JP4066936B2 - Engine output control device for vehicle - Google Patents

Description

  The present invention relates to a vehicle engine output control device, and more particularly to a device that controls engine output when starting a hill.

In general, when starting a slope on a vehicle equipped with a manual transmission, the right foot is quickly moved from the brake pedal to the accelerator pedal to increase the engine speed, and at the same time, the left foot gradually returns the clutch pedal to engage the clutch. An operation to connect is required.
Here, in order to prevent the vehicle from retreating or stalling when starting, it is necessary to depress the accelerator pedal in accordance with the road gradient, and in the clutch pedal returning operation, the accelerator pedal must be It is necessary to synchronize operation and timing. For this reason, a driver | operator's burden is large, and skill was required to perform operation of these three pedals (an accelerator pedal, a brake pedal, and a clutch pedal) appropriately.

Patent Document 1 includes a vehicle speed sensor, an inclination angle detection sensor, an engine speed sensor, a clutch stroke sensor, and a shift position sensor in order to simplify the operation when starting a hill in a vehicle travel control device. The vehicle and the tilt angle detection sensor detect that the vehicle is stopped on a slope, and the clutch stroke sensor and shift position sensor perform a starting operation such as putting the gear in the first speed or reverse position and releasing the clutch pedal. At times, by increasing the engine idling speed according to the road surface gradient, the driver can start the vehicle by operating only the brake and the clutch.
JP-A-6-146945

However, since the idling speed was increased to a predetermined value when the driver performed the starting operation, the power was not completely transmitted in the half-clutch state at the starting operation, so the idling speed was increased. Not all of the generated torque is used as vehicle propulsion. For this reason, there was a problem that fuel consumption could not be suppressed.
In addition, when the driver performs the start operation, the idling speed is increased to a predetermined value, and therefore the difference in rotational speed between the clutch disk and the clutch cover and flywheel that presses the clutch disk increases during the start operation. However, there is a problem that heat generation and wear of the clutch disk are increased as compared with a case where the start operation is performed from the normal idling speed.

  The present invention has been made paying attention to such problems, and it is an object of the present invention to control engine output when starting a vehicle on a slope to reduce fuel consumption and heat generation and wear of a clutch disk.

Therefore, the present invention provides a vehicular engine output control device that increases engine output torque when starting on a slope, and calculates a clutch transmittable torque that can be transmitted by the clutch according to the degree of engagement of the clutch by a driver's operation. and to limit the engine output torque during hill start so as not to exceed the clutch transmission torque.

  According to the present invention, it is possible to reduce fuel consumption in order to prevent the engine output torque from being increased more than necessary when starting a slope. Further, since the difference in rotational speed between the clutch disk and the clutch cover and flywheel that presses the clutch disk is reduced, heat generation and wear of the clutch disk are reduced as compared with the case where the starting operation is performed from the normal idling speed. can do.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing a basic configuration of a vehicle engine output control device of the present invention.
An output shaft 2 of the engine 1 is connected to an input shaft 5 of a manual transmission 4 via a clutch (clutch main body) 3.
The clutch 3 includes a flywheel 6 that rotates integrally with the output shaft 5 of the engine, a clutch cover 7 attached to the flywheel 6, and a clutch disk (wear plate) attached to the input shaft 5 of the manual transmission 4. 8 and. The clutch cover 7 is provided with a pressure plate 10 that rotates integrally with the clutch cover 7 and is biased toward the clutch disk 8 by a pressure spring 9.

The pressure plate 10 is configured to be separated from the clutch disk 8 via the link mechanism 12 in accordance with the stroke amount (depression amount) CLST of the clutch pedal 13. With this configuration, it is possible to change the half-clutch state by the clutch operation of the driver, that is, the degree of clutch engagement and disconnection.
When the stroke amount CLST of the clutch pedal 13 is small, the frictional force between the clutch disk 8 and the flywheel 6 and the pressure plate 10 is strong, and the clutch disk 8, the flywheel 6 and the pressure plate 10 rotate integrally, Power is transmitted from the engine 1.

