JPS611852A - Fuel injection device - Google Patents

Abstract

PURPOSE:To drive an engine in stable operation when a trouble is generated, by providing a means which releases the internal-combustion engine from its operation stopped condition in response to the turn-on of a starting switch when a servo control part is in the trouble. CONSTITUTION:A PID arithmetic part 14 outputs a PID control data D5, PID controlling an actuator 15. If a trouble discriminating part 12 discriminates a trouble in a servo control part, a fuel-cut solenoid valve 25 is closed, stopping an engine 4. Here generation of the trouble is displayed in a display device 24. Thereafter, 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. Consequently, control on the basis of the second arithmetic part 18 is performed by feeding a data D6 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.

Conventional technology The conventional electronic fuel injection system in this building calculates the optimal fuel injection amount at any given time according to information indicating the operating state of the engine, such as the engine rotation speed, accelerator position, etc. The position of the fuel adjustment member is controlled so that the difference between the target fuel adjustment member position required to obtain the amount of fuel 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, the engine became completely uncontrollable, and the engine had no choice but to stop rotating. - However, the reliability of the system is seriously impaired if the engine must 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 is extremely inconvenient because it becomes impossible to move the engine by itself. If this is done, there is a risk that an accident may occur that could threaten 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 are problems such as sudden changes in torque, sudden deceleration, sudden acceleration, etc., and deterioration of drivability. OBJECT OF THE INVENTION Therefore, in the event that a failure occurs in the sensor that detects the position of the fuel adjustment member, the operation of the engine is temporarily stopped and then, if desired, the operation of the engine is resumed as described above. An object of the present invention is to provide an electronic fuel injection device that can stably perform the injection without a signal from a sensor.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; The reference pulse includes means for outputting a reference/4' pulse each time the crankshaft of the internal combustion engine reaches a predetermined reference rotational position, and a position sensor for outputting a position signal indicating the position of the fuel adjustment member of the fuel injection pump. and a servo control unit that outputs a signal in response to at least the position signal and positioning of the fuel adjustment member so as to obtain a required target injection amount depending on the current operating state of the internal combustion engine. , and a drive unit that positions the fuel adjustment member in response to the servo control number, in the electronically controlled fuel injection device, the determination is made to determine whether or not a failure has occurred in the servo control unit. means for stopping the operation of the internal combustion engine and displaying a malfunction when a failure occurs in the servo control unit in response to the determination result of the determining means; A failure has occurred in the control unit of the output means, the calculation means for calculating the control target position of the fuel adjustment member in response to the accelerator signal and the reference pulse, and the determination means. means for canceling the operation stop state of the internal combustion engine in response to the start switch being turned on when it is determined that According to the above-described configuration, when some kind of failure occurs in the servo control section, the operation of the internal combustion engine is temporarily stopped, and an appropriate failure indication is displayed. If the driver is notified of the occurrence of a failure and then the start switch is turned on completely, the engine can be released from the stopped state. In conjunction with this release operation, the position of the fuel adjustment member can be controlled by open-loop control, and thereby the internal combustion engine can be continuously controlled. Therefore, in the case of a vehicle internal combustion engine, even if the servo control unit fails, it is possible to move on its own. Furthermore, the failure indication continues even when the position of the fuel adjustment member is controlled by open-loop control. Since this is done, the driver can be made aware of the emergency operation, which is extremely preferable from the viewpoint of safety measures.

Example Hereinafter, the present invention will be explained in detail with reference to the illustrated embodiments.

FIG. 1 shows a block diagram of an embodiment of an electronically controlled fuel injection device according to the present invention. Fuel injection device 1
electronically controls the position of a control sleeve (not shown) which is the fuel adjustment part of the fuel injection bomb f2,
This is a device for controlling the fuel supplied to the diesel engine 4 to a required value commensurate with its operating state. 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 4 pedal 6, speed data N indicating the rotation speed of the diesel engine 4, and boost of the diesel engine 4 are used. A first calculation unit 5 is provided to which boost pressure data 9 indicating the pressure is input. 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, a TDC is installed on the crankshaft of the diesel engine 4 that outputs TDC at the rotation angle position of the crankshaft when the cylinder cylinder of the diesel engine 4 reaches the top dead center. With sensor 8 installed, is this top dead center A? When the period of the pulse TDC is calculated by the speed calculator 9, speed data N indicating the current rotational speed of the diesel engine 4 is outputted from the speed calculator 9.

