JPH04287726A - Constant-speed running device for vehicle - Google Patents

Abstract

PURPOSE:To prevent the constant-speed running control from being released frequently on a downhill. CONSTITUTION:A setting means setting the first preset vehicle speed V1 larger than the present vehicle speed VS and the second preset vehicle speed V2 larger than the first preset vehicle speed V1 respectively, a shift-down means 44 performing shift-down when the present vehicle speed VS exceeds the first preset vehicle speed V1, and a releasing means 46 releasing the constant-speed running control by a constant-speed running means when the present vehicle speed exceeds the second preset vehicle speed V2 are provided.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] This invention is an auto-speed system that maintains the vehicle speed at a preset speed and drives the vehicle at a constant speed.
The present invention relates to a vehicle constant speed traveling device such as a control device.

0002

2. Description of the Related Art Conventionally, as the above-mentioned constant speed traveling device for a vehicle, there is, for example, a device described in Japanese Patent Application Laid-Open No. 63-2740. In other words, the set vehicle speed is compared with the current vehicle speed (actual vehicle speed), and when a difference occurs between the two, the engine throttle valve is controlled in response to the difference, and the current vehicle speed converges to the set vehicle speed. a driving means, a downshifting means that shifts down when the throttle valve is fully closed and the vehicle speed increases, and a constant speed driving control that is canceled when the current vehicle speed increases by a certain value or more than the above-mentioned set vehicle speed while driving at a constant speed. This is a constant speed traveling device for a vehicle, which is equipped with a release means for a vehicle.

[0003] In this conventional device, on a gentle downhill slope with a relatively small downhill slope, the above-mentioned downshift means acts to downshift the gear stage of the automatic transmission based on an increase in vehicle speed. On the other hand, on steep downhill slopes with relatively large slopes, even if the above-mentioned downshift is performed, the current vehicle speed will frequently exceed the set vehicle speed by a certain value due to the acceleration caused by the steep slope. There was a problem that the constant speed driving control was canceled.

0004

SUMMARY OF THE INVENTION An object of the present invention is to provide a constant speed driving device for a vehicle that can prevent constant speed driving control from being frequently canceled on downhill slopes.

[0005]

[Means for Solving the Problems] The present invention provides a constant speed traveling device for a vehicle, which includes a constant speed traveling means for controlling an engine control amount so as to converge to a preset set vehicle speed, a first predetermined vehicle speed greater than the vehicle speed;
setting means for respectively setting a second predetermined vehicle speed that is greater than the first predetermined vehicle speed; a downshifting means for performing a downshift when the current vehicle speed exceeds the first predetermined vehicle speed; The constant speed traveling device for a vehicle is characterized in that it includes a canceling means for canceling the constant speed traveling control by the constant speed traveling means when the vehicle speed exceeds a predetermined vehicle speed.

[0006]

According to the present invention, the vehicle speed for canceling constant speed driving control (second predetermined vehicle speed) and the vehicle speed for downshift determination at a low vehicle speed relative to this vehicle speed (first predetermined vehicle speed) are determined. ), and the current vehicle speed exceeds the first predetermined vehicle speed mentioned above (when the vehicle speed has not reached the speed for canceling constant speed driving control).
, the downshifting means executes downshifting, so
The engine braking effect allows the vehicle to return to the set speed. As a result, it is possible to effectively prevent the constant speed driving control from being frequently canceled on a downhill slope.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. The drawing shows a constant speed traveling device for a vehicle. In FIG. 1, an air flow meter 2 is connected to the rear of an air cleaner 1 that purifies intake air, and the air flow meter 2 is configured to detect the amount of intake air. .

A throttle body 3 is connected to the rear of the air flow meter 2, and a throttle chamber 4 in the throttle body 3 is provided with a throttle valve 5 as a control valve for controlling the amount of intake air. There is.

A surge tank 6 as an expansion chamber having a predetermined volume is connected to the intake passage downstream of the throttle valve 5, and an intake manifold 8 communicating with the intake port 7 is connected downstream of the surge tank 6. , this intake manifold 8 is provided with an injector 9 .

