JP2002106401A - Fuel regulator for diesel engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To heighten a responsibility for fuel control. SOLUTION: A controller is made to be able to set a droop control line 19 which reduces a target number of revolutions in proportion to increased load of engine, the droop control line 19 is made to intersect with an isochronous control line 26. In addition, if the target number of revolutions of an electronic governor 3 is decreased from high-speed rotations 15 to prescribed low speed rotations 16, the droop control is performed before the isochronous controls.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a fuel metering device for a diesel engine.

[0002]

The present invention is based on the following technology. That is, as shown in FIG. 1, the fuel injection pump (1)
And an electronic governor (3), the fuel injection pump (1) includes a fuel metering section (4), and the electronic governor (3) includes a target rotational speed setting means (9) and an actual rotational speed detecting means (11). ), An actual adjustment position detecting means (12), a controller (8), and an actuator (27). As shown in FIG. 2, the controller (8) sets the target rotational speed to a constant value regardless of the engine load. Set the isochronous control line (26) to be maintained, and set the electronic governor (3)
Is a fuel metering device for a diesel engine that performs isochronous control based on an isochronous control line (26) based on detection of a target rotation speed, an actual rotation speed, and an actual adjustment position.

[0003]

2. Description of the Related Art Conventionally, in this type of apparatus, as shown in FIG. 5, a target rotation speed of an electronic governor (3) is set to a predetermined high speed rotation speed.
Even when the rotational speed is reduced from (15) to a predetermined low speed (16), the isochronous control based on the isochronous control line (26) is performed.

[0004]

The above prior art has the following problems. In other words, in the above case, as shown by the rotation speed-actual adjustment amount position curve (135) of FIG. 5, the actual adjustment speed decreases from the fuel non-injection position (17) by a predetermined amount while the actual rotation speed decreases. It reaches the minimum metering area (A) up to the fuel increasing position (18). The actual rotation speed converges to the target rotation speed (16) while largely hunting around the target rotation speed (1). For this reason, the rotation settling time is long, and the control response is low. The reason is as follows. That is, in the above case, if the isochronous control is always performed, the PID control is started early, and the integral value increases unnecessarily. Therefore, in order to set the actual rotation speed to the target rotation speed (16),
In order to cancel the increased integral value, it is necessary to greatly overshoot the actual rotational speed from the target rotational speed, and it takes time for the actual rotational speed to converge on the target rotational speed (16).

An object of the present invention is to provide a fuel metering device for a diesel engine which can solve the above problems.

[0006]

The configuration of the present invention is as follows. In the above-mentioned base technology, as shown in FIG. 2, the controller (8) enables to set a droop control line (19) for decreasing the target rotational speed as the engine load increases, and the droop control line (19)
Crosses the isochronous control line (26),

When the target rotation speed of the electronic governor (3) is reduced from a predetermined high speed rotation (15) to a predetermined low speed rotation (16), the actual adjustment position becomes the fuel non-injection position (17). When the controller (8) reaches the minimum metering area (A) from the predetermined fuel increasing position (18) to the predetermined fuel increasing position (18), the controller (8)
The electronic governor (3) performs droop control based on the droop control line (19),

The actual adjustment amount position is determined by both control lines (19) and (26).
Is located in the small fuel metering area (B) on the fuel reduction side relative to the predetermined metering position (33) corresponding to the intersection (34), and the actual engine speed is equal to the target engine speed (16) of the electronic governor (3). The electronic governor (3) maintains the droop control during the medium-to-high-speed rotation area (C) above, and the actual adjustment position exceeds the minor adjustment area (B), or Number of medium and high speed rotation area (C)
The controller (8) releases the droop control line (19), and the electronic governor (3) performs isochronous control based on the isochronous control line (26). Metering device.

[0009]

The present invention has the following functions and effects. As shown in FIG. 2, when the target rotation speed of the electronic governor (3) is reduced from a predetermined high rotation speed (15) to a predetermined low rotation speed (16), a rotation speed-actual adjustment amount position curve is obtained. (35)
As shown by, while the actual rotational speed decreases, the actual adjustment amount position moves from the fuel no-injection position (17) to the minimum adjustment amount area (A) from the predetermined fuel increase position (18). Since the droop control is performed before performing the control, hunting of the actual rotational speed is less likely to occur, and the target rotational speed (16) is converged in a short time. Therefore, the settling time of the rotation is short, and the response of the control is high. The reason is as follows. That is,
If the droop control is performed before the isochronous control, the P control is performed based on the proportional value during the droop control, and the PID control is started from the time when the control is switched to the isochronous control. Can be avoided. Therefore, when setting the actual rotation speed to the target rotation speed (16), it is not necessary to cancel the unnecessarily increased integral value, and it is not necessary to largely overshoot the actual rotation speed from the target rotation speed (16). Therefore, it does not take much time until the actual rotational speed converges to the target rotational speed (16).

