JPH09177574A - Controller of in-cylinder direct injection type gasoline engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate cruise control performed for controlling a car speed constant by making selective switching between a car speed constant control time and a normal control time and calculating the fuel injection amount and the air intake amount of an injection valve when the car speed constant control is selected. SOLUTION: When car speed constant control is selected by operating a changeover switch 15, a target car speed is read by a car speed setter 16 and an actual car speed is read from a car speed sensor 14 in a control unit 19. Then, a pseudo target axle operation amount is calculated from the target car speed and the actual car speed. When the pseudo target axle operation amount is selected by the changeover switch 15 instead of an axle operation amount, the target torque of an engine main body is calculated as a target torque for a car speed constant control time from a torque calculation map based on an engine revolution speed and the pseudo target axle operation amount, a target air-fuel ratio is obtained from an air-fuel ratio calculation map, a fuel injection amount for the car speed constant control time is calculated from an injection amount calculation map to control an injection valve 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control system for a direct injection type gasoline engine, in which a direct injection type injection valve is provided in a gasoline engine known as a spark ignition type engine, and more particularly, The present invention relates to a control device for a direct injection gasoline engine in a cylinder, which is capable of performing so-called cruise control for controlling a traveling speed (vehicle speed) of a vehicle at a constant level.

[0002]

2. Description of the Related Art Generally, an engine body of a gasoline engine mounted on a vehicle and a throttle provided in the intake passage of the engine body for varying the amount of intake air supplied into the combustion chamber of the engine body according to the opening degree. A valve, a throttle actuator that opens and closes the throttle valve to change the opening of the throttle valve, an injection valve that injects gasoline fuel from the intake passage side toward a combustion chamber of the engine body, and an injector provided on the vehicle. A control device for an indirect injection type gasoline engine including an accelerator that variably adjusts the traveling speed (vehicle speed) of the vehicle and an operation amount detection unit that detects an operation amount of the accelerator as an accelerator operation amount (hereinafter, referred to as a first conventional type). Technology) is known.

In the control device for an indirect injection type gasoline engine according to the first prior art of this kind, for example, when a driver of a vehicle depresses an accelerator pedal or the like, the operation amount detecting means detects the operation amount and the throttle The throttle actuator is configured to open and close the throttle valve so that the valve opening corresponds to the accelerator operation amount, and the throttle valve opening is variably controlled according to the accelerator operation amount.

Since the intake air amount of the engine increases or decreases according to the opening of the throttle valve, the fuel injection amount is calculated based on the intake air amount and the engine speed at this time, and the calculated result is obtained. By injecting and supplying the corresponding fuel from the injection valve toward the combustion chamber of the engine body,
The air-fuel ratio of the indirect injection type gasoline engine is controlled so that the air-fuel ratio between the intake air and the fuel becomes a required air-fuel ratio.

Further, when performing so-called cruise control for controlling the vehicle speed of the vehicle to be constant, for example, a target vehicle speed is set (command) by a vehicle speed setting means provided in a driver's cab.
Then, the deviation between the target vehicle speed and the actual vehicle speed (actual vehicle speed) is calculated, and the throttle valve opening is changed by the throttle actuator so as to reduce the deviation, and the intake air amount and the engine speed at this time are changed. The fuel injection amount is calculated and controlled based on the number and the number.

On the other hand, as a second conventional technique, an engine main body of a gasoline engine mounted on a vehicle, an injection valve for directly injecting gasoline fuel into a combustion chamber of the engine main body, and a traveling of the vehicle provided on the vehicle. An accelerator for variably adjusting the speed (vehicle speed), an operation amount detecting means for detecting an operation amount of the accelerator as an accelerator operation amount, and a rotation speed detecting means for detecting an engine speed of the engine body,
In-cylinder direct-injection gasoline engine provided with calculating means for calculating the fuel injection amount and the intake air amount of the injection valve based on the engine speed by the speed detecting means and the accelerator operation amount by the operation amount detecting means. The control device of is also known.

