JPS62191645A - Device for controlling fuel injection for engine - Google Patents

Abstract

PURPOSE:To detect abnormality in fuel injection and give an alarm, and improve reliability by detecting the final moving condition of a piston in a fuel injection system. CONSTITUTION:A control device has a valve driving means 2 for making opening/closing control of a fuel feed valve 1, a fuel storing means 3 having chambers 32, 33 for temporarily storing fuel and a piston 31 for pushing out fuel to an injection nozzle 6 side, a piston driving means 4 for pressing the piston 31, and an arithmetic and control means 5 which operates the quantity of fuel and injection timing and controls said driving means 2, 4. A means 507 for generating a movement end signal for the piston 31 which consists of a magnet 37 and a magnetic field detecting element 8, is attached to the fuel storing means 3. And, when the movement end signal for the piston 31 is not generated even when a certain time has elapsed, an alarm command signal is generated by the arithmetic and control means 5.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a fuel injection control device for an engine, and more particularly to a novel configuration for accurately electronically controlling the fuel injection amount of a diesel engine.

(Prior art) Performing fuel injection with the highest IA'X is an important matter for improving drivability and for exhaust gas countermeasures, especially for engines with fuel injection nozzles located in or near the combustion chamber of the engine. It is important in diesel engines. In recent years, electronic control has been proposed for such fuel injection control (for example, Japanese Patent Application Laid-Open No. 80-95157
number, etc.).

According to this type of electronic fuel injection control device, there is provided a valve driving means for controlling the opening and closing of a fuel supply valve that supplies fuel to be injected, and a valve drive means for temporarily storing at least a portion of the fuel supplied by the fuel supply valve. a fuel accumulating means having a chamber and a piston for pushing the fuel in the chamber toward the injection nozzle; a piston driving means for pressing the piston of the fuel accumulating means in order to guide the fuel in the fuel accumulating means to the injection nozzle; The apparatus includes calculation control means for calculating and determining the amount of fuel to be injected and the injection timing based on operating parameters including at least the throttle opening of the engine, and controlling the valve driving means and the piston driving means, respectively.

(Problem to be Solved by the Invention) However, according to such a conventional device, if the injection nozzle is clogged with dirt or the like, the piston of the fuel accumulating means does not operate normally and fuel injection is interrupted. Be accurate.

Accordingly, the present invention provides a fuel injection control device for an engine that generates an alarm when it detects that the fuel storage means and each driving means do not operate accurately due to clogging of the fuel injection nozzle with dirt or the like. The purpose is to

(Means and operations for solving the problem) In order to achieve this object, the fuel injection control device for an engine according to the present invention provides a fuel supply valve (1) that supplies fuel to be injected.
A first stage valve drive (2) for controlling opening and closing, a chamber (33) for temporarily storing at least a portion of the fuel supplied by the fuel supply valve (1), and this chamber (3).
3) a fuel accumulating means (3) having a piston (31) for pushing out the fuel in the fuel accumulating means (3) toward the injection nozzle (6); Piston drive means (4) for pushing the piston (31) of the fuel storage means (3), and fuel to be injected based on parameters including at least the accelerator pedal angle (0) of the engine! , i: (Q) and an oil quality control means (5) that calculates and determines the injection timing (ts) and controls the valve drive means (2) and the piston drive means (4), respectively, and the fuel storage means (3) is
The apparatus further comprises a movement end signal generating means (507) for detecting whether the amount of movement of the piston (31) during fuel injection reaches a predetermined value and generating an electric signal; is configured such that an alarm command signal (AL) is generated when the movement end signal generating means (507) does not generate the output signal (fl) even after a predetermined period of time has elapsed. 507) does not generate an end signal after a certain period of time, an alarm is generated.
Abnormalities in the movement of the piston of the fuel accumulating means or other abnormalities in the actuation of the yA control means operating for fuel injection can be detected.