[0010]

Embodiments of the present invention will be described with reference to the drawings. FIGS. 1 to 4 are diagrams for explaining a fuel metering device for a diesel engine according to an embodiment of the present invention. In this embodiment, an example in which the present invention is applied to a multi-cylinder diesel engine having an in-line fuel injection pump is shown. As shown in FIG. 1, a fuel supply device of the engine includes a fuel injection pump.
(1), a mechanical governor (2) and an electronic governor (3). The fuel injection pump (1) includes a fuel metering unit (4) that slides in a fuel increasing / decreasing direction, and the fuel metering unit (4)
The urging means (5) urges the fuel in the fuel increasing direction.

The structure of the mechanical governor (2) is as follows. The mechanical governor (2) is the governor lever (20)
And a governor spring (21) and governor force generating means (22). The governor lever (20) is provided so as to be swingable, and has a governor lever (2) via a governor spring (21).
Linked to 3). The governor spring (21)
Governor lever according to the governor setting of governor lever (23)
Governor spring force (24) is applied to (20). The governor force generating means (22) faces the governor lever (20) and applies a governor force (25) corresponding to the rotation speed to the governor lever (20). The swinging end of the governor lever (20) is a mechanical output
(6), and the mechanical output unit (6) is a fuel metering unit.
The (4) mechanical input unit (7) faces from the fuel increasing side. The mechanical output section (6) receives the mechanical input section (7) of the fuel metering section (4) biased by the biasing means (5), and generates a governor spring force (24) and a governor force (25). The fuel metering section (4) is metered and moved by the operation using the unbalanced force.

The structure of the electronic governor (3) is as follows. The electronic governor (2) includes an electronic actuator (27), a controller (8), a target rotation speed setting unit (9), a target rotation speed detection unit (10), an actual rotation speed detection unit (11), and an actual adjustment amount position detection. Means (12). Electronic actuator
(27) is a linear solenoid, the output rod of which is an electronic output unit (13). The electronic output unit (13) faces the electronic input unit (14) of the fuel metering unit (4) from the fuel increasing side. The electronic output unit (13) receives the electronic input unit (14) of the fuel metering unit (4) energized by the urging means (5), and is controlled by the controller (8) to operate the fuel metering unit ( 4) The metering movement is performed. The configuration of the controller (8) is as follows. The controller (8) includes a rotational speed PID control unit (28)
And a metering position PID control unit (29). The rotation speed PID control unit (28) calculates a rotation speed deviation based on the target rotation speed detection signal from the target rotation speed detection unit (9) and the actual rotation speed detection signal from the actual rotation speed detection unit (11). Then, a target adjustment position setting signal is transmitted to the adjustment position PID control unit (29). The metering position PID control unit (29) calculates a metering position deviation based on the target metering position setting signal and the actual metering position detection signal from the actual metering position detecting means (12), and calculates the electronic actuator ( 27) sends a control output signal to the electronic output section
The operation of (13) is controlled. Note that the target rotation speed setting means
(9) is also used as a speed control lever (23). The actual adjustment position detecting means (12) is attached to the urging means (5),
Output rod (5a) of biasing means (5) that follows the movement of (4)
, The actual adjustment position of the fuel adjustment section (4) is indirectly detected. In FIG. 1, reference numeral (30) denotes a boost compensator, (31) denotes a phase compensator, and (32) denotes an emergency circuit.