In the control apparatus for the direct injection type gasoline engine according to the second prior art, the direct injection valve of the direct injection type provided on the cylinder head side of the engine body or the like is directed toward the combustion chamber of the engine body. By directly injecting fuel, the atomization and mixing of intake air and fuel in the combustion chamber is enhanced, so-called lean burn control that enables lean combustion of the air-fuel mixture is performed, and significant fuel consumption can be realized. I am trying.

Further, in the control apparatus for the direct injection type gasoline engine of the second prior art, in order to calculate the fuel injection amount and the intake air amount of the injection valve, the engine speed detected by the engine speed detecting means is used. The number and the accelerator operation amount by the operation amount detection means are used, and the opening control of the throttle valve and the like is merely an auxiliary control target.

[0009]

By the way, in the control apparatus for a direct injection type gasoline engine according to the second prior art described above, the fuel injection amount and the intake air amount are determined based on the engine speed and the accelerator operation amount. Is calculated and the opening degree of the throttle valve is only supplementarily controlled based on the calculation result. Therefore, as in the control device for the indirect injection type gasoline engine according to the first prior art described above, the vehicle speed of the vehicle is reduced. There is a problem that it is difficult to easily perform so-called cruise control for controlling the cruise control to be constant.

The present invention has been made in view of the above-mentioned problems of the prior art. The present invention can easily perform so-called cruise control for controlling the vehicle speed of the vehicle to be constant, and can stably perform the vehicle speed control. It is an object of the present invention to provide a control device for a direct injection gasoline engine of the type described above.

[0011]

In order to solve the above problems, the present invention provides an engine body of a gasoline engine mounted on a vehicle, an injection valve for directly injecting gasoline fuel into a combustion chamber of the engine body, An operation amount detecting means for detecting an operation amount of an accelerator provided in the vehicle, a rotation speed detecting means for detecting an engine rotation speed of the engine body, an engine rotation speed and the operation amount detecting means by the rotation speed detecting means. The present invention is applied to a control device for a direct injection gasoline engine of a direct cylinder type, which includes a calculating means for calculating the fuel injection amount of the injection valve and the intake air amount based on the accelerator operation amount by

A feature of the configuration adopted by the invention of claim 1 is a switching means for selectively switching between a constant vehicle speed control for controlling the vehicle speed of the vehicle substantially constant and a normal control time. A vehicle speed setting means for setting a target vehicle speed of the vehicle during the constant vehicle speed control; and a target operation amount calculating means for calculating a target accelerator operation amount from a deviation between the target vehicle speed by the vehicle speed setting means and the actual vehicle speed of the vehicle, The calculation means is
When the constant vehicle speed control is selected by the switching means, the fuel injection amount and the intake air amount of the injection valve are calculated based on the engine speed by the speed detecting means and the target accelerator operation amount by the target operation amount calculating means. This is because it is configured to perform calculations.

With this configuration, when the switching means is switched from the normal control side to the constant vehicle speed control side,
While obtaining the deviation between the target vehicle speed of the vehicle set by the vehicle speed setting means and the actual vehicle speed, the target accelerator operation amount can be calculated from this deviation by the target operation amount calculating means. Then, the intake air amount and the fuel injection amount from the injection valve required during the constant vehicle speed control can be calculated on the basis of the target accelerator operation amount and the actual engine speed, and the actual vehicle speed is substantially equal to the target vehicle speed. Can be matched.

According to the second aspect of the present invention, the target torque of the engine body is set based on the target accelerator operation amount by the target operation amount calculating means and the engine speed by the speed detecting means during the constant vehicle speed control. The calculating means includes a torque calculating means for calculating, and when the vehicle speed constant control is selected by the switching means, the calculating means of the injection valve is based on the target torque by the torque calculating means and the engine speed by the speed detecting means. The fuel injection amount and the intake air amount are calculated.