(Embodiments of the Invention) The present invention will be described in detail below with reference to the accompanying drawings. Note that the same reference numerals in each figure indicate similar objects.

FIG. 1 shows a fuel injection control device according to an embodiment of the present invention. In the figure, (1) is a fuel supply valve that supplies fuel to be injected via fuel supply pipes (10) and (11), (2) is a valve driving means that controls the opening and closing of this fuel supply valve (1), and ( 3) is a fuel storage means for temporarily storing at least a part of the fuel supplied through the fuel supply valve (1), and (4) is a fuel storage means (3) for injecting fuel.
) A piston driving means for driving a piston (31) to be described later, (5) is an engine rotation a (N), a carrot salt fi
(T), accelerator pedal angle (0), top dead center signal (TD
calculation control means for calculating and determining the fuel Ec (Q) to be injected and the injection timing (ts) based on operating parameters such as C signal) (S) and controlling each of the driving means (2) and (4); (6) is an injection nozzle supplied by the fuel supply valve (1) and for injecting fuel into the engine cylinder by the fuel storage stage (3); (7) is the injection nozzle of the piston (31) of the fuel storage means (3); A magnetic sensor forming part of the displacement detection means (505) installed in the fuel storage means (3) to detect the amount of movement (text), and (8) a piston which is the moving body of the fuel storage means (3). (31), a movement end signal generating means (5) for generating a movement end signal (f) indicating whether or not the movement of the predetermined area to be moved during injection has been achieved;
07), and (9) is an alarm means activated by the alarm output (AL) of the arithmetic and control means (5).

Fuel is supplied under pressure by the main vibe (lO). The end of this main pipe (10) is piston driven = L
This piston drive means (4) is connected to the stage (4).
) Depending on the state of the main pipe (lO), fuel flows from the main pipe (lO) to the pipe (15) to drive the piston (31), or from the pipe (15) to the pipe (16) for reflux. Further, the main pipe (lO) branches in the middle, and the branched pipe (11) is connected to the inlet (IA) of the fuel supply valve (1) via the valve driving means (2). A pipe (12) is connected to the outlet (IB) of the fuel supply valve (1), and this pipe (12) is connected to two pipes (+3).

Branches to (14). The pipe (13) is a fuel storage means (
3), and the pipe (14) is connected to the injection nozzle (8). The main components are detailed below.

The fuel supply valve (1) is also called a check valve, and is, for example, a pole valve, with a pole (IC) serving as a valve body.
is urged toward the inlet (IA) by a spring (10). The pressing force of this spring (ID) is adjusted so that when fuel flows in by the valve driving means (2), it is compressed by the inflow pressure and the fuel can pass through the fuel supply valve (1). The valve drive means (2) that drives this fuel supply valve (1) by the outflow of fuel is, for example, a solenoid valve, and the valve body (21) pressed by a spring (20) blocks the fuel supply pipe (11). are doing. The valve body (21) is raised when the electromagnetic coil (22) is excited by the drive signal (SQ) of the arithmetic control means (5), and the pipe (11) is brought into a flowing state.

Here, the valve body (IC) that moves for fuel supply, (
21) etc. will be collectively referred to as mobile objects.

The fuel storage means (3) comprises a piston (31), also called a servo piston, within a housing (30). In the housing page 30), a large-diameter first chamber (32) and a small-diameter second chamber (33) are coaxially connected.

The first chain (32) is connected to a pipe (15) whose one end is connected to the piston drive means (4). The second chietsuba (33) is connected to the pipe (13),
Fuel is supplied through pipes (12) and (13), while fuel is injected through pipes (13) and (+4).

