JPS627945A - Operation region control device for engine - Google Patents

Abstract

PURPOSE:To enable to always perform control of an engine well suitable to an operating condition irrespective of the temperature of intake air, by a method wherein an operating region, where a throttle opening and the number of revolutions of an engine produce parameter, is corrected according to the temperature of intake air. CONSTITUTION:In a controller 21, a region map is set, the region map being formed such that the portion, except an idle region A, of the whole operation region of an engine 10, where a throttle opening and the number of revolutions of an engine produce parameter, is partitioned at a given region set line X into a fuel feed region B on the acceleration side and a fuel shut-off region C on the deceleration side. An intake air temperature signal (g) is inputted to the controller 21 from an intake air temperature sensor 24 detecting the temperature of the intake air and located in a suction passage 14 situated closer to a combustion chamber 11. According to an intake air temperature indicated by the signal (g), the region set line X is corrected to the high throttle opening side when the intake air has high temperature, and the line X is corrected to the low throttle opening side when having low temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an engine operating range control device used to perform various engine controls depending on the operating range.

(Prior art) Various types of engine control are performed in automobile engines, and one such control is, for example, the
As shown in Japanese Patent No. 9-11736, fuel cutoff control may be performed to improve fuel efficiency and exhaust performance during deceleration operation. This divides the engine operating region into a fuel supply region and a fuel cutoff region using a predetermined region setting line such as a steady running line, and determines which region the current operating state belongs to, and determines the result of the determination. It supplies or cuts off fuel depending on the situation.

By the way, when setting the engine operating range as described above, it is customary to use the load or intake air volume and engine speed as parameters, which indicate the operating state of the engine. is often substituted with the throttle opening, which is easy to detect. However, when the throttle opening is used as a parameter, the density of the intake air changes depending on the temperature, so the throttle opening does not correspond correctly to the intake air amount. It will not be understood. This tendency is especially noticeable when the engine is equipped with a supercharger and intercooler, as the cooling capacity of the intercooler fluctuates depending on the driving speed, etc., and the temperature of the intake air changes significantly. Become. As a result, when controlling the engine according to the operating range as described above, for example, in fuel cutoff control, control that does not match the operating state may occur, such as not cutting off the fuel supply even though the deceleration state is in progress. There are cases where this is done.

(Object of the Invention) The present invention solves the above-mentioned problems when performing various engine controls according to the engine operating range using the throttle opening degree and engine speed as parameters. It is an object of the present invention to always perform engine control suitable for operating conditions regardless of air temperature.

(Structure of the Invention) In order to achieve the above object, the present invention is characterized by the following structure.

That is, as shown in FIG. 1, an operating range determining means 2 that determines the operating range of the engine 1, and a control device 3 that performs predetermined engine control according to the range determined by the determining means 2. In addition, a plurality of regions are set in the region determination means 2, which are divided by predetermined region setting lines using engine speed and throttle opening as parameters, and A signal a indicating the engine speed and a signal l indicating the throttle opening.
) is input to the determination means 2, the intake air temperature detection means 4 detects the temperature of the intake air taken into the engine 1, and the temperature of the intake air detected by the detection means 4 determines The present invention is characterized by comprising a correction means 5 for correcting the operating region determined by the operating region determining means 2. In this case, the correction means 5 may correct the throttle opening indicated by the signal l) or may correct the area setting line to which the throttle opening is compared. In this case, as the temperature of the intake air increases, the throttle opening degree is corrected to be smaller relative to the area setting line than the actual value. According to such a correction, the throttle opening degree always corresponds to the engine load or the amount of intake air, regardless of the temperature of the intake air.

(Effects of the Invention) According to the above configuration, when performing a predetermined engine control according to the operating range using the thrower 1-hell opening degree and the engine speed as parameters, regardless of the temperature of the intake air, Engine control that is always properly adapted to the operating state of the engine will be performed. For example, when performing control to cut off the fuel supply during deceleration driving, inappropriate control such as not cutting off the fuel supply even though the deceleration state is actually performed can be avoided, and fuel efficiency and exhaust performance can be improved. will be improved.

(Example) Examples of the present invention will be described below. Note that this embodiment relates to an embodiment in which fuel cutoff control is performed depending on the operating range of the engine.

As shown in FIG. 2, an intake passage 14 and a υ1 air passage 15 are communicated with the combustion chamber 11 of the engine 10 via intake and exhaust valves 12.13, and the intake passage 14 is connected to the combustion chamber 11 from the upstream side. It includes an air sensor 16 for detecting the amount of intake air taken into the combustion chamber 11, a throttle valve 17 for controlling the intake air amount or engine output, and a fuel injection nozzle 18 for supplying fuel to the combustion chamber 11. It is being Further, the exhaust passage 15 is equipped with an exhaust purification device 19, a muffler (not shown), etc., and the combustion chamber 1
1 is equipped with a spark plug 20.

On the other hand, this engine 10 is equipped with a controller roller 21 that controls the fuel injection nozzle 18. This controller 21 inputs an intake air amount signal C output from the air flow sensor 16 and a rotation speed signal d output from an engine rotation sensor 22 that detects the engine rotation speed, and Fuel injection according to air volume and engine speed! 1) Set jfi and output the fuel control signal e to the fuel injection nozzle 18 so that this injection amount is achieved.

6. Also, as shown in FIG. 3, this controller 21 is configured to define, for example, a steady running line for a portion of the entire operating range of the engine 10 excluding the idle range A, in which the throttle opening degree and the engine speed are parameters. A region map is set which is divided into a fuel supply region B on the acceleration side and a fuel cutoff region C on the deceleration side by a predetermined region setting line X such as . Then, the throttle opening degree signal f from the throttle distance sensor 23 which detects the opening degree of the throttle valve 17 and -1-
The value indicated by the distribution speed signal d is combined with this map to determine which region the operating state of the engine 10 is in, and the fuel injection is performed so as to supply or cut off fuel depending on the region. A fuel control signal e is output to the nozzle 18.