Thus, during constant vehicle speed control, the torque calculating means can calculate the target torque to be generated in the engine body based on the target accelerator operation amount and the engine speed, and the calculation is performed from the target torque and the engine speed. The fuel injection amount of the injection valve and the intake air amount can be calculated by the means.

Further, according to a third aspect of the present invention, a throttle valve provided in the middle of the intake passage of the engine body and opened / closed by a throttle actuator, and the throttle valve of the throttle valve corresponding to the intake air amount by the calculating means are provided. A throttle opening calculation means for calculating a target opening is provided, and the throttle actuator is configured to open and close the throttle valve based on the target opening calculated by the throttle opening calculation means.

Thus, the throttle opening calculation means can calculate the target opening of the throttle valve corresponding to the intake air amount, and the throttle actuator can open / close the throttle valve based on the target opening.

Further, according to the invention described in claim 4,
Combustion state detecting means for detecting the state of combustion gas generated in the combustion chamber of the engine body, and correction for calculating a correction value of the target opening degree by the throttle opening degree calculating means based on a signal from the combustion state detecting means. The throttle actuator is configured to open and close the throttle valve based on the target opening degree by the throttle opening degree calculating means and the correction value by the correction value calculating means.

As a result, the mixture of the intake air and the fuel is actually burned in the combustion chamber of the engine body, and the state of the combustion gas due to the combustion can be detected by the combustion state detecting means. Can be read, and the correction value for feedback control of the target opening by the throttle opening calculation means can be calculated by the correction value calculation means. As a result, the opening / closing operation of the throttle valve by the throttle actuator can be feedback-controlled based on this correction value, and the actual air-fuel ratio can be adjusted to a value corresponding to the target air-fuel ratio by finely adjusting the opening of the throttle valve by the correction value. You can control.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings.

1 to 8 show a controller for a direct injection type gasoline engine according to a first embodiment of the present invention.

In the figure, reference numeral 1 denotes an engine body of a gasoline engine mounted on a vehicle.
Is a multi-cylinder 2 (only one cylinder is shown), a piston 3 that reciprocates in each cylinder 2, a cylinder head 4 mounted on each cylinder 2 and having an intake port 4A and an exhaust port 4B formed therein. A combustion chamber 5 is formed between the cylinder head 4 and the piston 3 in each cylinder 2.

Here, the intake port 4 of the cylinder head 4
A is connected to an intake manifold (not shown) or the like and constitutes a part of an intake passage for supplying intake air into the combustion chamber 5. A throttle valve (not shown) that is opened / closed by a throttle actuator 17 described later is provided in the middle of the intake passage, and the throttle valve has an opening degree θ as shown by a characteristic line 23 described later in FIG.
The intake air amount is changed according to the (target opening θt).

Further, the exhaust port 4B of the cylinder head 4
Is connected to an exhaust pipe 6 to exhaust the exhaust gas from the combustion chamber 5 to the outside. Further, the cylinder head 4 is provided with an intake valve 7 located on the intake port 4A side, and an exhaust valve 8 is provided on the exhaust port 4B side.

Reference numeral 9 denotes an in-cylinder direct injection type injection valve provided in the cylinder head 4. The injection valve 9 is connected to a fuel pump on the fuel tank side through a fuel pipe (neither is shown) or the like. The control unit 19 described later, shown in FIG.
When the injection pulse signal is output from, for example, 5MP
High-pressure gasoline fuel is directly injected into the combustion chamber 5 with an injection pressure of about a (megapascal). The fuel directly injected from the injection valve 9 into the combustion chamber 5 is
It is mixed and agitated with the intake air flowing into the combustion chamber 5 from the intake port 4A in a swirling flow state, and becomes thicker near the ignition plug (not shown) in the combustion chamber 5 and becomes thinner on the peripheral side. A mixture is formed.

Reference numeral 10 denotes a crank angle sensor as a rotation speed detecting means. The crank angle sensor 10 detects the rotation output of the engine body 1 as an engine rotation speed N, and the detection signal is sent to a control unit 19 shown in FIG. Output.

