JP2000337195A - Rotation speed control device of diesel engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the rotation speed control device of a diesel engine which does not produce the engine rotation speed undershoot without inviting the deterioration of the operation feeling relating to the responsiveness of the engine rotation speed against the acceleration operation at the speed reduction time. SOLUTION: This rotation speed control device of a diesel engine for setting a target rotation speed V responding to an accelerator opening and controlling the engine rotation speed by feedbacking the engine rotation speed is provided with a means for setting the intermediate target rotation speed V2' between the target rotation speed V1 change and target rotation speed V2 after change at the speed reduction time by the change of the accelerator opening, a means for controlling the speed reduction so as to make the engine rotation speed to this intermediate target rotation speed V2' and a means for controlling the speed reduction so as to make the engine rotation speed to the target rotation speed V2 after change by detecting the matching the engine rotation speed with the intermediate target rotation speed V2'.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotational speed control device for a diesel engine mounted on a vehicle and a ship.

[0002]

2. Description of the Related Art A conventional vehicle and marine diesel engine (hereinafter simply referred to as "engine") will be described with reference to FIGS. 2 is an overall block diagram of the engine speed control system, FIG. 3 is an explanatory diagram of the electronic governor controller in FIG. 2, FIG. 4 is a relationship diagram between the accelerator opening and the target speed, and FIG. FIG. 4 is an explanatory diagram of a time change of an engine rotation speed at the time of engine deceleration.

As shown in FIG. 2, the engine speed control system includes an electronic governor controller 1, an actuator 2, a fuel injection pump 3, an engine 4, and the like.

As shown in FIG. 3, the electronic governor controller 1 incorporates a digital microcomputer 5 therein, and according to a control program thereof, an engine rotary pickup signal 7a detected by the magnetic rotary pickup 7 of the engine 4. Is input to calculate the actual engine speed Va. On the other hand, an accelerator opening signal 6a of the opening A of the accelerator 6 is input, and the actuator operation amount 1a is output based on the input signal.

The target rotational speed V corresponding to the opening A of the accelerator 6 is calculated by an arithmetic unit in advance from the accelerator opening signal 6a of the opening A of the accelerator 6, and is transmitted to the digital microcomputer 5. May be entered,
The actual engine speed Va calculated in advance by the calculator from the rotary pickup signal 7a may be input to the digital microcomputer 5, and the actual engine speed Va may be directly detected by a rotational speed detector attached to the engine. It may be detected and input.

That is, the above-described conventional engine speed control system is a closed loop control system that feeds back the actual engine speed Va, and the target engine speed V determined by the opening A of the accelerator 6 and the actual engine speed Speed V
PID control (Proportional-plus-Integral-plus-DerivativeCo) based on speed deviation ΔV = V−Va
ntrol; proportional-integral-derivative control) to determine the actuator operation amount 1a. According to the actuator operation amount 1a, the actuator 2 increases or decreases the fuel amount of the fuel injection pump 3, determines the increase or decrease of the engine generated torque, and controls the actual engine rotation speed Va.

FIG. 4 shows an example of a conventional setting of the target rotation speed V determined by the opening degree A of the accelerator 6. The target rotation speed V is set linearly with respect to the opening degree A of the accelerator 6 in a predetermined section. The target rotation speed V is set to be increased or decreased according to the opening A, and the target rotation speed V is set to the low idling Vli which is the minimum engine speed at no load when the opening A is lower than a certain value. Have been.

[0008]

In the conventional diesel engine speed control device, the change in the actual engine speed Va depends on the response of the speed control system. The change in the actual engine rotation speed Va increases, and especially when the vehicle decelerates, the accelerator 6
When the vehicle is suddenly released, there is a problem that the engine rotational speed undershoot is large, and in the worst case, there is a possibility that the engine stops when the vehicle or the boat is mounted.

For example, as shown in FIG. 5, at time T ₁ , the accelerator 6 is suddenly released and the actual engine speed Va is changed from the high idle speed Vhi which is the highest engine speed at no load to the lowest engine speed at no load. when decelerating the low idle Vli is, the target rotational speed V is changed suddenly from high idle Vhi at time T ₁ as shown by the solid line in low idle Vli, it as shown by the actual engine revolution speed Va is also broken lines to respond to rapidly decelerated, but caused an undershoot of the engine rotational speed exceeds the low idle Vli is the target value and thereafter stabilizes at low idle Vli generally at time T _2.

In the example of a diesel engine of the 600PS class, when the high idle Vhi = 2100 rpm and the low idle Vli = 800 rpm, the actual engine speed Va becomes 300 rpm due to undershoot of the engine speed.
m, and T ₂ -T ₁ is about 3 sec.

[0011] This is generally the case during deceleration.
As shown in FIG. ₁From A_TwoReduced to
Set target rotation speed V to V₁To V_TwoSimilar when decelerating to
There is a problem, especially the target rotation speed V during deceleration._TwoBut low eye
In the case of dollar Vli, as described above,
Large dark shoots may cause the engine to stop.
That was the big thing.

