JPS611851A - Fuel injection device - Google Patents

Abstract

PURPOSE:To drive an engine in stable operation, by providing a means which both stops operation of the internal-combustion engine and displays a trouble when it occurs in a servo control part. CONSTITUTION:The first arithmetic part 5 outputs a target quantity of injection to be input through a converting part 10 to an error detecting part 11 and a trouble discriminating part 12. A PID arithmetic part 14 outputs control data D5 for PID controlling an actuator 15. If a trouble discriminating part 28 discriminates a trouble in a servo control part, a fuel-cut solenoid valve 25 is closed, stopping an engine. Here generation of the trouble is displayed in a display device 24. And if a starting switch 26 is turned on, a switch control part 23 opens the fuel-cut solenoid valve 25 and switches a selector switch 16. As the result, a data D6 is fed to a driving circuit 17. In this way, the engine can be driven in stable operation.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a fuel injection system for an internal combustion engine, and more particularly, the present invention relates to a fuel injection system for an internal combustion engine, and more particularly to a fuel injection system in which a signal indicating the position of a fuel adjustment member drives an actuator that drives the fuel adjustment member. This invention relates to an electronically controlled fuel injection device that is fed back to a control system.

BACKGROUND OF THE INVENTION Conventional electronic fuel injection devices of this type calculate the optimal fuel injection amount at any given time according to information indicating engine operating conditions such as engine rotational speed, accelerator position, etc. The position of the fuel adjustment member is controlled so that the difference between the unnecessary target fuel adjustment member position and the actual fuel adjustment member position becomes zero. Therefore, a sensor is provided that outputs a signal indicating the position of the fuel adjustment member, and this signal is fed back to form a closed loop control system, but if the sensor for detecting the position fails for some reason. Then, control became completely impossible, and the engine had no choice but to stop operating. However, the reliability of the system is significantly impaired if the engine operation has to be stopped simply due to a failure of the sensor that detects the position of the fuel adjustment member. Particularly in the case of equipment for vehicles, if the engine becomes completely unable to operate, it will become impossible to move on its own, which is extremely inconvenient. So,
In some cases, there is a possibility that an accident may occur that threatens the lives of the passengers.

Therefore, in the event of any failure in the above-mentioned sensor, the system is configured to change the return path of the control system, use the engine rotational speed as a return signal, and continue controlling the injection amount. has been proposed (Utility Model Application Publication No. 57-53040). However, when the return route is switched as described above while the vehicle is running, there is a problem in that sudden changes in torque cause sudden deceleration, sudden acceleration, etc., and drivability deteriorates. ing.

OBJECTS OF THE INVENTION It is therefore an object of the present invention to stop the operation of the engine once a failure occurs in the sensor that detects the position of the fuel adjustment member, and to optionally stop the operation of the engine without receiving a signal from the sensor. An object of the present invention is to provide an electronic fuel injection device that can stably perform fuel injection at low temperatures.

Structure of the Invention The structure of the present invention includes a fuel injection pump for injecting and supplying fuel to an internal combustion engine, a means for outputting a single noculus every time the crankshaft of the internal combustion engine reaches a predetermined reference rotational position, and A required target injection amount responsive to at least the reference signal and the position signal, including a position sensor that outputs a position signal indicative of the position of the fuel adjustment member of the fuel injection pump, and corresponding to the current operating state of the internal combustion engine. An electronically controlled type comprising: a servo control unit that outputs a servo signal for positioning the fuel adjustment member so that the fuel adjustment member is positioned; and a drive unit that performs a positioning operation of the fuel adjustment member in response to the servo signal. In the fuel injection device, there is provided a determining means for determining whether or not a failure has occurred in the servo control section; a means for stopping the internal combustion engine and displaying a failure; a calculating means for calculating a required target rotational speed; and a calculating means for calculating a required target rotational speed; means for calculating and outputting a control signal for setting the speed to the target rotational speed, and a start switch being turned on when it is determined by the determining means that a failure has occurred in the nib control section and is transmitted. The present invention is characterized in that it includes means capable of canceling the stoppage of the internal combustion engine in response to this, and supplying the control signal to the drive unit in place of the servo signal.