Further, the first chamber (32) has an exhaust port (38) for releasing pressure on the second chamber side. Corresponding to such chambers (32) and (33), a piston (31) having a coaxial large diameter portion (three holes and a small diameter portion (35)) is provided.
) (the moving body of this fuel storage means (3)) is slidably fitted in the housing (30). A magnet (36) serving as a magnetic field generating means constituting a displacement detecting means (505) is mounted on the upper surface of the large diameter portion (34) of the piston (31). A magnetic field detection element (7) sensitive to the magnetic field of this magnet (3B) is arranged on the housing surface facing this magnet (36). Therefore, when the piston (31) is pushed up by the fuel from the pipe (13),
The magnetic field detection element (7) forms an electric signal (!;L) proportional to this upward movement. Also, the piston (3
The lower surface of the large diameter portion (34) of 1), that is, the chamber (33
) side is equipped with a magnet (37) which is a magnetic field generating means forming a movement end signal generating means (50?). A magnetic field detection element (8) sensitive to the magnetic field of this magnet (37) is arranged on the housing surface facing this magnet (37). Therefore, when the piston (31) is pressed by the fuel from the pipe (15), the chambers (32), (33
) The pressure increased according to the area ratio of the second chamber (33) pushes out the fuel that has been accumulated in the second chamber (33), and the injection nozzle (6) becomes able to inject the fuel. Because of this injection,
When the piston (31) is completely lowered, the movement end signal generating means (507) generates a movement end signal (f).

The injection nozzle (6) is attached to a pin (81) by a spring (80).
) (moving body of the nozzle (8)), and the bottle (et) is pushed up by the fuel supply pressure from the pipe (14), injecting fuel into the engine cylinder.

The screw driving means (4) is, for example, a solenoid valve, and the valve body C pressed by a spring (40)
41) (The moving body of this driving means (4)) is a fuel bar r
(10) and (IEI) are alternately occluded. The Kono valve body (41) usually has one end (41A) connected to the pipe (lO).
The pipes (15) and (+8) can circulate through the housing (45) of the valve body (41). On the other hand, the electromagnetic coil (42) is excited by the drive signal (ST) of the arithmetic control means (5) and rises, the pipe (10) becomes in a flowing state and the pipe (16) becomes in a closed state. , fuel flows into the first chamber (32) of the fuel massing means (3) via the pipe (lO), the housing (45) and the pipe (15), lowering the piston (31). Drive means (4
) also has an exhaust port (49) on the pipe (10) side.

The main parts of the calculation control means (5) are shown in FIG. In the figure, (501) is a pedal angle sensor that provides a pedal angle signal (θ) corresponding to the accelerator pedal angle that changes due to accelerator operation, (502) is an engine rotational speed sensor that detects engine rotational speed (N), and (502) is an engine rotational speed sensor that detects engine rotational speed (N).
03) is an engine temperature sensor that detects the engine temperature (T), (505) is a displacement detection sensor, (506) is a TDC detection sensor that provides a TUG signal (S) corresponding to the top dead center of the engine piston, (507) ) is the movement end signal (
(511) is a reference injection amount memory that provides a reference injection amount (QO); (512) is a reference injection amount memory that provides a reference injection amount (QO);
) is an injection amount correction calculation means that corrects the reference injection amount (QO) according to the operating state of the engine and calculates the amount of fuel to be injected (Q), and (513) is the displacement of the piston (31) of the fuel storage means (3). lift amount memory that determines the amount (statement 0);
(514) is a comparator, (522) is an injection timing control means for controlling injection timing according to the operating state, (5
23) is a timer that forms the injection timing (ts);
(521) is an inputter, (531) is a first solenoid drive circuit that drives a first solenoid that is a valve drive means (2), and (532) is a drive circuit that drives a second solenoid that is a piston drive means (4). a second solenoid drive circuit,
(533) is a timer that sends the injection end confirmation command (tR), and (534) takes the AND of the output (f) of the movement end signal generation means (50?) and the output (tR) of the timer (533). NAND circuit, (535) is NAND circuit (534
) alarm signal forming means driven by the output of (540
) is a main control device that controls each of the above components at predetermined timing. The main-trade components will be explained below.

