JP2016056775A - Control device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a vehicle occupant from feeling uncomfortable about noise generated from a vehicle and improve fuel economy by correcting target fuel pressure by considering an attributable proportion of the noise generated by an internal combustion engine to the overall noise of the vehicle.SOLUTION: A control device for an internal combustion engine for controlling the internal combustion engine mounted to a vehicle includes: vehicle speed detection means for detecting the speed of the vehicle; gear detection means for detecting a gear stage of a transmission of the vehicle; and target fuel pressure calculation means for calculating target fuel pressure within a common rail of the vehicle. The target fuel pressure calculation means corrects target fuel pressure on the basis of the vehicle speed detected by the vehicle speed detection means and the gear stage detected by the gear detection means.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a control device for an internal combustion engine, and more particularly to a control device for an internal combustion engine that can improve fuel consumption while preventing passengers from feeling uncomfortable with noise.

A vehicle equipped with a compression ignition type internal combustion engine (diesel engine) has a problem of propagation of noise (particularly noise caused by combustion) generated from the internal combustion engine to the passenger compartment during low-speed driving and idling. Reduction is required. However, since the fuel consumption is increased by reducing the combustion noise of the internal combustion engine, the two problems of noise suppression and fuel consumption reduction are contradictory.
On the other hand, Patent Document 1 discloses that an internal combustion engine is corrected by correcting a basic value of an operation parameter used for control of the internal combustion engine so that the degree of fuel consumption becomes smaller according to the vehicle speed while the vehicle is traveling at high speed. A technique for reducing fuel consumption while allowing the combustion noise generated by the noise to rise to a level smaller than the outer noise is disclosed.

JP 2014-58875 A

By the way, the noise in the passenger compartment is greatly influenced by outer noise such as road noise and wind noise accompanying the increase in vehicle speed. Further, the noise generated from the internal combustion engine has a smaller contribution ratio to the overall noise due to an increase in outer noise such as road noise and wind noise as the vehicle speed increases.
Road noise among exterior noises has a correlation with not only the vehicle speed but also the gear stage. Therefore, as in Patent Document 1, it is not possible to sufficiently reduce noise and improve fuel efficiency by reducing the degree of fuel consumption only in accordance with the vehicle speed.

  The present invention corrects the target fuel pressure in consideration of the contribution ratio of the noise generated by the internal combustion engine to the overall noise of the vehicle, thereby preventing the vehicle occupant from feeling uncomfortable noise generated from the vehicle and improving the fuel efficiency. It aims to improve.

  The present invention provides a control device for an internal combustion engine that controls an internal combustion engine mounted on a vehicle, a vehicle speed detection unit that detects a vehicle speed of the vehicle, a gear detection unit that detects a gear stage of a transmission of the vehicle, and a common rail in the vehicle. Target fuel pressure calculating means for calculating the target fuel pressure, and the target fuel pressure calculating means corrects the target fuel pressure based on the vehicle speed detected by the vehicle speed detecting means and the gear stage detected by the gear detecting means. And

  Since the present invention corrects the target fuel pressure based on the vehicle speed and the gear stage, the target fuel pressure can be corrected in consideration of the contribution ratio of the noise generated by the internal combustion engine to the entire vehicle noise, and the vehicle occupant is generated from the vehicle. It is possible to prevent the generated noise from being uncomfortable and improve the fuel efficiency.

It is a system block diagram of the control apparatus of an internal combustion engine. (Example) It is a figure which shows the fuel pressure correction map by vehicle speed and a gear stage. (Example) It is a control flowchart of the control apparatus of an internal combustion engine. (Example)

  Embodiments of the present invention will be described below with reference to the drawings.

1 to 3 show an embodiment of the present invention. In FIG. 1, an internal combustion engine 1 mounted as a power source in a vehicle includes a high pressure pump 2 that pressurizes fuel to a high pressure, a common rail 3 that is supplied with fuel from the high pressure pump 2, and an injector that is supplied with fuel from the common rail 3. 4. The internal combustion engine 1 is a compression ignition type internal combustion engine (diesel engine) that generates fuel by injecting fuel from the injector 4 into the air in the combustion chamber 5 compressed and heated by a piston to cause self-ignition. The power generated by the internal combustion engine 1 is transmitted to the drive wheels 8 by the drive axle 7 via the transmission 6 to drive the vehicle.
The control device 9 that controls the internal combustion engine 1 includes a control unit 10. A high pressure pump 2 and an injector 4 are connected to the control unit 10. Further, a fuel pressure detecting means 11 for detecting the fuel pressure (fuel pressure) in the common rail 3 is connected to the control unit 10. The control unit 10 controls the operation of the high-pressure pump 2 based on the fuel pressure detected by the fuel pressure detection means 11 to control the fuel pressure in the common rail 3, and controls the operation of the injector 4 to determine the fuel injection amount and fuel injection timing. Control.