According to the above-mentioned configuration, if any failure occurs in the servo control section, the operation of the internal combustion engine is temporarily stopped, an appropriate failure display is displayed, the driver is informed of the occurrence of the failure, and the engine is then restarted. When the switch is turned on, the engine can be released from the stopped state. Along with this release operation, a control signal from the rotational speed feed is supplied to the drive section in place of the servo signal from the position feedback of the fuel adjustment member, thereby allowing the internal combustion engine to continue operating. be able to. For example, control using rotational speed feedback is configured to perform control calculations and output the calculation results in synchronization with a reference signal indicating the timing at which the piston of an internal combustion engine reaches the top dead center position. It is possible to reduce the instability of rotation that occurs in the rotational speed control section, and to realize a stable rotational speed control section. Therefore, in the case of internal combustion engines for vehicles, the sir? Even if the control unit fails, it will still be able to move with its own blade.

Incidentally, even in the case of rotational speed feedback control using a control signal, the failure display continues, so that the driver can be made aware of the emergency operation.

EXAMPLES Hereinafter, the present invention will be explained in detail with reference to illustrated examples.
- FIG. 1 shows a block diagram of an embodiment of an electronically controlled fuel injection device according to the invention.

A fuel injection device 1 electronically controls the position of a control sleeve (not shown), which is a fuel adjustment member of a fuel injection pump 2, to adjust the fuel supplied to a diesel engine 4 to a required value commensurate with its operating state. This is a device for controlling so that In order to calculate the optimal fuel injection amount according to the operating state of the engine at that time, accelerator data A indicating the operation amount of the accelerator pedal 6, speed data N indicating the rotation speed of the diesel engine 4, and boost pressure of the diesel engine 4 are used. The first boost pressure data P shown in FIG.
A calculation section 5 is provided. Accelerator data A is output from an accelerator sensor 7 that converts the amount of operation of the accelerator pedal 6 into an electrical signal. In order to obtain the speed data N, the top dead center/4'rus TDC is output to the crankshaft of the diesel engine 4 at the rotation angle position of the crankshaft when the cylinder piston of the diesel engine 4 reaches the top dead center. T.D.
C sensor 8 is installed, and this top dead center pulse TDC
By calculating the period of , the speed calculator 9 outputs speed data N indicating the rotational speed of the diesel engine 4 at each time.

The calculation result calculated in the first calculation section 5 based on the above-mentioned data A, N, and P is output as data D1 indicating the target injection amount Qt. The data D1 is input to the conversion section 10, where it is converted into target position data D2 indicating the target position Rj of the control sleeve necessary to obtain the target injection amount Qt, and is sent to the error detection section 11 and the failure determination section 12, respectively. is input. Data D3 indicating the current position RIL of the control sleeve is inputted to the error detection section 11 from the position sensor 13, respectively. The error detection unit 11 calculates the deviation of the position RIL from the target position J based on the data D2 r Da, and calculates the deviation ΔR (=Rt R
Data D4 indicating a) is output. Data D4 is P
The data is input to the ID calculation unit 14, where data processing necessary for performing PID control is performed.Based on the deviation ΔR, the PIDI is used to perform PID control on the actuator 15 so that the position Ra of the control sleeve matches the target position JK.
D control data is output. PIDID control data 5
The signal is input to the drive circuit 17 via the changeover switch 16, where it is converted into a control signal S1, and this control signal S1 is applied to the actuator 15.

Therefore, when the changeover switch 16 is switched as shown by the solid line, the data D output from the position sensor 13 is
A closed-loop control system is configured in which 3 is input as foot check data, and a sir & control unit is configured to control the position of the control sleeve so that the target injection amount Qt calculated in the first calculation unit 5 is obtained. Sir? Data Ds will be output as the output of the control section.