Based on the above-mentioned data A, N, and P, the nine calculation results are calculated in the first calculation section 5 and output as data D indicating the target injection amount Qt. Data D.

is input to the converting section 10, where it is converted into target position data D indicating the target position R4 of the control sleeve necessary to obtain the target injection amount Qt, and is input to the error detecting section 11 and the failure determining section 12, respectively. Data D indicating the current position R1 of the control sleeve is inputted from the position sensor 13 to the O error detection section 11. The error detection unit 11 calculates the deviation of the position R1 from the target position Rt based on the data Dt and rDm, and calculates the deviation ΔR.
Data D4 indicating (=Rt-R,) is output. The data D4 is input to the PID calculation unit 14, where data processing necessary for performing PID control is performed, and as a result, the actuator 15 is controlled by PID so that the position kR& of the control sleeve matches the target position Rt based on the deviation ΔRK. PIDID control data is output.

The PIDID control data box is input to the drive circuit 17 via the changeover switch 16, where the control signal S is input.

This control signal S1 is applied to the actuator 15.

In the above-mentioned surging control section to which the data D outputted from the position sensor 13 is input as feedback data, the target injection amount QA calculated by the first calculation section 5 is inputted as feedback data.
Closed loop control is performed so as to obtain the data D, and data D is output as the output of the servo control section.

The second calculation unit 1
8 is provided.Accelerator data A1 speed data N and top dead center pulse TDC are input to the second calculation unit 18, and according to the accelerator data A and speed data N, a target for open loop control is calculated. The injection amount is calculated, and the data indicating the position of the control sleeve necessary to obtain the injection amount according to the calculation result is preliminary control data D.
It is output as 6. The above-mentioned calculation in the second calculation unit 18 is performed by storing data in advance in memory in accordance with predetermined speed regulating characteristics for open-loop control, and each data A,
The configuration can be such that data corresponding to the contents of N is read out from the memory as data indicating the control target position of the control sleeve at that time. The above calculation in the second calculation section 18 is configured to be performed in synchronization with the generation timing of the top dead center pulse TDC.

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 diesel engine 4
Since the preliminary control data D can be obtained under the same operating conditions, the diesel engine 4 can be stably controlled using the preliminary control data D6.

The preliminary control data D thus obtained is input to the changeover switch 16 and 1. As will be described later, when it is determined that some kind of failure has occurred in the servo control section, gutter D is applied to the drive circuit 17 instead of data D.

In order to determine whether there is a failure in the servo control section, a failure determination section 12 to which data D, , D, is input is provided. The failure determination unit 12 determines whether the difference between the target position Rj of the control rack 3 and the actual position R, ih, is continuously greater than or equal to a predetermined value for a predetermined period of time or more based on the data D, D3. Based on the result of this determination, it is determined whether or not some kind of failure has occurred in the servo control section. In other words, if the difference remains above a predetermined value continuously for a predetermined period of time or more, it is determined that some kind of failure has occurred in the servo control section, and in other cases, the servo control section does not operate normally. It is determined that the A determination signal S2 indicating this determination result is output from the failure determination section 12 and input to the switch control section 23 and the display 24, respectively.

When the discrimination signal S indicates a failure in the servo control section, the display 24 displays an indication of the occurrence of the failure using an appropriate means such as a lamp or a buzzer. The switch control unit 23 is provided for switching control of the changeover switch 16 and for controlling on/off of a fuel cut electromagnetic valve 250 which is provided in the fuel injection I/P 2 and controls fuel supply and stop. The switch control unit 23 operates in response to a starting signal ST and a discrimination signal S2 that are output when a starting switch 26 for starting the diesel engine 4 is turned on.

The switch control unit 23 closes the fuel cut solenoid valve 25 to cut the fuel when the discrimination signal S indicates that a failure has occurred in the servo control unit while the engine is running. That is, in a state where the starting signal ST is being output, the determination signal S is output.

indicates the occurrence of a fault, the selector switch 16 is switched from the state shown by the solid line to the state shown by the dotted line, the fuel cut solenoid valve 25 is opened, and the start signal ST is output. , if the content of the discrimination signal S indicates that the servo control etc. is normal,
In order to open the fuel cut solenoid valve 25 with the changeover switch 16 switched as shown by the solid line, the fuel power, the control signal S for controlling the opening and closing of the solenoid valve 25, and the control signal S4 for controlling the changeover switch 16 are applied. Output.

