JP2004084475A - Automotive travel drive control system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automotive travel drive control system that can avoid a feeling of discomfort given to a driver owing to generation of a shock when executing idling stop control. <P>SOLUTION: An automatic transmission 6 for travel switchable to a plurality of speed gears is so configured that a one-way clutch 19 for blocking transmission of torque from travel devices to an engine operates in a low speed gear. Controlling means H for executing shift control of shifting the automatic transmission 6 and idling stop control of stopping the engine 1 when given engine stop conditions are met are configured to stop the engine 1 if the automatic transmission 6 is in the speed gear triggering one-way clutch operation when the engine stop conditions are met, and not to stop the engine 1 if the automatic transmission 6 is not in the speed gear triggering one-way clutch operation when the engine stop conditions are met. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention is configured such that an automatic transmission for traveling that can be switched to a plurality of shift speeds, and a one-way clutch that prevents transmission of torque of a traveling device to an engine at a lower shift speed. A control unit for controlling a traveling driving state of the vehicle includes a shift control for shifting the automatic transmission based on control information for a shift operation, and an idle for stopping the engine when predetermined engine stop conditions are satisfied. The present invention relates to a vehicle drive control device configured to execute stop control.
[0002]
[Prior art]
By executing the idle stop control, the vehicle drive control device configured as described above can automatically stop the engine in a situation where a predetermined engine stop condition is satisfied, thereby suppressing fuel consumption. It is like that. Further, since the one-way clutch is operated at the low speed side of the automatic transmission for traveling, the shift control is executed when, for example, the accelerator operation is stopped to reduce the vehicle speed. As a result, when the automatic transmission is switched from the higher gear to the lower gear, the vehicle tends to move forward due to the inertial force, and the traveling device attempts to rotate. The clutch allows the traveling device to rotate at a higher speed than the rotation speed on the engine side so that the traveling device can travel smoothly.
[0003]
Conventionally, the control means is configured to stop the engine as soon as a predetermined engine stop condition is satisfied, regardless of the shift state of the automatic transmission. The predetermined engine stop condition includes at least a condition for canceling the accelerator operation, and other conditions include a condition that the vehicle speed is reduced to a set speed or less and an engine speed. Some include conditions where the rotation speed is reduced to a predetermined speed or less.
[0004]
[Problems to be solved by the invention]
In the above-described conventional configuration, the engine is stopped immediately after a predetermined engine stop condition is satisfied, regardless of the shift state of the automatic transmission. Therefore, there are the following disadvantages and there is room for improvement. was there.
[0005]
For example, when the vehicle stops at a high speed, the accelerator operation is stopped to stop the vehicle, and the vehicle speed is reduced by the brake operation. When the engine is stopped, if the automatic transmission is at a high speed side where the one-way clutch does not operate, a shock occurs with the stop of the engine, causing discomfort to the driver. May give. In other words, a state in which the traveling device attempts to rotate in the forward direction while the vehicle body is moving forward due to the inertial force, but the rotation of the traveling device in the forward direction is prevented by stopping the engine. As a result, a shock occurs.
In those having the automatic transmission as described above, a configuration in which the power of the engine is transmitted to the automatic transmission via a torque converter is generally used. Although it is possible to reduce the shock, it is difficult to sufficiently reduce the shock, which may cause discomfort to the operator.
[0006]
The present invention has been made in view of such a point, and an object of the present invention is to make it possible to avoid giving a discomfort to a driver due to the occurrence of a shock when performing idle stop control. Another object of the present invention is to provide a driving control device for an automobile.
[0007]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a traveling drive control device for an automobile, in which an automatic transmission for traveling which can be switched to a plurality of speeds transmits torque of a traveling device to an engine at a low speed. A shift control for shifting the automatic transmission based on shift control information, and a predetermined engine stop condition, wherein a control means for controlling a traveling driving state of the vehicle is configured so as to actuate a one-way clutch for blocking. Is established, an idle stop control for stopping the engine is executed, and the control means controls the automatic transmission when the predetermined engine stop condition is satisfied in the idle stop control. If the machine is in a gear position where the one-way clutch operates, the engine is stopped, and when the predetermined engine stop condition is satisfied, the If the shift stage at which the dynamic transmission is applied is the one-way clutch, characterized in that it is configured so as not to stop the engine.