This sir? Is there any abnormality in the control unit and the above mentioned server? A rotational speed foot knob control section 18 is provided so that the injection amount can be controlled as desired even if the control does not operate normally. The rotation speed feed zf control unit 18 includes a second calculation unit 19 that calculates and outputs target speed data Nj according to the amount of operation of the accelerator pedal based on the accelerator data A, and a second calculation unit 19 that calculates and outputs target speed data Nj according to the operation amount of the accelerator pedal, and a second calculation unit 19 that calculates and outputs target speed data Nj according to the operation amount of the accelerator pedal, and a second calculation unit 19 that calculates and outputs the target speed data Nj according to the operation amount of the accelerator pedal. The control calculation unit 20 is provided for calculating and outputting preliminary control data D6 for performing feed/duck control.

The control calculation unit 20 calculates target speed data Nt and speed data N
and an adder 21 for performing an addition operation with the polarity shown in the figure, and a PID for performing data processing necessary for performing PID control on data D7 indicating the addition result of the adder 21.
The control calculation unit 20 has a calculation unit 22, and the control calculation in the control calculation unit 20 is performed in synchronization with the timing at which the top dead center/second pulse TDC occurs. When the calculation of the preliminary control data D6 is executed in synchronization with the generation timing of the top dead center pulse TDC, the preliminary control data D6 can be obtained under the same operating conditions of the diesel engine 4, so that the preliminary control data Rotational speed feedback control using DaK can be performed stably.

The preliminary control data D6 obtained in this way is input to the changeover switch 16, and when it is determined that some kind of failure has occurred in the servo control section as described later, the data is replaced with the data Dls. D6 is applied to the drive circuit 17.

In order to determine whether there is a failure in the servo control section, a failure determination section 12 to which data DM+D3 is input is provided. In the failure determination unit 12, the data DB r
Based on the DB, it is determined whether the value of the difference between the target position Rt and the actual position R6 of the control sleeve is greater than or equal to a predetermined value for a predetermined period of time, and based on this determination result, it is determined whether there is any fault in the servo control unit. A determination is made as to whether or not this has occurred.

That is, if the difference is greater than or equal to a predetermined value for a predetermined period of time, it is determined that some kind of failure has occurred in the servo control section, and in other cases, it is determined that the servo control section is operating normally. be done. Discrimination signal S indicating this discrimination result
2 is output from the failure determination section 12, and the switch control section 23
and are input to the display 24, respectively.

The display 24 displays the discrimination signal S! By the way, sir? If a failure is detected in the control section, an appropriate means such as a lamp or buzzer is used to indicate the occurrence of the failure. The switch control section 23 is
It is provided in the switching control of the changeover switch 16 and the fuel injection bong 762 to supply fuel.

Fuel cut solenoid valve 250, which performs stop control, is turned on.

This is for performing off control, switch control section 2
3 is a starting signal B that is output when the starting switch 26 for starting the diesel engine 4 is turned on.
T and discrimination signal S! It works especially in response.

The switch control unit 23 outputs the discrimination signal 8. during operation of the engine. When the content indicates that a failure has occurred in the servo control section, the fuel cut solenoid valve 25 is closed and the fuel is turned off.When the engine is started, that is, when the start signal 8T is output, the discrimination signal is output. S! However, when the content indicates that a failure has occurred in the servo control section, the 1 changeover switch 16 is switched from the state shown by the solid line to the state shown by the dotted line, and the fuel cut solenoid valve 25 is opened, and the start signal ST is activated. If the determination signal S2 indicates that there is no fault in the output state, the fuel cut solenoid valve 2 is set so that the fuel cut solenoid valve 25 is opened with the changeover switch 16 switched as shown by the solid line.
5 and a control signal S4 for controlling the changeover switch 16.

According to such a configuration, when the failure determination unit 28 determines that some kind of failure has occurred in the servo control unit of the diesel engine 4 during operation, the fuel cut solenoid valve 25 is activated.
is closed, and the diesel engine 4 remains in a stopped state.

At this time, since the occurrence of the fault is displayed on the display 24, the driver can immediately know the occurrence of the fault and can immediately take necessary measures by stopping the operation of the diesel engine 4.

