JP3331773B2 - 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 capable of realizing an operation for reducing fuel consumption without being affected by running resistance and capable of sufficiently reducing fuel consumption. It relates to a control device.

[0002]

2. Description of the Related Art In a vehicle, a transmission is interposed in a power transmission system between an engine and wheels because the engine is not suitable when the characteristics of the engine remain unchanged.

[0003] In the engine of this vehicle, in order to perform a so-called eco-run operation in order to reduce the fuel consumption, the engine is automatically stopped when a predetermined operation determination condition is satisfied during traveling. Some systems include an engine stop / start device for starting control.

[0004] For example, there is an engine stop / start device provided in an engine connected to a transmission provided with a clutch. In such an engine stop / start system, as a method of determining a state for performing the eco-run operation, first, a method of connecting the clutch and stopping fuel supply when the throttle is fully closed, and second, a method of determining whether the throttle is fully closed. The third method is to release the clutch at the time and prepare for stopping the vehicle at a low vehicle speed. Thirdly, perform the eco-run operation by determining the driver's intention to decelerate the vehicle from the throttle opening and the deceleration of the vehicle at the time of deceleration during the deceleration operation. Fourth, there is a method in which the throttle opening and the deceleration of the vehicle with respect to the vehicle speed at the time of constant speed running determine the driver's intention to drive at a constant speed, and the vehicle is driven for eco-run.

[0005] Further, as such an engine automatic stop / start device, for example, Japanese Patent Application Laid-Open No. 4-246252,
It is disclosed in JP-A-4-358729 and JP-A-5-1592. Japanese Patent Laying-Open No. 4-246252 discloses a system in which, when an accelerator pedal is depressed while the engine is stopped, a starter is operated and a restart of the engine is automatically performed when predetermined starting conditions are satisfied. is there. Japanese Unexamined Patent Publication No. 4-358729 discloses a case in which a condition that a predetermined time has elapsed since the engine was stopped, a condition that the transmission is in a neutral state, and a condition that the vehicle is stopped are satisfied while the engine is stopped. , The engine is automatically restarted. Japanese Patent Laid-Open No. 5-
According to the technology disclosed in Japanese Patent No. 1592, stop conditions are satisfied when the vehicle is stopped while the engine is running, when the clutch pedal is in a depressing operation state that is less than a predetermined value, and when the electric device is de-energized. If so, control is performed to stop the engine, and if the start condition that the clutch pedal is more than a predetermined depression state is satisfied after the stop of the engine due to satisfaction of the stop condition, control is performed to start the engine, If the prohibition condition that the vehicle does not continue at or above the set vehicle speed for a predetermined time or more after the start of the engine by the satisfaction of the start condition is satisfied, the stop of the engine by the satisfaction of the stop condition is prohibited.

[0006]

However, conventionally, in the operation for reducing the fuel consumption, that is, the so-called eco-run operation, the running resistance is loaded during the deceleration running or the constant speed running which is the third and fourth methods described above. In order to set the trigger value of the throttle opening with respect to the vehicle speed in accordance with the road characteristics, it was impossible to adapt to the change in the running resistance.

The running resistance is affected by the gradient of the road surface, a change in the coefficient of friction, a wind strength, a change in vehicle characteristics, and the like. For this reason, at the time of the above-mentioned deceleration driving or constant speed driving,
In many cases, the load / load characteristics are not the same.

Further, even if the condition of the throttle opening is satisfied, if the deceleration condition of the vehicle is not satisfied, the eco-run operation is not performed, so that a high-performance vehicle speed sensor is required for detecting the vehicle speed. .

As a result, in the conventional method of eco-run driving, during deceleration driving or constant-speed driving, the eco-run driving is performed.
The inconvenience is that the vehicle is affected by the running resistance, the driving time is reduced, the fuel consumption cannot be sufficiently reduced, the driving performance is reduced, and the cost is increased due to the need for expensive sensors. was there.

