stored in a memory 301c of a computer 30. Then, deviation of these two signals is calculated by a processor 301a and a signal VAS for instructing the quantity of injected fuel, proportional to the above deviation, is produced. On the basis of this signal VAS, the fuel supply rate is controlled by producing a valve control instructing signal VCS via a transistor PT, etc. If the output ABS of an uncontrolled operation detecting circuit 37 becomes ''0'' due to the uncontrolled operation of the computor 30, an AND gate AND1 is rendered inoperative, and a pulse signal VBS having a duty ratio proportional to the signal PPS and inversely proportional to the signal RS of a signal generating circuit 36 is produced as the instruction signal VCS.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an engine control device that controls the rotation of an engine (particularly a diesel engine). The present invention relates to an engine control device equipped with a backup circuit that can continue rotation control.

2. Description of the Related Art In recent years, there has been a remarkable wave of electronic control of internal combustion engines in automobiles and the like, and micro combinators are being used to control internal combustion engines. In such a computer-based engine hook control circuit, the combiator periodically captures the accelerator opening, engine speed, engine temperature, etc., and uses fuel supply pulp, etc. to ensure that the appropriate amount of fuel is supplied. There is something that can be controlled.

In general, control by a combiator involves sequentially executing control programs stored in advance in its built-in memory.
Therefore, as long as the control is performed and is operating normally, no abnormality will occur in the control. On the other hand, when using a combiator to control the engine, if the computer goes out of control, the engine speed will become abnormally high and the engine will rev up, making it impossible to control the engine.
There is a risk that it could damage the engine or even human life. It is inconceivable that the comviator would run out of control for no reason, but in carrot control, etc.
Since it is placed in a place with a poor electrical environment, depending on external conditions such as noise intrusion, abnormally high temperature, etc., it is possible that a program loop may occur and the device may go out of control. Conventional computer-controlled engine control devices do not have these countermeasures, and there is a need for a solution in the unlikely event that the engine goes out of control.

In general, in the field of computer technology, a runaway detection program is installed in a part of the control program to detect a runaway in a combiator, and a circuit is installed to monitor the output of the bus line. If the engine outputs too many addresses or outputs an address that has not been set, it is judged as a runaway and the operation of the combination engine is immediately disabled, but this is done by engine control. If applied to a device, the engine would be stopped, which is not desirable.

In other words, when the engine control device's 117 pump goes out of control, stopping the engine immediately will cause the car that was running at 11 to suddenly stop, which could lead to a rear-end collision or other dangers to human life. Conceivable.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an engine control device that can replace a combination controller for engine control even if a computer goes out of control.

Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a configuration diagram of an embodiment of the present invention.

In FIG. 1, 1 is an accelerator pedal, 2 is a potentiometer that detects the amount of depression of the accelerator pedal as an electric signal PPS, and 6 is a control device incorporating a combiator. 4 is a pneumatically driven actuator, 4a#i transmission shaft, 5 is a pneumatic pressure regulating valve, 6#i vacuum pressure regulating valve, 5
a and 5b are pipes attached to the air pressure control valve, 6a*6b
This is also a pipe attached to the vacuum pressure control valve. 7 is a crank, 8 is a shirt), 9 is a control lever, io is a spring that applies rotational force to the lever 9 in one direction, and 11 is a potentiometer that detects the amount of rotation of the shaft 80 as an electric signal SLS.
It is a meter. 21 is a cam rotationally driven by the shaft 8, 22 is a control rack, and 25 is a plunger that controls the fuel injection amount.As the control rack 22 moves, the plunger 25 rotates, changing the effective stroke of the plunger 23. , plunger 25
This is a well-known fuel injection pump for diesel engines that changes the amount of fuel delivered by vertical movement of the pump.

Next, to explain the operation shown in Figure 1, when the driver depresses the accelerator pedal 1, the potentiometer 2
Electric signal PPS with a voltage level corresponding to the amount of pedaling
occurs. This electrical signal PPS is input to the control device 5, and is input as a depression command amount (accelerator opening amount) to a converter, which will be described later. On the other hand, Comte Party - Le Lac 2
The position 2 is shown at the 80 rotational position of the shaft, and the electrical signal SLS has a voltage level corresponding to the rotational position of the shaft 8.
is outputted from the potentiometer 11 and inputted to the computer of the control device 3, and a revolution speed signal R8 of the diesel engine is inputted from a revolution speed detector (not shown). The control device 3 creates a fuel injection amount signal from the accelerator opening amount PPS and the rotation speed signal R8, calculates the difference between the fuel injection amount signal and the same rotation position signal SLS, and adjusts the air pressure control valve 5 and the vacuum based on this difference pressure. A valve control command signal C8 is given to the pressure control valve 6 to control both of these control valves. As a result, the supply air pressure is controlled by the air pressure control valve 5 and the degree of vacuum is controlled by the vacuum pressure control valve 6, so that the degree of vacuum on the right side of the actuator 4 is controlled. The driving force transmission shirt 4a moves according to the mosquito vacuum degree, and this movement causes the crank 7 to move.
rotates the shaft 8 against the force of the spring 10, and the cam 2
1 to move the controller rack 22,
The plunger 25 is rotated to increase or decrease the effective stroke of the plunger 25 to control the amount of fuel delivered. According to the rotational movement of the shaft 8, the bottefushimometer 11 also rotates by an amount commensurate with the rotational movement of the shaft 8.

