JPS6268139A - Traveling controller for car - Google Patents

Abstract

PURPOSE:To permit the coasting traveling of a car by the revolution energy of a flywheel by connecting the flywheel with the driving shaft of the car through a transmission and keeping the revolution of the flywheel within a prescribed revolution region by ON/OFF-controlling the driving shaft. CONSTITUTION:A main clutch 2 switches-ON and OFF the transmission of the engine output to a transmission 4 by the connection/disconnection of a clutch plate 2a with the engine output shaft 1a, and the ON/OFF-control is carried out by the first actuator 3 operated by the hydraulic pressure sent from a hydraulic controller 50 through an oil passage 50a. A V-belt type continu ously variable transmission 10 is connected to the output shaft 5 of a gear type transmission 4, and the variable control for reduction rate is carried out by the oil pressure supplied into the first and the second hydraulic cylinders 11a and 12a from the hydraulic controller 50 through the oil passages 50c and 50d. When an auto-cruise releasing clutch 21 is turned-ON, the revolution of the output shaft 5 is transmitted to a flywheel 25, which is revolved according to the continuously variable transmission 10.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a travel control device that maintains a vehicle speed at approximately a desired set value while driving the vehicle. - (Prior Art) In recent years, constant speed traveling devices that automatically maintain the vehicle speed of a vehicle at a desired speed set by the driver have 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 this set vehicle speed with the actual vehicle speed. Therefore, when a difference occurs between the two, the throttle valve of the engine is controlled according to the difference, thereby making the actual vehicle speed match the set vehicle speed.

In order to drive 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. When the vehicle speed is within a certain range, the clutch is disengaged to cut off the transmission of drive power between the engine and the wheels, causing the vehicle to coast, and during this time the engine is reduced to idle speed. By doing so, constant speed driving control with good fuel efficiency can be performed.

For this reason, for example, Japanese Unexamined Patent Publication No. 56-22113 proposes that a predetermined speed range is determined based on the set vehicle speed when a constant speed running condition occurs, and that the speed is set between the upper and lower limits in this range. 2. Description of the Related Art Vehicle travel control methods and devices have been proposed in which acceleration and coasting are repeated. Hereinafter, conventional constant speed cruise control using engine throttle valve opening control will be referred to as autocruise, and constant speed cruise control using repeated slow acceleration and coasting as proposed above will be referred to as economy cruise.

In this driving control, when the vehicle speed reaches an upper limit value, the clutch is disengaged and the engine throttle valve is fully opened to perform coasting, and when the vehicle speed reaches the lower limit value, the engine rotation is increased to a rotation corresponding to the vehicle speed, and then, By engaging the clutch, the engine speed is gradually increased, and the vehicle speed is controlled to perform gentle acceleration until it reaches the upper limit value, and the vehicle speed is maintained within a certain range determined by the upper and lower limit values, and the vehicle is driven at a constant speed. .

When such constant speed driving control is performed, it is possible to maintain the vehicle speed within a certain range determined by the upper and lower limits, but by repeating slow acceleration and coasting within this certain range, this range can be maintained. There is a problem in that the vehicle speed changes repeatedly within the vehicle, which may impair the driving feeling. In order to reduce this medium-speed fluctuation, it is possible to reduce the width of the fixed range determined by the above upper and lower limits, but in this case, the frequency of repetition of slow acceleration and coasting increases, which causes the problem that the fuel efficiency reduction effect decreases. be.

(Object of the Invention) In view of the above-mentioned problems, it is an object of the present invention to provide a vehicle travel control device that can perform economy cruise control with almost no variation in vehicle speed.