On the other hand, when the stroke amount CLST of the clutch pedal 13 is large, the pressure plate 10 overcomes the spring force of the pressure spring 9 and is pushed to the clutch cover 7 side (right side in the figure), and is separated from the clutch disk 8. For this reason, the clutch disk 8 loses the frictional force and is released, and the power from the engine 1 is not transmitted.
A stroke amount CLST of the clutch pedal 13 is detected by a clutch stroke sensor 14 as a stroke amount detecting means.

Various sensors are provided for detecting the driving state at the time of starting the hill, such as the vehicle speed VSP, the gear position GP, the vehicle inclination angle SLP, and the accelerator opening APO.
As shown in the figure, the accelerator opening sensor 15 outputs a signal corresponding to the depression amount of the accelerator pedal 15a. The vehicle speed sensor 16 outputs a signal corresponding to the vehicle speed. The gear position sensor 17 outputs a signal corresponding to the driver's gear position. The vehicle inclination angle sensor 18 outputs a signal corresponding to the angle at which the vehicle is inclined from the horizontal direction.

  These signals are input to an engine control module (hereinafter referred to as “ECM”) 20. In the ECM 20, based on the clutch stroke sensor 14, the accelerator opening sensor 15, the vehicle speed sensor 16, the gear position sensor 17, and the vehicle inclination angle sensor 18, the clutch stroke amount CLST, the accelerator opening APO, the vehicle speed VSP, the gear position GP, and the vehicle inclination. Each corner SLP is calculated. Then, the ECM 20 controls the engine 1 based on these calculation results.

Next, the engine output control configuration of the ECM 20 when starting on a slope will be described with reference to FIG. In addition, the time of starting on a slope includes not only when the vehicle moves forward (starts with the gear set to the first speed) but also when the vehicle moves backward (starts with the gear set to reverse).
The ECM 20 includes a first target engine torque calculation unit 21, a clutch transmittable torque calculation unit (half-clutch state detection unit) 22, a minimum torque selection unit 23, a second target engine torque calculation unit 24, a maximum torque selection unit 25, an idle rotation. A friction torque calculation unit 26, a torque addition unit 27, and a target throttle opening degree control unit (torque generation means) 28 are configured to input an accelerator opening APO, a vehicle speed VSP, a gear position GP, a vehicle inclination angle SLP, and a clutch stroke amount CLST. The throttle valve 1a of the engine 1 is controlled based on the signal.

The first target engine torque calculation unit 21 only requires a slope start engine torque required as a vehicle propulsion force during a slope start operation only when input signals of the vehicle speed VSP, the gear position GP, and the vehicle inclination angle SLP satisfy predetermined conditions. The first target engine torque Tslp0 is calculated. Calculation of the target engine torque Tslp0 and predetermined conditions will be described later.
The clutch transmittable torque calculation unit 22 calculates the transmittable torque of the clutch 3 based on the stroke amount CLST of the clutch pedal 13 using the table of FIG.

  The table of FIG. 3 is determined by characteristics such as the size and frictional force of the clutch disk 8. The table indicates that when the clutch disk 8 is completely disconnected, the torque is not transmitted, so that the transmittable torque Tclst is zero. In the case of the half-clutch state, torque can be transmitted as the degree to which the clutch disk 8 is connected increases, so that the transmittable torque Tclst increases. Further, when the clutch disk 8 is completely connected, it is indicated that the entire torque (H in the drawing) can be transmitted.

The minimum torque selection unit 23 compares the first target engine torque Tslp0 with the clutch transmittable torque Tclst and selects the smaller torque.
The second target engine torque calculation unit 24 calculates the target engine torque based on the accelerator opening APO of the accelerator opening sensor 15.
The maximum torque selection unit 25 compares the second target engine torque and the torque selected by the minimum torque selection unit 23, and selects the larger torque.

The idle rotation friction torque calculation unit 26 calculates the friction torque (friction torque) of the clutch disk 8 when the engine 1 is in the idle rotation state.
The torque adding unit 27 adds the idle rotation friction torque and the torque selected by the maximum torque selecting unit 25.
The target throttle opening degree control unit 28 controls the throttle valve 1a of the engine 1 from the torque calculated by the torque addition unit 27 to generate torque.