According to such a configuration, when the failure determination unit 8 determines that some kind of failure has occurred in the servo control unit during operation of the diesel engine 4, the fuel cut solenoid valve 25 is closed and the diesel engine 4 is operated. Seki 4 is in a stopped state. At this time, the display 24 indicates the occurrence of a failure, so
The driver can immediately know the occurrence of a failure 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
In response to the control signal S from 3, the electromagnetic valve 25 is opened, 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
, data D6 is supplied to the drive circuit 17, and the position of the control sleeve is controlled by open-loop control so that the speed regulating characteristic is based on the control result of the second calculation section 18. During each of the above-mentioned control operations, in order to stop the operation of the diesel engine 4 when the rotation speed of the diesel engine 4 becomes equal to or higher than the predetermined upper limit rotation speed Nm1X, the r-ta D indicating the value of the rotation speed Nma , and speed data N are input, and when N>N Shimata~, the fuel cut solenoid valve 2 is provided.
Control signal S for closing 5.

is output from the speed determining section 27. For this reason, data D
, or if the engine speed increases abnormally for some reason during the control operation based on D6, the speed determination unit 27 stops the fuel supply to the sieve easel engine 4 to ensure safe operation of the engine. can do.

As mentioned above, in this device, if a failure occurs in the servo control section, the control is switched to open loop control according to data D, so for example, in the case of an internal combustion engine/device for a vehicle, You can move it to a safe place with your own blade. In this case as well, the display 24 displays a message indicating that the vehicle is in emergency operation mode, which 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 of the control system of the apparatus shown in FIG. 1 surrounded by a chain line.

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 FE I FST is reset and the counter CTR is also reset to zero. Next, data such as data A, N, and P are read (STELLA f32), and it is determined whether the flag F8 is "1" (STELLA f33). Flag F! ! teeth,
Sir? This is a flag that is set to "1" when some abnormality occurs in the control system, and in this case, flags F and U.
It has become rOJ. Then, in step 34, the data N, A.

A target injection amount Qt is calculated based on P, and this calculation result Qt is converted into a corresponding target sleeve position Rt.
(step 35), and the converted data is output as data D (step 36).

Next, data D3 is read (step 37), and data D
, , D, is calculated for the deviation ΔR (step 38), and it is determined whether ΔR is smaller than the predetermined value A (step 89).

ΔR (In case of A, the value of counter CTR is reset to zero.

(step 40) and returns to Stella f32.

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 counter CTR0 value is less than or equal to B, the
Return to Zo 32, but if CTR) B, step 43
Then, the flags F are set to "1". That is, ΔR
If the state where the value of is greater than the predetermined value A continues for more than the time indicated by the predetermined value B, 7 lag F. 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 FB becomes the month, the determination result in step 330 becomes YES, and the start switch 26 is turned on in step 45.
If the start switch 26 is off, it is determined in step 46 whether or not the 72g FIIT is "1". Flag FsT is flag F0
This is a flag indicating whether or not the start switch 26 is turned on when is "1". Therefore, in this case, the flag FMT is "0" and the process proceeds to step 44. Therefore, when it is detected that a fault has occurred in the servo control section, the fuel cut solenoid valve 25 is closed and the indication of the fault occurrence continues to be displayed on the display 16 until the start switch 26 is turned on. becomes.

When the start switch 26 is turned on, the determination result in step 45 is YES, the flag F8T is set to "1" (step 47), and the fuel cut 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).

If the determination result in step 46 is YES, that is,
Flag F. The starting switch is in the state of "1".

If the switch 26 is turned on, the process advances to step 48;
Open the fuel cut solenoid valve 25 and enter the emergency control mode (
Step 49).

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

To explain the flowchart of FIG. 3, first, in the Stella f50, the switch 16 is switched as shown by the dotted line in FIG.

Next, it is determined whether the speed data N and the boost pressure data P are each larger than a predetermined maximum value NrnlLX + pmax (step 51.52), and both of the determination results in step 51.52 are NO. If so, return to step 32 of FIG.