Reference numeral 11 denotes an accelerator sensor as an operation amount detecting means. The accelerator sensor 11 detects an operation amount of an accelerator pedal (not shown) or the like provided on the vehicle as an accelerator operation amount α and outputs a detection signal thereof. Output to the control unit 19.

Reference numeral 12 denotes a throttle sensor as an opening detecting means for detecting the opening θ of the throttle valve, 13 denotes a combustion pressure sensor as a combustion state detecting means, and the combustion pressure sensor 13 is the combustion chamber 5 of the engine body 1. The combustion pressure P generated inside is detected, and the detection signal is output to the control unit 19.

Reference numeral 14 is a vehicle speed sensor as a vehicle speed detecting means for detecting the traveling speed of the vehicle as an actual vehicle speed Vr, and 15 is a changeover switch constituting a changeover means. The changeover switch 15 is provided in a driver's cab of the vehicle. A vehicle speed constant control (cruise control) in which the vehicle speed of the vehicle is controlled to be substantially constant by a driver switching operation, and other normal control time are selectively switched.

Reference numeral 16 denotes a vehicle speed setter as a vehicle speed setting means for setting a target vehicle speed Vt during constant vehicle speed control. The vehicle speed setter 16 is manually operated by the driver when the vehicle speed constant control is selected by the changeover switch 15. Target vehicle speed V by operating
The configuration is such that t is set arbitrarily and a command is issued.

Reference numeral 17 denotes a throttle actuator for opening and closing the throttle valve. The throttle actuator 17 is composed of an electric motor or the like and variably controls the opening θ of the throttle valve according to a target opening θt described later. Is.

Reference numeral 18 denotes a display device provided in a driver's cab (front board) of the vehicle. The display device 18 displays the actual vehicle speed Vr of the vehicle detected by the vehicle speed sensor 14 and the like to the driver. Etc.

Reference numeral 19 denotes a control unit as an arithmetic and control unit mounted on the vehicle. The input side of the control unit 19 is a crank angle sensor 10, an accelerator sensor 11, a throttle sensor 12, a combustion pressure sensor 13, and a vehicle speed sensor 14. , The changeover switch 15, the vehicle speed setting device 16, etc., and the output side is connected to the injection valve 9, the throttle actuator 17, the display device 18, etc. The control unit 19 stores a calculation program for the fuel injection amount, the intake air amount, etc. in its memory circuit, and controls the drive of the injection valve 9, the throttle actuator 17, etc. according to the control processing procedure shown in FIG. Has become.

In the storage circuit of the control unit 19, the characteristic line 2 shown in FIG.
The target torque T of the engine body 1 from the engine speed N and the accelerator operation amount α along 0A, 20B, 20C, etc.
Torque calculation map for calculating t and characteristic line 2 shown in Fig. 5
An air-fuel ratio calculation map for determining a target air-fuel ratio A / F from the engine speed N and the target torque Tt is stored along 1A, 21B, 21C, etc.

Further, in the storage area 19A of the control unit 19, the characteristic lines 22A and 22 shown in FIG.
B, 22C, etc., the injection amount calculation map for calculating the fuel injection amount Ft from the engine speed N and the target air-fuel ratio A / F, and the throttle valve for the intake air amount Q along the characteristic line 23 shown in FIG. A target opening calculation map for calculating the target opening θt and an increase / decrease value calculation map for calculating the increase / decrease value Δαt of the pseudo target accelerator operation amount αt along the characteristic line 24 shown in FIG. 8 are stored.

The control apparatus for the direct injection type gasoline engine according to the present embodiment has the above-mentioned structure. Next, referring to FIG. 3 and the like, for the control processing procedure of the fuel injection amount and the like by the control unit 19. explain.

First, in step S1 shown in FIG. 3, the engine speed N is read from the crank angle sensor 10, and step S2 is executed.
Then, the operation amount of the accelerator pedal by the driver is read from the accelerator sensor 11 as the accelerator operation amount α. And
When the changeover switch 15 is switched to the normal control side, the target torque Tt of the engine body 1 is calculated in step S3 from the torque calculation map shown in FIG. 4 based on the engine speed N and the accelerator operation amount α.