The control characteristics of the electronic governor (3) and the metering characteristics of the mechanical governor (2) are as follows. FIG. 2 shows a characteristic diagram of the electronic governor and the mechanical governor. The horizontal axis indicates the rotation speed, and the vertical axis indicates the metering position. A mechanical adjustment characteristic diagram (33) by the mechanical governor (2) is shown by a solid line, and an electronic control characteristic diagram by the electronic governor (3) is shown by a chain line. Mechanical metering characteristic diagram
(33) is provided with a horizontal upper limit metering line (33a) and a sloping full load metering line (33b), and a full load metering line (33b) extends from the high rotation side end of the upper limit metering line (33a). ) Is inclined downward toward the high rotation side. The electronic control characteristic diagram includes an isochronous control line (26) and a droop control line (19). The isochronous control line (26) is vertical, and its upper end is the upper limit adjustment line (33a) of the mechanical adjustment characteristic diagram (33).
Extending to the high-speed side end. Droop control line (1
9) The target speed of the electronic governor (3) is changed from a predetermined high speed (15) to a predetermined low speed (16) as described later.
Set when lowered to The isochronous control based on the isochronous control line (26)
The droop control based on the droop control line (19) is performed by P control.

The functions of the electronic governor (3) and the mechanical governor (2) based on the above characteristics are as follows. Electronic governor
When the target rotation speed of (3) is relatively high, during the electronic control operation by the electronic governor (3), the isochronous control line (2)
The control according to 6) is performed, and the electronic output unit (13) receives the electronic input unit (14), thereby separating the mechanical output unit (6) from the mechanical input unit (7), and the mechanical governor (2). Does not act on the fuel metering section (9), and the electronic governor
In (3), the rotation speed is maintained at a constant value. When the load exceeds the full load, the metering along the upper limit metering line (33a) is performed, and the mechanical output unit (6) receives the mechanical input unit (7).
The upper limit of the fuel injection amount in the electronic control operation is defined, and the electronic output unit (13) is separated from the electronic input unit (14) so that the electronic governor (3) does not act on the fuel metering unit (4). Thus, the amount of fuel increase is limited by the mechanical metering operation by the mechanical governor (2). The target rotation speed of the electronic governor (3) is increased from a predetermined high speed rotation (15) to a predetermined low speed rotation (16).
If so, the controller (8) sets the droop control line (19).

The processing functions of the controller (8) are as follows. FIG. 3 shows a flowchart of the processing of the controller (8). In step S1, it is determined whether or not the actual adjustment position is within the minimum adjustment area (A) from the fuel non-injection position (17) to a predetermined increase position (18). As shown in FIG. 2, when the target rotation speed of the electronic governor (3) is reduced from the rated rotation speed (15) to the idle rotation speed (16), the actual adjustment position is within the minimum adjustment amount area (A). Therefore, the determination in step S1 is affirmed, and the process proceeds to step S2. In step S2,
The droop control line (19) is set, and in step S3, droop control based on the droop control line (19) is performed. As shown in FIG. 2, the droop control line (19)
Crosses the isochronous control line (26). Upon completion of the process in the step S3, the process returns to the step S1.

Thereafter, the actual adjustment position is changed to the minimum adjustment area.
If (A) is exceeded, the determination in step S1 is denied, and the process proceeds to step S4. In step S4, it is determined whether the droop control line (19) is set. In this case, since the droop control line (19) is set, the determination is affirmative, and the process proceeds to step S5. In step S5, the actual metering position is within the small metering area (B) on the fuel reduction side from the predetermined metering position (33) corresponding to the intersection (34) of both control lines (19) and (26). In step S6, it is determined whether or not the actual rotational speed is within the medium / high-speed rotational speed area (C) which is equal to or higher than the target rotational speed (16) of the electronic governor (3). The actual adjustment position is on both control lines (19)
Predetermined metering position (33) corresponding to the intersection (34) of (26)
While the engine speed is within the small fuel metering area (B) on the fuel reduction side and the actual speed is within the medium / high speed speed area (C) which is equal to or higher than the target speed (16) of the electronic governor (3). , Step S5
-The judgment in S6 is affirmed, and steps S1 → S4 → S5
The cycle of → S6 → S3 is repeated, and the droop control in step S3 is maintained.

If the actual adjustment position exceeds the small adjustment area (B), or if the actual rotation speed falls below the medium / high speed rotation area (C), at least one of steps S5 and S6 is performed. The determination is negative, and the process proceeds to step S7. Step S7
Then, the droop control line (19) is released, and step S
At 8, the isochronous control based on the isochronous control line (26) is performed. After the processing in step S8, the process returns to step S1.