The reference injection amount memory (511) determines the necessary and sufficient fuel injection 1 (Qo) required when the engine is in a standard operating condition (engine temperature, air-fuel ratio, etc.), and is a primary The accelerator pedal angle (0) and engine speed (N) are determined as operating parameters. in general,
R that can be accessed using (Q) and (N) as addresses
With respect to this standard injection 1 (Qo) configured with OM, operating parameters such as engine temperature (T) and vehicle speed (V) are further considered, and the deviation from the engine's target I4P and operating condition is determined and the corrected acid is determined. is calculated to determine the final required fuel injection amount (Q). This injection amount correction calculation means (
512) can be configured with, for example, a comparator that compares each parameter (T) and m with a reference value, and a ROM that can be accessed using the deviation output of the comparator as an address.

The lift amount memory (513) stores the necessary fuel to be injected;
It determines how much the target displacement amount (text 0) of the bis]・n (31) of the fuel storage means (3) should be in response to the I amount (Q), and the injection @(Q ) can be configured as a ROM that can be accessed as an address.

In addition, the target displacement amount (statement 0) for injection ffl (Q)
are the volume of the second chamber (33) and the pipe (12),
It is determined experimentally from the volumes of (+3) and (+4).

The comparator (514) compares the target lift amount (statement 0) which is the output of this memory (513) with the displacement amount detection sensor (505).
Compare the displacement amount (vertical) of the piston (31) which is the output of 1. For example, if (seen) ≠ (sentence 0), output logic O, and when (U) = (sentence 0), output logic O. This outputs a logic 1 to the output signal. The output of the comparator (514) is connected to the inverter (
521), it becomes a command signal (CCI) and is manually inputted to the first thread/eat drive circuit (531).

The injection timing control means (522) determines whether the engine piston is at the top dead center (TD) according to each operating parameter a5.
The injection timing is determined, that is, how much time (ts) should elapse after reaching C) before the injection should be performed. This determined value (ts) is input to the timer (523) as a preset value. The timer (523) is activated by the TDC signal (S) of logic 1, and after the set time (ts) by the timing control means (522) has elapsed, it sends out a command signal (CC2) to activate the second solenoid drive circuit (532). let

Each solenoid drive circuit (531), (532) operates the valve drive means (2) and the piston drive means (4), respectively, when the manual command signal (CCI), (CC:2) is logic I. command signal (SQ') to
, (ST). Second solenoid drive circuit (53
The output (ST) of 2) also starts a timer (533), and after the set time (tR) of this timer (533) has elapsed, the operation of this drive circuit (532) is stopped. That is, the timer (533) is a timer for confirming the continuation of fuel injection.

The movement end signal generation means (507) includes a magnetic field detection element (8
Based on the signal (B) from ), for example, when the detected magnetic field reaches the maximum set value, it is determined that the movement is normal and a movement end signal (f) of logic 1 is generated.

The alarm signal forming means (535) is a NAND circuit (534)
It activates when the output logic of
and energizes an alarm means (8) (FIG. 1), for example an alarm lamp.

Next, the operation of this embodiment will be explained with reference to FIGS. 3 and 4. In the following explanation, the symbols (401) to (418) correspond to the respective block numbers in FIG. 4. Also, (40
A code such as (8-Y) or (408-N) indicates that the decision of the decision block (408) is positive or negative.

During an appropriate stroke of the engine, for example during exhaust, the main processing unit (
540) (Figure 2) commands the start of control.
1) Initial values such as necessary operating parameters and detected values are input to a buffer register (none of which is shown) via an input port, and various registers of the main controller (540) are cleared (402). ).