The botehushi meter 11 outputs a voltage signal SL corresponding to this rotation.
When the control rack 22 is moved by an amount corresponding to the opening (depression) of the accelerator pedal minus 1,
The difference becomes zero, and the leftward pulling force and the rightward pulling force of the actuator 4 are balanced and the actuator 4 stops. Of course, at that point, the control device 5 does not output the valve control command signal VC5 to the air pressure control valve 5 and the vacuum pressure control valve 6, and these control valves are closed. These control operations are performed instantaneously. Conversely, similar control is performed when the accelerator pedal is released. In addition, in Figure @1, the shaft 8 and lever 9 are separated.

For example, when it is necessary to forcibly open the throttle a small amount according to the opening of the throttle valve when it is cold or when the throttle valve is activated, the throttle can be opened independently of the position of the second link 7 according to a command from the accelerator pedal. It is a device that can open the valve 12.

FIG. 2 is a block diagram of an embodiment of the control device of the present invention. In FIG. 2, numeral 50 denotes a combiator, which has a micro combinator main body 501 and an input/output interface 502. Note that 503 is the bus line.

The microcomputer 501 includes a processing device 501a and a control program memory 301b that stores a control program.
and a data memory 501c, which periodically reads the output of each sensor installed in each part of the automobile at high speed (polling control) or performs predetermined arithmetic processing under the control of the control program by interrupt, The processing results are output to each operation section (not shown). Input/output interface 502
indicates an AD converter 302a that converts an accelerator opening signal PPS indicating the amount of depression of the accelerator pedal into a digital PDK analog-to-digital (AD conversion), a buffer register 302b that stores the digital value FD, and the rotation speed of the diesel engine. It has an AD converter 302C that converts the rotation speed signal R8 into a digital value RDKAD, and a buffer register 302d that stores the digital value RD. 51ij is a DA converter that converts the digital output value of the copier 50 into an analog quantity VAS, and 52 is a differential amplifier that calculates the difference between the position signal SLS of the potentiometer 11 and the command value S of the DA converter 51. The output device, 35, is an analog-to-duty conversion circuit that generates a pulse signal with a constant period, changes the duty ratio of the pulse signal according to the input analog amount, and outputs it. If the quantity is zero, the deity ratio is zero,
That is, it outputs a pulse signal with zero pulse width. P
T is a power transistor for amplification, and converts the output pulse signal of the analog-to-death converter circuit 35 into a valve control command signal VC.
It increases the width by 5K. 54 is a voltage meter 11
55 is a waveform shaping circuit that shapes the output of the rotational speed detection device to form a rotational speed signal R8. 5
Reference numeral 6 denotes a signal generation circuit, into which the rotational speed signal R5 and the accelerator pedal accelerator opening signal PPS are input, and the rotational speed signal R5 is input.
It generates a pulse signal with a duty ratio that is inversely proportional to PP5K and proportional to the accelerator opening signal PP5K. A runaway detection circuit 57 is connected to the bus line of the combiator 301, receives data on the Nox line, and determines that the computer has runaway if the same address is output on the bus line multiple times in succession. It can be thought of as consisting of multiple registers that receive data on the line and a comparison circuit that compares the contents of these registers.

AND1 and AND2 are AND gates, which constitute a switching circuit, and when the detection output BS of the runaway detection circuit 57 is 1 (at the time of non-runaway detection), AND1 is opened, and the detection output ABS is set to %OI (runaway detection). time) and gate AND
2 is the one that opens. NOT is an inversion gate.

To explain this operation, the accelerator opening signal PPS is sent to the input/output interface circuit 3020AD converter 502a.
The digital value is converted into PDKAD, and then stored in the opening storage area 504 of the data memory 301C at a predetermined period
K is remembered.

On the other hand, the rotation speed signal R5 is converted into a digital value SD by the AD converter 502C, and then stored in the data memory 50.
It is stored in the opening degree storage area 305 of 1C.

