JPH0659788B2 - Vehicle running control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a traveling control device for traveling while maintaining a vehicle speed at a substantially desired set value.

(Prior Art) In recent years, a constant speed traveling device that automatically maintains the vehicle speed of a vehicle at a desired vehicle speed set by a driver has been put into practical use. This constant speed traveling device sets the vehicle speed as a target value for constant speed traveling by a set operation by the driver when the vehicle speed reaches a desired vehicle speed, and thereafter compares the set vehicle speed with the actual vehicle speed. Then, when there is a difference between the two, the actual vehicle speed is made to match the set vehicle speed by controlling the throttle valve of the engine according to the difference.

In order to run at a constant speed using such a device, it is necessary to always maintain the throttle valve opening at a predetermined opening so as to maintain the engine rotation corresponding to the set vehicle speed, but the set vehicle speed is within a certain range. Considering the purpose of maintaining the vehicle speed at a certain level, when the vehicle speed is within a certain range, the clutch is disengaged to disconnect the driving force transmission between the engine and the wheels to coast the vehicle, and during this time, the engine is reduced to idling speed. With this setting, constant-speed running control with good fuel economy can be performed.
For this reason, for example, in Japanese Unexamined Patent Publication No. 56-22113, a predetermined speed range is determined with reference to a set vehicle speed when a constant speed running condition occurs, and relaxation is made between upper and lower limit values in this range. A vehicle travel control method and device have been proposed in which high speed and inertial travel are repeated. Hereinafter, the constant speed traveling control by controlling the opening degree of the engine throttle valve in the related art will be referred to as auto cruise, and the constant speed traveling control by repeating the slow acceleration and the inertia traveling as described above will be referred to as the economy cruise.

In this travel control, when the vehicle speed reaches the upper limit value, the clutch is disengaged and the engine throttle valve is fully closed to allow coasting, and when the vehicle speed or the lower limit value is reached, the engine speed is increased to a speed corresponding to the vehicle speed, and then, Engage the clutch to gradually increase the engine speed and perform gradual acceleration until the vehicle speed reaches the upper limit value, maintain the vehicle speed within a certain range determined by the upper and lower limit values, and drive at a constant speed. .

By performing such constant speed traveling control, it is possible to maintain the vehicle speed within a certain range determined by the upper and lower limit values, but by repeating the slow acceleration and coasting within this certain range, this range can be maintained. There is a problem that the vehicle speed fluctuations are repeated inside the vehicle, which may impair the driving feeling. In order to reduce this vehicle speed fluctuation, the width of the fixed range defined by the upper and lower limits may be reduced, but in this case, the frequency of repeated gentle acceleration and coasting increases and the fuel consumption reduction effect decreases. is there.

(Object of the Invention) In view of the above problems, it is an object of the present invention to provide a vehicle travel control device capable of performing economy cruise control with almost no change in vehicle speed.

(Structure of the Invention) In the traveling control device of the present invention, the engine and the drive shaft of the vehicle are connected by an intermittent clutch means, and the flywheel is connected to the drive shaft via a transmission means capable of changing the rotation transmission ratio. However, when performing constant speed running control, first, the driving force from the engine is transmitted to the flywheel via the drive shaft and the speed changing means, the rotation of the flywheel is increased to a predetermined upper limit rotation speed, and then by the clutch means. The connection between the engine and the drive shaft is disconnected, the inertia energy of the flywheel is transmitted to the drive shaft via the speed changing means, and this drive shaft is rotated at a substantially constant speed, and the vehicle speed is maintained at the substantially set vehicle speed. When the rotation speed reaches the lower limit rotation speed, the clutch means reconnects the engine and drive shaft, and the engine rotates the flywheel to change the speed. Vehicle speed by the operation of the means is characterized in that so as to increase to the upper limit rotational speed of the flywheel keeping.