[0010]

SUMMARY OF THE INVENTION In order to eliminate the above-mentioned disadvantages, the present invention provides an engine mounted on a vehicle connected to a transmission provided with a startable clutch that can be connected and released. An engine stop / start device for stopping and starting the engine is provided, and a condition in which the engine generated torque is zero is used as a determination condition.If the determination condition is satisfied, the engine is stopped and the start clutch is released to perform eco-run operation, As a result of estimating the state of the engine speed during the eco-run operation and comparing the estimated engine speed with the input speed of the transmission unit for exiting the eco-run, the judgment condition that the engine generated torque deviates from the zero state is obtained. A control means for automatically starting the engine when the condition is not established and connecting the starting clutch is provided.

[0011]

According to the structure of the present invention, the control means sets the condition that the torque generated by the engine is zero as a determination condition, and when the determination condition is satisfied, stops the engine and releases the starting clutch to perform the eco-run operation. As a result of estimating the state of the engine speed during this eco-run operation and comparing the estimated engine speed with the input speed of the transmission unit for exiting the eco-run, a determination condition that the engine generated torque deviates from zero is obtained. If not, the engine is automatically started and the starting clutch is connected. As a result, it is possible to realize the operation for reducing the fuel consumption without being affected by the running resistance, and also to increase the operation time to sufficiently reduce the fuel consumption and further improve the driving performance. Can be.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention; 1 to 8 show an embodiment of the present invention. 8, reference numeral 2 denotes an engine mounted on a vehicle (not shown), 4 denotes a control device of the engine 2, 6 denotes an intake manifold, 8 denotes an intake passage, 10 denotes a fuel injection valve, 12 denotes a throttle valve, and 14 denotes an air cleaner. , 16
Is a starter. A transmission (continuously variable transmission: CVT) (so-called continuously variable transmission) 20 having a transmission section 18 is continuously provided with the engine 2. The transmission 20 includes a driving pulley 22, a driven pulley 24, and a belt 26 wound around the driving pulley 22 and the driven pulley 24.

The drive pulley 22 includes a drive shaft 28 and a drive-side fixed pulley piece 3 provided integrally with the drive shaft 28.
0, and a drive-side movable pulley portion 32 provided on the drive shaft 28 so as to be movable in the axial direction and not to rotate.

The driven pulley 24 includes a driven shaft 34 disposed substantially parallel to the drive shaft 28, a driven fixed pulley piece 36 provided integrally with the driven shaft 34, and the driven shaft 3.
4 has a driven-side movable pulley portion 38 provided so as to be movable in the axial direction and not to rotate.

The crankshaft 40 of the engine 2 and the transmission 20
The startable clutch 4 that can be connected and released between the drive shafts 28
2 are provided. Further, the engine 2 is provided with an engine stop / start device 44 as shown in FIG. The engine stop / start device 44 automatically stops and starts the engine 2 by the control means 46 when predetermined stop conditions and start conditions are satisfied.

That is, in the engine stop / start device 44, the control means 46 comprises an engine stop / start unit 48 and an engine control unit 50, and the engine stop / start unit 48 transmits an engine stop request signal to the engine control unit. Output to the fuel injection valve 1
0, the fuel supply to the engine 2 is stopped, and an ignition control signal is output to the ignition plug 52. On the other hand, when the engine stop / start unit 48 outputs a start signal to the starter 16, the starter 16 operates. The engine 2 starts.

More specifically, in the engine stop / start device 44, as shown in FIG. 7, during normal operation of the engine 2, an engine stop request signal is not output, and the fuel injection valve 10 and the spark plug 52 are turned off. The engine 2 is normally controlled to operate normally, and the starter 16 is stopped. While the engine 2 is stopped, the engine stop request signal is output, the operation of the fuel injection valve 10 and the spark plug 52 is stopped, and the starter 16 is stopped. Further, when the engine 2 is started, it is time to escape from the operation for reducing the fuel consumption, without outputting the engine stop request signal, and operating the fuel injection valve 10 and the spark plug 52 normally to start the engine 2. Normally, the starter 16 is operated.

As shown in FIG. 8, the control means 46 includes:
On the output side, an engine stopping device 54 for stopping the operation of the fuel injection valve 10, an engine starting device 56 for operating the starter 16, a starting clutch device 58 for connecting and releasing the starting clutch 42 , Transmission section 18
And a speed ratio adjusting device 60 for adjusting the speed ratio of the vehicle.