Next, engine output control processing of the ECM 20 when starting on a slope will be described with reference to the flowchart of FIG. This process is performed every predetermined time.
In step 1 (shown as “S1” in the figure, the same applies hereinafter), it is determined whether or not the vehicle speed VSP = 0. In step 2, the vehicle inclination angle SLP exceeds 0 (SLP> 0). In step 3, it is determined whether the gear position GP is 1 or not. If all of these conditions are met, that is, if all of the results in steps 1 to 3 are YES, the vehicle is stopped in a state of facing upward on the inclined surface, and the driver is making a slope start operation. Judgment is made and processing of starting a slope in the case of vehicle advance is performed.

When the condition is not satisfied in either step 1 or step 3, that is, when the vehicle speed VSP is not 0 or the gear position GP is any one other than the first speed, the engine output control process is terminated. . If the condition is not satisfied in step 2, a slope starting process in the case of a vehicle retreat described later is performed.
In step 4, the first target engine torque calculation unit 21 calculates an engine torque Tslp0 required for starting (moving forward) on a slope using the following equation.

Tslp0 = (Mv × sin (SLP) ÷ (GRf × GR1)) × Tr
Mv represents the weight of the vehicle, GRf represents the final gear ratio of the transmission, GR1 represents the gear ratio when the transmission is set to the first speed, and Tr represents the radius of the tire. As a result, when the driver detects a slope start operation, a force for the vehicle to move down the hill is calculated from the vehicle weight Mv, the vehicle inclination angle SLP, and the gear position GP (GRf, GR1).

  In step 5, the minimum torque selector 23 compares the first target engine torque Tslp0 with the clutch transmittable torque Tclst, and selects the smaller torque as the engine torque in the hill start. As a result, the engine torque at the start of the hill is limited so that the first target engine torque Tslp0 does not become larger than the clutch transmittable torque Tclst at the start of the hill.

  In Step 6, it is determined whether or not the vehicle speed VSP is greater than 0 (VSP> 0), that is, whether or not the vehicle is moving forward on a slope. If the vehicle is starting on a slope (in the case of YES), the process proceeds to step 7 where the slope start engine torque is reset and the slope start process is terminated. On the other hand, when the vehicle speed VSP is 0 or less (VSP ≦ 0), the process proceeds to step 8 to determine whether or not the gear position GP is in a state other than the first speed (GP ≠ 1 speed).

If the gear position GP is other than the first speed (YES) in step 8, the process proceeds to step 7. On the other hand, when the gear position GP is the first speed (NO), the process returns to the above-described step 4 and the process is repeated.
Next, the engine output control process when the vehicle inclination angle SLP is 0 or less (SLP ≦ 0) in step 2, particularly when the vehicle is on an inclined road surface, will be described with reference to FIG. 5.

  In step 9, it is determined whether the vehicle inclination angle SLP is less than 0 (SLP <0), that is, whether the vehicle is on an inclined road surface, and in step 10, it is determined whether the gear position GP is in the reverse (reverse) position. . When all of these conditions are satisfied, that is, when all of the results in step 9 and step 10 are YES, the vehicle is stopped with the vehicle facing downward on the inclined surface, and the driver is performing a slope retreat operation. It is judged that the vehicle is going backwards and the slope starts when the vehicle is moving backward.

If the condition is not satisfied in either step 9 or step 10, that is, if the vehicle inclination angle SLP is 0 or more or the gear position GP is not in the reverse position, the engine output control process is terminated.
In step 11, the first target engine torque calculation unit 21 calculates an engine torque Tslp0 for starting (retreating) on a slope using the following equation.

Tslp0 = (Mv × sin (−SLP) ÷ (GRf × GR1)) × Tr
Thereby, a torque required for the vehicle to move backward with respect to the inclination (climb the slope) is calculated.
In step 12, as in step 3 described above, the minimum torque selector 23 compares the first target engine torque Tslp0 and the clutch transmittable torque Tclst, and uses the smaller torque as the engine torque for starting (retreating) on a hill. select.

