JP3239748B2 - Engine control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine control device, and more particularly to an engine control device which can realize a sufficient eco-run condition and a fuel-saving effect by a sufficient eco-run operation. The present invention relates to an engine control device capable of achieving both.

[0002]

2. Description of the Related Art Some engines mounted on vehicles are provided with an engine control device in order to reduce fuel consumption. There are various types of engine control devices that realize such fuel savings as described below.

[0003] For example, a first engine control device stops the supply of fuel to the engine and disengages the clutch when an eco-run condition set by the driving state of the vehicle or the driving operation state of the driver is satisfied. Some stop the engine. When returning the stopped engine to the normal operation, the engine is restarted.

[0004] As a second engine control device,
In some cases, when an eco-run condition set according to a running state of a vehicle, a driving operation state of a driver, or the like is satisfied, an intake pipe of an engine is fully closed, a clutch is released, and the engine is set to an idle operation.

[0005] Further, the third engine control device includes an intake / exhaust air supply and a fuel supply to a part of a cylinder of the engine when an eco-run condition set by a driving state of a vehicle or a driving operation state of a driver is satisfied. (Japanese Patent Laid-Open No. 7-84849).

Further, a fourth engine control device adjusts the torque capacity of the clutch when the vehicle is running on the engine brake, and stops the supply of fuel to the engine.
Alternatively, there is a type in which the intake pipe of the engine is completely closed.

[0007]

However, the first engine control device has a problem that a device for restarting the engine is required, so that the system becomes complicated and the frequency of restart is high. There is a disadvantage that the cost is increased due to the improvement of the durability and reliability of the parts. In addition, this first
In the engine control device, the responsiveness of the vehicle is deteriorated due to the release of the clutch, and the drivability is deteriorated.

[0008] Further, the second engine control device merely causes the engine to be in the idle operation during the eco-run operation, so that there is a disadvantage that the fuel saving effect is inferior. In addition, the second engine control device has a disadvantage that the responsiveness of the vehicle deteriorates with the release of the clutch, and the drivability deteriorates.

Further, the third engine control device includes:
In order to stop the intake and exhaust, a significant engine remodeling is required. For this reason, the third engine control device has a disadvantage that the cost of the engine is increased by remodeling the engine.

Further, the fourth engine control device has a low drivability during the eco-run operation, but has few opportunities to satisfy the eco-run condition, and has a low fuel saving effect during the eco-run operation. There is a disadvantage that it is difficult to obtain the eco-run effect.

As described above, the conventional engine control device has:
There have been inconveniences such as an increase in cost and deterioration in drivability. Conventional engine control devices for implementing eco-run control generally have a trade-off relationship between fuel-saving characteristics and good drivability, and the drivability deteriorates as more eco-run driving is performed to enhance the fuel-saving effect. I do.

In the conventional engine brake control, the drivability is extremely deteriorated as compared with other eco-run controls, but the eco-run conditions are insufficient and the fuel saving effect by the eco-run operation is small, so that the eco-run control is sufficiently reduced. There is a disadvantage that the effect cannot be obtained, and it has been desired to realize an engine control device that is inexpensive, has a high fuel saving effect, and has good drivability.

[0013]

SUMMARY OF THE INVENTION In order to eliminate the above-mentioned disadvantages, the present invention provides an intake pipe fully closing means for fully closing an intake pipe of an engine mounted on a vehicle. A fuel stopping means for selectively stopping fuel supplied every time, a clutch capable of electronically adjusting a torque capacity in a transmission path from the engine to a driving wheel of the vehicle, and a torque capacity of the clutch being reduced. A torque capacity adjusting means for adjusting is provided, an engine torque is estimated based on an accelerator operation amount of the vehicle and an engine rotation speed, and an engine braking condition is determined. When the engine braking condition is satisfied, the intake pipe is completely closed by the intake pipe fully closing means. The fuel supply to some or all cylinders is stopped by the fuel stopping means and the estimated engine torque is obtained. Characterized in that a control means for adjusting and controlling the torque capacity adjusting means.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An engine control device according to the present invention
The control means estimates the engine torque based on the accelerator operation amount of the vehicle and the engine rotation speed to determine an engine braking condition.When the engine braking condition is satisfied, the intake pipe fully closing means completely closes the intake pipe,
The supply of fuel to some or all cylinders is stopped by the fuel stopping means, and the torque capacity adjusting means is adjusted and controlled so as to obtain the estimated engine torque.

