JPH0337347A - Controller for internal combustion engine - Google Patents

Abstract

PURPOSE:To improve the fuel consumption by prolonging the cut-off period in fuel feed by relaxing the prescribed conditions when a shift pattern switch is set to an economic operation mode, in the constitution in which fuel feed into an internal combustion engine is cut off when the prescribed conditions are satisfied. CONSTITUTION:In an automatic transmission 28, the speed change ratio is selected in accordance with the operation mode (normal mode, economy mode, and power mode) set by a shift pattern switch 31, and when the normal mode or power mode is selected, fuel feed is cut off if the engine revolution speed detected by a crank angle detector 27 is over the level L1 (about 2,000 rpm). Further, when the revolution speed lowers and becomes less than the level L2 (about 1,500 rpm), fuel feed is restarted. While, when the economy mode is selected, fuel feed is cut off if the level L1a (about 1,700 rpm) is realized, while if the level L2 (about 1,000 rpm) is realized, fuel feed is restarted.

Description

[Detailed Description of the Invention] Overview In a control device for an internal combustion engine, during deceleration when the throttle valve is fully closed, the internal combustion engine is A configuration is used in which the fuel supply is cut off. On the other hand, in connection with an automatic transmission that decelerates and derives the output of an internal combustion engine, a configuration is used in which a shift pattern switch is provided that is operated by a driver to set a desired driving mode.

In response to the output of the shift pattern switch, the economic driving mode is selected, and when the driver desires driving that emphasizes fuel economy rather than output, the fuel supply cutoff condition is relaxed. As a result, the restart time of fuel supply is delayed compared to the normal operation mode or the high output operation mode, and the fuel supply cutoff period can be extended.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an internal combustion engine that shuts off fuel supply to the engine when predetermined conditions are satisfied.

Conventional Technology As mentioned above, in internal combustion engine control devices, during deceleration with the throttle valve fully closed, fuel is supplied to the internal combustion engine to prevent heating of the catalyst in the exhaust gas purification device and to save fuel. A configuration is used that blocks the

The fuel supply cutoff condition is satisfied when, for example, the rotational speed of the internal combustion engine exceeds a predetermined value while the throttle valve is in the fully closed state as described above.

Referring to FIG. 3, in the typical prior art, as described above, when the throttle valve is in the fully closed state and the rotational speed of the internal combustion engine is at a predetermined level 11 or higher, fuel supply cutoff control is performed; When the rotational speed of the internal combustion engine decreases to a level lower than level L1 by, for example, 20 rpm, the fuel supply is restarted. In this way, 3+ of fuel supply! Fuel supply cutoff control is performed with so-called hysteresis characteristics during cutoff control and restart control.

On the other hand, in connection with an automatic transmission that decelerates and derives the output of an internal combustion engine, a configuration is used in which an operation mode setting means called a shift pattern switch is provided. When this shift pattern switch is selected for economy mode, the automatic transmission shifts at a lower vehicle speed than in normal mode, the standard mode, and the internal combustion engine is used at low output. Ru. Furthermore, when the power mode, which is a high-output operation mode, is selected, the gear change operation is performed at a higher vehicle speed than in the normal mode, and the internal combustion engine is used in a high-output state.

Problems to be Solved by the Invention In the prior art as described above, when the rotational speed of the internal combustion engine reaches a predetermined single level 11 or higher, the fuel supply starts at 3+! Shut-off control is initiated and fuel supply is resumed once the single level is below 2. These levels Ll and L2 are referred to as L l a and L 2 , respectively.
When set to a low value as shown in a, the fuel supply
1! The shut-off period becomes longer, and fuel efficiency can be improved.

However, when the fuel supply cutoff period becomes longer in this way, the start-up becomes slower when the fuel supply is restarted, and drivability deteriorates. In this way, with conventional technology, the fuel supply is cut off at a certain level, regardless of the driver's will, that is, regardless of whether the driver wants to drive with an emphasis on fuel efficiency or whether the driver wants to drive with an emphasis on output. control is in place.

An object of the present invention is to improve fuel efficiency by relaxing the conditions for cutting off the fuel supply between internal combustion engines and lengthening the period of cutting off the fuel supply when the economical driving mode is selected, reflecting the will of the driver. An object of the present invention is to provide a control device for an internal combustion engine that can perform the following steps.

Means for Solving the Problems The present invention provides a vI control device for an internal combustion engine that cuts off fuel supply to the internal combustion engine when predetermined conditions are satisfied. respond,
The control device for an internal combustion engine is characterized in that when the shift pattern switch is selected to be in an economical operation mode, the condition is relaxed to lengthen the fuel supply cutoff period.

According to the present invention, the iM control device supplies fuel between the internal combustion engines when a predetermined condition is satisfied, for example, the throttle valve is fully closed and the rotational speed of the internal combustion engine is equal to or higher than a predetermined value. cut off. As a result of such fuel supply cutoff control, the rotational speed of the internal combustion engine decreases, and when the rotational speed of the internal combustion engine becomes less than the above-mentioned value and the cutoff condition is no longer satisfied, fuel supply is restarted.