(Structure of the Invention) The travel control device of the present invention connects the engine and the drive shaft of the vehicle by a latching means that can be switched on and off, and connects the flywheel to the drive shaft through a transmission means that can change the rotational 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 transmission means, and the rotation of the flywheel is increased to a predetermined upper limit rotation speed, and then the rotation is increased by the clutch means. The connection between the engine and the drive shaft is disconnected, and the inertial energy of the flywheel is transmitted to the drive shaft through the transmission means to rotate the drive shaft at a substantially constant rate, thereby maintaining the vehicle speed at approximately the set vehicle speed;
After this, when the rotation of the flywheel has decreased to the lower limit rotation speed, the clutch means reconnects the engine and the drive shaft, the engine rotates the flywheel, and the speed change means operates to maintain the vehicle speed while shifting the flywheel. This is characterized in that the rotational speed is increased to the upper limit.

(Example) Fig. 1 shows one example of a vehicle drive system having a travel control device of the present invention.
This is a schematic diagram showing an embodiment, in which 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 conventionally used for vehicles, and the output shaft 5 of this transmission is connected to the drive shaft of the vehicle through a propeller shaft (not shown). Traveling is driven by the output shaft 5. The clutch 2 changes the engine output speed [4] by connecting and disconnecting the clutch plate 2a and the engine output shaft 1a.
This is to turn the transmission to 0N-OFF.
The F ti control is carried out from the hydraulic controller 50 to the oil passage 50.
This is done by the first actuator 3 which is actuated by hydraulic pressure sent through a. When the clutch 2 is turned on, the output of the engine 1 is transmitted to the gear type transmission R4, and the engine output shifted by the transmission 4 is transmitted to the output shaft 5.

This output shaft 5 is equipped with a ■belt adult gear shift II.

are connected. This continuously variable transmission 10 is the 11th
1. The frame was passed between the second pulley 12 and both boars.■
It consists of a belt 13, and both pulleys 11 and 12 can have their groove widths variably controlled by the action of first and second hydraulic cylinders 11a and 12a arranged laterally, thereby creating a continuously variable transmission. The reduction ratio of 10 can be changed steplessly. Note that this variable reduction ratio control is performed by the hydraulic pressure supplied from the hydraulic controller 50 to the first and second hydraulic cylinders 11a, 128 via the oil passage 50C150d. The first pulley 11 of this continuously variable transmission is directly connected to the output shaft 5, while the 27th pulley 12 is connected via an auto-cruise release clutch 21 which is turned on and off by a second actuator 22 and a connecting gear train 23. and is directly connected in series with the flywheel 25. Therefore, when the auto-cruise release clutch 21 is ON, the rotation of the output shaft 5 is controlled by the continuously variable transmission 10 and the auto-cruise release clutch 2.
1. It is transmitted to the flywheel 25 via the connecting gear train 23, and is driven to rotate at a rotational speed determined according to the reduction ratio of the continuously variable transmission IIO.

In the vehicle drive system configured in this manner, hydraulic pressure is supplied to the first and second actuators 3.22 and the first and second hydraulic cylinders lla and 12a from the hydraulic controller 50 via oil passages 50a to 5e. but,
The operation of this hydraulic controller 50 is controlled by signals sent from a control unit 60 via lines 62a to 62d. This signal is line 62
There is a reduction ratio increase signal from line 62b, a main clutch operation signal from line 62C, and an auto-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 and 12a is controlled according to this signal. be done. Note that the reduction ratio is the number of rotations of the first pulley 11 divided by the number of rotations of the second pulley, and as the reduction ratio increases, even if the number of rotations of the 11th pulley 11 is the same, the number of rotations of the 11th pulley 11 is the same.
9, the rotation of the flywheel 25 becomes smaller. On the other hand, the main clutch operation signal operates the first actuator 3 to perform ON-OFF control of the main clutch 2, and the auto-cruise release clutch operation signal operates the second actuator 2 to control the auto-cruise release clutch 21 to 0N. - It is something that turns OFFυJllll. Note that the auto cruise release cooler latch 21 is for turning off the connection between the output shaft 5 and the flywheel 25, and by turning it off, the gear type gear shift llI4
The engine output that has been changed in speed is now directly transmitted to the drive wheels, allowing normal driving.