The processing device i1a constantly calculates the difference between the digital values PD and SD under the control of the control program, and outputs a fuel injection amount command signal VAS proportional to the difference.

Further, the detection outputs of the exhaust gas concentration sensor and the engine temperature sensor are inputted to the microcombination controller 301, and the optimum fuel injection amount command signal VAS is determined.

This command signal VAS is converted into a so-called analog signal by an A converter 51 and inputted to a differential amplifier 52. Differential amplifier 5
2 inputs the position signal SLS of the potentiometer 11 from the position detection circuit s4, so the command signal VAS
A difference signal between the position signal SLS and the position signal SLS is output. This differential signal is converted into a pulse signal with a duty ratio corresponding to the analog-to-digital amount of the differential signal in an analog-to-duty conversion circuit. On the other hand, the runaway detection circuit 57 monitors the runaway of the combination vehicle 50 via its bus line 505.
7, when runaway is not detected, the detection output ABS is %1
1, the output pulse signal of the conversion circuit 55 is connected to the transistor PT.
K is transmitted and amplified as a valve adjustment command signal vC8,
It is used to drive the control valves 5 and 6 (Fig. 1). As a result, the actuator 4 operates as described above, the control 2 knob 22 moves, the plunger 25 is rotated, and the amount of fuel delivered is controlled. When the combination engine 50 is not running out of control, the combination engine 50 determines the optimum fuel injection amount according to the accelerator opening degree, engine speed, etc., and controls the injection amount of the fuel pump. The runaway detection circuit 37 always takes in the data of the path @SO5 of the combination Todoroki 50, and determines whether the address information in the data is continuously fmJ -. If the same address is output continuously, it is considered that the program is running out of control or the combiator is running out of control.
The runaway detection power is expressed as t-%Ol. As a result, the AND gate λNDI is closed and the output of the conversion circuit 35 is not transmitted to the transistor FT, so the combinator 501/C
fuel injection control will be disabled. On the other hand, and gate A
ND2 is opened by inputting the detection output ABS via the inverting gate (NOT), so the output of the signal generation circuit 56 is transmitted to the transistor PTK and the valve adjustment command signal vC.
8 to the control valve 5.6. That is, the fuel injection amount is controlled by the output of the signal generation circuit 56.

The signal generation circuit 56 will be explained using the block diagram in FIG. 3 and the characteristic diagrams in FIGS. 4 to 6. In the figure, 506 is an oscillator, 307 is a triangular wave conversion circuit that converts the oscillation output of the oscillator 506 into a triangular wave signal TWS (in the 6th cycle), and 308 is a frequency-voltage converter (FV converter) that rotates. A voltage corresponding to the frequency of the number signal RS is output, and the fourth
It has pronation rotation speed-voltage output characteristics. A buffer amplifier 509 amplifies the accelerator opening signal PPS and has the opening signal (PPS)-voltage output characteristic shown in FIG. 4(6). 510 is a differential amplifier, which outputs the actuator opening signal PP.
It generates a differential output DFS by subtracting the rotational speed voltage output from S, and the accelerator opening signal PPS and differential output DF
The relationship with S has the characteristics as shown in FIG. 5, using the rotation speed as a parameter. 520 is a comparison circuit, as shown in the 6th article,
Compare the differential output DFS and the triangular wave signal TWS, and as shown in FIG. 6 (6), when the differential output DFS is greater than the triangular wave signal TWS, the output of the level turtle 11 is used, and when it is less than that, the level % is used.
It outputs a pulse signal VH8 indicating an output of 01. That is, as is clear from Figure 4 β), the output pulse signal VBS has the oscillation period of the oscillator 504 and its pulse width is proportional to the differential output DFSK, and is a kind of pulse width modulation signal. To explain the operation of FIG. 3, the accelerator opening degree signal PPS is amplified by the buffer amplifier 509 and input to the differential amplifier 510, while the rotation speed signal R5 converted to voltage is input to the differential amplifier. and the difference is output. The output DFS of the difference amplifier 51G indicates the difference between the rotation speed command signal predetermined according to the opening amount of the accelerator opening signal PPS and the actual rotation speed signal R5. This differential output DFS is compared with the triangular wave signal TWS of the triangular wave conversion circuit 307 in a comparison circuit 520, and a pulse signal VBS having a pulse width corresponding to the magnitude of the differential output DFS is generated.
K-transformed. This pulse signal VBS is a fuel injection amount signal, and its pulse width is inversely proportional to the rotational speed and proportional to the accelerator opening. That is, as shown in FIG. 6 (QK), the duty ratio of the pulse signal is inversely proportional to the rotation speed and proportional to the accelerator opening.In this way, even if the combiator 30 goes out of control, the signal generation circuit 36 The rotation is controlled as instructed by the accelerator.Comparing the control amount of the signal generation circuit s6 with the optimal control amount of the combiator 30, the output of other sensors is used as the determining factor for the control amount, and the vehicle is sent to a service factory. In the above-mentioned embodiment, the control valves 5 and 6 are commonly controlled by the valve control command signal vC8, but the two valve controls are controlled so that the control valves 5 and 6 are controlled separately by Ic. Command signals VC5I and VC52 may be created.For this reason, the combination signal 50 and the command output VA
If S is larger than the position signal SLS, the control valve 60 command signal VC
If 51 is small, it can be configured to issue a command/command signal VC32 for the control valve 5. For example, another set of a combination of a difference amplifier 52, an analog-to-deality conversion circuit 53, an AND gate AND1, and a transistor PT is provided. That's fine. 1. Also in the signal generation circuit 36, the axle opening degree signal P
If PS is greater than the rotational speed signal R8, the control valve 6 command signal V
If C31 is small, it may be configured to issue a command signal VC32 for the control valve 5. For example, the differential amplifier 510 shown in FIG.
, it is sufficient to provide one more set of comparison circuits 320. Furthermore, the actuator 4.5.6 is not limited to the above-mentioned configuration, and other pneumatically controlled actuators, electric motors, etc. may also be used. Furthermore, as the aforementioned runaway detection circuit s7, the path 41303-
It is possible to use a device that detects that the address of the user is indicating an address that has not been set, or a device that detects that the bus or @5osyc data is not activated for a predetermined period of time. You may communicate with each other.