  In Step 13, as in Step 6 described above, it is determined whether or not the vehicle speed VSP exceeds 0 (VSP> 0), that is, whether or not the vehicle is moving backward on a slope. When the vehicle is starting (retreating) on the hill (in the case of YES), the process proceeds to step 14 where the hill starting engine torque is reset and the process is terminated. On the other hand, when the vehicle speed VSP is 0 or less (VSP ≦ 0), the routine proceeds to step 15 where it is determined whether or not the gear position GP is in a state other than reverse (GP ≠ reverse).

If the gear position GP is other than reverse (YES) in step 15, the process proceeds to step 14. On the other hand, if the gear position GP is reverse (NO), the process returns to step 11 described above, and the process is repeated.
Next, the state of each parameter when the above-described engine output control is performed will be described with reference to FIG. FIG. 7 is a diagram showing the state of each parameter in the conventional slope start assist control. In FIGS. 6 and 7, (a), (b), and (c) show the clutch stroke amount, engine rotation, and torque with respect to time.

  As shown in the figure, at the time point A to B, the driver steps on the clutch pedal 13 and the clutch is completely disconnected. In this state, the clutch transmittable torque Tclst is 0, and the engine 1 is operating at idle rotation, and idle rotation friction torque is generated as torque. This torque is calculated by the idle rotation friction torque calculator 26.

6 and 7, the clutch disk 8 is gradually connected by the half-clutch operation from the state where the clutch is completely disconnected (time B) to the state where the clutch disk 8 is completely connected (D Time).
The engine output torque (see (c) of FIG. 7) in the conventional slope start assist control is performed because the driver increases the engine speed to a predetermined idle speed at the start of the slope, and then performs the slope start operation. The inertia torque when the rotational speed changes and the friction torque corresponding to the increase in the engine rotational speed is generated, and torque that is not used as the driving force of the vehicle is generated (see the hatching section).

For this reason, in the conventional slope start assist control, the engine speed increases, so that the fuel consumption cannot be suppressed. And since the rotational speed difference at the time of friction between the clutch disk and the clutch cover and flywheel that presses the clutch disk increases, problems such as increased heat generation and wear of the clutch disk occur.
However, in the present application, at times B to C in FIG. 6, the torque transmission possible torque calculation unit 22 and the first target engine torque calculation unit 21 calculate the torques Tslp0 and Tclst as described above, and the minimum torque (clutch transmission) is calculated. The possible torque Tclst) is selected by the minimum torque selector 23. The torque adding unit 27 adds the minimum torque and the idle rotation friction torque.

  Therefore, in the vehicle engine output control device of the present application, as shown in the figure, when the vehicle starts to move on a slope (forward or backward), the engine rotation is prevented from being increased more than necessary. For this reason, fuel consumption is reduced. Since the difference in rotational speed between the clutch disk 8 and the clutch cover 7 and the flywheel 6 that presses the clutch disk 8 is reduced, the heat generated in the clutch disk 8 is higher than that in the case where the start operation is performed from the normal idle speed. And reduce wear.

  According to the present embodiment, the clutch transmittable torque calculating means 22 that calculates the torque Tclst that can be transmitted by the clutch 3 in the half-clutch state when starting on a slope (steps 1 to 3 and 9 to 10), and the clutch transmittable. Torque generating means (target throttle opening control unit) 28 for generating engine output torque based on the torque Tclst. For this reason, it is possible to reduce fuel consumption in order to prevent the engine speed from being increased more than necessary when starting on a slope. Since the difference in rotational speed between the clutch disk 8 and the clutch cover 7 and the flywheel 6 that presses the clutch disk 8 is reduced, the heat generated in the clutch disk 8 is higher than that in the case where the start operation is performed from the normal idle speed. And wear can be reduced.

  Further, according to the present embodiment, the clutch transmittable torque calculating means 22 has the stroke amount detecting means (clutch stroke sensor) 14 for detecting the stroke amount CLST of the clutch 3, and based on the stroke amount CLST, in the half-clutch state. A torque Tclst that can be transmitted by the clutch 3 is calculated. Therefore, the clutch engagement state can be reliably detected from the output of the clutch stroke sensor 14 by using a table (FIG. 3) or the like.