Thereafter, the reference injection amount memory (511
) determines the reference injection quantity (Qo) 403), and the injection quantity correction calculation means (512) executes correction calculation of the reference value (Qo) 404), and determines the necessary injection quantity (Q) (405). ). Based on the determination of this injection M (Q), lift ff1(io) is determined (4013),
At this stage, when a signal indicating that the engine has entered the intake stroke is input to the main controller (540), the main controller (540) sends an operation command to the comparator (514). In this case, since (M)', (statement 0), the comparator (
The output logic of the inverter (514) is O, so the output logic of the inverter (514) is O.
The first thread/id drive circuit (531) operates via the first thread/id drive circuit (531), and the first thread/id drive circuit (531) operates via the command signal (SQ).
) is energized (407 and FIG. 3(C)). Therefore, the fuel supply valve (1) is opened and the fuel is supplied to the fuel storage means (3).
) side and begins to push up the piston (31) (Fig. 3 (e)). This rise of the piston (31) is caused by the comparator (
514), and turns on the solenoid (2) until (5L) = (JLa) (408).

(again) = (statement 0) (408-Y), the output logic of the comparator (514) is converted to l, and the inverter (52
1) according to the output logic of the first solenoid drive circuit (53
The input logic of 1) is O. For this reason, the solenoid (2
) is turned off (409) (FIG. 3(C)), and fuel supply is stopped.

On the other hand, the main controller (540) detects that the engine is in the compression stroke, and at this time the TDC signal (S) (Fig. 3 (
When b)) occurs, the timer (523) starts (41
0). As mentioned above, this timer (523) sends out the command output (CC2) after the time (ts) determined by the injection timing control means (522).
540) is the output flag (F) (t
s) shall be constantly monitored. This flag (F) (ts) is
When the timer forms an output logic 1, it sets logic 1, and otherwise it sets logic O, and the same goes for other streams (533). Therefore, the timer (5
23) counts the time (ts), the main control unit! (
540) cr) Timer 7 lag is (F) (ts) =
1 (411-Y), the second inlenoid drive circuit (
532) output signal (ST) causes the solenoid (4) to
is activated (412). Therefore, the fuel supply pressure presses the piston (31) of the fuel storage means (3) through the pipe (15) (Fig. 1), and fuel is injected from the injection nozzle (6) (Fig. 3). (d), (e), (f)). At this time, the timer (533) is activated by the output (ST) of the drive circuit (532) (413). This timer (5
33) is the fixation time (tR) which is longer than the injection time (t”).
) to count. The main controller (540) monitors the timer flag (F) (tR)=1 of this timer (533). When the timer (533) finishes counting the time (tR), the flag (F) of the main controller (540) (
tR) becomes 1 (414-Y), then the main controller (
540) is the output status flag (F
) (f) is checked (415). In other words, the injection nozzle (6) (Fig. 1) is normal and the fuel storage means (
3), when the piston (31) descends to the lowest position, the movement end signal generating means (507) generates a movement end signal (f) of logic 1. Since the output (tR) of is also logic 1, the NAND circuit (534
) is a logic O and no alarm signal (AL) is generated. However, if the piston (31) cannot descend to the lower end due to some abnormality in the injection system including the injection nozzle (6), the movement end signal (f) will not be generated.However, at this time, the output of the timer (533) Since (tR) is logic 1, the input logic (f, tR) of the NAND circuit (534)
= (0,1), the output of the NAND circuit (534),
Therefore, the flag (F) (f) becomes 1. Therefore, an alarm signal (AL) is formed by the alarm signal forming means (535), and the alarm lamp (9) flashes to issue an alarm (41B). Such flag (F) (tR),
(F) After checking (f), the second solenoid drive circuit (532) is reset by the output (tR) of the timer (533), the circuit (532) is in the OFF state, and therefore the solenoid (4 ) is turned off (417
), the end of fuel injection is confirmed (FIG. 3(d)). Therefore, the process returns to the beginning (418).

In addition, a solenoid valve (5) with a configuration as shown in Fig.
0), the valve driving means (
2) and the piston drive means (4) can be combined into one. In this case, the fuel supply valve (1) is controlled only by the fuel supply pressure. That is, the fuel supply valve (1
), the valve (50) operates to shut off only the pipe (10), so the fuel supply pressure opens the supply valve (1) and fuel flows into the storage means (3). do. During injection, the solenoid valve (50)
It operates to close only the pipe (16), and the fuel presses the piston (31) of the storage means to perform injection. At this time, in the fuel supply valve (1), since the pressure on the pipe (12) side is higher than the pressure on the pipe (10) side (the piston
31)), the fuel to be injected will not flow back to the pipe (10) through the supply valve (1).