If the determination result is YES in at least one of steps 51 and 52, the fuel cut solenoid valve 2
5 is closed (step 53), thereby stopping the operation of the diesel engine 4, setting the FBT to "0" (stellar 7661), and returning to step 32 in FIG.

That is, if N>Nr118x or P>PmaX, there is a danger in continuing to operate the engine, so the engine operation is forcibly stopped.

When the top dead center pulse TDC is output, an interrupt program INT shown in FIG. 3 is executed. In step 54, the interrupt program determines whether the flag FT is "1". The flag FT is used to determine whether or not a timer that operates in response to the top dead center pulse TDC is in operation in order to measure the cycle of the top dead center pulse TDC. If 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 "l" (step 55). The determination result in step 54 is No.
In this case, the execution of this interrupt program is completed by executing only step 55 mentioned above, and the process returns to the control program shown in FIG. In this case, the timer is still operating, and when the interrupt program INT is executed in response to the next generation of the top dead center pulse TDCO, in this case, the determination result at step 54 is YES (! :, the timer is stopped in step 56, and the flag F,
is reset to "0". Therefore, the opening content of the timer indicates the time from when one top dead center i4 pulse TDC is output until the next top dead center pulse TDC is output, and based on the timing content of this timer, diesel Engine 4
Speed data N indicating the rotational speed at that time is calculated (step 57), and it is determined whether the flag FE is "1" (step 58).

Flag Fl! , is "0", the program returns to the control program shown in FIG. 2 after just calculating the data N, indicating that some kind of failure has occurred in the servo control section, and the program returns to 7 lag F. but"
1'', the process advances to step 59, where data D for open loop control is calculated. The calculation of data D6 has been explained in detail with reference to FIG.
Ru. In this way, the performance @ of data D is top dead center and Lus T
Executed when DC is output, data D is Stella f
6.0. That is, the calculation of data D is configured to be executed in synchronization with the generation of the top dead center pulse TDC. Position control can be carried out stably.◇In the above embodiment, if any failure occurs in the servo control section, the switch 16 is automatically switched as shown by the dotted line using the control signal S4. However, the switch 16 may 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 temporarily stopped, then if the switch 16 is switched as shown by the dotted line before turning on the start switch 26, the failure will occur. After that, when the engine is started, the position of the control rack 3 can be controlled by open loop control.

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. When the start switch is turned on, the engine is released from the stopped state, and the engine can be operated in the emergency control mode as desired. Therefore, even if a failure occurs in the servo control section, the engine will not become inoperable, and the vehicle can be moved with its own blade. Additionally, emergency mode operation is executed when the engine has stopped and then the driver turns on the start switch, so unlike when the control mode is suddenly changed while the engine is running, the engine Since sudden acceleration and deceleration can be prevented and failures are displayed, safe driving can be performed, which is extremely desirable from the viewpoint of safety measures. Furthermore, since the operation in the emergency control mode involves controlling the position of the fuel adjustment member by open-loop control, it can be expected that the control will be almost the same as normal control.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one implementation of the present invention, and FIGS. 2 and 3 are flowcharts showing a program when a microcomputer executes part of the blocks shown in FIG. 1. . 1...Fuel injection device, 2...Fuel injection pump, 3.
...Controller, Ri, 4...Diesel IUS'
J, s...first calculation section, 6...accelerator pedal, 8
... TDC sensor, 9... Speed calculator, 12...
Failure determination unit, 13... Position sensor, 15... Actuator, 16... Changeover switch, 18... Second calculation unit, 23 - Switch control unit, '24... Indicator, 2
5...Fuel cut solenoid valve, 26...Start switch,
D,,D,...data, N...speed data, A...
・Accelerator data, S2...discrimination signal, S3, S,
...Control signal, ST...Start 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. a means for outputting an accelerator signal indicating the amount of operation of the accelerator operating member; a calculating means for calculating a control target position of the fuel adjustment member in response to the accelerator signal and the reference pulse; means for canceling the operational stop state of the internal combustion engine in response to turning on the start switch when it is determined that a failure has occurred in the control unit; A fuel injection device comprising means for supplying a signal indicating a calculation result to the drive section.