As shown in FIG. 8, the control means 46 has a throttle opening sensor 62 for detecting the throttle opening (θ) of the throttle valve 12 on the input side and an engine rotation speed (Ne), a transmission unit input rotation speed sensor 66 that detects the rotation of the drive shaft 28 of the transmission 20 as the transmission unit input rotation speed (Ni), and a driven shaft 34 of the transmission 20. A vehicle speed sensor 68 that detects the rotation of the vehicle as a vehicle speed (Nv) communicates with another sensor 70.

The control means 46 inputs various signals,
According to the required engine load, for example, the state where the engine generated torque is zero is determined according to the throttle opening, the intake pipe negative pressure amount, etc., and if the engine required torque is zero based on the required engine load, When it is determined, the engine 2 is stopped and the starting clutch 42 is released to perform the eco-run operation. Specifically, the condition for determining the eco-run operation is when the engine generated torque is zero (see FIGS. 4 and 5). When the engine-generated torque becomes zero and the conditions for eco-run operation are satisfied, the engine 2 is stopped and the starting clutch 42 is released to perform eco-run operation (step 1 in FIG. 1).
At this time, the shift control of the transmission 20 suitable for the eco-run operation is performed (step 1 in FIG. 1).
14). During the eco-run operation, the state of the engine speed (Ne) when the start clutch 42 is connected is estimated using the transmission unit input speed (Ni), and the estimated engine speed (Ne) and the eco-run speed are estimated. As a result of comparison with the escape transmission unit input rotation speed, if the condition for eco-run operation is not satisfied such that the engine generated torque deviates from zero, the engine 2 is automatically started and the starting clutch 42 is connected. (Refer to step 118 in FIG. 1), the normal shift control of the transmission 20 is performed (see step 120 in FIG. 1).

For this reason, the program of the control means 46 includes a map of the engine generated torque characteristic (see FIG. 4),
A map (see FIG. 5) of an eco-run rotation speed trigger for judging the operation for reducing the fuel consumption, that is, the so-called eco-run operation, is incorporated.

Next, the operation of this embodiment will be described with reference to the flowchart of FIG. 1 and the time chart of FIG.

When the program is started in the control means 46 (step 102), first, it is determined whether the condition for judging the eco-run operation is satisfied or not (step 10).
4).

The determination condition of the eco-run operation in step 104 is performed based on the flowchart of FIG.

That is, as shown in FIG. 3, when the program for determining the conditions for eco-run operation starts (step 20).
2) Rotation speed trigger (NiTRθ1,
NiTRθ2, NiTRθ3, NiTRθ4) are set. First, it is determined whether or not the eco-run operation is being performed based on the map of the eco-run rotation speed trigger shown in FIG. 5 (step 204).

If the answer to step 206 is NO, and if the eco-run operation is not being performed, the transmission unit input rotational speed (N
i) is compared with the first eco-run entry transmission section input rotation speed trigger (NiTRθ1) (step 208).

In step 208, Ni ≧ NiTRθ1
, The transmission unit input rotation speed (Ni) and the second eco-run entry transmission unit input rotation speed trigger (NiTRθ2)
Are compared (step 210).

In this step 210, Ni ≧ NiTRθ2
In this case, it is determined that the condition for eco-run driving is not satisfied (step 212). In step 208, Ni
In the case of <NiTRθ1, it is immediately determined that the condition for eco-run operation is not satisfied (step 212).

On the other hand, if step 206 is YES and the eco-run operation is in progress, the transmission unit input rotation speed (Ni) is compared with the first eco-run escape transmission unit input rotation speed (NiTRθ3) ( Step 214).

In step 214, Ni ≧ NiTRθ3
In the case of, the transmission unit input rotation speed (Ni) is compared with the second eco-run escape transmission unit input rotation speed (NiTRθ4) (step 216).

In step 214, Ni <NiTRθ3
In the case of (2) and in the case of Ni ≧ NiTRθ4 in the step 216, the routine proceeds to the step 212, and the judgment condition of the eco-run operation is not satisfied.

In step 216, Ni <NiTRθ4
In the case of, it is assumed that the condition for eco-run driving is satisfied (step 218). In step 210, Ni
In the case of <NiTRθ2, the process proceeds to step 218, and it is assumed that the determination condition of the eco-run operation is satisfied.