[0008]
That is, the control means executes the idle stop control for stopping the engine when the predetermined engine stop condition is satisfied. However, when performing the idle stop control, the control means performs the automatic shift operation when the engine stop condition is satisfied. The timing at which the engine is stopped changes according to the gear stage of the machine.
That is, if the automatic transmission is switched to the gear position where the one-way clutch operates when the predetermined engine stop condition is satisfied, the engine is immediately stopped. At this time, the automatic transmission is in a state in which the one-way clutch for preventing transmission of the torque of the traveling device to the engine side is in effect. Since the rotation in the vehicle body running direction is not prevented, no shock is caused by stopping the engine.
[0009]
Further, the control means does not stop the engine unless the automatic transmission is in a gear position where the one-way clutch operates when a predetermined engine stop condition is satisfied. In this case, the engine is continuously operated without stopping the engine, and thereafter, when the automatic transmission is switched to the gear position where the one-way clutch operates, the engine is stopped.
[0010]
Therefore, when the idling stop control is executed, when a predetermined engine stop condition is satisfied, even if the automatic transmission is shifted to a gear position where the one-way clutch is not operated, a shock occurs with the stop of the engine. It is possible to provide a vehicle drive control device that can prevent the driver from feeling uncomfortable due to the occurrence of a shock.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a case where the vehicle drive control device according to the present invention is applied to a hybrid vehicle as an example of a vehicle will be described with reference to the drawings.
As shown in FIG. 1, in the hybrid vehicle, an engine 1 for driving and an electric motor 2 for driving are directly connected so as to rotate integrally. That is, an electric motor 2 for driving is provided in a state of being directly connected to the output shaft 1a of the engine 1 for driving, and the left and right wheels 3 as driving devices are driven by these powers to drive. A drive unit KU is configured as a means. The electric motor 2 is connected to an output shaft 1a of the engine 1 so that a rotor 2a rotates integrally with the same axis, and a stator 2b surrounding an outer peripheral portion of the rotor 2a is fixed to a vehicle body supporting portion (not shown) in a fixed state. The configuration is supported.
[0012]
The electric motor 2 is configured to start the engine 1 by applying a driving force to its output shaft 1a in a state where the operation of the engine 1 is stopped, and after the engine 1 starts. Can be switched between a power running state in which a driving force is applied to the output shaft 1a in the same direction as the engine rotation direction to perform torque assist, and a regenerative state in which a driving force is applied from the output shaft 1a to generate power. Is configured. That is, when the engine 1 is operating, the electric motor 2 performs a powering operation to output torque in the same direction as the rotation direction of the output shaft 1a that is driven to rotate by the engine 1, thereby achieving a desired operation. In order to reduce the fuel consumption of the engine 1 while outputting the driving force for driving, the power of the engine 1 can be assisted, that is, torque assist can be performed. When the state of charge of the battery is low, the electric motor 2 is in a regenerative state, and the battery 4 can be charged with regenerative electric power obtained by generating electric power by applying a driving force from the output shaft 1a. It has become.
[0013]
The power of the drive unit KU is transmitted to the automatic transmission 6 via the torque converter 5 and is transmitted to the left and right wheels 3 via the differential mechanism 7 after being shifted by the automatic transmission 6. I have.
The automatic transmission 6 is an automatic transmission having a well-known configuration. As shown in FIG. 2, a plurality of hydraulic shift clutches 18 are provided, and the plurality of hydraulic shift clutches 18 are selectively provided. The transmission ratio is switched by turning the vehicle in and out, so that it is possible to switch to, for example, four forward speeds and one reverse speed, and as described later, information on the accelerator operation amount, information on the vehicle speed, etc. The gear is automatically shifted based on the speed.
The automatic transmission 6 operates such that the one-way clutch 19 that prevents the torque on the wheels 3 from being transmitted to the engine 1 acts at the lower gear, that is, at the first forward gear. It is configured. In other words, the one-way clutch 19 is provided to prevent the torque on the wheel side from being transmitted to the engine side, and the one-way clutch 19 is in an operating state in the first forward speed, and is not active in the other speeds. The transmission state is switched so that the state is not performed.
[0014]
Next, a control configuration for driving the hybrid vehicle will be described.
