JPH11270359A - Maximum torque control method for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide high engine speed as torque increases, prevent lowering of engine speed so much regardless of a high load and avoid lowering of ship speed by controlling an engine by a special map data capable of providing the maximum torque to the maximum engine allowable torque at the time of the high load. SOLUTION: This method is to store a standard rack characteristic map Ml to control the maximum rack position so as to make the maximum torque lower than the maximum engine allowable torque and a special rack characteristic map M2 to increase the maximum torque up to the maximum engine allowable torque and to select either of them by switching on a controller. Thereafter, counting of a special map using time timer A is made not to exceed special map using allowable time A1 at the time of selecting the special rack characteristic map M2, and it is made to exceed special map using prohibition time B1 in the case when it is changed over again to the special rack characteristic map M2 after it is retrned to the standard rack characteristic map M1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic governor-controlled internal combustion engine, and more particularly to a maximum torque control method for a marine internal combustion engine of a fishing boat or the like which is subject to a high load and whose rotation speed is likely to decrease.

[0002]

2. Description of the Related Art Conventionally, an electronic governor-controlled marine internal combustion engine has been known, but the maximum torque control method in this case is to obtain a maximum torque obtained at each rotation speed in order to avoid damage to the internal combustion engine. Is set so that the torque becomes lower than the maximum allowable torque of the internal combustion engine to control the position of the fuel injection amount setting rack of the electronic governor.
That is, the maximum rack position at each rotation speed is suppressed to be lower than the original maximum rack position at which the allowable maximum torque of the internal combustion engine is obtained.

[0003]

In a marine internal combustion engine such as a fishing boat, a large torque is required at the time of waves or heavy loading. In this case, when the maximum torque is suppressed as described above, the amount of reduction in the number of rotations is large, and the boat speed is significantly reduced. Fishing boats are required to arrive at fishing grounds or landing positions after catching quickly, so that a decrease in boat speed is fatal.

Therefore, it is conceivable to set the maximum torque temporarily as high as the internal combustion engine permits so that the ship speed does not decrease so much in such a situation. However, when the engine is set at a high setting, the operating time when the internal combustion engine is set high so as not to cause damage to the internal combustion engine and the protection of the engine after returning to the original state are set. Time must be guaranteed.

[0005]

The present invention uses the following means to solve the above problems. First, in the electronic governor control type internal combustion engine, regarding the setting map of the maximum rack position with respect to the engine speed, a standard map in which the maximum rack position is set so as to keep the limit torque lower than the engine allowable maximum torque, and the engine allowable maximum torque The two maps including the special map in which the maximum rack position is set so as to be obtained are stored, and the map can be arbitrarily switched.

Further, in the electronic governor control type internal combustion engine adopting the above-described maximum torque control method, the control time of the internal combustion engine based on the special map is limited, and the fixed time is returned after the control is returned to the internal combustion engine control based on the standard map. Switching to the special map is disabled.

[0007]

FIG. 1 is a block diagram of a maximum torque control system for an electronic governor of a marine internal combustion engine, and FIG. 2 is a diagram showing a standard map and a special map for setting a maximum rack position with respect to an engine speed for electronic governor control. FIG. 3 is a diagram showing a standard map and a special map for setting the maximum torque with respect to the engine speed, and FIG. 4 is a flowchart of the electronic governor control of the internal combustion engine when the standard map and the special map are switched.

Referring to FIG. 1, a description will be given of a maximum torque control system for an electronic governor. The internal combustion engine 1 is provided with a governor 2 having a fuel injection amount setting rack, and the position of the rack is adjusted by a governor actuator 3. A rotation speed sensor 4 is attached to an output shaft portion of the internal combustion engine, and detects an actual rotation speed of the output shaft of the internal combustion engine.
On the other hand, a controller 6 for the electronic governor is built in a controller box 5 installed on the hull, and a remote control head 7 for setting the engine speed is arranged in the control section. Is detected by the accelerator sensor 8 attached to the controller box 5. Furthermore,
The setting panel 9 installed on a bridge or the like of a ship includes a standard rack characteristic map M1 and a special rack characteristic map M2 described later.
And a switch 10 for switching between. The detection signal of the rotation speed sensor 4, the accelerator sensor 8, and the setting signal of the switch 10 are input to the controller 6, and based on these input signals, output signals are transmitted to the governor actuator 3 to control the rack position of the governor 2. Then, the fuel injection amount is adjusted.

In a memory section in the controller 6, a standard rack characteristic map M1 and a special rack characteristic map M2 are stored as data maps.
Is to select one of the two maps M1 and M2. The switch 10 may be an ON / OFF switch, and electronic governor control based on the standard rack characteristic map M1 may be performed when the switch 10 is turned off, and electronic governor control may be performed based on the special rack characteristic map M2 when the switch 10 is turned on. . The structure of the ON / OFF switch is disclosed in FIG. 4 described later.