On the other hand, the output of the internal combustion engine is decelerated by an automatic transmission. A shift pattern switch operated by the driver is provided in connection with the automatic transmission, and when the shift pattern switch is selected in the economical driving mode, the automatic transmission operates at a lower vehicle speed than in the standard driving mode. A gear shifting operation is performed, and when the high output driving mode is selected, the gear shifting operation is performed at a higher vehicle speed than in the standard driving mode.

The control device is also responsive to the output of the shift butter switch and relaxes the cut-off condition of the fuel supply, i.e. lowers the predetermined value of the rotational speed of the internal combustion engine, when an economical driving mode is selected. do. As a result, the start time of fuel supply it VORr:M becomes earlier,
Furthermore, the restart timing is delayed, and the fuel supply cutoff period can be extended.

Embodiment FIG. 1 is a block diagram showing an M-leg device 1 of an internal combustion engine according to an embodiment of the present invention and its related configuration. Inlet port 2
Combustion air introduced from the combustion air is purified by an air cleaner 3, passes through an intake pipe 4, and after its inflow amount is adjusted by a throttle valve 5 interposed in the intake pipe 4, it flows into a surge tank 6. The combustion air flowing out from the surge tank 6 is
The fuel is mixed with the fuel injected from the combustion injection valve 8 disposed in the intake pipe 7, and flows into the combustion chamber 1 of the internal combustion engine 10 via the intake valve 9.
1. A spark plug 12 is provided in the combustion chamber 11, and exhaust gas from the combustion chamber 11 is passed through an exhaust valve 13.
and is discharged into the atmosphere from the exhaust pipe 14 via the three-way catalyst 15.

The intake pipe 4 is provided with an intake air temperature detector 21 for detecting the temperature of the intake air, a throttle valve opening detection 822 is provided in connection with the throttle valve 5, and a surge tank 6
Intake pressure detection! ) 23 is provided. Further, a cooling water temperature detector 24 is provided near the combustion chamber 11. In the exhaust pipe 14, an oxygen concentration detector 25 is provided upstream of the three-way catalyst 15, and an exhaust temperature detector 26 is provided downstream of the three-way catalyst 15. The rotational speed of the internal combustion engine 10 is detected by a crank angle detector 27.

In addition to the respective detectors 21 to 27, the control device 1 includes a vehicle speed detector 28, a start detector 29 that detects whether the starter motor 33 that starts the internal combustion engine 10 is activated, and the use of the air conditioner. The detection results from the air conditioning detector 30 that detects the air conditioner are input. Further, this control device 1 is powered by a battery 34.

The control device 1, which is realized by a microcomputer or the like, includes an input interface circuit 41, an analog/digital converter 42, a processing circuit 43, a memory 44 that stores various control maps, and an output interface. The face circuit 45 is configured to include a face circuit 45. This control device 1 is based on the detection results of each of the detectors 21 to 30, the power supply voltage of the battery 34 detected by the voltage detector 20, and the operation mode set in the shift pattern switch 31, which will be described later. , calculates the fuel injection amount, ignition timing, etc., and calculates the fuel injection valve 8 and the spark plug 1.
vtm 2 etc.

The intake pipe 4 is also formed with a side passage 35 that bypasses the upstream and downstream sides of the throttle valve 5, and this side passage 35 is provided with an itI1m valve 36. The flow rate control valve 36 adjusts and controls the flow rate of combustion air during idling, when the throttle valve 5 is substantially fully closed, based on the output from the control device 1. The control device 11 also drives the fuel pump 32 when the internal combustion engine rmio is operating.

Power generated by internal combustion engine 10 is transmitted to wheels 40 via automatic transmission 38. The automatic transmission 38 is controlled by the control device 1, and the control device 1 controls the driving mode set in the shift pattern switch 31 operated by the driver and the shift lever.
In response to the operation at 39, an electromagnetic solenoid within the automatic transmission 38 is selectively driven based on the output from the vehicle speed detector 28, thereby switching the reduction ratio as shown in FIG.

That is, when the shift lever 39 is in the drive position and the shift pattern switch 31 is set to the normal mode, which is the standard operation mode, the control device 1 performs a shift operation as indicated by reference numeral 11 as the vehicle speed increases. In addition, when the economy mode, which is an economical driving mode, is set, as shown by reference numeral 12, the gear shifting operation is performed at a lower vehicle speed than the normal mode, and the power mode is a high output driving mode. When is selected, as indicated by reference numeral 13, the gear shifting operation is performed at a higher vehicle speed than in the normal mode.

In the control device 1 configured as described above, with reference to FIG. 3, the control device 1 includes a throttle valve opening degree detector 2
When the opening degree of the throttle valve 5 detected by 2 is in the fully closed state and the shift pattern switch 31 is selected to normal mode or power mode, the rotational speed of the internal combustion engine 10 detected by the crank angle detector 27 is When the speed reaches a predetermined level 11 or higher of about 2000 rpm, the fuel supply from the fuel injection valve 8 is cut off, and the rotational speed decreases to 500 rpm below the above level 1.
The fuel supply is restarted when the temperature drops below a predetermined low level of 12.

