JPH0559982A - Engine control device for vehicle with automatic transmission in which manual mode can be selected - Google Patents

Abstract

PURPOSE:To increase an engine brake effect in manual mode and also improve fuel consumption. CONSTITUTION:When a specified shift position is selected in manual mode by a shift device 1, it is judged by a mode judgment means 3. In accordance with the judgment result, a rotational speed at which fuel is cut by a cut rotational speed set means 4 is set up. The cut rotational speed is lower than the cut rotational speed in auto-mode, and a fuel injection control means 2 makes fuel cut based on the set cut rotational speed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for controlling an engine of a vehicle equipped with an automatic transmission, and more particularly to a fuel injection of an engine in a vehicle equipped with an automatic transmission capable of selecting an automatic mode and a manual mode. It relates to a device for controlling the.

[0002]

2. Description of the Related Art As is well known, an automatic transmission for a vehicle is constructed to determine a gear stage to be set on the basis of a traveling state such as a vehicle speed and an engine load and execute a gear shift.
The shift point may be changed by changing the shift pattern such as the power pattern or the economy pattern, but in any case, basically, the shift point is changed according to the engine performance or the characteristics required for the vehicle. Decided in advance. Therefore, the automatic transmission can obtain acceleration and fuel efficiency determined at the design stage, but the degree of freedom of the driver's selection is low. Therefore, Japanese Patent Application Laid-Open No. 2-8545 proposes an automatic transmission that allows a driver to manually select a shift speed. This is a shift device provided in a normal automatic transmission with a manual shift function for outputting an upshift signal and a downshift signal added thereto. The shift lever is moved from the D range position to the manual shift position. However, here, each time the shift lever is tilted to the "+" (plus) side or the "-" (minus) side, upshifting or downshifting is performed by one step.

[0003]

By the way, recently, in order to improve the fuel efficiency of a vehicle, the fuel injection in the engine is electronically controlled, and the fuel injection is cut during coasting. Specifically, fuel injection is stopped when the throttle is fully closed and the engine speed is equal to or higher than a predetermined cut speed. Conventionally, in general, the cut rotation speed is relatively low in a vehicle equipped with an automatic transmission in order to prevent a shock and a feeling of deceleration caused by stopping fuel injection from becoming uncomfortable. It is set high.

However, if such a fuel cut control is performed by the above-described automatic transmission capable of selecting the manual mode, the fuel re-injection is performed at a relatively high rotational speed even when the manual mode is selected. Will be done. However, in the manual mode, the driver selects his or her own gear to obtain the desired acceleration performance and deceleration performance. Therefore, the deceleration feeling that is uncomfortable in the automatic mode is the expected deceleration feeling in the manual mode. Often not uncomfortable. Therefore, if the same fuel cut control as in the automatic mode is performed in the manual mode, the effect of engine braking is not necessarily sufficiently high, and there is a problem that fuel is wasted.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an engine control device capable of improving the engine braking effect in the manual mode and improving the fuel consumption.

[0006]

The present invention achieves the above object by adopting the configuration shown in FIG. That is, the present invention is directed to a shift device 1 for selecting an automatic mode in which a gear is automatically set based on a running state of a vehicle and a manual mode in which a gear selected by a manual operation is selected; Of a vehicle equipped with an automatic transmission A capable of selecting a manual mode including a fuel injection control means 2 that is stopped when the throttle opening is a predetermined value or less and the engine speed is a predetermined cut speed or more. In the engine control device, the mode determining means 3 for determining which one of the auto mode and the manual mode is selected, and the cut rotation speed when the mode determining means 3 determines that the manual mode is selected. And a cut rotation speed setting means 4 for setting the rotation speed lower than the cut rotation speed when the auto mode is selected. It is characterized in that there.