(Embodiment) FIG. 1 shows a vehicle drive system having a traveling control device according to the present invention.
In the schematic diagram showing the embodiment, the output transmission of the engine 1 is turned on.
It has a main clutch 2 that is turned off and a gear type transmission 4 that has been conventionally used for vehicles, and an output shaft 5 of this transmission is connected to a drive shaft of a vehicle by interposing a propeller shaft (not shown), The output shaft 5 is driven to run. The clutch 2 engages and disengages the clutch plate 2a and the engine output shaft 1a, so that the transmission 4 of the engine output
This is to turn ON / OFF the transmission to
The control is performed by the first actuator 3 that is operated by the hydraulic pressure sent from the hydraulic controller 50 via the oil passage 50a. When the clutch 2 is turned on, the output of the engine 1 is transmitted to the gear type transmission 4, and the engine output shifted by the transmission 4 is transmitted to the output shaft 5.

A V-belt type continuously variable transmission 10 is connected to the output shaft 5. The continuously variable transmission 10 includes a first pulley 11 and a second pulley 11.
Pulley 12 and V-belt 1 spanned between both pulleys
3 and the first and second pulleys 11 and 12 are arranged laterally.
Also, the groove width of the pulley can be variably controlled by the action of the second hydraulic cylinders 11a, 11a, which allows the reduction gear ratio of the continuously variable transmission 10 to be continuously changed. The speed reduction ratio variable control is performed by the hydraulic controller 50 via the oil passages 50c and 50d.
It is performed by the hydraulic pressure supplied to the hydraulic cylinders 11a and 12a. The first pulley 11 of this continuously variable transmission is directly connected to the output shaft 5, while the second pulley 12 is connected via an automatic cruise releasing clutch 21 and a connecting gear train 23 which are turned on and off by a second actuator 22. Directly connected to the flywheel 25 in series. Therefore, when the automatic cruise releasing clutch 21 is ON, the rotation of the output shaft 5 is transmitted to the flywheel 25 via the continuously variable transmission 10, the automatic cruise releasing clutch 21, and the connecting gear train 23, and the continuously variable transmission is transmitted. It is rotationally driven at a rotational speed determined according to a reduction ratio of 10.

In the vehicle drive system configured as described above, the hydraulic pressure is supplied to the first and second actuators 3 and 22 and the first and second hydraulic cylinders 11a and 12a from the hydraulic controller 50 via the oil passages 50a to 5e. But,
The operation control of the hydraulic controller 50 is performed by a signal sent from the control unit 60 via lines 62a to 62d. This signal includes line 62
There is a reduction ratio increase signal from a, a reduction ratio decrease signal from line 62b, a main clutch operation signal from line 62c, and an automatic cruise release clutch operation signal from line 62d. The reduction ratio increase or decrease signal is for increasing or decreasing the reduction ratio of the continuously variable transmission 10, and the hydraulic pressure supply from the hydraulic controller 50 to the first and second hydraulic cylinders 11a, 12a is controlled according to this signal. To be done. The speed reduction ratio is the number of rotations of the first pulley 11 divided by the number of rotations of the second pulley. When the speed reduction ratio is increased, the second pulley 12 is rotated even if the number of rotations of the first pulley 11 is the same.
That is, the rotation of the flywheel 25 becomes smaller. On the other hand, the main clutch operation signal operates the first actuator 3 to control ON / OFF of the main clutch 2, and the automatic cruise release clutch operation signal is the second clutch operation signal.
The actuator 2 is operated to control ON / OFF of the automatic cruise release clutch 21. In addition,
The auto-cruise release clutch 21 turns ON / OFF the connection between the output shaft 5 and the flywheel 25. By turning this OFF, the engine output shifted by the gear type transmission 4 is transmitted to the drive wheels as it is. Becomes,
It is designed to be able to run normally.

Further, an operation signal is sent from the control unit 60 to a throttle actuator (not shown) via a line 62e, and the engine throttle opening is controlled by this signal to control the engine rotation.