However, in order to avoid an undershoot of the engine rotation speed, the response of the actual rotation speed of the engine to the accelerator operation is moderately reduced by introducing a response delay element into the speed control system to make the change in the actual rotation speed Va slow. The operation feeling of the vehicle deteriorates, which causes a trouble in the driving operation of the vehicle or the ship, and must be avoided.

The present invention solves the problem of the conventional rotational speed control device for a diesel engine, and describes the response of the actual engine speed to the accelerator operation at the time of deceleration even in a sudden operation such as suddenly releasing the accelerator. It is an object of the present invention to provide a rotational speed control device for a diesel engine that does not cause an engine rotational speed undershoot without deteriorating the operational feeling of the engine.

[0014]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and has a target rotation speed set in accordance with an accelerator opening and feeds back the engine rotation speed to control the engine rotation speed. Means for setting an intermediate target rotation speed between the target rotation speed before the change and the target rotation speed after the change at the time of deceleration by changing the accelerator opening, Means for controlling deceleration so as to be the same intermediate target rotational speed, means for detecting coincidence between the engine rotational speed and the intermediate target rotational speed and performing deceleration control so that the engine rotational speed becomes the target rotational speed after the change. The present invention provides a rotational speed control device for a diesel engine, comprising:

According to the present invention, the undershoot of the engine rotational speed does not occur without deteriorating the operational feeling of the response of the engine rotational speed to the accelerator operation at the time of deceleration.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A diesel engine rotational speed control apparatus according to one embodiment of the present invention will be described with reference to FIG. In the embodiment of the present invention, the time change of the engine rotation speed at the time of engine deceleration shown in FIG. 1 is different from that of the conventional device of FIG. 5, and the speed is determined only by the relationship between the accelerator opening and the target rotation speed of FIG. Except that the control is not performed, it is as shown in the other drawings, and the description will be appropriately omitted.

In the present embodiment shown in FIG. 1, at time T ₁ , as shown in FIG.
Subtracted from ₁ to A _2, when the target rotational speed V decelerated from V ₁ to V _2, digital microcomputer 5 of the electronic governor controller 1 the target rotational speed, V ₁ and V ₂
The intermediate V ₂ 'of the set as an intermediate target rotational speed, and outputs the actuator manipulated variable 1a.

That is, in the present embodiment, the control program of the digital microcomputer 5 determines the intermediate target rotation speed between the target rotation speed before the change and the target rotation speed after the change at the time of deceleration by changing the accelerator opening. And means for controlling deceleration so that the engine rotation speed becomes the same intermediate target rotation speed.

Thereafter, the actual engine speed V indicated by a broken line
When the digital microcomputer 5 detects that a has become the intermediate target rotation speed V ₂ ′ from the rotary pickup signal 7 a of the magnetic rotary pickup 7 (time T ₂ ′),
The digital microcomputer 5 sequentially changes the target rotation speed V from the intermediate target rotation speed V ₂ ′ to the final target rotation speed V ₂ . Therefore, the actual engine rotational speed Va, as shown in FIG. 1, it is possible to Va = V ₂ to approximately time T _2, without causing the engine rotational speed undershoot.

That is, in the present embodiment, the control program of the digital microcomputer 5 detects the coincidence between the engine speed and the intermediate target speed so that the engine speed becomes the target speed after the change. Means for deceleration control.

[0021] In FIG. 1, in particular, low is the minimum engine speed at no load from the high idle Vhi is the maximum engine speed at no load suddenly away the actual engine rotational speed Va accelerator 6 at time T ₁ Explaining the case of deceleration to the idle Vli, the digital microcomputer 5 changes the target rotational speed V to the low idle Vli according to the relationship between the accelerator opening A and the target rotational speed V in FIG. The target rotation speed V ₁ before the change
A high-idle Vhi is, sets the intermediate V ₂ 'of low idle Vli is the last target rotation speed V ₂ of the deceleration based on the relationship of FIG. 4 after subtracting the accelerator opening degree A as an intermediate target rotational speed Then, the actuator operation amount 1a is output.

Thereafter, the actual engine speed V indicated by the broken line
When the digital microcomputer 5 detects that a has become the intermediate target rotation speed V ₂ ′ from the rotation pickup signal 7a of the magnetic rotary pickup 7 (time T ₂ ′), the digital microcomputer 5 sets the target rotation speed V to the intermediate target rotation speed. from V ₂ 'successively changing into low idle Vli, actual engine revolution speed Va may be decelerated to a low idle Vli without causing engine speed undershoot (time T _2).

In the example of the diesel engine of the 600PS class, when the high idle Vhi = 2100 rpm and the low idle Vli = 800 rpm, the intermediate target rotation speed V ₂ ′
When = 1100 rpm, T ₂ ′ −T ₁ was about ₂ sec, T ₂ −T ₂ ′ was about 3 sec, and no undershoot occurred.

In this case, high idle Vhi = 2100r
pm from low idle Vli = 800 rpm, it takes about 5 sec.
sec, but V ₂ ′ = 1 at the beginning of deceleration.
Deceleration to 100 rpm is performed in about 2 seconds,
In the initial deceleration, low idle Vli = 800 rpm
There is no inferiority to the conventional one in which deceleration control is performed by directly targeting m.