Thus, the engine control device can realize the same engine-generated torque as during normal running with low fuel consumption during eco-run operation by fully closing the intake pipe and stopping the supply of fuel, thereby suppressing fuel consumption. While the clutch is connected, an engine braking effect can be obtained.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 15 show an embodiment of the present invention. In FIG. 11, reference numeral 2 denotes a vehicle, and reference numeral 4 denotes an engine mounted on the vehicle 2. The engine 4 has a plurality of cylinders, for example, first to third cylinders 6 to 10.

As shown in FIG. 12, the engine 4 has an intake passage 18 formed by an air cleaner 12, an intake pipe 14 and an intake manifold 16, a throttle valve 20 provided in the intake passage 18 of the intake pipe 14, and a throttle valve. An idle bypass passage 22 that bypasses 20 and communicates with the intake passage 18 is provided.

The intake passage 18 is provided with an intake manifold 16.
Thus, the first to third cylinders 6 to 10 communicate with each other. The intake manifold 16 is provided with first to third fuel injection valves 24 to 28 that are directed to the first to third cylinders 6 to 10, respectively.

In the engine 4, as shown in FIG. 11, a clutch 32 whose torque capacity can be adjusted is connected to a crankshaft 30. The clutch 32 comprises a clutch capable of electronically adjusting the torque capacity, and includes a drive-side clutch plate 34 connected to the crankshaft 30 and a driven-side clutch plate connected to a forward / reverse switching mechanism 42 to be described later by the clutch shaft 36. 38 and a clutch solenoid 40.

The clutch 32 is connected to a forward / reverse switching mechanism 42 by a clutch shaft 36. The forward / reverse switching mechanism 42 includes a forward gear train 44, a reverse gear train 46, and a switching unit 48. The switching section 48 is switched by a later-described selector lever 114 of the transmission 50, and selectively meshes the forward gear train 44 and the reverse gear train 46.

The forward / reverse switching mechanism 42 is connected to a transmission (continuously variable transmission: CVT) 50. The transmission 50 has a driving pulley 52, a driven pulley 54, and a belt 56.

The drive pulley 52 includes a drive shaft 58 having one end connected to a switching portion 48 of the forward / reverse switching mechanism 42, a drive-side fixed pulley piece 60 fixed to the drive shaft 58, and A drive-side movable pulley portion 62 provided on the drive shaft 58 so as to be axially movable and non-rotatable. A drive-side hydraulic chamber 66 is formed by a drive-side housing 64 on the back side of the drive-side movable pulley piece 62.

The driven pulley 54 includes a driven shaft 68 disposed in parallel with the driving shaft 58, a driven fixed pulley piece 70 fixedly provided on the driven shaft 68, and a driven shaft 68. And a driven-side movable pulley portion 72 provided so as to be movable in the axial direction and non-rotatable. On the back side of the driven-side movable pulley piece 72, a driven-side hydraulic chamber 76 is formed by a driven-side housing 74, and a driven-side spring 78 that presses the driven-side movable pulley piece 72 toward the belt 56 is incorporated. .

The driving-side hydraulic chamber 66 and the driven-side hydraulic chamber 7
6 are supplied with hydraulic pressures of a primary pressure and a line pressure by a hydraulic control circuit 80, respectively. The hydraulic pressures of the primary pressure and the line pressure relatively increase or decrease the groove widths of the driving pulley 52 and the driven pulley 54 to increase or decrease the radius of rotation of the belt 56 and change the speed ratio continuously.

The driven shaft 68 of the transmission 50 is
2 through a differential mechanism 84. Differential mechanism 84
Is connected to a drive wheel 88 by an axle 86.