Next, in step S4, the target air-fuel ratio A / F is obtained from the air-fuel ratio calculation map shown in FIG. 5 based on the engine speed N and the target torque Tt.
The fuel injection amount Ft is calculated on the basis of the engine speed N and the target air-fuel ratio A / F by the injection amount calculation map shown in Fig. 1, and gasoline fuel corresponding to this injection amount Ft is supplied from the injection valve 9 to the engine body 1 in step S14. It is directly injected into the combustion chamber 5 of.

In step S6, the intake air amount Q is calculated from the injection amount Ft and the target air-fuel ratio A / F by

[0040]

## EQU1 ## Q = Ft.times.A / F is calculated, and in step S7, the target opening .theta.t of the throttle valve with respect to the intake air amount Q is calculated from the target opening calculation map shown in FIG.

On the other hand, in step S8, the combustion pressure P generated in the combustion chamber 5 of the engine body 1 is read from the combustion pressure sensor 13, and in step S9, the actual combustion by the combustion gas (exhaust gas) from the combustion pressure P at this time is read. Estimated air-fuel ratio A corresponding to the state
Calculate i / Fi. Then, in the next step S10, the estimated air-fuel ratio Ai / Fi is compared with the target air-fuel ratio A / F to obtain the corrected air amount ΔQ, and in step S11, the corrected air amount ΔQ is obtained.
The correction value Δθ of the opening degree by the throttle valve is obtained from Q.

Next, in step S12, the above-mentioned target opening degree θt of the throttle valve is corrected by the correction value Δθ.

[0043]

[Mathematical formula-see original document] By performing a correction calculation as θt ← θt + Δθ, the procedure proceeds to the next step S13, and a drive signal is output to the throttle actuator 17, so that the throttle actuator 17 opens and closes the corrected target opening θt. To control.

As a result, the throttle valve can adjust the intake air amount with an opening corresponding to the target opening θt, and in step S14, the injection valve 9 to the combustion chamber 5 of the engine body 1 is adjusted.
While the gasoline fuel directly injected inward and the intake air are mixed and stirred in the combustion chamber 5 of the engine body 1, the mixture is ignited by a spark plug or the like, so that the mixture becomes combustion gas. Then, the exhaust gas after combustion is discharged from the exhaust pipe 6 side to the outside.

Next, when the driver selects the constant vehicle speed control (cruise control) by switching the changeover switch 15, the vehicle speed setter 16 is selected in step S15.
The target vehicle speed Vt is read, and in step S16, the current actual vehicle speed Vr is read from the vehicle speed sensor 14. Then, in the next step S17, the pseudo target accelerator operation amount αt as the target accelerator operation amount is calculated from the target vehicle speed Vt and the actual vehicle speed Vr.

That is, in step S17, the deviation ΔV between the target vehicle speed Vt and the actual vehicle speed Vr is

[0047]

## EQU00003 ## Obtained as .DELTA.V = Vt-Vr, and the increase / decrease value .DELTA..alpha.t corresponding to the deviation .DELTA.V at this time is calculated from the increase / decrease value calculation map shown in FIG.
By adding this increase / decrease value Δαt to the previous accelerator operation amount α, the pseudo target accelerator operation amount αt (αt = α +
Δαt) is calculated.

In this case, since the pseudo target accelerator operation amount αt is selected by the changeover switch 15 in place of the accelerator operation amount α, in step S3, the engine speed N is changed from the torque calculation map shown in FIG. The target torque T of the engine body 1 is calculated based on the pseudo target accelerator operation amount αt.
Calculate t as the target torque during constant vehicle speed control.