The present invention is not limited to the above embodiments and modifications, and various other embodiments and modifications are possible within the technical scope of the present invention, and equivalent components may be replaced. It is clear to those skilled in the art that this is possible. For example, in the above explanation, the application to a diesel engine was shown, but the application to a normal gasoline engine is also possible.

Furthermore, the movement end signal generating means may include not only the fuel storage means but also a component having a moving body that is required to be displaced by a predetermined amount upon fuel injection, such as the piston driving means (4) or the injection nozzle (6). Alternatively, multiple units may be deployed.

(Effects of the Invention) According to the present invention, by detecting the final movement state of the piston of the fuel injection system as described above, a highly reliable engine fuel injection system capable of detecting an injection abnormality and generating an alarm can be achieved. A control device can be obtained.

[Brief explanation of drawings]

FIG. 1 is a system diagram of a fuel injection control device for an engine according to an embodiment of the present invention, FIG. 2 is a system diagram of main parts of a fuel injection control device for an engine according to an embodiment of the present invention, and FIG. 3 is a system diagram of a fuel injection control device for an engine according to an embodiment of the present invention. FIG. 4 is a flow chart for explaining the operation of the engine fuel injection control device according to the embodiment of the present invention; FIG. 5 is a flowchart for explaining the operation of the engine fuel injection control device according to the embodiment of the present invention; FIG. 2 is a system diagram of an engine fuel injection control device according to another embodiment of the present invention. In the drawings, (1) is the fuel supply valve, (2) is the valve drive means, (3) is the fuel M product means, (4) is the piston drive means, (5) is the calculation control means, and (6) is the injection (3B), (505) is a displacement detection means (8). (37) and (507) are movement end signal generating means; (8)
is the alarm means, (31) is the piston, (32), (3
3) is a chamber.

Claims (1)

[Scope of Claims] 1. Valve driving means for controlling the opening and closing of a fuel supply valve that supplies fuel to be injected, a chamber for temporarily storing at least a portion of the fuel supplied by the fuel supply valve, and a chamber within this chamber. a piston drive means for pushing the piston of the fuel accumulating means to guide the fuel in the fuel accumulating means to the injection nozzle; and at least an accelerator of the engine. A fuel injection control device for an engine, comprising: arithmetic control means for calculating and determining the amount of fuel to be injected and the injection timing based on parameters including a pedal angle, and controlling the valve driving means and the piston driving means, respectively; The accumulating means includes a movement end signal generating means for detecting whether the amount of movement of the piston during fuel injection reaches a predetermined amount of movement and generating an electric signal, and the arithmetic control means detects whether the amount of movement of the piston during fuel injection reaches a predetermined amount of movement and generates an electric signal. A fuel injection control device for an engine, wherein an alarm command signal is generated when the movement end signal generating means does not generate an output signal even after a period of time has elapsed. 2. The fuel injection control device for an engine according to claim 1, wherein the piston driving means is a solenoid valve, and the back pressure of the piston is controlled by opening and closing the valve. 3. In the device according to claim 1 or 2, the movement end signal generating means includes magnetism generating means provided on the chamber side of the piston of the fuel accumulating means, and a magnetism generating means provided on the chamber side of the piston of the fuel accumulating means, and a magnetism generating means provided on the chamber side of the piston of the fuel storage means, A fuel injection control device for an engine, comprising: a magnetic sensor that is provided near an end position and responds to the magnetism of the magnetism generating means. 4. The device according to any one of claims 1 to 3, wherein the calculation control means provides fuel injection timing to the piston drive means based on a top dead center signal of the engine. Fuel injection control device for engines with