Thus, the clutch 32 which can electronically adjust the torque capacity is provided between the engine 4 and the transmission 50 in the transmission path of the driving force from the engine 4 to the driving wheels 88. Is provided.

The engine 4 includes an engine control device 9
0 is provided. As shown in FIG. 12, the engine control device 90 includes an intake pipe fully closing means 92 and a fuel stopping means 94.
, The clutch 32, the torque capacity adjusting means 96, and the control means 98.

The intake pipe fully closing means 92 has a throttle actuator 100 such as a motor for opening and closing the throttle valve 20. The throttle valve 20 fully closes the intake pipe 14. The fuel stopping means 94 selectively stops fuel supplied to each of the first to third cylinders 6 to 10 of the engine 4. As described above, the clutch 32 is capable of electronically adjusting the torque capacity, and is provided on a transmission path from the engine 4 to the drive wheels 88. The torque capacity adjusting means 96 adjusts the torque capacity of the clutch 32. The control means 98 controls the operation of the intake pipe fully closing means 92, the fuel stopping means 94, and the torque capacity adjusting means 96.

The control means 98 of the engine control unit 90 includes the first to third fuel injection valves 24 to 28 and the clutch 3
The second clutch solenoid 40, the hydraulic control circuit 80 of the transmission 50, and the throttle actuator 100 are connected.

The control means 98 includes a throttle opening control section 102, an engine control section 104, and a transmission control section 106.
And an engine brake control unit 108.

A throttle actuator 100 is connected to the throttle opening control unit 102. The throttle opening control unit 102 is provided with the throttle actuator 100.
And the throttle valve 20 is fully closed, and the intake pipe 14 is fully closed. Thus, the throttle opening control unit 102 constitutes the intake pipe fully closing means 92.

The first to third fuel injection valves 24 to 28 are connected to the engine control unit 104. The engine control unit 104 controls the operation of the first to third fuel injection valves 24 to 28 so as to inject and supply fuel to each of the first to third cylinders 6 to 10, and also controls the operation of each of the first to third cylinders 6 to 10. First to third fuel injection valves 24 to selectively stop the fuel supplied to
To 28 are operated and controlled. Thereby, the engine control unit 1
A fuel supply unit 110 supplies fuel to each of the first to third cylinders 6 to 10 of the engine 4, and selects fuel to be supplied to each of the first to third cylinders 6 to 10 of the engine 4. The fuel stopping means 94 is configured to stop temporarily.

The transmission control unit 106 includes a clutch solenoid 40 for the clutch 32 and a hydraulic control circuit 8 for the transmission 50.
0 is connected. The transmission control unit 106 controls the clutch solenoid 4 to adjust the torque capacity of the clutch 32.
In addition to controlling the operation of the transmission 50, the operation of the hydraulic control circuit 80 is controlled so as to adjust the gear ratio of the transmission 50. Thus, the transmission control unit 106 constitutes the torque capacity adjusting means 96 for adjusting the torque capacity of the clutch 32 and also constitutes the gear ratio adjusting means 112 for adjusting the gear ratio.

The engine brake control unit 108 is connected to a throttle opening control unit 102, an engine control unit 104, and a transmission control unit 106.

The engine brake control unit 108 includes:
A shift switch 116 for detecting a selected position of a selector lever 114 of the transmission 50;
An accelerator sensor 120 for detecting an accelerator operation amount AC corresponding to the depression amount of the engine, an engine speed sensor 122 for detecting the rotation of the crankshaft 30 as the engine speed NE, and a speed change which is the rotation of the drive shaft 58 of the transmission 50 A transmission unit input rotation speed sensor 124 for detecting a transmission input rotation speed NI, a transmission unit input rotation speed sensor 126 for detecting a transmission unit output rotation speed NV that is a rotation of the driven shaft 68 of the transmission 50 corresponding to the vehicle speed, Throttle sensor 1 for detecting the opening state of throttle valve 20 as throttle opening θ
28, a DDT switch 130 that is turned on by detecting a state in which the driver operates the accelerator pedal 118, and an air conditioner switch 132 that detects the operating state of an air conditioner (not shown).