  In addition, according to the present embodiment, the first target engine torque calculation means 21 that calculates the slope start engine torque Tslp0 necessary as a propulsive force when starting the slope, the clutch transmittable torque Tclst, and the first target engine torque Tslp0 are smaller. Minimum torque selection means 23 for selecting one of the torques, and a torque generation means (target throttle opening control unit) 28 generates engine output torque based on the torque selected by the minimum torque selection means 23. For this reason, it is possible to prevent an excessive increase in torque due to an increase in the engine speed during a slope start operation.

Further, according to the present embodiment, the first target engine torque calculation means 21 calculates the hill start engine torque Tslp0 necessary as a propulsion force when starting the hill based on the vehicle inclination angle SLP. For this reason, it is possible to prevent the vehicle from retreating or stalling when performing an operation of moving forward on the slope.
Further, according to the present embodiment, the second target engine torque calculating means 24 for calculating the engine torque based on the accelerator opening APO, the torque selected by the minimum torque selecting means 23 and the second target engine torque calculating means 24 Maximum torque selecting means 25 for comparing the calculated torque and selecting the larger torque, and the torque generating means (target throttle opening control unit) 28 is the torque selected by the maximum torque selecting means 25. Based on the engine output torque is generated. For this reason, when the depression amount of the accelerator pedal 15a is increased, the opening degree of the throttle 1a can be determined based on the accelerator pedal operation, and the vehicle can be started.

  Further, according to the present embodiment, the idle rotation friction torque calculating means for calculating the friction torque of the engine 1 at the idle rotation at the time of clutch disconnection is provided, and the torque generating means (target throttle opening control unit) 28 is the idle rotation friction torque. And the torque selected by the maximum torque selection means 25 are added to generate the engine output torque. Therefore, as shown at time points B to C in FIG. 6, the engine speed does not change, and the torque that is not used as the driving force of the vehicle can be reduced.

The figure which shows the basic composition of the engine output control apparatus for vehicles The figure which shows the engine output control constitution at the time of hill starting Torque transmission torque calculation table Flow chart showing engine output control processing when starting on a slope Flowchart showing the engine output control process when the vehicle is on an inclined road surface The figure which shows the state of each parameter when engine output control is performed The figure which shows the state of each parameter in the conventional slope start assistance control

Explanation of symbols

1 Engine 3 Clutch 4 Manual Transmission 8 Clutch Disc 13 Clutch Pedal 14 Clutch Stroke Sensor 15 Accelerator Opening Sensor 16 Vehicle Speed Sensor 17 Gear Position Sensor 18 Vehicle Tilt Angle Sensor 20 ECM
21 First target engine torque calculation unit 22 Clutch transmittable torque calculation unit 23 Minimum torque selection unit 24 First target engine torque calculation unit 25 Maximum torque selection unit 26 Idle rotation friction torque calculation unit 27 Torque addition unit 28 Target throttle opening control Part

Claims (5)

An engine output control device for a vehicle that increases engine output torque when starting on a slope,
A clutch provided between the engine and the transmission;
Clutch transmittable torque calculating means for calculating a clutch transmit torque that can be transmitted by the clutch according to the degree of engagement of the clutch by a driver's operation;
Limiting means for limiting the engine output torque at the start of the hill so as not to exceed the clutch transmittable torque ;
A vehicle engine output control apparatus comprising: The clutch transmittable torque calculating means includes a stroke amount detecting means for detecting the stroke amount of the clutch, the vehicle of claim 1, wherein the calculating the clutch transmittable torque on the basis of the stroke amount Engine output control device. First target engine torque calculating means for calculating a first target engine torque required as a propulsive force when starting on a slope,
Minimum torque selection means for selecting a smaller torque of the clutch transmittable torque and the first target engine torque,
The vehicle engine output control apparatus according to claim 1 or 2, wherein an engine output torque is generated based on the torque selected by the minimum torque selection means. Wherein the first target engine torque calculating means, vehicle engine output control device according to claim 3, wherein the calculating the first target engine torque based on the vehicle inclination angle. A second target engine torque calculation means for calculating a second target engine torque based on the accelerator opening,
5. The engine output torque is generated based on the second target engine torque when the second target engine torque is larger than the torque selected by the minimum torque selection means. The vehicle engine output control apparatus according to the description.

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