As shown in FIG. 1 and FIG. 2, a vehicle control unit 8 that integrally controls the operation of the entire vehicle, a motor control unit 9 that controls the operation of the electric motor 2 based on control information from the vehicle control unit 8, The engine control unit 12 automatically adjusts the output of the engine 1 based on the control information from the vehicle control unit 8, specifically, the throttle opening of the electronic throttle valve 10 and the fuel injection amount by the injector 11, and the vehicle control unit 8. A shift control section 20 for controlling the shift speed of the automatic transmission 6 based on the control information of the automatic transmission 6, a potentiometer type accelerator operation amount detection sensor S 1 for detecting an operation amount of the accelerator operation tool 13, a brake operation tool 14 is a switch-type brake operation sensor S2 for detecting whether or not a stepping operation is performed, and a rotation speed detection means for detecting a rotation speed of the electric motor 2. Various kinds of detection information from a rotational speed sensor S3, a vehicle speed sensor S4 for detecting the vehicle speed based on the rotational speed of the axle of the wheels 3, a shift position sensor S5 for detecting the position of the shift position lever 17, and the like are transmitted to the vehicle control unit 8. It is configured to be input to.
[0015]
As shown in FIG. 3, the motor control unit 9 converts the DC power supplied from the battery 4 into three-phase AC power to control the driving power supplied to the electric motor 2, or controls the electric motor by a regenerative operation. And an inverter 28 for controlling the regenerative power generated and supplied to the battery 4, and a pulse drive signal subjected to pulse width modulation (PWM) based on control information from the vehicle control unit 8. It is provided with a PWM control circuit 29 and the like for supplying to each base terminal, and adjusts the driving torque and the rotation speed by changing the magnitude of the current flowing through the electric motor 2 and the frequency of the AC current. The regenerative power charged to the battery can be adjusted.
[0016]
The structure for generating a mechanical braking force by operating the mechanical braking means KS by the brake operation tool 14 will be described. When the brake operation tool 14 is operated by the driver's foot operation, the A well-known master cylinder 15 that generates a hydraulic operating force for braking in accordance with a stepping operating force is provided, and a hydraulic operating force output from the master cylinder 15 through a hydraulic oil supply path 15 a is used to generate a hydraulic operating force near the wheel 3. Is operated to operate the friction type braking device 16 to brake the vehicle body. Such a mechanical braking means KS is configured to be changeable and adjustable so that the hydraulic operating force, that is, the mechanical braking force, increases as the driver's operating force on the brake operating tool 14 increases. .
[0017]
The position of the shift position lever 17 includes "P" (parking position), "R" (reverse traveling position), "N" (neutral position), and "D" (forward traveling position). The switching operation is appropriately performed according to the situation.
[0018]
The vehicle control unit 8 is based on detection information of the shift position sensor S5, detection information of the accelerator operation amount detection sensor S1, detection information of the vehicle speed sensor S4, and control information for shift operation such as information on the amount of charge of the battery 4. The control information is commanded to the motor control unit 9 and the engine control unit 12, and the control information for the automatic transmission 6 is commanded to the transmission control unit 20.
Accordingly, each of the vehicle control unit 8, the motor control unit 9, the engine control unit 12, and the shift control unit 20 constitutes a control means H for controlling the traveling driving state of the vehicle. When the condition is satisfied, an idle stop control for stopping the engine 1 is executed. In the idle stop control, if the automatic transmission 6 is in a gear position where the one-way clutch 19 operates when a predetermined engine stop condition is satisfied. For example, the engine 1 is stopped, and when the predetermined engine stop condition is satisfied, the engine 1 is not stopped unless the automatic transmission 6 is in a gear position where the one-way clutch 19 operates.
[0019]
Hereinafter, a specific operation of each unit will be described.
First, control of the engine 1 and the electric motor 2 by the vehicle control unit 8 will be described. For example, when the shift position lever 17 is at “P” (parking position) or “N” (neutral position), basically, the engine 1 is stopped and the electric motor 2 does not perform torque assist. However, if the state of charge of the battery 4 drops below the set amount and the battery 4 needs to be charged, the vehicle control unit 8 operates the engine 1 and changes the power of the engine 1 to the electric motor 2. In order to control the operation of the engine 1 and the electric motor 2 so as to charge the battery 4 with the electric power generated by the regenerative operation, the control information is instructed to the motor control unit 9 and the engine control unit 12.