After the operation of the diesel engine 4 has been stopped in this way, when the start switch 26 is turned on, the switch control section 2
The fuel power solenoid valve 25 is opened by the control signal S3 from the fuel pump 3, and at this time the changeover switch 16 is switched as shown by the dotted line by the control signal S4. For this reason, data D
Instead of IK, data D6 is supplied to the drive circuit 17, and the diesel engine 40 is controlled by rotational speed feedback control.
The rotation speed can be controlled according to the amount of operation of the accelerator pedal 6. During each of the above control operations, the diesel engine 40 rotation speed reaches the predetermined upper limit rotation speed Nm1LX.
In order to stop the operation of the 1-diesel engine 4 in the event of a force exceeding Nmax) A control signal SB for closing the 1-fuel cut solenoid valve 25 is output from the speed determination unit 27 when the fuel cutoff solenoid valve 25 reaches Nmax. Therefore, data D.

Or, if the engine speed increases abnormally for some reason during the control operation based on D6, the speed determination section 27 will stop the fuel supply to the diesel engine 4.
Safe operation of the engine can be ensured. The speed data N1, the target speed data Nt, and the discrimination signal s2 are input to the failure determination section 28, and when the determination signal indicates that a failure has occurred in the servo control section, IN-Ntl is input to the failure determination section 28. It is determined whether a state in which the value is greater than or equal to a predetermined value α has occurred continuously for a certain period of time or not. If, IN-
If the state of Ntl>α occurs continuously for a predetermined period of time or more, the TDC sensor 8. It is determined that there is a failure in the actuator 15, etc., and the signal B4 is used to close the solenoid valve 25 using fuel power.
is output, and when this is K, the fuel cut solenoid valve 25 is closed and the operation of the diesel engine 4 is stopped.

As mentioned above, in this device, if a failure occurs in the servo control section, the control is switched to the rotational speed foot amount according to the data p6. It can be moved to a safe location. In this case as well, the display 24 will indicate that it is in emergency operation mode.
It can draw the driver's attention and is useful for safe driving.

FIGS. 2 and 3 show flowcharts of a control program when a microcomputer is used to configure the portion surrounded by a dashed line in the control system of the nine devices shown in FIG.

The control program will be explained with reference to FIG. 2. After the program starts, initialization is first performed in step 31, in which each flag FM and FBT are reset, and the counter CTR is also reset to zero. . Next, data such as data A, N, and P are read (step 32), and it is determined whether or not the flags F are "1" (step 33). The flag F is a flag that is set to "1" when some abnormality occurs in the servo control section, and in this case, the 7 lag F is set to "0". Next, data N at Stella 7'34.

A target injection amount Qt is calculated based on A and P, and this calculation result Qt is converted to the corresponding target sleeve position RjK (Stella 7'3'5), and the converted data is data D2.
(step 36).

Next, data D3 is read (step 37), and data D
The deviation ΔR is calculated based on 1+D3 (step 38), and it is determined whether ΔB is smaller than a predetermined value A (step 39). In the case of ΔR(A), the value of the counter CTR is reset to zero (Stella f40), and the process returns to Stella 7632.

If ΔR≧A, 1 is added to the contents of the counter CTR (step 41), and it is determined whether the value of the counter CTR is larger than a predetermined value B (step 4).
2). If the value of the counter CTH is less than or equal to B, the process returns to step 32, but if CTR>B, the process proceeds to step 43, where the flag F! ! is changed to "1" by 7. That is, ΔR
If the value of is greater than the predetermined value A continues for a period of time indicated by the predetermined value B, the flag F2 is set to "1",
A message indicating that some kind of failure has occurred in the servo control unit is displayed, and the fuel cut solenoid valve 25 is closed (step 44).
).

When the flag F becomes "1", the determination result in step 33 becomes YIS, and the start switch 2 is turned off in step 45.
6 is on or not, and if the start switch 26 is off, the 7 lag FIIT is set to "1" in step 46.
A determination is made as to whether or not.

Flag F8T is flag F. This is a flag indicating whether or not the start switch 26 is turned on when is "1". Therefore, in this case the flag FIIT is rOJ,
The process will proceed to step 44. Therefore, when it is detected that a failure has occurred in the servo control section, the start switch 2
6 is turned on, the fuel cut solenoid valve 25 is closed and the display 16 continues to indicate the occurrence of a failure.