Next, in step S4, the target air-fuel ratio A / F during constant vehicle speed control is obtained from the air-fuel ratio calculation map shown in FIG.
In step S5, the fuel injection amount Ft during constant vehicle speed control is calculated from the injection amount calculation map shown in FIG. 6, and gasoline fuel corresponding to this injection amount Ft is transferred from the injection valve 9 to the combustion chamber 5 of the engine body 1 in step S14. Directly injecting toward the target, and performing the processing from step S6 to step S13 in the same manner as the previous time,
The throttle actuator 17 controls the opening / closing of the throttle valve by the corrected target opening θt.

Thus, according to this embodiment, when the driver of the vehicle operates the changeover switch 15 to select the constant vehicle speed control (cruise control), the target vehicle speed Vt by the vehicle speed setter 16 and the actual vehicle speed of the vehicle are set. Since the pseudo target accelerator operation amount αt as the target accelerator operation amount is calculated from the speed Vr, the target torque Tt during cruise control is the same as in the normal operating state (during normal control).
The target air-fuel ratio A / F, the fuel injection amount Ft, the intake air amount Q, and the like can be easily calculated, and the target opening θt of the throttle valve to be opened / closed by the throttle actuator 17 can be accurately calculated.

As a result, the throttle actuator 17
By controlling the opening and closing of the throttle valve with an opening corresponding to the target opening θt, and directly injecting fuel from the injection valve 9, the actual vehicle speed Vr of the vehicle substantially matches the target vehicle speed Vt by the vehicle speed setter 16. As described above, the intake air amount Q (including the correction air amount ΔQ) and the fuel injection amount Ft can be adjusted stably, and the traveling stability during cruise control can be greatly improved.

Further, the high pressure fuel from the injection valve 9 is directly injected into the combustion chamber 5 of the engine body 1, and this fuel is mixed and stirred in the combustion chamber 5 with the intake air from the intake port 4A in a swirling flow state. At the same time, since the air-fuel mixture is ignited by a spark plug or the like, the combustion efficiency of the air-fuel mixture in the combustion chamber 5 can be reliably increased, lean combustion of the air-fuel mixture is possible, and significant fuel consumption can be realized. , Nitrogen oxides in exhaust gas (NO
x) etc. can be surely reduced.

Therefore, according to the present embodiment, while making full use of the advantages of the direct injection type gasoline engine, cruise control can be easily performed, and vehicle speed control can be stably performed. .

In the first embodiment, among the processing procedures shown in FIG. 3, steps S3 to S6 are specific examples of the calculating means, which is a feature of the present invention, and step S17 is a target manipulated variable calculation. A concrete example of the means, a step S3 shows a concrete example of the torque calculating means, a step S7 shows a concrete example of the throttle opening calculating means, and a step S11 and the like show a concrete example of the correction value calculating means. .

Next, FIGS. 9 and 10 show a second embodiment of the present invention. In this embodiment, the same components as those in the first embodiment are designated by the same reference numerals and the description thereof is omitted. It shall be. However, the feature of this embodiment is that the pseudo target accelerator operation amount αt is calculated in step S37 shown in FIG. 10, and the engine speed N and the pseudo target accelerator operation amount αt are calculated from the torque calculation map shown in FIG. 9 in the next step S38. The target torque Tt of the engine body 1 is calculated as the target torque during constant vehicle speed control based on the above.

Here, the torque calculation map shown in FIG. 9 is compared with the characteristic lines 20A, 20B and 20C (shown by dotted lines in FIG. 9) illustrated in FIG. 4 as represented by characteristic lines 30A, 30B and 30C. The target torque Tt is set to increase in the low engine speed N range and to decrease in the high engine speed range. It should be noted that the processing from step S21 to step S37 in FIG. 10 is performed in the same manner as the processing from step S1 to step S17 according to the first embodiment, and therefore the description thereof will be omitted.