[0007]

In the present invention, the shift device 1 selects between the automatic mode and the manual mode, which are the shift modes of the automatic transmission A. The mode selected by the shift device 1 is judged by the mode judging means 3. When the mode judging means 3 judges that the manual mode is selected, the cut rotation speed setting means 4
Sets the cut speed for manual mode. The cut speed is lower than the cut speed in the automatic mode, and therefore fuel injection is stopped even in the low speed state of the engine E during coasting in the manual mode. Better and less fuel consumed.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described based on embodiments. FIG. 2 is a block diagram showing a basic configuration of one embodiment of the present invention. An engine E has an injector 11 in its intake port 10. The fuel injection amount is changed by electronically controlling the fuel injection amount. An electronic control unit (E-ECU) 12 that controls the engine E including the fuel injection amount mainly includes a calculation element (CPU), a storage element (RAM, ROM), and an input / output interface (not shown). Is something that
The electronic control unit 12 has an intake air amount, an intake air temperature,
The throttle opening θ, the engine speed Ne, the brake signal, the signal from the neutral start switch, and other signals are input. The electronic control unit 12 is configured to change the fuel cut rotation speed during coasting. The details will be described later.

In the automatic transmission A connected to the engine E, a solenoid valve (not shown) in the hydraulic control device C has an electronic control unit (A-ECU) 13 for automatic transmission.
A manual valve (not shown) by a shift device 14 controlled by a shift lever and operated by a shift lever.
Is operated to set a predetermined shift speed. As shown in FIG. 2, the shift device 14 has each range of parking (P), reverse (R), neutral (N), drive (D), second speed holding (S), first speed holding (L). The position and the manual shift position of the first speed to the fourth speed are selected by a shift lever, and the manual shift position is operated by the shift lever and signaled to the automatic transmission electronic control unit 13. Switches Sw1, Sw2, Sw3, and Sw4 for outputting are output.

The electronic control unit 13 for the automatic transmission is
Central processing element (CPU) and storage element (ROM, RA
M) and an input / output interface (not shown) as main elements, and the switch S
When a signal is input from any one of w1 and Sw4, it is determined to be the manual mode, and a shift command signal is output to the hydraulic control device C so as to set the shift speed corresponding to the selected switch, and the manual mode is set. Is output to the engine electronic control unit 12. In addition, the electronic control unit 13 for the automatic transmission
When each of the range positions is selected by the shift lever, it is determined to be in the auto mode, the gear stage to be set is determined according to the traveling state, and the gear shift command signal is output to the hydraulic control device C. At the same time, a signal indicating the automatic mode is output to the engine electronic control unit 12. Signals such as the vehicle speed V, the throttle opening θ, the brake signal, the engine water temperature, and the pattern select signal are further input to the automatic transmission electronic control unit 13.

FIG. 3 shows a train of gear trains in the above-described automatic transmission A, and is a main part of a hydraulic control system C which executes gear shifting in the automatic mode and the manual mode for the gear trains. If you show the circuit part,
It is as shown in FIG.

That is, the automatic transmission A shown in FIG. 3 includes a torque converter 21 having a lockup clutch 20.
A second speed change unit 30 having a set of planetary gear mechanisms, and a first speed change unit 40 that sets a plurality of forward speeds and reverse speeds by the two sets of planetary gear mechanisms.

The second transmission section 30 is for performing two-stage switching between high and low, and the carrier 31 of the planetary gear mechanism is connected to the turbine runner 22 of the torque converter 21. Between the sun gear 32 and the sun gear 32, a clutch C0 and a one-way clutch Fo are provided in parallel relationship with each other.
A brake B0 is provided between the housing and the housing Hu.

The sun gears 41, 42 in each planetary gear mechanism of the first transmission portion 40 are provided on a common sun gear shaft 43, and in the planetary gear mechanism on the left side (front side) in the drawing of the first transmission portion 40. Ring gear 44 and second
A first clutch C1 is provided between the gear unit 30 and the ring gear 33, and a second clutch C2 is provided between the sun gear shaft 43 and the ring gear 33 of the second gear unit 30. The carrier 45 of the planetary gear mechanism on the left side of the drawing and the ring gear 46 of the planetary gear mechanism on the right side (rear side) of the first transmission unit 40 are integrally connected, and
The output shaft 47 is attached to the carrier 45 and the ring gear 46.
Are connected.