The operational feeling of the deceleration response depends on the initial deceleration.
In this embodiment,
Intermediate target rotation speed V_TwoTo the target rotation speed
Degree V _TwoIs close to the deceleration when decelerating to
Can make little difference
It is.

Further, after the actual engine rotation speed Va reaches the intermediate target rotation speed V ₂ ′, the target rotation speed is gradually changed to the final target rotation speed V ₂ having a small difference in speed, so that the engine is decelerated. The control amount is small, and the engine speed undershoot is prevented.

In the present invention, in the deceleration control of the engine, the conventional deceleration control that directly sets the target rotation speed V ₂ set according to the accelerator opening as the target rotation speed is not performed. set the intermediate target rotational speed V ₂ 'between the target rotational speed V ₁ and the target rotational speed (hereinafter referred to as "the final target rotational speed") V ₂ after the accelerator opening degree a changes, first intermediate target rotational speed V ₂ 'performs deceleration control of the actual engine rotational speed Va to be, its intermediate target rotational speed V _2' it is essential to perform the deceleration control such that the final target rotation speed V ₂ after is obtained, Depending on the characteristics of the engine and the range of deceleration, the target rotation speed V is sequentially and linearly changed from the intermediate target rotation speed V ₂ ′ to the final target rotation speed V ₂ as in the embodiment shown in FIG. Limited to those that set and decelerate Rukoto without the target rotational speed V 'or held briefly, the intermediate target rotational speed V _2' intermediate target rotational speed V ₂ is set from the batchwise to the final target rotation speed V ₂ or a specific target rotation It may be connected by a speed line.

The setting of the intermediate target rotation speed V ₂ ′ is determined by setting the relationship with respect to the final target rotation speed V ₂ or the relationship between V ₁ and V ₂ . It can be easily performed by programming it in the control program of the computer 5.

Although the embodiment of the present invention has been described above, it is needless to say that the present invention is not limited to the above embodiment, and various changes may be made within the scope of the present invention.

For example, as described in the conventional example, the target rotation speed V corresponding to the opening A of the accelerator 6 is calculated in advance by a calculator from the accelerator opening signal 6a of the opening A of the accelerator 6. The actual engine speed Va may be inputted to the digital microcomputer 5 from the rotation pickup signal 7a in advance by a calculator, and the actual engine speed Va may be inputted to the digital microcomputer 5, The engine speed may be directly detected and input by the speed detector.

Further, in the present invention, means for setting an intermediate target rotation speed between the target rotation speed before the change and the target rotation speed after the change at the time of deceleration by changing the accelerator opening, and setting the engine rotation speed to the same intermediate target speed. Some or all of the means for controlling the deceleration to be the rotation speed, and the means for detecting the coincidence between the engine rotation speed and the intermediate target rotation speed so as to reduce the engine rotation speed to the target rotation speed after the change. May be configured by a control circuit including individual discriminating circuits, arithmetic circuits, selection circuits, and the like, instead of the digital microcomputer 5 of the present embodiment and a control program therefor.

[0032]

As described above, according to the present invention, an engine rotation speed control apparatus is provided for a diesel engine which sets a target rotation speed in accordance with an accelerator opening and feeds back the engine rotation speed to control the engine rotation speed. Means for setting an intermediate target rotational speed between the target rotational speed before the change and the target rotational speed after the change at the time of deceleration by changing the accelerator opening in the rotational speed control device; And means for detecting a match between the engine rotation speed and the intermediate target rotation speed so as to reduce the engine rotation speed to the target rotation speed after the change. , Without deteriorating the operational feeling of the responsiveness of the engine speed to the accelerator operation during deceleration,
This does not cause an undershoot of the engine rotation speed, and eliminates the possibility of stopping the engine even during a sudden deceleration.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a time change of an actual engine speed at the time of engine deceleration of a rotational speed control device for a diesel engine according to an embodiment of the present invention.

FIG. 2 is an overall block diagram of an engine rotation speed control system.

FIG. 3 is an explanatory diagram of an electronic governor controller in FIG. 2;

FIG. 4 is a relationship diagram between an accelerator opening and a target rotation speed.

FIG. 5 is an explanatory diagram of a time change of an actual engine speed at the time of engine deceleration of a conventional diesel engine speed control device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electronic governor controller 2 Actuator 3 Fuel injection pump 4 Engine 5 Digital microcomputer 6 Accelerator 7 Magnetic rotary pickup

Claims (1)

[Claims] 1. A diesel engine rotation speed control device that sets a target rotation speed according to an accelerator opening and feeds back the engine rotation speed to control the engine rotation speed. Means for setting an intermediate target rotation speed between the target rotation speed of the target and the target rotation speed after the change, means for controlling deceleration of the engine rotation speed so as to become the intermediate target rotation speed,
Means for detecting a match between the engine rotation speed and the intermediate target rotation speed and performing deceleration control to reduce the engine rotation speed to the changed target rotation speed. apparatus.