The control means 98 controls the engine brake control unit 1 from various sensors and switches 116 and 120 to 132.
08, the engine torque is estimated based on the accelerator operation amount of the vehicle 2 and the engine speed to determine the engine braking condition. When the engine braking condition is satisfied, the intake pipe 14 is fully closed by the intake pipe full closing means 92. , The supply of fuel to some or all cylinders is stopped by the fuel stopping means 94, and the torque capacity adjusting means 96 is adjusted and controlled so as to obtain the estimated engine torque. The control is performed by the control unit 102, the engine control unit 104, the transmission control unit 106, and the engine brake control unit 108.

That is, the engine brake control reproduces the engine generated torque τ with a small amount of fuel consumption, which is the same as during normal running, so that the responsiveness of the vehicle is less likely to deteriorate as compared with the eco-run control in which the clutch is released. The deterioration of drivability is extremely small.

As shown in FIG. 9, the engine torque .tau.
Reproducible in C state and D state. The fuel consumption is smaller in the B, C, and D states in which the amount of intake air per unit time is small because the intake pipe 14 is fully closed.

The fuel consumption is proportional to the intake air amount of the engine. The intake air amount decreases as the throttle opening θ decreases, and decreases as the engine speed NE decreases. Further, the engine 4 draws air regardless of the presence or absence of fuel supply, but the air drawn into the cylinder for which fuel supply is stopped is not used for combustion.

Therefore, it is necessary to consider that the intake air amount is reduced by the amount corresponding to the cylinder in which the fuel supply is stopped. However, the amount of torque generated by combustion decreases, and the engine torque τ decreases.

Therefore, the engine speed NE is changed from NEA to NEB, NEC, and NED by controlling the clutch 32 to the release side by fully closing the intake pipe 14. Also,
Even when the supply of fuel to all the cylinders is stopped, the reproduction can be performed if the engine 4 is in a larger absorption torque state during normal running.

That is, the eco-run condition satisfying region in which the engine brake control can be performed is a region where the engine 4 is operating in the absorption torque state and the engine torque τ generated by the engine 4 in the eco-run operation can be reproduced.

FIG. 10 shows a comparison of engine brake control. The fuel saving effect during the eco-run operation is improved as the fuel supply during the eco-run operation is reduced. In FIG. 10, the fuel saving effect is # 4 → # 3 → # 2
→ Greater effects are obtained in the order of # 1. However, the eco-run driving is difficult to be performed in the order of # 4 → # 3 → # 2 → # 1.

As a result, in the case of # 1, the fuel saving effect at the time of the eco-run operation is large, but since the time of the eco-run operation is short, the fuel saving effect as a whole is small. On the other hand, in the case of # 4, the time for the eco-run operation is long, but the fuel-saving effect during the eco-run operation is small, so that the fuel-saving effect as a whole is small.

On the other hand, in the cases of # 2 and # 3, both the fuel saving effect during the eco-run operation and the time for the eco-run operation are moderate, but the overall fuel saving effect is large. The present invention realizes the states # 2 and # 3.

The engine control device 90 of this embodiment is provided with the intake pipe fully closing means 92 for fully closing the intake pipe 14 of the engine 4 as described above in order to realize the states # 2 and # 3 in FIG. And a fuel stopping means 94 for selectively stopping fuel supplied to each of the first to third cylinders 6 to 10 of the engine 4.
The transmission path from the engine 4 to the driving wheels 88 is provided with a clutch 32 capable of electronically adjusting the torque capacity, and a torque capacity adjusting means 96 for adjusting the torque capacity of the clutch 32 is provided.

The intake pipe 14 is fully closed by a throttle valve 20 already provided in the engine 4. To stop the supply of fuel to some or all cylinders, a so-called multi-injection type fuel device provided with first to third fuel injection valves 24 to 28 for each of the first to third cylinders 6 to 10 is used. Optimal. Examples of the clutch 32 capable of electronically adjusting the torque capacity include an electromagnetic powder clutch and an electromagnetic hydraulic clutch. Further, the present invention can be applied to the transmission 50 including the clutch 32 capable of electronically adjusting the torque capacity, such as a continuously variable transmission.