The first brake B1 which is a band brake is provided on the outer peripheral side of the clutch drum of the second clutch C2 so as to stop the rotation of the sun gear shaft 43, more specifically, the sun gear shaft 43 and the housing. A first one-way clutch F1 and a second brake B2 are arranged in series with Hu, and a second one-way clutch F2 with a carrier 48 and a housing Hu in the planetary gear mechanism on the rear side. The third brake B3 is arranged in parallel.

The automatic transmission A having the above gear train can set the first speed to the fourth speed at the forward speed, and among these, the first speed and the second speed are in the automatic mode and the engine brake is set. Since it does not work and it is necessary to apply the engine brake in the manual mode, the hydraulic circuit shown in FIG. 4 is incorporated in the hydraulic control device C. The numbers circled in FIG. 4 indicate that the lines with the numbers are connected to each other.

The manual valve 100 switches the supply / discharge state of hydraulic pressure by moving the spool 101 by the shift device 14, and the line pressure P regulated by a primary regulator valve (not shown).
A line pressure oil passage 60 for supplying L is connected to the input port 102, and in the D range, the spool 101 is at the position shown in the figure so that the input port 102 communicates with the D port 103. In the S range, spool 10
1 moves to the lower side of the figure and the input port 102 is the D port 1
03 and S port 104, in the L range, the spool 101 moves further downward so that the input port 102 communicates with the D port 103, the S port 104 and the L port 105, and vice versa. Then, spool 101 closes input port 102, and in R range, input port 10
2 communicates with the R port 106, closes the input port 102 in the P range, and communicates other ports with the drain port.

The 1-2 shift valve 200 for shifting between the first speed and the second speed is a spool 2 having four lands.
01 and a spring 202 arranged at one end thereof, the control port 203 formed at the end opposite to the spring 202 is connected to the second solenoid valve S2, and when the second solenoid valve S2 is OFF. From the line pressure oil passage 61 to the strainer 62 and the orifice 63.
The line pressure PL supplied through the control port 203 is generated at the control port 203. Below the control port 203 in the drawing, a second coast port 204 that is opened and closed by the uppermost land, and a first brake port 206 that is selectively communicated with the second coast port 204 and the drain port 205 are sequentially arranged. The second coast modulator valve 64 is formed on the first brake port 206.
The first brake B1 is connected via. The manual valve 1 is located below the drain port 205 in the figure.
A D port 207 connected to the D port 103 of 00 is formed, and this D port 207 and another drain port 2
Second brake port 209 selectively connected to 08
The second brake B2 is connected to. Further another drain port 2 below the other drain port 208 in the drawing.
10 is formed, and the third brake B3 is connected to the third brake port 212 that selectively communicates with the drain port 210 and the low coast port 211. A hold port 213 is formed at the lowermost end where the spring 202 is arranged.

A 2-3 shift valve 300 for shifting between the second speed and the third speed has a spool 301 having six lands, and a spring 302 arranged at one end (lower end in the figure) of the spool 301. And a control port 303 formed at the end opposite to the spring 302 is connected to the first solenoid valve S1.
At the time of FF, the line pressure PL supplied from the D port 103 of the manual valve 100 through the strainer 65 and the orifice 66 is generated at the control port 303. This 2-3 shift valve 300 has
A first drain port 304, a brake port 305, and a first D port 306 are formed in order from the top of the figure, and the brake port 305 is the 1-2 shift valve 200.
This brake port 305 is connected to the second coast port 204 of the first drain port 30.
4 and the first D port 306 are selectively connected. Continuing with the above ports, hold output port 307, input port 308, clutch port 309,
The second drain port 310 is formed in order, and when the first drain port 304 and the brake port 305 communicate with each other, the first D port 306 and the hold output port 307, and the input port 308 and the clutch port 309 are respectively formed. When the brake port 305 communicates with the first D port 306, the hold output port 30
7 and the input port 308, and the clutch port 309 and the second drain port 310 communicate with each other. Further, a brake port 311 and a second D port 312 are sequentially formed following the second drain port 310, and when the clutch port 309 communicates with the input port 308, the second drain port 310 communicates with the brake port 311. On the contrary, when the clutch port 309 communicates with the second drain port 310, the brake port 311 and the second D port 312 communicate with each other. Furthermore, a hold port 313 is formed at the lowermost end where the spring 302 is arranged. The second clutch C2 is connected to the clutch port 309, while the hold port 213 of the 1-2 shift valve 200 and the clutch port 309 are connected. Further, the brake port 311 is connected to the low coast port 211 of the 1-2 shift valve 200 via the low coast modulator valve 67. Further, the hold port 313 is connected to the L port 105 of the manual valve 100, and in the L range, the spool 301 is held at the pushed up position as shown in the right half of the figure.