[0020]
When the shift position lever 17 is operated to "D" (forward traveling position), when the accelerator operating tool 13 is depressed to start the vehicle body, if the engine 1 is stopped at that time, the electric motor When the engine 1 is started by rotating the engine 2 and the vehicle body moves forward, the output of the engine 1 is adjusted according to the accelerator operation amount, and the electric motor 2 executes the power running operation if the state of charge of the battery 4 is sufficiently high. Is configured to instruct the motor control unit 9 and the engine control unit 12 with control information. When the state of charge of the battery 4 decreases, the regenerative operation is executed instead of the power running operation.
When the shift position lever 17 is operated to “R” (reverse travel position), the output of the engine 1 is adjusted according to the accelerator operation amount, but both the power running operation and the regenerative operation of the electric motor 2 are performed. Not to do it.
[0021]
In addition to the description of the shift control, the vehicle control unit 8 sequentially switches the shift speed of the automatic transmission 6 according to map data set in advance based on the operation amount of the accelerator operation tool 13 and information on the vehicle speed. The control information for the automatic transmission 6 is instructed to the shift control unit 20 in order to selectively switch the plurality of shift clutches 18.
For example, when the shift position lever 17 is operated to “D” (forward traveling position), if the vehicle is stopped or the vehicle speed is low, the lowest speed among the forward traveling speeds of the automatic transmission 6 is selected. When the accelerator operation tool 13 is depressed, the speed is sequentially changed to a second forward speed, a third forward speed, and a fourth forward speed in accordance with the map data. Control to switch to the side. Further, when the vehicle body is being decelerated from a state in which the vehicle is traveling at a high speed, the speed is changed from a speed for a high-speed traveling, for example, a fourth speed to a third speed, a second speed, and a second speed. It is configured to control so as to sequentially switch to the low speed side, such as the first speed.
[0022]
Next, the idle stop control will be described.
When the depressing operation of the accelerator operation tool 13 is released to stop the running while the vehicle body is running, and the operation amount becomes zero, the vehicle speed gradually decreases and the engine 1 Although the rotation speed of the engine 1 decreases, the vehicle control unit 8 performs a predetermined engine stop condition for stopping the engine 1 in an idling state in which the rotation speed of the engine 1 decreases to the predetermined rotation speed. Is established, an idle stop control for instructing the engine control unit 12 to issue control information to stop the engine 1 is executed.
The predetermined engine stop condition is that the detection value of the accelerator operation amount detection sensor S1 is zero and the vehicle speed detected by the vehicle speed sensor S4 has decreased to a set speed or less. . That is, this is a condition for determining whether or not it is considered that the accelerator operation is released and the engine 1 may be stopped.
[0023]
Further, when the depressing operation of the accelerator operation tool 13 is released while the vehicle body is running and the vehicle speed gradually decreases, as described above, the speed of the automatic transmission 6 is sequentially reduced to the low speed. The shift control for switching to the side is also executed in parallel.
[0024]
In the idle stop control, the vehicle control unit 8 controls the engine 1 if the automatic transmission 6 operates at the speed at which the one-way clutch 19 operates when the predetermined engine stop condition is satisfied, that is, the first forward speed. When the engine stop condition is satisfied, the engine 1 is not stopped if the automatic transmission 6 is not at a speed at which the one-way clutch 19 operates, that is, at a speed other than the first forward speed. In addition, it is configured to instruct the engine control unit 12 with control information.
[0025]
Next, the idle stop control will be described based on the flowchart shown in FIG.
First, it is determined whether a predetermined engine stop condition is satisfied (step 1). That is, when it is determined that the value detected by the accelerator operation amount detection sensor S1 is zero and the vehicle speed detected by the vehicle speed sensor S4 has decreased to a set speed or less, the engine stop condition is satisfied. It is determined that you are doing.
[0026]
If the automatic transmission 6 is in the first forward speed when the engine stop condition is satisfied, that is, in the gear position where the one-way clutch 19 operates, control information is instructed to the engine control unit 12 to stop the engine 1. (Steps 2 and 3). As a result, the engine control unit 12 automatically adjusts the fuel injection amount by the injector 11 to zero so as to cut off the fuel supply to the engine 1.