Thus, in this embodiment having the above-described structure, it is possible to obtain substantially the same effects as the first embodiment, but in this embodiment, the normal control is selected by the changeover switch 15. At step S23, the target torque Tt is calculated from the torque calculation map shown in FIG. 4, and when the constant vehicle speed control is selected, the target torque Tt is calculated from the torque calculation map shown in FIG.
The target torque Tt during constant vehicle speed control (cruise control) can be stabilized in the low speed range or the high speed range of the engine speed N, and the running stability during cruise control can be increased more reliably.

In the second embodiment, among the processing procedures shown in FIG. 10, steps S23 to S26 are specific examples of the calculating means, which is a feature of the present invention, and step S37 is a target manipulated variable calculation. A concrete example of the means, a step S38 shows a concrete example of the torque calculating means, a step S27 shows a concrete example of the throttle opening calculating means, and a step S31 and the like show a concrete example of the correction value calculating means. .

In each of the above embodiments, the case where the combustion pressure sensor 13 is used as the combustion state detecting means has been described as an example. However, the present invention is not limited to this, and may be an air-fuel ratio sensor or an oxygen sensor, for example. The combustion state detecting means may be configured to obtain the estimated air-fuel ratio Ai / Fi corresponding to the actual combustion state of the combustion gas (exhaust gas) based on the detection signal of the air-fuel ratio sensor or the oxygen sensor.

[0060]

As described in detail above, according to the first aspect of the present invention, when the switching means is switched from the normal control side to the constant vehicle speed control side, the target vehicle speed of the vehicle set by the vehicle speed setting means is set. While obtaining the deviation from the actual vehicle speed, the target accelerator operation amount is calculated from this deviation by the target operation amount calculating means, and the intake air amount required for constant vehicle speed control is calculated based on this target accelerator operation amount and the actual engine speed. And the fuel injection amount from the injection valve are calculated, the cruise control can be performed easily and stably while fully utilizing the advantages of the direct injection gasoline engine of the cylinder. You can greatly improve the property.

According to the second aspect of the present invention, the target torque of the engine body is calculated based on the target accelerator operation amount by the target operation amount calculating means and the engine speed by the speed detecting means during the constant vehicle speed control. Since it is configured to include a torque calculating means for performing a constant vehicle speed control, it is possible to reliably calculate the target torque to be generated in the engine body based on the target accelerator operation amount and the engine speed, and the target torque and the engine speed. The actual vehicle speed of the vehicle can be promptly made to correspond to the target vehicle speed while calculating the fuel injection amount of the injection valve and the intake air amount from.

Further, in the invention according to claim 3, the throttle opening calculation means calculates a target opening of the throttle valve corresponding to the intake air amount, and based on this target opening, the throttle actuator operates the throttle valve. Since the opening / closing operation is performed, the intake air amount can be accurately adjusted according to the target vehicle speed, and the constant vehicle speed control can be stably executed.

Further, in the invention according to claim 4,
The state of the combustion gas generated in the combustion chamber of the engine body is detected by the combustion state detecting means, and based on this, the correction value of the target opening by the throttle opening calculating means is calculated by the correction value calculating means. From this, the actual air-fuel ratio can be read from the combustion state when the mixture of intake air and fuel is actually combusted in the combustion chamber of the engine body, and correction for feedback control of the target opening is performed. The value can be calculated, and the opening / closing operation of the throttle valve by the throttle actuator can be feedback-controlled based on this correction value. Therefore, the actual air-fuel ratio can be controlled to a value corresponding to the target air-fuel ratio by finely adjusting the opening of the throttle valve by the correction value, and the running stability during constant vehicle speed control can be more reliably improved. .

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a direct injection type gasoline engine in a cylinder according to a first embodiment of the present invention.

FIG. 2 is a control block diagram of a control device for the direct injection gasoline engine of the cylinder shown in FIG.

3 is an operation explanatory view showing a control processing procedure by a control unit in FIG.

FIG. 4 is an explanatory diagram showing a torque calculation map stored in a storage area of a control unit.

FIG. 5 is an explanatory diagram showing an air-fuel ratio calculation map stored in a storage area of a control unit.