Further, an actuation signal is sent from the control unit 60 to a throttle actuator (not shown) via a line 62e, and this signal controls the engine throttle opening and engine rotation. . - The output signals via the lines 62a-62e are output from within the control unit 60 based on the input signals via the lines 61a-61e. These input signals include an accelerator pedal opening signal input via line 61a, an engine rotation signal input via line 61b, a vehicle speed signal input via line 6ic, and a signal input via line 61d. There is an engine throttle valve opening signal input via line 61e and a flywheel rotation signal input via line 61e.

Control unit 60 based on such input signals
The operation of each part under control will be explained using the graph in FIG.

First, consider the case where the driver operates the cruise control switch at time A to change from normal driving (1 mode) to economy cruise mode (constant speed driving mode).At this time, the reduction ratio of the continuously variable AIO is set to a predetermined speed. The flywheel rotation speed at this time is NF.When switching to economy cruise mode, main clutch 2 remains ON and controls the engine throttle rim to keep the vehicle speed constant and continuously variable speed! The speed reduction ratio of the flywheel 25 is gradually increased by gradually decreasing the speed reduction ratio of the flywheel 25. After that, when the speed of the flywheel 25 reaches the upper limit value NFH (point B), the main clutch 2 is turned off. At the same time, the engine is put into an idle state and shifts to a coasting state.During coasting, the rotational energy of the flywheel 25 is transmitted to the wheels to keep the vehicle speed constant, and as the rotation of the flywheel 25 decreases, the vehicle speed is kept constant. By increasing the reduction ratio of the stepped transmission 110, the vehicle speed V is kept constant even if the rotation of the flywheel 25 decreases.In this way, the rotation of the flywheel 25 decreases while keeping the vehicle speed constant, and this is the lower limit. 1iINFL (at time C), turn on main clutch 2 again.
At the same time, the engine rotation is increased to a predetermined value, and while the vehicle speed is kept constant by controlling the throttle opening υ, the reduction ratio of the continuously variable transmission is gradually decreased, and the rotation speed of the flywheel 25 is gradually increased. Thereafter, in the same manner, by turning ON/OFF the main clutch 2 and variable control of the reduction ratio of the continuously variable transmission 10, acceleration of the rotation of the flywheel 25 and coasting are repeated, and the vehicle is driven at a constant speed while keeping the vehicle speed almost constant. can be made to do so.

Next, the above-mentioned control contents will be shown in chronological order using the flowchart of FIG. This flow shows the control content when economy cruise is selected, starting from step S1, starting the 20m5 timer in step S2, and following the steps below.
Repeat this flow every 0m5. First, in step S3, it is determined whether the acceleration mode signal ACC is 1''.

This acceleration mode signal ACC is set to J during economy cruise.
') and distinguishes whether the flywheel rotation is in an accelerated state or in a coasting state. 171 +1 indicates an acceleration state, and "011" indicates a coasting state. Acceleration mode When the signal is 1'', the process proceeds to step S4, where it is determined whether the actual rotation NF of the flywheel 25 is greater than the upper limit ff1NFH. When this is smaller than NFH, that is, when the vehicle speed has not yet reached the upper limit value, the process proceeds to step S4. Proceeding to S5, a predetermined throttle control signal THBl is determined from the function FN2'(VS) for determining the throttle opening degree necessary to accelerate the rotation of the flywheel 25 while maintaining the current vehicle speed. This throttle tomorrow control signal THB
1, the throttle IPf is controlled by one degree to accelerate the rotation of the flywheel 25. At the same time, the reduction ratio of the continuously variable transmission 10 is changed in steps 86 to S8 so that the vehicle speed VS does not exceed the set vehicle speed VSS. 1
Perform iIJ11I. That is, when VS>VSS, the reduction ratio is increased to transmit more engine power to the flywheel 25, and when VSSvSS, the reduction ratio is lowered to transmit more engine power to the vehicle drive side. This changes the vehicle speed to approximately the set vehicle speed (
It is possible to accelerate the flywheel 25 while maintaining the distance near VSS. Further, when it is determined in step 24 that NF≧NFH, step 89
〜Proceed to 811 and change the throttle control signal T]”B1 to “
0'' to fully open the throttle 1711 degrees, turn off the main clutch control signal CLB to turn off the main clutch 2, and shift to a coasting state.
Further, the acceleration mode signal @ACC is set to 1101+ to indicate that the state has shifted to the coasting state.