The intake pipe fully closing means 92 includes a control means 98.
Of the throttle valve 20 by the throttle opening control unit 102 of FIG.
Is operated to close the intake pipe 14 completely. The fuel stopping unit 94 selectively stops the fuel supplied to each of the first to third cylinders 6 to 10 by the engine control unit 104 which controls the supply of fuel by the control unit 98. The torque capacity adjusting means 96 adjusts the torque capacity by the transmission control unit 106 for controlling the operation of the clutch 32 of the control means 98.

Control means 98 together with throttle opening control section 102, engine control section 104 and transmission control section 106
Are input from the various sensors and switches 116 and 120 to 132 to the engine brake control unit 108.

The engine brake control unit 108 controls the vehicle 2
The engine braking condition is determined by estimating the engine torque based on the accelerator operation amount and the engine rotation speed. When the engine braking condition is satisfied, the intake pipe full closing means 92 fully closes the intake pipe 14 and the fuel stopping means 94
To stop supplying fuel to some or all cylinders,
Further, the torque capacity adjusting means 96 is adjusted and controlled so as to obtain the estimated engine torque.

A sufficient fuel saving effect can be obtained by using only the states # 2 and # 3 in FIG.
By combining with the states of # 1 and # 4, a further fuel saving effect can be obtained. Engine control device 9 of this embodiment
0 is implemented by combining the states of # 1 to # 4 in FIG.

Next, the operation of the engine control device 90 will be described.

In FIG. 1, when the control program is started in FIG. 1 (step 202), the control means 98 determines whether or not an engine braking condition is satisfied (step 20).
4).

Whether or not the engine brake condition is satisfied in this determination (step 204) is made based on the flowchart shown in FIG.

In FIG. 3, when the program for determining the engine braking condition is started (step 302),
It is determined whether the transmission unit input rotation speed NI is equal to or higher than the transmission unit input rotation speed trigger NITR (step 304).

If this determination (step 304) is YES (N
If I ≧ NITR), it is determined whether the control mode is the drive mode DRV (step 306).

If the determination (step 306) is YES (drive mode DRV), the engine torque τ is estimated (step 308). As shown in FIG. 5, the estimation of the engine torque τ is performed based on the transmission input speed NI, which is the clutch output speed, using the accelerator operation amount AC as a parameter.

The reason for using the transmission input speed NI, which is the clutch output speed, instead of the engine speed NE for estimating the engine torque τ is that the engine speed NE during engine brake control is different from that during normal running. This is because the value is in accordance with the engine brake control.

From the obtained engine torque τ, the engine 4
Determines whether or not it is in the absorption torque state (step 3
10).

If the determination (step 310) is YES (absorbed torque state), the engine braking condition is satisfied (step 312), and the process ends (step 314).

On the other hand, if the judgment (step 304) is NO
If (NI <NITR), the determination is made (step 30).
If 6) is NO (non-drive mode DRV), and if the determination (step 310) is NO (non-absorbing torque state), it is determined whether engine braking conditions are satisfied (step 316).

If the determination (step 316) is YES (the engine brake condition is satisfied), a control mode other than the drive mode DRV is set (step 318).
It is determined that the engine brake condition is not satisfied (step 320),
The process ends (step 314).

If the judgment (step 316) is NO (the engine brake condition is not satisfied), it is determined that the engine brake condition is not satisfied (step 320) and the process is terminated (step 314).

When the flowchart shown in FIG. 3 ends,
Returning to the flowchart shown in FIG.

In the determination (step 204), if the engine brake condition is satisfied and the result is YES, the intake pipe 14 is completely closed by the intake pipe full closing means 92 (step 20).
6), the engine torque τ is estimated as shown in FIG. 5 (step 208), and the fuel supply stop flag register FSSR
G is determined (step 210).

Fuel supply stop flag register FSSRG
(Step 210) is performed based on the flowchart shown in FIG.

In FIG. 4, when the determination program of the fuel supply stop flag register FSSRG is started (step 402), it is determined whether the engine torque τ is less than or greater than the first engine torque trigger τETR1 (step 402). Step 404).