When the start switch 26 is turned on, the determination result in Step 45 becomes YES, the flag F8T is set to "1" (Step 47), and the solenoid valve 25 is opened (Step 48). . Thereafter, the switch 16 is switched as shown by the dotted line in FIG. 1 to enter the emergency control mode (step 49).

Thereafter, if the determination result in step 46 is YES, and the operation in the emergency control mode is continued, the result is K.

FIG. 3 shows a detailed flowchart of the program when the emergency control mode is entered.

To explain the 70-chart in Figure 3, Stella f
At 50, the switch 16 is switched as shown by the dotted line in FIG. 1, and the target speed N is set based on the accelerator data A.
j is calculated (step 51).

Next, it is determined whether the speed data N and the boost pressure data P are each larger than a predetermined maximum value Nuni+PmaX (step 52.53);
If all of the determination results are NO, the process returns to step 32 in FIG.

If the determination result is YES in at least one of the steps 7652.53, the fuel power solenoid valve 25 is closed (step 54), thereby stopping the operation of the buisel engine 4 and setting the flag F8T. It is set to "0" (step 69) and returns to Stella f32 in FIG.

In other words, if N>Nm1Lx or P>Pmax, it is dangerous to continue operating the engine.
This is a configuration in which engine operation is forcibly stopped.

When the top dead center pulse TDC is output, the interrupt program shown in FIG. 3 is executed. In step 55, the interrupt program determines whether flag F is "1". The flag FA is used to determine whether or not a timer that operates in response to the top dead center pulse TDC to measure the period of the top dead center pulse TDC is in operation. When FT=rOJ, it indicates that the timer is in a non-operating state, and therefore, the timer is started in response to the input of the top dead center pulse TDC, and the flag FT is set to "1" (Step 56). . If the determination result in step 55 is No, the execution of this interrupt program is completed by executing only step 56, and the process returns to the control program shown in FIG. Note that the timer continues to operate in this case as well, and when the interrupt program INT is executed in response to the occurrence of the next top dead center nors TDC, in this case,
The determination result of Stella f55 is YES, step 57
The timer is stopped and the flag F1 is set to rOJK.
will be reset.

Therefore, the timing content of the timer is one top dead center point T.
This timer indicates the time from when DC is output until the next top dead center pulse TDC is output. Based on the time measurement contents of this timer, speed data N indicating the rotational speed of the diesel engine 4 at that time is calculated. (step 58), 7 lag FI
It is determined whether N is “1” (step 59).
.

If the flag F is "0", the operation returns to the control program shown in FIG. 2 after just performing the calculation of the data N, indicating that some kind of failure has occurred in the servo control section and the flag F8 is "1".
If so, proceed to Stella Pro 0, and calculate the difference between the actual speed of the diesel engine 4 and the target speed from the target speed data Nt calculated in step 51 and the speed data N calculated in step 58. Difference ΔN (=N
j-N) is calculated (step 60). Next, in the Stella 7D61, it is determined whether ΔN is larger than the predetermined value G, and if the determination result is No, the counter CT
After setting RI to 0 (step 62), t, the calculation for PID control is performed on the difference ΔN obtained in step 60 (stellar f67), and the resulting data D6 is output ( Step 8) Return to the program shown in Figure 2.

If the determination result of Stella 7'61 is YES,
The contents of the counter CTR1 are incremented by 1 (Step 3), and it is determined whether the value of the counter CTR1 is greater than a predetermined value (Step 4).

Step 67 if the determination result of Step 4 is No.
Step 64 proceeds to step 64, and PID control is performed, but if the determination result in step 64 is Y or Es, the fuel power is closed.
Step 65) After that, the flag F8T is set to "0" and the program returns to the program shown in FIG.

In this way, it is determined whether or not the state in which the value of ΔN is greater than or equal to the predetermined value C continues for a predetermined time determined by the value or not, and the value of ΔN continues to be the predetermined value for a predetermined time or more. If the condition is C or higher, the operation of the diesel engine will be stopped.