On the other hand, in step $3, the acceleration mode signal ACG is set to O.
'', that is, in a coasting state, the process proceeds to step 812, where it is determined whether the actual rotation NF of the flywheel 25 is smaller than the lower limit NFL.Here, if NF≦NFL, the flywheel Since the wheel rotation has reached the lower limit value and needs to be accelerated again, the process proceeds to steps 813 to S15, where the function FN2 calculates the throttle opening degree necessary to accelerate the rotation of the flywheel 25 while maintaining the vehicle speed. A predetermined throttle control signal @TH81 is obtained from (VS), the main clutch control signal CLB is turned ON to operate the main clutch 2, and the acceleration mode signal ACC is set to rr to indicate that the flywheel 25 has shifted to the acceleration state. 1 u.Also, step 81
In step 2, when it is determined that NF>NFL, it is possible to continue coasting as it is, so step 316 to
Proceeding to 818, it is determined whether the actual vehicle speed vSffi is smaller than the set vehicle speed VSS, and if ■S≦■SS, the continuously variable transmission 11
10, and when VS>VSS, the reduction ratio is increased to maintain the actual vehicle speed vS near the set vehicle speed.

After the above control, in step 819, this flow is ended after 20 m5 has elapsed by the 20 m5 timer, and control based on this flow is performed every 20 m5.

(Effects of the Invention) As explained above, according to the present invention, the flywheel is connected to the drive shaft of the vehicle via the transmission means, and while the flywheel rotation is within a predetermined rotation range, the drive shaft from the engine is is turned OFF, the vehicle is coasted while maintaining the vehicle speed at approximately the set speed using the rotational energy of the flywheel, and when the flywheel rotation falls below the predetermined rotation range, the vehicle speed is maintained approximately at the set vehicle speed by drive of the engine and the vehicle is coasted. Since the wheel rotation is increased, economy cruise control can be performed without changing the vehicle speed, and the vehicle can be driven at a constant speed with good fuel efficiency and a good driving feeling.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram showing a vehicle drive system of an automobile having a running control device according to the present invention, and Fig. 2 shows a vehicle drive system controlled by the running control device of the present invention! FIG. 3 is a flowchart showing the details of control by the travel control device of the present invention. 1...Engine 2...Main clutch 4
... Gear type transmission 5 ... Output shaft 10 ... Continuously variable speed t1 11, 12 ... Pulley 13 ... V-belt 25 ... Flywheel Fig. 2

Claims (1)

[Scope of Claims] A travel control device for a vehicle that performs constant speed travel control by maintaining the vehicle speed near the set vehicle speed based on a set vehicle speed signal input from the outside, the device being connected to a drive shaft of the vehicle. a flywheel that rotates in response to driving force from an engine; a speed change means disposed between the flywheel and the drive shaft to change a rotational transmission ratio between the two; and a clutch means that connects and disconnects the connection, and when performing constant speed running control, the flywheel is raised to a predetermined upper limit rotational speed by the driving force from the engine transmitted through the drive shaft and the speed change means. After that, the connection between the engine and the drive shaft is disconnected by the clutch means, and the inertial energy of the flywheel is transmitted to the drive shaft via the transmission means to rotate the drive shaft at a substantially constant speed to set the vehicle speed. While maintaining the vehicle speed near the set vehicle speed, when the rotation of the flywheel has decreased to a predetermined lower limit rotation speed, the clutch means connects the engine and the drive shaft, and while maintaining the vehicle speed near the set vehicle speed, the flywheel A driving control device for a vehicle, characterized in that the engine is driven by the engine via the transmission means to increase the rotation speed to a predetermined upper limit.