FIG. 6 is an explanatory diagram showing an injection amount calculation map stored in a storage area of a control unit.

FIG. 7 is an explanatory diagram showing a target opening calculation map stored in a storage area of a control unit.

FIG. 8 is an explanatory diagram showing an increase / decrease value calculation map of a pseudo target accelerator operation amount stored in a storage area of a control unit.

FIG. 9 is an explanatory diagram of a torque calculation map used in the control device for a direct injection gasoline engine according to the second embodiment of the present invention.

FIG. 10 is an operation explanatory diagram of a control processing procedure showing a control device for a direct injection type gasoline engine according to a second embodiment of the present invention.

[Explanation of symbols]

 1 Engine Main Body 2 Cylinder 3 Piston 4 Cylinder Head 4A Intake Port 4B Exhaust Port 5 Combustion Chamber 9 Injection Valve 10 Crank Angle Sensor (Rotation Detecting Means) 11 Accelerator Sensor (Operation Quantity Detecting Means) 13 Combustion Pressure Sensor (Combustion State Detecting Means) ) 14 vehicle speed sensor 15 changeover switch (switching means) 16 vehicle speed setting device (vehicle speed setting means) 17 throttle actuator 19 control unit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masaya Nakayama, 1370 Onna, Atsugi, Kanagawa Prefecture, within Unisia Jecs Co., Ltd. (72) Inventor, Rin Taniuchi, 1370, Onna, Atsugi, Kanagawa

Claims (4)

[Claims] 1. An engine body of a gasoline engine mounted on a vehicle, an injection valve for directly injecting gasoline fuel into a combustion chamber of the engine body, and an operation amount detection for detecting an operation amount of an accelerator provided in the vehicle. Means, and a rotation speed detection means for detecting an engine rotation speed of the engine body,
In-cylinder direct-injection gasoline engine provided with calculating means for calculating the fuel injection amount and the intake air amount of the injection valve based on the engine speed by the speed detecting means and the accelerator operation amount by the operation amount detecting means. In the control device, switching means for selectively switching between constant vehicle speed control and normal control for controlling the vehicle speed of the vehicle substantially constant, and vehicle speed setting means for setting a target vehicle speed of the vehicle during the constant vehicle speed control. And a target operation amount calculation means for calculating a target accelerator operation amount from a deviation between the target vehicle speed by the vehicle speed setting means and the actual vehicle speed of the vehicle, and the calculation means selects the constant vehicle speed control by the switching means. At this time, the fuel injection amount and the intake air amount of the injection valve are calculated based on the engine rotation speed by the rotation speed detection unit and the target accelerator operation amount by the target operation amount calculation unit. Control apparatus for a cylinder direct injection gasoline engine, characterized in that a configuration in which calculation. 2. A torque calculation means for calculating a target torque of the engine body based on a target accelerator operation amount by the target operation amount calculation means and an engine speed by the rotation speed detection means during the constant vehicle speed control, The computing means, when the vehicle speed constant control is selected by the switching means,
The fuel injection amount and the intake air amount of the injection valve are calculated based on the target torque by the torque calculating means and the engine speed by the speed detecting means.
The control device for a direct injection gasoline engine according to claim 1. 3. A throttle valve provided in the middle of the intake passage of the engine body and operated to be opened and closed by a throttle actuator, and a throttle opening for calculating a target opening of the throttle valve corresponding to an intake air amount by the computing means. 3. The control of a direct injection gasoline engine according to claim 1, wherein the throttle actuator is configured to open and close the throttle valve based on a target opening by the throttle opening calculating means. apparatus. 4. A combustion state detecting means for detecting a state of combustion gas generated in a combustion chamber of the engine body, and a target opening degree correction by the throttle opening degree calculating means based on a signal from the combustion state detecting means. Correction value calculation means for calculating a value, and the throttle actuator is configured to open and close the throttle valve based on a target opening by the throttle opening calculation means and a correction value by the correction value calculation means. The control device for a direct injection type gasoline engine according to claim 3.