The 3-4 shift valve 400 is controlled by the hydraulic pressure sent from the second solenoid valve S2 and the hold output port 307 of the 2-3 shift valve 300,
The second gear shifting unit 30 is configured to carry out gear shifting, and includes a spool 401 having four lands formed therein and a spring 402 arranged at one end thereof, and an end opposite to the spring 402. Control port 4 formed on
03 is connected to the second solenoid valve S2 similarly to the control port 203 of the 1-2 shift valve 200 described above, and the hold port 404 formed at the end where the spring 402 is arranged has a 2-3 shift. It is connected to the hold output port 307 of the valve 300. This 3-4 shift valve 400 has an input port 405 connected to the line pressure oil passage 61 when the second solenoid valve S2 is OFF and the line pressure PL is acting on the control port 403. , The brake B0 is connected to the connected brake port 406, and conversely, when the pressure is discharged from the control port 403 or when the hydraulic pressure acts on the hold port 404, the input port 4
05 is the clutch port 4 to which the clutch C0 is connected
It is designed to communicate with 07.

A first clutch C1 is connected to the D port 103 of the manual valve 100, and an oil passage extending from the first clutch C1 to the first and second D ports 306 and 312 of the 2-3 shift valve 300. In the middle of 68, in order to apply the engine braking in the first speed and the second speed in the manual mode, in other words, the coast for preventing the engine braking in the first speed and the second speed in the automatic mode. A brake cutoff valve 500 is provided. This selectively connects the clutch port 501 connected to the first clutch C1 and the brake port 502 connected to the first and second D ports 306 and 312 of the 2-3 shift valve 300. In addition, the hold port 505 which has the spool 504 which is pressed in one direction by the spring 503 and which is formed at the end portion where the spring 503 is arranged is connected to the S port 104 of the manual valve 100. A control port 506 formed at the opposite end is connected to the third solenoid valve S3. The third sonoid valve S3 connects the first clutch C1 and the control port 506 to the strainer 69 and the orifice 70.
Is connected to the oil passage 71, and the drain port is closed in the OFF state, and the line pressure P is applied to the control port 506.
When L is generated, the drain port is opened in the ON state to exhaust the pressure from the control port 506.

The above solenoid valves S1, S2, S
Since 3 is turned on or off as shown in FIG. 5, in the 1-2 shift valve 200, the spool 201 is pushed down as shown in the right half at the first speed, and at other forward speeds, the spool 201 is not shown. In the 2-3 shift valve 300, the spool 301 is pushed up in the first and second gears as shown in the right half of the figure, and in the third and fourth gears, the spool 301 is pushed up. 301
Is pushed down as shown in the left half of the figure, and in the 3-4 shift valve 400, the spool 401 is pushed up as shown in the right half of the figure in the first to third speeds, and left in the figure in the fourth speed. Pushed down as shown in half. as a result,
As shown in FIG. 5, each friction engagement device is engaged or released to set each gear.

FIG. 5 is an operation table. The circles indicate ON for solenoid valves, the friction engagement devices indicate engagement, and the crosses indicate OF for solenoid valves.
F, the friction engagement device indicates release.