After the processing of steps 212 and 218, the program of the conditions for judging the eco-run operation is ended (step 220).

If it is determined in step 104 in FIG. 1 that the conditions for eco-run operation are satisfied, it is determined whether a predetermined time (t ₁ ) has elapsed (step 106). The predetermined time (t ₁ ) in step 106 is a trigger for the elapsed time after the eco-run driving determination condition is satisfied.

If NO in step 106, the engine 2 is stopped (step 108), that is, the operation of the fuel injection valve 10 is stopped, and the transmission 20 is controlled normally (step 110).

If YES in step 106,
As shown in FIG. 2, the engine generated torque is substantially zero (0 kg
m), the engine 2 is stopped (step 1).
12) Then, the starting clutch 42 is disengaged, and the transmission 20 is controlled for a shift suitable for the disengaged state of the starting clutch 42 (step 114).

On the other hand, if it is determined in step 104 that the condition for eco-run operation is not satisfied, it is determined whether the engine 2 has been started (step 116).

If NO in step 116, the engine 2 is started (step 118), that is, the starter 16 is operated, and the transmission 20 is controlled normally (step 120).

If YES in step 116,
The engine 2 is controlled normally (step 122), and the transmission 20 is also controlled normally (step 124).

Then, steps 110, 114, 12
After the processing of 0 and 140, the program ends (step 126).

That is, in this embodiment, the engine generated torque is 0 kgm at point a in the engine generated torque characteristic shown in FIG.
Is released, the torque of the output portion of the starting clutch 42 is 0 kgm. Therefore, the engine generated torque is 0
In the case of kgm, even if the starting clutch 42 is connected / disengaged, the torque of the output portion of the starting clutch 42 has the same value, so that the power characteristics of the vehicle are the same. Therefore, the engine running torque can be determined to be 0 kgm to realize the eco-run operation.

As shown in FIG. 5, the engine rotation speed (Ne) at which the engine generated torque is 0 kgm for each throttle opening (θ) based on the engine generated torque characteristic of FIG.
Find the characteristics of With reference to this characteristic, the input rotation speed trigger (NiTR θ1, NiTR
θ2) and an eco-run escape speed change section input rotational speed trigger (NiTRθ3, NiTRθ4) are set. The eco-run entry speed change unit input rotation speed trigger and the eco-run escape speed change unit input rotation speed trigger are provided with hysteresis in order to prevent the escape from the entry of the eco-run operation and the hunting of the entry from the escape.

Further, the condition for judging the eco-run operation is not the engine rotation speed (Ne) but the transmission unit input rotation speed (N
The reasons for the implementation of i) are as follows:
As a result of the start clutch 42 being released and the engine 2 being stopped, Ne = 0 rpm, and Ne <NiTRθ3
Holds, and the vehicle escapes from the eco-run operation. Also, when the starting clutch 42 is connected, Ne = Ni, and when the starting clutch 42 is disengaged and connected, the engine rotational speed (Ne) changes. Therefore, the transmission unit input rotation speed (Ni) is equal to the transmission unit input rotation speed (Ni).
Is used, it is possible to estimate the value of the engine rotation speed (Ne) in the connected state even when the starting clutch 42 is released.

Therefore, according to this embodiment, the eco-run operation is the engine stop system, and when the conditions for judging the eco-run operation are satisfied, the starting clutch 42 is released and the engine 2 is automatically stopped. When the vehicle escapes, the engine 2 is automatically started to realize eco-run operation without being affected by running resistance.
In addition, the operation time can be increased to sufficiently reduce the fuel consumption, and further, the operation performance can be improved.

Further, this can be dealt with only by changing the program of the control means 46, so that additional hardware is not required, the configuration is simple and the cost can be reduced.

Further, a high-performance vehicle speed sensor is not required,
An inexpensive vehicle speed sensor 68 can be used, thereby preventing an increase in cost.

Furthermore, the present invention can be applied to all transmissions having the starting clutch 42, which is practically advantageous.

It should be noted that the present invention is not limited to the above-described embodiment, and it is needless to say that various applications and modifications are possible.