The rack characteristic map indicates a set position of the maximum rack position R according to each engine speed N. A standard rack characteristic map M1 and a special rack characteristic map M2 are shown in FIG. It is as follows. As can be seen, at each engine speed N, the maximum rack position R of the standard rack characteristic map M1 is
2 is always kept low. Also, regarding the maximum rack position R at the time of rated torque output, the engine speed N ₁ at the time of rated torque in the standard rack characteristic map M1.
Is suppressed less than the engine speed N ₂ at rated torque in the special rack characteristic map M2, rack position R ₁ during rated torque at standard rack characteristic map M1 is rated torque at rack position in the special rack characteristic map M2 R It is kept low compared to ₂ .

The torque characteristics shown in FIG. 3 (representing the maximum torque value T obtained for each engine speed N) are derived from the respective rack characteristic maps M1 and M2. That is, the standard torque characteristic X1 is obtained by the internal combustion engine control based on the standard rack characteristic map M1, and the special torque characteristic X2 is obtained by the internal combustion engine control based on the special rack characteristic map M2. Conversely, the two rack characteristic maps M1 and M2 are set so that the standard torque characteristic X1 and the special torque characteristic X2 can be obtained.

As can be seen from the graphs of the two torque characteristics X1 and X2, regarding the maximum torque T obtained for each engine speed N, the one based on the special torque characteristic X2 is always higher than the standard torque characteristic X1. ing. The maximum torque T obtained by the special torque characteristic X2 is the engine allowable maximum torque, and is a value that cannot be actually output any more. On the other hand, the maximum torque T obtained by the standard torque characteristic X1 is lower than the maximum allowable engine torque from the viewpoint of protecting the engine.

FIG. 3 shows a graph Y of the marine running steady torque characteristic, which shows the torque T obtained in the steady running at each engine speed. The torque point indicates a torque obtained at a rated rotation speed in steady running. During operation with the standard rack characteristic map M1, even when the engine speed N is increased at a high load and the rack position is increased, the maximum rack position is limited to M1, so the maximum torque T is also changed to the standard torque characteristic X1. limited, the engine speed also is limited to the rated speed N _1.

On the other hand, if the engine is operated based on the special rack characteristic map M2, the maximum torque T obtained at each engine speed N can be obtained as high as indicated by the special torque characteristic X2, and the rated rotational speed can be obtained during steady running. The rated torque obtained by the number is
Since the maximum rack position R ₂ at the rated torque is set to a high position, it is possible to increase the rated torque up to T _2,
The engine speed N ₂ at this time also, standard rack characteristic map M1
To a higher value than the engine speed N ₁ obtained when operated at. Therefore, a high rotation speed can be obtained under a high load, so that compared with the operation based on the standard rack characteristic map M1,
The engine speed N does not need to be reduced so much, and a drastic decrease in the boat speed can be avoided.

As described above, during normal operation, the engine is operated based on the standard rack characteristic map M1 from the viewpoint of engine protection, and when the load is high, the engine is switched to the engine operation based on the special rack characteristic map M2 to increase the maximum torque T. As a result, the engine speed N can be increased. However, the special rack characteristic map M2 increases the maximum torque T to the maximum allowable engine torque, and if the operation time is not limited, the engine may be damaged. Further, even if the operation based on the special rack characteristic map M2 is ended and the operation is switched to the standard rack characteristic map M1, the influence of the engine temperature rise due to the operation using the special rack characteristic map M2 for a certain period of time remains. Therefore, switching to the period operation based on the special rack characteristic map M2 again during this period causes the same problem.

[0016] For this reason, special rack characteristic map M2 engine operation time based on (a special map use allowable time) and A _1, then the special rack characteristic map after the end of engine operation according to the special rack characteristic map M2 M2 standard racks characteristic map M1 engine operation time by (special map disabled time) until the selected set a and B ₁ and may be stored in a memory unit of the controller 6, thereby achieving an engine protection.

That is, from the point when the special rack characteristic map M2 is selected by the switch 10, the special map use time timer A starts counting by the controller 6, and the timer A measures the special map use allowable time A.
_If it exceeds ₁ , the switch 10 is forcibly switched and set to the selected state of the standard rack characteristic map M1. Further, to start counting the standard map use time timer B from the time when switching from the special rack characteristic map M2 in standard rack characteristic map M1, if the measurement time of the timer B is B ₁ within the special maps used prohibition time, the switch 10 Cannot select the special rack characteristic map M2, and the engine is forcibly operated with the standard rack characteristic map M1.

FIG. 4 is an engine operation control flowchart for the electronic governor in accordance with the switching operation between the standard rack characteristic map M1 and the special rack characteristic map M2 by the switch 10. In the case where the special rack characteristic map M2 is selected, by a timer action based on special maps used allowed time a ₁ and the special map disabled time B ₁ of, sometimes forcibly in the standard rack characteristic map M1, it is to carry out the electronic governor control.