Next, the operation will be described. When the shift lever of the shift device 14 is moved from the D range position to one of the manual shift positions, the switches Sw1 to Sw4 provided at the manual shift position operate to output a signal. Then, based on the signal, the predetermined solenoid valves S1 and S2 are turned on or off, and the selected shift speed is set. If the selected gear is the first speed or the second speed, the third solenoid valve S3 is turned on, so that the coast brake cutoff valve 500 is exhausted from its control port 506, and as a result, the spool 504. Is pushed up to the position shown in the left half of FIG.
And the brake port 502 communicate with each other. Therefore 2-3
Since the line pressure PL is supplied to the D ports 306 and 312 of the shift valve 300, in the case of the first speed, the second D
Port 312, brake port 311, low coast modulator valve 67, 1-2 shift valve 200
The hydraulic pressure is supplied to the third brake B3 through the low coast port 211 and the third brake port 212, and the third brake B3 is engaged. In the case of the second speed, the first D port 3
06, brake port 305 and 1-2 shift valve 2
Hydraulic pressure is supplied to the first brake B1 via the second coast port 204 of 00, the second brake port 206, and the second coast modulator valve 64, and the first brake B1 is engaged therewith. That is, in manual mode, the third
The engine braking is effective not only in the first speed and the fourth speed but also in the first speed and the second speed where the engine braking does not work in the automatic mode.

The engine electronic control unit 1 described above
In No. 2, the fuel injection from the injector 11 is stopped during coasting with the throttle valve fully closed, but the engine speed at which fuel injection is stopped (fuel cut) is changed between the automatic mode and the manual mode.

FIG. 6 is a flow chart showing a control routine for changing the engine speed (fuel cut speed) for fuel cut.
Input processing of various signals such as vehicle speed V, throttle opening θ, and manual mode signal is performed. Then, in step 2, it is judged whether the D range or not. If the judgment result is "yes", then it is judged whether the manual mode is selected. These judgments in step 1 and step 2 are made based on whether the shift lever in the shift device 14 is in the D range position and a predetermined switch is ON.
Alternatively, it can be determined by whether or not any one of the switches Sw1 to Sw4 provided at the manual shift position is ON. If the result of the determination in step 2 is "yes", the process proceeds to step 4 and it is determined whether or not the selected shift pattern is the power (P) pattern. This is because when a P pattern that requires high acceleration and a large engine braking force is selected, fuel cut is performed so that the engine braking effect meets the request. If the determination result in step 4 is "yes", the process proceeds to step 5 and it is determined whether or not the hydraulic pressure for applying the engine brake can be controlled. That is, if the fuel cut is performed, the engine braking force is increased, but if the timing of supplying the hydraulic pressure to the friction engagement devices (B1, B2) for the engine brake or the pressure thereof cannot be controlled, the shock caused by the fuel cut and the engine braking This is because shocks due to improper control of supply of hydraulic pressure and pressure may be overlapped and the riding comfort may be impaired.

Then, the judgment result of step 5 is "yes".
If so, in step 6, the fuel cut speed Nc is set to Nc1.

On the other hand, if the hydraulic pressure supplied to the frictional engagement devices (B1, B2) for engine braking cannot be controlled, the result of step 5 is "NO". Next, set the fuel cut speed Nc to Nc3 (> Nc1).

On the other hand, if the result of the determination process in any of steps 2 to 4 is "no", the process proceeds to step 8 and the fuel cut speed Nc is set to Nc2.
Set to (Nc1 <Nc2 <Nc3). FIG. 7 is a diagram showing the relationship between these fuel cut rotational speeds Nc1, Nc2, Nc3.

The engine electronic control unit 12 performs fuel cut during coasting based on the fuel cut rotation speed set as described above. FIG. 8 is a flowchart showing the control routine. In step 10, it is judged whether or not the throttle is fully closed. If the result is "yes", in step 11, the engine speed Ne is the fuel cut speed Nc. It is determined whether or not the above. The value of this fuel cut rotation speed is a value determined by the above control. If the determination result is "yes", the fuel cut is immediately performed (step 12). That is, the injection of fuel by the injector 11 is stopped.