In addition to the above configuration, this controller 21 receives an intake air temperature signal g from an intake air temperature sensor 24 that is provided in the intake passage 14 near the combustion chamber 11 and detects hot stones in the intake air. There is. And this signal 0
According to the intake air temperature indicated by , when the temperature is high, set the above area setting line X to a high slot! When the temperature is low, the line X is corrected to the low throttle opening side.

Next, the operation of the above embodiment will be explained according to the flowchart of FIG. 4 showing the operation of the controller 21. Note that this flowchart does not show control for adjusting the fuel injection amount.

First, the controller 21 executes the flowchart 11-1 in FIG.
In step 31.82 of ~, the intake air temperature T indicated by the signal @g from the intake air temperature sensor 24 is read, and the correction corresponding to the intake air temperature T indicated by the signal q is calculated from the correction amount map shown in FIG. Set ff1K. Next, in step S3, the engine rotational speed N indicated by the rotational speed signal d is read, and in step S4, the engine rotational speed N is set to a predetermined rotational speed No.
It is determined whether the rotation speed is smaller or larger, that is, whether it is in the low rotation speed region including the idle region A shown in FIG. Then, when it is determined that the operating state of the engine 10 is in the low rotational speed region, the controllers 1 to 521 output the combustion 1 control signal e to the fuel injection nozzle 18 to supply fuel in step S5. On the other hand, when the operating state of the engine 10 is in the medium-high rotation speed region equal to or higher than the predetermined rotation speed No, steps S4 to S6 are executed, and the actual throttle opening θ indicated by the throttle opening signals f is read. and,
In step S7, the reference area setting line X shown in FIG.
The correction amount 1< set in step S2 above for the gradient α0 of o
A new area setting line X is set by multiplying by the corrected slope α. In that case, as shown in FIG. 5, when the intake air temperature T IJ is higher than the reference temperature To, the correction amount is greater than 1, so the gradient α is the reference gradient α0.
When the intake air temperature T is lower than the reference temperature To, the gradient α becomes smaller than the reference gradient α0. Therefore, as shown in FIG. 6, the area setting line When the temperature T is high, the line on the high throttle temperature side is set to x1 from the reference area setting line XO, and when the temperature T is low, the reference area setting line XO
There will be 2 lines on the lower throttle opening side. and,
In the next step S8, the controller 21 determines the actual throttle opening θ and the value N×α obtained by multiplying the engine speed N by the gradient α, that is, the current time on the new area setting line X set by the new gradient α. The throttle opening corresponding to the engine rotational speed N is compared. In other words, for example, when the intake air temperature T is high, a region setting line x 1 with a large slope α is set, so the actual throttle opening θ
The value (Nxα) to which is compared is the throttle opening degree θ in Figure 6.
1, and when the intake air temperature T is low, the actual throttle opening θ is determined by the area setting line where the slope α is small x 2
It is compared with the throttle opening degree θ2 corresponding to the engine speed N shown above. When the actual throttle opening θ is larger than the throttle opening (NXα) on the region setting line corrected as described above, it is determined that the operating state of the engine 10 belongs to the fuel supply region B, and step S
At step 5, a fuel control signal e is output to the fuel injection nozzle 18 so as to supply fuel to the engine 10. Further, when the actual throttle opening θ is smaller than the throttle opening (NXα) on the corrected area setting line, it is determined that the operating state of the engine 10 belongs to the fuel cutoff area, and step S9
A fuel control signal e is outputted to cut off the fuel supply to the engine 10. As a result, for example, when the operating state is in the state indicated by point P as shown in FIG.
When the intake air temperature 11ffT is at or below the base tIL temperature To (corresponding to the area setting line XO),
Fuel is supplied when the actual throttle opening θ′ is located on the high throttle opening side of the area setting line.
If the intake air temperature T is high even at the same throttle opening θ', in other words, the amount of intake air or charging amount actually supplied to the engine 10 is relatively small compared to the throttle opening O. When the area setting line is corrected to the high throttle opening side (line x 1), the actual throttle opening θ' becomes smaller than the throttle opening θ1 on the line x 1, and the fuel is cut off. will be done. In other words, even if the throttle opening is the same, when the intake air temperature is low and sufficient charging amount is secured, the engine 1
0 is an acceleration state and fuel is supplied, whereas when the intake air temperature is high and the charge voltage is low, the engine 10 is in a deceleration state and fuel is cut off. In this way, regardless of the temperature of the intake air, the fuel cutoff control is always performed in accordance with the operating state of the engine.

In the above embodiment, the area setting line that serves as a reference for comparison is corrected based on the intake air temperature.
The area setting line may be fixed and the actual throttle opening compared to the line may be corrected.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the overall configuration of the present invention. Figures 2 to 6 show examples of the present invention, with Figure 2 being a control system diagram, Figure 3 being a map showing the operating range, Figure 4 being a flowchart showing the operation, and Figure 5 being the amount of correction. FIG. 6 is an explanatory diagram for explaining control examples for each operating state using the map. 1.10...Engine, 4,24...Intake air temperature detection means, 5.21...Correction means (controller).

Claims (1)

[Claims] (1) An operating range control device that controls an operating range using throttle opening and engine speed as parameters used for engine control, and includes an intake air temperature detection means that detects the temperature of air taken into the engine. 1. A control device for an engine operating range, comprising: a correction means for correcting the operating range according to the temperature of intake air detected by the detection means.