The output signals from the lines 62a to 62e are output from the control unit 60 based on the input signals from the lines 61a to 61e. As this input signal, an accelerator pedal opening signal input via line 61a, an engine rotation signal input via line 61b, a vehicle speed signal input via line 61c, and a line 61d input. Engine throttle valve opening signal and a flywheel rotation signal input through the line 61e.

Control unit 60 based on such an input signal
The operation of each part under the control of 1 will be described with reference to the graph of FIG.

First, consider the case where the driver operates the cruise control switch at time A to switch from the normal traveling mode to the economy cruise mode (constant speed traveling mode). At this time, the reduction ratio of the continuously variable transmission 10 is at a predetermined value, and the flywheel speed at this time is NF. When switching to the economy cruise mode, the main clutch 2 remains ON and the engine throttle opening is controlled to keep the vehicle speed V constant, while the reduction ratio of the continuously variable transmission 10 is gradually decreased to change the rotation speed of the flywheel 25. Gradually increase. After that, when the number of revolutions of the flywheel 25 reaches the upper limit value NFH (point B), the main clutch 2 becomes O.
At the same time as being set to FF, the engine is set to the idle state and shifts to the coasting state. During coasting, the rotational energy of the flywheel 25 is transmitted to the wheels to keep the vehicle speed constant, and the reduction ratio of the continuously variable transmission 10 is increased in accordance with the decrease in the rotation of the flywheel 25 to increase the speed of the flywheel 25. The vehicle speed V is kept constant even if the rotation of the vehicle decreases.
In this way the flywheel 2 while keeping the vehicle speed constant
When the rotation speed of No. 5 decreases and reaches the lower limit value NFL (time C), the main clutch 2 is turned on again, the engine speed is increased to a predetermined value, and the vehicle speed is kept constant by the throttle opening control. The reduction ratio of the continuously variable transmission is gradually reduced, and the rotational speed of the flywheel 25 is gradually increased. In the same manner, the acceleration / rotation of the flywheel 25 and the inertia traveling are repeated to keep the vehicle speed substantially constant by the ON / OFF control of the main clutch 2 and the variable control of the reduction gear ratio of the continuously variable transmission 10 in the same manner. Can be done.

Next, the above control contents will be shown in time series by the flowchart of FIG. This flow shows the control contents when the economy cruise is selected, starts from step S1, starts the 20 mS timer in step S2, and executes the following 2
This flow is repeated every 0 ms. First, in step S3, it is determined whether the acceleration mode signal ACC is "1". This acceleration mode signal ACC distinguishes between the acceleration state of flywheel rotation and the coasting state during the economy cruise. The acceleration state is "1" and the coasting state is "0". When the acceleration mode signal is "1", which indicates the state, the process proceeds to step S4,
It is determined whether or not the actual rotation NF of the flywheel 25 is larger than the upper limit value NFH, and if it is smaller than NFH, that is, if the vehicle speed has not yet reached the upper limit value, the process proceeds to step S5 while maintaining the current vehicle speed. Flywheel 2
The predetermined throttle control signal TH is calculated from the function FN2 (VS) for obtaining the throttle opening required to accelerate the rotation of No.5.
Find B1. The throttle opening degree is controlled based on the throttle control signal THB1 to accelerate the rotation of the flywheel 25. At this time, at the same time, in steps S6 to S8, the continuously variable transmission is used so that the vehicle speed VSS does not exceed the set vehicle speed VSS. 10 speed reduction ratio control is performed. That is, when VS> VSS, the reduction ratio is increased to transmit more engine power to the flywheel 25, and when VS ≦ VSS, the reduction ratio is decreased to increase more engine power to the vehicle drive side. This means that the flywheel 25 is accelerated while maintaining the vehicle speed in the vicinity of the substantially set vehicle speed (VSS). If it is determined in step 24 that NF ≧ NFH, the process proceeds to steps S9 to S11 to set the throttle control signal THB1 to “0” to fully close the throttle opening and to close the main clutch control signal CL.
B is turned off and the main clutch 2 is turned off to shift to the coasting state, and further, the acceleration mode signal ACC is set to "0" to indicate that the coasting state is shifted.