As explained above, the present invention provides a device for controlling the fuel supply amount of an engine using a combiator, which includes a combiator runaway detection circuit, and a signal generation circuit that generates a fuel supply amount signal from the accelerator opening degree and engine rotation speed. Since it has a support circuit that switches engine control between the comviator and the signal generation circuit, even if the comviator runs out of control for some reason, the engine can be controlled normally according to the accelerator pedal. The engine will not rotate abnormally or stop, the vehicle will not be damaged, and there is no danger of human life. In addition, since the vehicle can be driven with its own blade, it is possible to safely take the vehicle to a service factory or the like. Historically, even if the combination engine runs out of control, it automatically detects the runaway and switches control, so there is no interruption in engine control, and this is also a high level of safety.

5. Although the present invention has been explained using one embodiment, the present invention is not limited to this embodiment, and various modifications can be made within the scope of the gist of the present invention, and these are not excluded from the scope of the present invention. do not have.

[Brief explanation of drawings]

Fig. 1 is a block diagram of an embodiment of the present invention, Fig. 2 is a block diagram of an embodiment of the invention, Fig. 5 is a block diagram of a signal generation circuit of the embodiment of Fig. 2, and Figs. FIG. 5 is a characteristic diagram of the main part, and FIG. 6 is an explanatory diagram of the output operation of FIG. 3. In the figure, 1... Accelerator pedal, 2.11... Potency, meter, 3... Control device, 4... Actuator, 5.6... Mil valve, 22... Control rack, 23 ... Plunger, 30... Combinator, 56... Signal generation circuit, 37... Runaway detection circuit. Patent applicant: Isuso Automobile Co., Ltd. Agent: Patent attorney: 2 people (Figure 2)

Claims (4)

[Claims] (1) It has a combiator that calculates a fuel supply amount signal by receiving at least an accelerator opening degree signal indicating the accelerator opening degree and a rotation speed signal indicating the engine rotation speed, and the fuel supply amount signal from the combiator is used to calculate the fuel supply amount signal from the engine. An engine control device that controls the amount of fuel supplied to the engine, comprising: a detection circuit that detects runaway of the computer; a signal generation circuit that generates a fuel supply amount signal from the accelerator opening signal and the rotational speed signal; A switching circuit is provided for outputting a fuel supply amount signal of a cough signal generation circuit to the engine instead of a fuel supply amount signal of the cough comviator when detecting runaway of the combiator according to the output of the circuit. engine control device. (2) Claim (1) characterized in that the signal generation circuit generates a signal proportional to the accelerator opening signal and inversely proportional to the rotational speed signal as the fuel supply amount signal.
The engine control device described in Section 1. (3) The fuel supply amount signal is provided to a fuel injection pump of the engine.
The engine control device according to item 1) or item (2). (4) The engine control device according to claim (2), wherein the fuel supply amount signal of the signal generation circuit is a pulse signal whose duty ratio changes.