[0027]
If the automatic transmission is not in the first forward speed when the engine stop condition is satisfied, the engine 1 is not stopped (step 2). At this time, the engine 1 continues to operate. At this time, control information is instructed to the motor control unit 9 so as to stop the supply of the operating power to the inverter 28 and stop the output of the inverter 28 (step 4). Therefore, the motor control section 9 does not supply a signal from the PWM control circuit 29 to the base terminal of each switching transistor of the inverter 28, and maintains each switching transistor in the cutoff state. In this way, each connection terminal of the electric motor 2 is in a state equal to the open state, the electric motor 2 is in a state in which neither the power running operation nor the regenerative operation is performed, and the occurrence of a shock due to the operation of the electric motor 2 can be prevented.
[0028]
If the automatic transmission 6 is not in the first forward speed and the engine 1 is not stopped when the engine stop condition is satisfied as described above, the engine 1 continues to operate. The automatic transmission 6 is switched from the higher gear to the first forward speed by executing the above-mentioned shift control even while the operation is continued. Speed, and if it is determined in step 2 that the automatic transmission 6 has been switched to the first forward speed, the process proceeds to step 3 and the engine 1 is stopped.
[0029]
[Another embodiment]
Hereinafter, other embodiments will be listed.
[0030]
(1) In the above-described embodiment, as a predetermined engine stop condition, the detection value of the accelerator operation amount detection sensor S1 is zero, and the vehicle speed detected by the vehicle speed sensor S4 is reduced to a set speed or less. However, the present invention is not limited to such a configuration, and may include at least a condition for canceling the accelerator operation. For example, the detection value of the accelerator operation amount detection sensor S1 is zero, and the engine Or that the vehicle speed detected by the vehicle speed sensor S4 is equal to or less than the set speed. The condition may be that the engine speed has decreased and the engine speed has decreased to a predetermined speed or less.
[0031]
(2) In the above-described embodiment, the configuration for shutting off the fuel supply to the engine has been exemplified as the process for stopping the engine. However, the process for stopping the engine is not limited to such a configuration, and may be as follows. You may implement with various structures.
For example, the engine may be stopped by controlling the rotation speed of the electric motor so that the rotation speed of the electric motor decreases. At this time, the degree of change in the target speed of the rotation speed control of the electric motor may be, for example, such that the rotation speed is reduced so as to draw a substantially S-shaped smooth curve as shown in FIG. Good. With such control, it is possible to reduce the shock caused by stopping the engine.
In addition, in addition to such a configuration, if the engine includes an igniter, the ignition operation by the igniter may be stopped as a process of stopping the engine.
[0032]
(3) In the above-described embodiment, the automatic transmission in which only the first forward speed is targeted as the low speed side on which the one-way clutch operates is described. However, the present invention is not limited to such a configuration. An automatic transmission having a configuration in which a one-way clutch operates in a shift speed may be used. For example, the present invention can also be applied to an automobile having an automatic transmission in which the first forward speed and the second forward speed are targeted as the lower speeds on which the one-way clutch operates.
[0033]
(4) In the above-described embodiment, a hybrid vehicle having a configuration in which a driving engine and a driving electric motor are directly connected has been described as an example. Instead of such a configuration, a general configuration including only an engine as a driving source is used. It may be an automobile having a simple configuration.
[Brief description of the drawings]
FIG. 1 is a diagram showing a schematic configuration of a hybrid vehicle. FIG. 2 is a control block diagram. FIG. 3 is a diagram showing a control configuration of an electric motor. FIG. 4 is a flowchart of a control operation. Diagram showing change in target rotation speed [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Engine 3 Traveling device 6 Automatic transmission 19 One-way clutch H control means

Claims (1)

An automatic transmission for traveling that can be switched to a plurality of shift speeds is configured such that a one-way clutch that prevents transmission of torque from the traveling device to the engine side operates at a low speed shift speed,
A control means for controlling a traveling driving state of the vehicle, a shift control for shifting the automatic transmission based on shift control information, and an idle stop control for stopping the engine when a predetermined engine stop condition is satisfied. A drive control device for a vehicle configured to execute
The control means, in the idle stop control,
If the automatic transmission is in a gear position where the one-way clutch operates when the predetermined engine stop condition is satisfied, the engine is stopped,
A travel drive control device for an automobile, wherein the engine is not stopped unless the automatic transmission is in a gear position at which the one-way clutch operates when the predetermined engine stop condition is satisfied.

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