On the other hand, when it is determined in step S3 that the acceleration mode signal ACC is "0", that is, in the inertia traveling state, the process proceeds to step S12, and it is determined whether the actual rotation NF of the flywheel 25 is smaller than the lower limit value NFL. To do.
When NF ≦ NFL, the flywheel rotation has reached the lower limit value and needs to be accelerated again.
Proceeding to steps S13 to S15, a predetermined throttle control signal THB1 is obtained from the function FN2 (VS) for obtaining the throttle opening required to accelerate the rotation of the flywheel 25 while maintaining the vehicle speed, and the main clutch control signal CL is obtained.
B is turned on to operate the main clutch 2 to set the acceleration mode signal ACC to "1" to indicate that the flywheel 25 is in the acceleration state. In addition, step S12
When it is determined that NF> NFL, the coasting may be continued as it is, so steps S16 to S16.
In step 18, it is determined whether or not the actual vehicle speed VS is lower than the set vehicle speed VSS. When VS ≦ VSS, the reduction ratio of the continuously variable transmission 10 is decreased, and when VS> VSS, the reduction ratio is increased to increase the actual vehicle speed. The VS is maintained near the set vehicle speed.

After the above control, in step S19, the flow of 20 mS by the 20 mS timer elapses, and then the present flow ends, whereby the control based on the present flow is performed every 20 mS.

(Effects of the Invention) As described above, according to the present invention, the flywheel is connected to the drive shaft of the vehicle through the speed changing means, and the drive from the engine is performed while the flywheel rotation is within the predetermined rotation range. Is turned off, and the vehicle is coasted while maintaining the vehicle speed at the substantially set vehicle speed by the rotational energy of the flywheel. When the flywheel rotation falls below the predetermined rotation range, the engine is driven to maintain the vehicle speed at the substantially set vehicle speed, Since the wheel rotation is increased, the economy cruise control can be performed without changing the vehicle speed, and the constant speed running with good fuel consumption and good driving feeling can be performed.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a vehicle drive system of an automobile having a traveling control device according to the present invention, FIG. 2 is a graph showing the operation of each part when controlled by the traveling control device according to the present invention, and FIG. It is a flow chart which shows the contents of control by the run control device of the present invention. DESCRIPTION OF SYMBOLS 1 ... Engine, 2 ... Main clutch 4 ... Gear type transmission, 5 ... Output shaft 10 ... Continuously variable transmission, 11, 12 ... Pulley 13 ... V belt, 25 ... Flywheel

Claims (1)

[Claims] 1. A vehicle traveling control device for performing constant-speed traveling control while maintaining a vehicle speed in the vicinity of the set vehicle speed on the basis of a set vehicle speed signal input from the outside, which is connected to a drive shaft of the vehicle. A flywheel that receives a driving force from an engine to rotate; a speed change unit that is arranged between the flywheel and the drive shaft to change a rotation transmission ratio between the flywheel and the drive shaft; and a connection between the engine and the drive shaft. When the constant-speed running control is performed, the flywheel is raised to a predetermined upper limit rotation speed by the driving force from the engine transmitted through the drive shaft and the speed changing means. , Disconnecting the connection between the engine and the drive shaft by the clutch means, and transmitting the inertial energy of the flywheel to the drive shaft via the speed changing means so that the drive shaft is substantially Maintaining the vehicle speed near the set vehicle speed by constant rotation, and when the rotation of the flywheel drops to a predetermined lower limit rotation speed, the clutch means connects the engine and the drive shaft to maintain the vehicle speed near the set vehicle speed. While
A travel control device for a vehicle, characterized in that the flywheel is driven by the engine via the speed change means to raise the flywheel to a predetermined upper limit rotation speed.