The flowchart of FIG. 4 will be described.
First, when the switch 10 is in the OFF state (01), the standard rack characteristic map M1 is used (0).
2) When the switch 10 is turned on, (0
3), the controller 6 firstly reads the standard map use time timer B, if the timer count B ₁ within the special maps used prohibition time (B ≦
B ₁ ), the switch 10 is forcibly returned to OFF immediately (04), and the standard rack characteristic map M1 is used. If the standard map used time counting timer B is greater than the special maps used prohibition time B ₁ (B
> B ₁ ) (05), the switch 10 is kept ON and the special rack characteristic map M2 is used (06), while the special map use time timer A starts counting, and the count value of this timer is special maps unless use allowable time not exceeding _{a 1 (a ≦ a 1)} (08), the electronic governor control by special rack characteristic map M2 is performed. If the special map using time timer A exceeds the special maps used allowed time A ₁ is (A> A _1), the switch 10 is forcibly is OFF (07), standard rack characteristic map M1
To control the electronic governor.

A flowchart of the electronic governor control will be described. The internal combustion engine 1 is controlled by the rotation speed sensor 4 shown in FIG.
Is read, and the controller 6 calculates the rotation speed (09). On the other hand, by operating the remote control head 7, an input signal relating to the target rotation speed is input from the accelerator sensor 8 to the controller 6, and the target rotation speed is calculated (10).

In this way, the controller 6 calculates the target rack position based on the accelerator opening and the actual rotation speed in order to set the actual rotation speed as the target rotation speed. Is limited based on the rack characteristic map data of either the standard rack characteristic map M1 or the special rack characteristic map M2 (11).

When the target rack position is calculated in the controller 6 in this manner, the output value of the rack actuator 3 is calculated based on the calculated value, an output signal is transmitted to the rack actuator 3, and the rack position of the governor 2 is calculated. (12). This output signal uses, for example, a PWM output.

[0023]

According to the present invention, the following effects can be obtained by using the above-described maximum torque control method in the electronic governor control type internal combustion engine. First, a standard map and a special map are stored as to the maximum rack position and can be arbitrarily switched, so that in a fishing boat or the like equipped with such a marine internal combustion engine, protection of the engine during normal times is provided. From a viewpoint, engine control is performed using standard map data that sets the maximum torque to a value that is lower than the maximum allowable torque of the engine. By controlling the engine with special map data that can be obtained up to the maximum allowable torque, the torque increases and a high engine speed can be obtained.
The engine speed does not decrease so much that a drastic decrease in the ship speed can be avoided, so that even at such a high load, it is possible to arrive at the fishing ground or landing position quickly.

Further, in the electronic governor control based on the special map data, the data use time is limited, and after returning to the internal combustion engine control based on the standard map, the special map is maintained for a predetermined time. By disabling the switching to, the engine can be prevented from being damaged due to an extreme increase in the engine temperature or the like, and safe engine operation can be ensured, while obtaining a state where the maximum torque becomes the maximum allowable engine torque.

[Brief description of the drawings]

FIG. 1 is a block diagram of a maximum torque control system of an electronic governor of a marine internal combustion engine.

FIG. 2 is a diagram showing a standard map and a special map for setting a maximum rack position with respect to an engine speed for electronic governor control.

FIG. 3 is a diagram showing a standard map and a special map for setting the maximum torque with respect to the engine speed.

FIG. 4 is an electronic governor control flowchart for the internal combustion engine when switching between the standard map and the special map.

[Explanation of symbols]

Reference Signs List 1 internal combustion engine 2 governor 3 governor actuator 4 rotation speed sensor 6 controller 8 accelerator sensor 9 operation panel 10 switch M1 standard rack characteristic map M2 special rack characteristic map X1 standard torque characteristic X2 special torque characteristic Y steady running torque characteristic A special map Use time timer A ₁ Special map use allowable time B Standard map use time timer B ₁ Special map use prohibition time

Claims (2)

[Claims] In an electronic governor control type internal combustion engine, a map for setting a maximum rack position with respect to an engine speed is a standard map in which a maximum rack position is set so as to keep a limit torque lower than an engine allowable maximum torque; A maximum torque control method for an internal combustion engine, wherein two maps including a special map in which a maximum rack position is set so as to obtain a maximum torque are stored, and the map can be arbitrarily switched. 2. An electronic governor-controlled internal combustion engine employing the maximum torque control method according to claim 1, wherein the control time of the internal combustion engine based on the special map is limited, and the internal combustion engine control is returned to the standard map. A method for controlling maximum torque of an internal combustion engine, wherein switching to the special map is disabled for a predetermined time.