The vehicle interior noise of a vehicle equipped with the compression ignition type internal combustion engine 1 is greatly influenced by so-called road noise. The road noise has a correlation with the vehicle speed and the gear stage. Further, when the road noise increases, the contribution of the combustion sound of the internal combustion engine 1 to the vehicle interior noise decreases.
Therefore, the control device 9 connects to the control unit 10 vehicle speed detection means 12 for detecting the vehicle speed of the vehicle and gear detection means 13 for detecting the gear stage of the transmission 6 of the vehicle. The control unit 10 includes target fuel pressure calculation means 14 that calculates a target fuel pressure in the common rail 3 of the vehicle. The target fuel pressure calculation means 14 corrects the target fuel pressure based on the vehicle speed detected by the vehicle speed detection means 12 and the gear stage detected by the gear detection means 13. In the correction of the target fuel pressure, the target fuel pressure calculation means 14 corrects the target fuel pressure to be higher as the gear stage detected by the gear detection means 13 is higher.
As shown in FIG. 2, the target fuel pressure calculation means 14 calculates a target fuel pressure correction value from a target fuel pressure correction map set based on the vehicle speed and gear position, and calculates the calculated target fuel pressure correction value in the conventional manner. The target fuel pressure is corrected by adding to the target fuel pressure. The maximum combustion pressure of the internal combustion engine 1 is guaranteed with respect to the engine speed. That is, since the maximum combustion pressure is guaranteed at the vehicle speed for each gear stage, the value of the target fuel pressure correction map is set in consideration of the maximum combustion pressure. The target fuel pressure before correction is obtained from the engine speed of the internal combustion engine 1, the throttle opening, and the like.

Next, the operation will be described.
As shown in FIG. 3, the control device 9 of the internal combustion engine 1 starts the control program (S01), and calculates the fuel pressure correction value Pvsp by the target fuel pressure calculation means 14 (S02). The fuel pressure correction value Pvsp is obtained from a target fuel pressure correction map (see FIG. 2) set based on the vehicle speed VSP and the gear stage GEAR so as to be equal to or less than the maximum combustion pressure {Pvsp = P (VSP, GEAR)}.
The target fuel pressure calculating means 14 calculates the corrected target fuel pressure Prailplus (Prailplus = Prail + Pvsp) by adding the fuel pressure correction value Pvso to the target fuel pressure Prail calculated in the conventional manner (S03).
The target fuel pressure calculation means 14 applies the restriction of the maximum combustion pressure to the obtained target fuel pressure Prailplus (S04), and performs fuel discharge control to the target fuel pressure Prailplus using the fuel pressure detection means 11 and the high pressure pump 2 (S05). Then, fuel injection is performed by the injector 4 (S06), and the program is terminated (S07).

The control device 9 of the internal combustion engine 1 corrects the target fuel pressure in accordance with the vehicle speed and the gear stage, and changes the degree of suppression of the combustion noise of the internal combustion engine 1. The fuel efficiency can be improved by increasing the target fuel pressure against the increase in vehicle interior noise caused by the increase in vehicle speed, and the target fuel pressure due to the increase in vehicle interior noise can be increased by taking into account the difference in engine speed due to the difference in gear. The fuel consumption can be improved by raising it.
Increasing the target fuel pressure increases the combustion pressure. By not exceeding the fully open output (maximum combustion pressure), there is no effect on the internal combustion engine body (such as increased rigidity). Therefore, it can be implemented with the conventional parts. In addition, since it is incorporated in the conventional target fuel pressure control, the allowable value of the maximum combustion pressure is not exceeded, and there is no influence on fuel system parts. Therefore, it can be implemented with the conventional parts.
Thus, the control device 9 of the internal combustion engine 1 corrects the target fuel pressure based on the vehicle speed and the gear stage by the target fuel pressure calculation means 14 that calculates the target fuel pressure in the common rail 3 of the vehicle. The target fuel pressure can be corrected in consideration of the contribution ratio of the noise generated by the internal combustion engine 1, so that the vehicle occupant does not feel the noise generated from the vehicle uncomfortable and the fuel efficiency can be improved.
Further, the control device 9 of the internal combustion engine 1 makes the target fuel pressure higher as the gear stage detected by the gear detection means 13 is higher by the target fuel pressure calculation means 14, so that the vehicle occupant is uncomfortable with the noise generated from the vehicle. The fuel efficiency can be improved while avoiding the feeling.

  The present invention corrects the target fuel pressure in consideration of the contribution ratio of the noise generated by the internal combustion engine to the overall noise of the vehicle, thereby preventing the vehicle occupant from feeling uncomfortable noise generated from the vehicle and improving the fuel efficiency. It can be improved and can be applied to an internal combustion engine capable of adjusting the fuel pressure.

DESCRIPTION OF SYMBOLS 1 Internal combustion engine 2 High pressure pump 3 Common rail 4 Injector 5 Combustion chamber 6 Transmission 7 Drive axle 8 Drive wheel 10 Control part 11 Fuel pressure detection means 12 Vehicle speed detection means 13 Gear detection means 14 Target fuel pressure calculation means

Claims (2)

  In a control device for an internal combustion engine that controls an internal combustion engine mounted on a vehicle, vehicle speed detection means for detecting a vehicle speed of the vehicle, gear detection means for detecting a gear stage of the transmission of the vehicle, and a common rail of the vehicle Target fuel pressure calculating means for calculating a target fuel pressure, and the target fuel pressure calculating means corrects the target fuel pressure based on a vehicle speed detected by the vehicle speed detecting means and a gear stage detected by the gear detecting means. A control device for an internal combustion engine.   2. The control apparatus for an internal combustion engine according to claim 1, wherein the target fuel pressure calculation means increases the target fuel pressure as the gear stage detected by the gear detection means increases.

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