For example, in the above-described embodiment, the case where the starting clutch 42 is located upstream of the transmission unit 18 has been described. However, when the starting clutch 42 is located downstream of the transmission unit 18, the vehicle speed is controlled when the starting clutch 42 is released. (Nv: Corresponding to the clutch output rotation speed) and the gear ratio (Rc), the above-described embodiment can be used as it is, simply by using the transmission unit input rotation speed (Ni) obtained by the following equation. Ni = Nv * Rc * Rg (where Rg: gear ratio)

Although the starting clutch 42 of the continuously variable transmission (CVT) is used, the starting clutch 42 may be an electronic control clutch. Examples of the electronic control clutch include an electromagnetic clutch, an electronic control hydraulic clutch, an electronic control mechanical clutch, and an electronic control pneumatic clutch.

Further, the engine control according to the present invention can be applied to an automatic transmission (A / T) and a manual transmission (M / T).

[0052]

As is apparent from the above detailed description, according to the present invention, the condition in which the torque generated by the engine is zero is used as a judgment condition, and when the judgment condition is satisfied, the engine is stopped and the starting clutch is released. During the eco-run operation, the engine rotational speed state is estimated during the eco-run operation, and the estimated engine rotational speed is compared with the input rotational speed of the transmission unit for exiting the eco-run. When such a determination condition is not satisfied, by providing a control means for automatically starting the engine and connecting the starting clutch, the operation for reducing the fuel consumption without being affected by the running resistance is realized, Further, the operation time can be increased to sufficiently reduce the fuel consumption, and further, the driving performance can be improved.

Further, the present invention can be dealt with only by changing the program of the control means, does not require additional hardware, can be simple in construction, and can be inexpensive.

Further, a high-performance sensor is not required, an inexpensive sensor can be used, and an increase in cost can be prevented.

Furthermore, the present invention can be applied to all transmissions having a clutch, which can be practically advantageous.

[Brief description of the drawings]

FIG. 1 is a flowchart of engine control.

FIG. 2 is a time chart of engine control.

FIG. 3 is a flowchart of a determination condition for eco-run driving.

FIG. 4 is a characteristic diagram of an engine generated torque.

FIG. 5 is a diagram illustrating an eco-run driving rotation speed trigger.

FIG. 6 is a system configuration diagram of a stop and start device.

FIG. 7 is a view for explaining stop and start.

FIG. 8 is a system configuration diagram of an engine control device.

[Explanation of symbols]

 Reference Signs List 2 engine 4 control device 10 fuel injection valve 12 throttle valve 16 starter 18 transmission unit 20 transmission 42 start clutch 44 stop / start device 46 control means 48 engine stop / start unit 50 engine control unit 62 throttle opening sensor 68 vehicle speed sensor

────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI F02D 29/02 321 F02D 29/02 321A F16D 48/02 F16D 25/14 640H (56) JP-A-62-238126 (JP, A) JP-A-61-287828 (JP, A) JP-A-61-278429 (JP, A) JP-A-61-287827 (JP, A) 62-68139 (JP, A) JP-A-50-90020 (JP, A) JP-A-60-161228 (JP, A) JP-A-55-140617 (JP, A) JP-A-55-136624 (JP, A) A) JP-A-61-249840 (JP, A) JP-A-59-100941 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F02D 29/00-29/06 B60K 41 / 00-41/28

Claims (2)

(57) [Claims] 1. A transmission provided with a startable clutch connectable to and disengageable from an engine mounted on a vehicle is provided in connection therewith,
An engine stop / start device for stopping and starting the engine is provided, and a condition in which the engine generated torque is zero is used as a determination condition.
When the determination condition of the above is satisfied, the engine is stopped and the starting clutch is released to perform the eco-run operation.
Estimate the engine speed during this eco-run operation
And this estimated engine rotation speed and eco-run escape
As a result of comparison with the speed
The above-mentioned judgment condition that lux deviates from zero state is not satisfied
In this case, the engine is started automatically and
An engine control device provided with control means for connecting a forward clutch . 2. The engine control device according to claim 1, wherein the control unit is a control unit that determines a state in which the engine generated torque is zero in accordance with an engine required load amount.