This determination (step 404) is based on τ ≧ τET
In the case of R1, the fuel supply stop flag register FSSR
The fuel supply stop 0 flag FSFLGO is put in G (step 406), and the process ends (step 418).

The determination (step 404) is that τ <τET
In the case of R1, it is determined whether the engine torque τ is less than or greater than the second engine torque trigger τETR2 (step 408).

This determination (step 408) is based on τ ≧ τET
In the case of R2, the fuel supply stop flag register FSSR
The fuel supply stop first flag FSFLG1 is set in G (step 410), and the process ends (step 418).

If the judgment (step 408) is τ <τET
In the case of R2, it is determined whether the engine torque τ is less than or greater than the third engine torque trigger τETR3 (step 412).

This determination (step 412) is based on τ ≧ τET
In the case of R3, the fuel supply stop flag register FSSR
The fuel supply stop second flag FSFLG2 is set in G (step 414), and the process ends (step 418).

The above-mentioned judgment (step 412) indicates that τ <τET
In the case of R3, the fuel supply stop flag register FSSR
The fuel supply stop third flag FSFLG3 is set in G (step 416), and the process ends (step 418).

When the flowchart shown in FIG. 4 ends,
Returning to the flowchart shown in FIG.

In the above judgment (step 210), if the fuel supply stop flag register FSSRG is the fuel supply stop 0 flag FSFLGO, all the cylinders (first
To the third cylinders 6 to 10) (step 212), and as shown in FIG. 6, the target engine rotation is determined from the absolute value ABS of the engine torque τ using the fuel supply stop 0 flag FSFLGO as a parameter. Speed NES
P is set (step 214), and as shown in FIGS. 7 and 8, the closing control is performed to adjust the torque capacity of the clutch 32 (step 216), and the process ends (step 218).

In the determination (step 210), when the fuel supply stop flag register FSSRG is the first fuel supply stop flag FSFLG1, the supply of fuel to one cylinder (for example, the first cylinder 6) is stopped. As shown in FIG. 6, the target engine speed NESP is determined from the absolute value ABS of the engine torque τ using the first fuel supply stop flag FSFLG1 as a parameter as shown in FIG.
Is set (step 222), and as shown in FIGS. 7 and 8,
The closing control is performed to adjust the torque capacity of the clutch 32 (step 216), and the process ends (step 218).

In the above judgment (step 210), when the fuel supply stop flag register FSSRG is the fuel supply stop second flag FSFLG2, the fuel is supplied to two cylinders (for example, the first and second cylinders 6.8). Control is performed to stop the supply (step 224), and as shown in FIG. 6, the target engine rotational speed NESP is set from the absolute value ABS of the engine torque τ using the second fuel supply stop flag FSFLG2 as a parameter (step 226). 7. As shown in FIG. 8, close control is performed so as to adjust the torque capacity of the clutch 32 (step 216), and the process is terminated (step 21).
8).

In the determination (step 210), when the fuel supply stop flag register FSSRG is the fuel supply stop third flag FSFLG3, all the cylinders (first
To the third cylinders 6 to 10) (step 228), and as shown in FIG. 6, the target engine is determined from the absolute value ABS of the engine torque τ using the fuel supply stop third flag FSFLG3 as a parameter. Rotation speed NE
SP is set (step 230), and as shown in FIGS. 7 and 8, the closing control is performed so as to adjust the torque capacity of the clutch 32 (step 216), and the process ends (step 218).

In the above judgment (step 204), if the engine brake condition is not satisfied and the judgment is NO,
As shown in FIG. 13, the throttle opening .theta.
The normal air flow rate is adjusted so that the target throttle opening degree θ _SP = AC according to C (step 232), and the fuel supply stop flag register FSSRG is set to 0 (step 2).
34), normal fuel supply control is performed to all cylinders (first to third cylinders 6 to 10) (step 236), clutch 32 is controlled normally (step 238), and the process ends (step 218).