On the other hand, if the engine speed Ne is lower than the fuel cut speed Nc and the result of the judgment in step 11 is "No", the routine proceeds to step 13 to judge whether or not the fuel cut is being executed. If the result of the judgment is "yes", the routine proceeds to step 14 where it is judged if the engine speed Ne is below the injection restart speed NR.
The injection restart speed NR may be substantially the same as the fuel cut speed Nc, but is set to a predetermined value in order to prevent frequent fuel injection and stop near the fuel cut speed Nc. It is preferable to set the hysteresis rotational speed α to a rotational speed that is subtracted from the fuel cut rotational speed Nc. Alternatively, the injection restart speed NR may be the lowest speed within the range where the engine does not stall. If the determination result in step 14 is "NO", it means that the fuel cut is being executed and the injection restart speed NR has not yet been reached. Therefore, the routine proceeds to step 12, and the fuel cut is continued.

The judgment result of step 10 is "no".
If so, the vehicle is not in the coasting state, so the routine proceeds to step 15 and normal fuel injection is performed. Step 13
If the result of the determination is "No", it means that the engine speed Ne is lower than the fuel cut speed Nc and the fuel is being injected.
Continue to inject fuel. If the result of the determination in step 14 is "yes", it means that the engine speed Ne is lower than the injection restart speed NR. Therefore, the process proceeds to step 15 to inject fuel.

That is, in the above-described control device, the fuel cut speed Nc in the auto mode is Nc2, but during coasting in the manual mode, even if the engine speed Nc1 is lower than that during coasting in the auto mode, the fuel cut is performed. I do. Therefore, according to the control device described above, the engine braking effect in the manual mode is improved, and the fuel consumption is improved. Further, during coasting in a state where the hydraulic pressure for engine braking cannot be controlled, the fuel cut is performed at the highest rotation speed Nc3 or higher, so that it is possible to prevent the occurrence of a shock that gives a driver discomfort.

The present invention is not limited to the above-described embodiment, and an automatic transmission having a gear train other than the gear train shown in FIG. 3 and a hydraulic circuit other than the hydraulic circuit shown in FIG. 4 is connected. It can also be applied to a control device that targets the engine.

[0035]

As described above, according to the control device of the present invention, when the shift mode of the automatic transmission is set to the manual mode, the engine rotation speed at which the fuel injection is stopped during coasting is set to the automatic mode. Since it is lower than the case, the engine braking effect in the manual mode is improved, and at the same time, the fuel consumption can be improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing a basic configuration of the present invention.

FIG. 2 is a block diagram showing an embodiment of the present invention.

FIG. 3 is a skeleton diagram showing an example of a gear train.

FIG. 4 is a hydraulic circuit diagram showing a part of the hydraulic system.

FIG. 5 is an operation table.

FIG. 6 is a diagram showing a comparison of respective fuel cut rotation speeds.

FIG. 7 is a flowchart showing a control routine for changing a fuel cut rotation speed according to a shift mode.

FIG. 8 is a flowchart showing a fuel cut control routine.

[Explanation of symbols]

 1 shift device 2 fuel injection control means 3 mode determination means 4 cut speed setting means A automatic transmission E engine

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuo Hojo, 1 Toyota Town, Toyota City, Aichi Prefecture, Toyota Motor Corporation (72) Inventor, Takayuki Okada, 1 Toyota Town, Aichi Prefecture, Toyota Motor Corporation ( 72) Inventor Takeshi Inuzuka, Takane Fujii-cho, Anjo City, Aichi Prefecture, Aisin A / Daburiyu Co., Ltd.

Claims (1)

[Claims] 1. A shift device for selecting an automatic mode for automatically setting a shift speed based on a running state of a vehicle and a manual mode for setting a shift speed selected by a manual operation, and a fuel injection for an engine, In an engine control device for a vehicle having an automatic transmission capable of selecting a manual mode, which includes fuel injection control means for stopping when a throttle opening is a predetermined value or less and an engine speed is a predetermined cut speed or more. The mode determining means for determining the mode selected from the auto mode and the manual mode, and the cut rotation speed when the manual mode is determined by the mode determining means is selected by the auto mode. And a cut rotation speed setting means for setting the rotation speed to a lower rotation speed than the current cut rotation speed. The engine control device for a vehicle with an automatic transmission with selectable manual mode.