In this way, the configuration is such that the calculation of data D6 is executed in synchronization with the generation of the top dead center pulse TDC. If a failure occurs in the control section, stable engine rotational speed control can be performed by feedback control of the rotational speed.

In addition, in the above embodiment, the sir? Although the configuration is such that the switch 16 is automatically switched as shown by the dotted line in response to the control signal S4 when some kind of failure occurs in the control section, it is preferable that the switch 16 be switched manually by the driver as desired. In this case, if a failure occurs in the servo control unit and the engine operation is stopped, if the 1 switch 16 is switched as shown by the dotted line before turning on the start switch 26, it will be possible to prevent the failure from occurring. After that, when the engine is started, the rotation speed can be controlled by feedback of the rotation speed.

In the above embodiment, the target speed data Nj is determined according to the amount of depression of the accelerator pedal. However, in the present invention, the target speed data Nt may be fixed to a predetermined constant value. If the target speed data Nj is set to a fixed value, the engine speed will be controlled to a predetermined constant value during operation in the emergency control mode.

Effects of the Invention According to the present invention, as described above, when any failure occurs in the servo control unit, the operation of the diesel engine is temporarily stopped and a display indicating that the failure has occurred is displayed to notify the driver of the occurrence of the failure. Let me know what you can do. and,
When the start switch is turned on, the stopped state of the engine is canceled, and the engine can be operated in the emergency control mode if desired. Therefore, even if a failure occurs in the servo control section, the engine will not become inoperable, and the machine can move with its own blade. In addition, the operability in emergency mode is different from when the control mode is suddenly changed while the engine is running, as it is executed when the engine is stopped and the start switch is turned on by the driver. It is possible to prevent the engine from suddenly accelerating or decelerating, and since a failure is displayed, safe operation can be carried out, which is extremely preferable in terms of safety measures. In addition, since the emergency mode operation is configured such that the control data for increasing the rotation speed is calculated in synchronization with the predetermined rotation timing of the internal combustion engine, the emergency mode operation can be stably performed. It is something that can be done by force.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention, and FIGS. 2 and 3 are flowcharts showing a program when a part of the function of the block diagram shown in FIG. 1 is executed by a microconbeater. Chiru. 1...Fuel injection device, 2...Fuel injection pump, 3.
...Control rack, 4...Diesel engine, 5
...first calculation section, 6...accelerator pedal, 8...
TDC sensor, 9...Speed calculator, 12...Failure determination section, 13...Position sensor, 15...Actuator, 16...Selector switch, 18...Rotation speed filter
)* ,,*Tsuku control section, 19... second calculation section, 20
... control calculation section, 23 ... switch control section, 24.
...Indicator, 25...Smoke cut electromagnetic decay, 26...
Start switch, D5' D6...Data, N...
-Speed data, A...accelerator data, S2...discrimination signal, 8m, S4...control signal, 8T...starting signal.

Claims (1)

[Claims] 1. A fuel injection pump for injecting and supplying fuel to an internal combustion engine, means for outputting a reference pulse every time the crankshaft of the internal combustion engine reaches a predetermined reference rotational position, and a fuel adjustment member of the fuel injection pump. The fuel adjustment member includes a position sensor that outputs a position signal indicating the position, and is responsive to at least the reference pulse and the position signal, and is configured to adjust the fuel adjustment member so as to obtain a required target injection amount according to the current operating state of the internal combustion engine. An electronically controlled fuel injection device comprising: a servo control unit that outputs a servo signal for positioning; and a drive unit that performs a positioning operation of the fuel adjustment member in response to the servo signal; a determining means for determining whether or not a failure has occurred in the servo control section; and means for stopping operation of the internal combustion engine and displaying a failure indication in response to the determination result of the determining means when a failure occurs in the servo control section. and a calculation means for calculating a required target rotational speed, and control for adjusting the speed of the internal combustion engine to the target rotational speed in synchronization with the reference pulse in response to the calculation result of the calculation means and the reference pulse. means for calculating and outputting a signal; and canceling the stoppage of the internal combustion engine in response to turning on of a start switch when it is determined by the determining means that a failure has occurred in the servo control section. and means capable of supplying the control signal to the drive section in place of the servo signal.