The adjustment of the torque capacity of the clutch 32 is as follows.
This is performed as shown in FIGS. In FIG. 7, the engine torque τ is estimated from the accelerator operation amount AC (throttle opening θ) and the transmission unit input rotational speed NI (502), and the absolute value processing is performed to obtain the absolute value of the engine torque (50).
4).

From this absolute value, the clutch operation amount is estimated as shown in FIG. 8 (506), and the filter processing is performed (50).
8). Further, a target engine speed NESP is set from this absolute value as shown in FIG. 6 (510), and the target engine speed NESP is filtered to obtain a filtered target engine speed NESPF (512).

Target engine speed N after filtering
The difference between the ESPF and the actual engine speed NE is calculated (514), and the value obtained by this calculation is proportionally integrated (516). In the integration section of the proportional integration control, a limiter process is performed based on the upper limit value c and the lower limit value d.

The sum of the value obtained by the filter processing (508) and the value obtained by the proportional integral control (516) is calculated (518), and the value obtained by this calculation is set to the upper limit a and the lower limit a. A limiter process is performed using the value b (52
0).

The value obtained in the limiter process (520) is output to the clutch solenoid 40 as a clutch operation amount. The torque capacity of the clutch 32 is adjusted by a clutch solenoid 40 whose operation is controlled in accordance with the clutch operation amount.

As shown in FIG. 2, the engine control device 90 estimates the engine torque based on the accelerator operation amount of the vehicle 2 and the engine rotation speed to determine the engine braking condition, and determines the engine braking condition. When the brake condition is satisfied, the intake pipe 14 is fully closed by the intake pipe full closing means 92, the supply of fuel to some or all cylinders is stopped by the fuel stopping means 94, and the estimated engine torque is reduced. The torque capacity adjusting means 96 is adjusted and controlled so as to obtain.

As a result, the engine control device 90 can realize the same engine-generated torque as during normal running with low fuel consumption during the eco-run operation by completely closing the intake pipe 14 and stopping the supply of fuel. The engine braking effect can be obtained by connecting the clutch 32 while suppressing the pressure.

For this reason, the engine control device 90
It is possible to realize an opportunity to establish sufficient eco-run conditions and a fuel-saving effect by sufficient eco-run driving, and to achieve both fuel-saving characteristics and good drivability.

The engine control device 90 can be implemented by a small change in the device and a change in the program of the control means 98, and can be applied to any type of transmission having a clutch capable of electronically adjusting the torque capacity. It can be adopted and is practically advantageous.

The intake pipe fully closing means 92 of this embodiment
Moves the throttle valve 20 to the throttle actuator 10
Although the fully closed operation is performed by 0, it may be configured as shown in FIGS.

In FIG. 14, reference numeral 134 denotes intake pipe fully closing means. The intake pipe fully closing means 134 is provided with a fully closed valve 136 in the intake passage 18 in series with the throttle valve 20 and downstream of the inlet of the idle bypass passage 22, and a fully closed solenoid that operates the fully closed valve 136. 138 are provided. The operation of the fully closed solenoid 138 is controlled by the control means 98.

As shown in FIG. 15, when the engine braking condition is satisfied, the control means 98 fully closes the intake valve 14 by fully closing the fully closing valve 136 by the fully closing solenoid 138, as shown in FIG. Is not established, the fully closed valve 136 is fully opened by the fully closed solenoid 138, and the intake pipe 14 is fully opened. At this time, the air flow rate is adjusted to an air flow rate according to the accelerator operation amount AC.

The throttle valve 20 is mechanically connected to an accelerator pedal 118.
The opening / closing operation is directly performed by the stepping operation of No. 8. Therefore, the intake pipe fully closing means 134 can cope with the case where the throttle valve 20 is directly mechanically opened / closed by the accelerator operation amount AC due to the depression operation of the accelerator pedal 118, and the engine brake control. During this operation, the air flow rate to the engine 4 can be controlled irrespective of the throttle opening state of the throttle valve 20.