Further, when the shift pattern switch 31 is selected to the economy mode, the rotational speed of the internal combustion engine 10 is
The fuel supply is cut off at a level Lla of about 170 Qrpm, which is lower than the above-mentioned Level Upper 1, and the fuel supply is lower than the above-mentioned Level Upper 2, and 6500 rpm lower than the above-mentioned level Lla.
Fuel supply is restarted when the level reaches L2a, which is about p rn lower.

FIG. 4 is a flowchart for explaining the fuel supply cutoff control operation as described above. In step n1,
It is determined whether the driving mode set in the shift pattern switch 31 is the economy mode, and if so, the process moves to step n2, and if not, that is, if the normal mode or power mode is selected, the process moves to step n3. Move.

In step n2, the level L2a is assigned to the fuel supply restart rotation speed NA, and then the process moves to step n4.
is substituted and the process moves to step n4, whereupon the rotational speed NA at which fuel supply is to be restarted is determined in step n2 or n3.

In step n4, it is determined whether fuel supply cutoff control is currently being performed, and if not, the process moves to step n5, where it is determined whether the shift pattern switch 31 is selected to the economy mode, and if so, the process proceeds to step n5. The process moves to step n6, and if not, the process moves to step n7.

In step n6, the rotation speed NA is updated by adding a level L3a for giving it a hysteresis characteristic when the fuel supply is cut off and when it is restarted, and in step n7, the rotation speed NA is made to have a hysteresis characteristic. The level 3 above is added and updated. Thus Stellaf n6. When the rotational speed level at which the fuel supply cutoff control is started is set at step n8, the process moves to step n8. Also,
When the fuel supply cutoff control is being performed in step n4, the process directly moves to STERAPH'n8.

In step n8, the rotational speed NE of the internal combustion engine 10 detected by the crank angle detector 27 is determined in step n2.
n3. n6. Rotation speed NA set with either n7
It is determined whether or not the above is true, and if so, the process moves to step n9, and it is determined whether the cutoff condition for the remaining fuel supply is satisfied, that is, whether the throttle valve 5 is fully closed. When , step n
At step 10, fuel supply cutoff control is performed and the operation ends.

Further, when the rotational speed NE is not equal to the rotational speed NA in step n8, and when the fuel supply cutoff condition is no longer satisfied in step n9, the process moves to step n1l, where fuel supply is restarted and the operation ends.

As described above, in the internal combustion engine control device ll according to the present invention,
Shift pattern switch 31 set by the driver
When economy mode is selected, fuel supply cutoff control is performed at a lower rotation speed than when normal mode or power mode is selected, so fuel supply cutoff The period can be lengthened and fuel efficiency can be improved. Also,
In normal mode or power mode, the rotational speed rises quickly when fuel supply is restarted.

In this way, reflecting the driver's will, fuel efficiency can be improved when the economy mode is selected, and drivability can be improved when the power mode or normal mode is selected.

Note that in the above embodiment, the same levels Ll and L2 were used in the normal mode and the power mode;
In other embodiments of the invention, mutually overlapping levels may be used, and although both the levels are changed during the fuel supply cut-off control and the restart control, only one of the levels is changed. It may be changed.

Effects of the Invention As described above, according to the present invention, the economical driving mode is selected in response to the output of the shift pattern switch that is provided in connection with the automatic transmission and operated by the driver, so that the driver can prioritize output. When you want to drive with more emphasis on fuel efficiency, we have relaxed the conditions for cutting off the fuel supply.
When performing the fuel supply cutoff III control, the cutoff 11i start time is earlier and the restart time is later than in the normal operation mode or high output operation mode, so that the fuel supply cutoff period can be extended. Therefore, fuel efficiency can be improved reflecting the intention of the driver who has selected the economical driving mode.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an I control device 1 for an internal combustion engine and its related configuration according to an embodiment of the present invention, and FIG. FIG. 3 is a graph showing the level of rotational speed at which fuel supply cutoff control is performed, and FIG. 4 is a flowchart for explaining the fuel supply cutoff control operation. DESCRIPTION OF SYMBOLS 1... Control device, 8... Fuel injection valve, 10... Internal combustion engine, 20-30... Detector, 31... Shift pattern switch, 38... Automatic transmission, 39...・Shift lever 43...processing circuit, 44...memory

Claims (1)

[Scope of Claims] In an internal combustion engine control device that cuts off fuel supply to the internal combustion engine when a predetermined condition is satisfied, responsive to an output of a shift pattern switch of an automatic transmission,
A control device for an internal combustion engine, characterized in that when the shift pattern switch is selected to be in an economical operation mode, the condition is relaxed to lengthen the fuel supply cutoff period.