If the target rotation speed of the electronic governor (3) is not set to the low speed, the droop control line (19) is not set, so that the actual adjustment position is set to the minimum adjustment area (A). ), Even if the determination in step S1 is denied, the determination in step S4 is denied, and
At 7, the cycle up to step S8 is repeated without performing any substantial processing, and the isochronous control is continuously performed.

FIG. 4 shows control results of the actual rotation speed and the actual adjustment amount position. Solid lines are according to embodiments of the invention, dashed lines are
An example of a conventional technique in which isochronous control is always performed is shown. When the target rotation speed of the electronic governor (3) is reduced from the rated rotation speed (15) to the idle rotation speed (16), in the embodiment of the present invention, as shown by the actual adjustment position curve (35), Unlike the actual adjustment position curve (135) of the technique, hunting hardly occurs, and the convergence time to the target adjustment position is short. In the embodiment of the present invention, the actual rotation speed curve (36)
As shown by, hunting hardly occurs, and the convergence time to the target rotational speed is shorter than that of the actual rotational speed curve (136) of the related art. Specifically, convergence took 3.2 seconds in the case of the prior art, but was reduced to 0.5 seconds in the embodiment of the present invention.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a fuel supply device for a diesel engine according to an embodiment of the present invention.

FIG. 2 is a characteristic diagram showing control characteristics of an electronic governor of the apparatus of FIG. 1 and adjustment characteristics of a mechanical governor.

FIG. 3 is a flowchart showing a process performed by a controller of the apparatus shown in FIG. 1;

FIG. 4 is a graph comparing the control results of the apparatus of FIG. 1 and the prior art.

FIG. 5 is a diagram corresponding to FIG. 2 of the prior art.

[Explanation of symbols]

(A): very low metering area, (B): low metering area, (C): medium and high speed area, (1): fuel injection pump, (3): electronic governor, (4): fuel metering Part, (8) ... controller,
(9) Target rotational speed setting means, (10) Target rotational speed detecting means, (11) Actual rotational speed detecting means, (12) Actual adjusting position detecting means, (15) predetermined high-speed rotational speed (16): a predetermined low speed, (17): no fuel injection position, (18): a predetermined fuel increase position, (19): droop control line, (26): isochronous control line, (33) ... Predetermined metering position,
(34)… Intersection.

Continuation of the front page (72) Inventor Yamaichi 3-8, Chikushinmachi, Sakai-shi, Osaka F-term in Kubota Sakai Coastal Plant (reference) 3G301 HA02 JA03 JA06 JA07 KA24 KA25 LB14 MA16 ND00 ND01 PB04Z PE01A PE01Z

Claims (1)

[Claims] 1. A fuel injection pump (1) and an electronic governor (3), the fuel injection pump (1) includes a fuel metering section (4),
The electronic governor (3) includes a target rotation speed setting unit (9), an actual rotation speed detection unit (11), an actual adjustment position detection unit (12), a controller (8), and an actuator (27). 8) sets an isochronous control line (26) for maintaining the target speed at a constant value regardless of the engine load,
The electronic governor (3) detects an isochronous control line (26) based on detection of the target rotation speed, the actual rotation speed, and the actual adjustment amount position.
In a fuel metering device for a diesel engine that performs isochronous control based on the following, a controller (8) enables a droop control line (19) to be set to decrease a target rotation speed as the engine load increases, and the droop control line (19) ) Intersects with the isochronous control line (26), and sets the target rotation speed of the electronic governor (3) to a predetermined high speed rotation speed (15).
When the engine speed is reduced to a predetermined low speed (16), the actual adjustment position reaches the minimum adjustment area (A) from the no fuel injection position (17) to the predetermined fuel increase position (18). And the controller (8) sets the droop control line (19),
The electronic governor (3) performs droop control based on the droop control line (19), and the actual adjustment amount position is determined at the intersection (3) of both control lines (19) and (26).
4) It is located within the small fuel metering area (B) on the fuel reduction side from the predetermined metering position (33) corresponding to (4), and the actual speed is equal to or higher than the target speed (16) of the electronic governor (3). When the electronic governor (3) maintains the droop control while in the medium / high speed rotation area (C), and the actual adjustment position exceeds the small adjustment area (B), or
When the actual rotational speed falls below the medium / high rotational speed area (C), the controller (8) releases the droop control line (19), and the electronic governor (3) releases the isochronous control line (2).
A fuel metering device for a diesel engine, which performs isochronous control based on (6).