[0093]

As described above, according to the present invention, the engine torque is estimated based on the accelerator operation amount of the vehicle and the engine rotation speed to determine the engine braking condition. When the engine braking condition is satisfied, the intake pipe is fully closed. Means to fully close the intake pipe, stop fuel supply to some or all cylinders by fuel stopping means, and adjust and control the torque capacity adjusting means to obtain the estimated engine torque. During eco-run operation by fully closing the intake pipe and stopping the supply of fuel, the same engine generated torque as during normal running can be realized with less fuel consumption, and the engine braking effect is obtained by connecting the clutch while suppressing fuel consumption. be able to.

Therefore, the engine control apparatus can realize a sufficient opportunity to satisfy the eco-run condition and a fuel-saving effect by a sufficient eco-run operation, and can achieve both a fuel-saving characteristic and good drivability. In addition, this engine control device can be implemented by making small changes to the device for eco-run control and changing the program of the control means, and is used in all types of transmissions equipped with a clutch capable of electronically adjusting the torque capacity. It is practically advantageous.

[Brief description of the drawings]

FIG. 1 is a flowchart of engine brake control.

FIG. 2 is a time chart of engine brake control.

FIG. 3 is a flowchart for determining an engine braking condition.

FIG. 4 is a flowchart of setting a fuel supply stop flag.

FIG. 5 is a diagram showing estimation of engine torque.

FIG. 6 is a diagram showing setting of a target engine speed.

FIG. 7 is a block diagram of clutch control during engine brake control.

FIG. 8 is a diagram illustrating estimation of a clutch operation amount.

FIG. 9 is a diagram illustrating engine brake control.

FIG. 10 is a diagram showing a comparison of engine brake control.

FIG. 11 is a schematic configuration diagram of a vehicle.

FIG. 12 is a schematic configuration diagram of an engine control device.

FIG. 13 is a view for explaining air flow control by the intake pipe fully closing means shown in FIG. 12;

FIG. 14 is a schematic configuration diagram showing another embodiment of the intake pipe fully closing means.

FIG. 15 is a view for explaining air flow control by the intake pipe fully closing means shown in FIG. 14;

[Explanation of symbols]

 2 Vehicle 4 Engine 6 First cylinder 8 Second cylinder 10 Third cylinder 14 Intake pipe 16 Intake manifold 18 Intake passage 20 Throttle valve 22 Idle bypass passage 24 First fuel injection valve 26 Second fuel injection valve 28 Third fuel injection Valve 32 Clutch 40 Clutch solenoid 50 Transmission 80 Hydraulic control circuit 88 Driving wheel 90 Engine control device 92 Intake pipe fully closing means 94 Fuel stopping means 96 Torque capacity adjusting means 98 Control means 100 Throttle actuator

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI F02D 29/00 F02D 29/00 H 29/02 341 29/02 341 41/12 330 41/12 330J 330M F16D 48/02 F16D 25 / 14 640H (56) References JP-A-8-67174 (JP, A) JP-A-3-61726 (JP, A) JP-A-62-1199540 (JP, A) JP-A-5-172162 (JP, A A) JP-A-61-211536 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60K 41/00-41/18 F02D 9/02 315 F02D 17/02 F02D 29/00 -29/02 F02D 41/12 F16D 48/02

Claims (2)

(57) [Claims] An intake pipe for completely closing an intake pipe of an engine mounted on a vehicle; a fuel stopping means for selectively stopping fuel supplied to each cylinder of the engine; electronically providing an adjustable clutch torque capacity transmission path from the engine to the drive wheels of the vehicle, the torque capacity adjusting means for adjusting the torque capacity of the clutch is provided, the accelerator operation amount of the vehicle and the engine rotational speed Estimate engine torque by <br/> to determine engine braking conditions
Was determined, the engine that has been stopped the supply of fuel to some cylinders or all the cylinders and the estimated by the fuel stop means while fully closed the intake pipe by the intake pipe fully closed unit during the establishment of the engine brake condition An engine control device provided with control means for adjusting and controlling the torque capacity adjusting means so as to obtain torque . 2. The engine control device according to claim 1, wherein
Set the target engine speed according to the engine torque
And the actual engine control apparatus according to claim 1, the engine rotational speed and adjusting controls so that the torque capacity adjustment means matches the target engine rotational speed.