On the other hand, the above-mentioned intake port 7 and exhaust port 12, which communicate with the combustion chamber 11 of the engine 10 as appropriate, include:
Intake valve 13 that is opened and closed by a valve mechanism (not shown)
and an exhaust valve 14, and an ignition plug (not shown) with a spark gap facing the combustion chamber 11 is attached to the cylinder head 15.

[0011] An O2 sensor is disposed in an exhaust passage 17 downstream of the exhaust manifold 16 that communicates with the above-mentioned exhaust port 12, and a catalytic converter, so-called catalyst, is connected downstream of this exhaust passage 17 to render harmful gases harmless. are doing.

By the way, an automatic transmission 18 is attached to the rear end of the engine 10 mentioned above. This automatic transmission 18
is a hydraulically operated automatic transmission equipped with a torque converter 19 and a multi-stage gear mechanism 20 with, for example, four forward speeds and one reverse speed, and within the torque converter 19 described above, a turbine liner is directly connected to the front cover as appropriate. A lock-up clutch 21 as a friction type clutch is incorporated.

Further, the automatic transmission 18 described above is equipped with a hydraulic control device 25 that includes a plurality of shift solenoids 22 . . . , a lock-up solenoid 23 , and a duty solenoid 24 .

Here, by changing the combination of ON and OFF for the above-mentioned shift solenoids 22..., the gear change (upshift, downshift) of the multi-stage transmission gear mechanism 20 is performed, and also for the above-mentioned lock-up solenoid 23... By switching ON and OFF, the lock-up clutch 21 is engaged and engaged, and by controlling the duty of the duty solenoid 24 described above, the line pressure of the hydraulic circuit of the automatic transmission 18 is variably controlled.

In other words, the above-mentioned duty solenoid 24
When the solenoid is excited (ON), the hydraulic pressure in the main line is drained into the tank, so the ON/OFF ratio (
By controlling the line pressure (duty rate), line pressure can be variably controlled.

On the other hand, the CPU 30
, a signal from a command switch 31 consisting of a set switch 27, a resume switch 28, and a coast switch 29, an inhibitor signal from an inhibitor switch 32 that detects the shift position of the shift lever of the automatic transmission 18, and a throttle opening TVO. The output signal is stored in the ROM 36 based on the inputs of the throttle opening signal from the throttle sensor 33, the brake signal from the brake switch 34 which outputs a constant speed driving control release signal when turned on, and the vehicle speed signal from the vehicle speed sensor 35. According to the programmed program, the throttle opening actuator 37 and the hydraulic control device 25 are driven and controlled, and the RAM 38 stores the set vehicle speed V.
0, a first predetermined vehicle speed V1 (vehicle speed for downshift determination) data, and a second predetermined vehicle speed V2 (vehicle speed for canceling constant speed driving control) data, which is greater than the first predetermined vehicle speed V1. Necessary data such as throttle opening α data close to the fully closed state and throttle opening β data (see FIG. 3) for determining the end of a downhill slope, which is larger than the throttle opening α, are stored.

Here, the main switch 26 in the above-mentioned command switch 31 is a power switch for a constant speed running device, so-called auto cruise, the set switch 27 is a switch for setting constant speed running, and the resume switch 28 is a switch for setting constant speed running.
is a switch for automatically returning to constant speed driving after canceling constant speed driving control, and coast switch 29
is a deceleration switch.

Further, the CPU 30 described above controls the engine control amount (throttle opening degree TVO in this embodiment) so as to converge to a set vehicle speed V0 (see FIG. 3) preset by the command switch 31 described above. a shift-down means (see fourth step 44 in the flowchart of FIG. 2) that executes a downshift when the current vehicle speed VS exceeds the above-mentioned first predetermined vehicle speed V1; When the vehicle speed exceeds a predetermined vehicle speed V2, a canceling means (FIG. 2
(see sixth step 46 in the flowchart). Furthermore, the above-mentioned RAM 38 is a setting means for setting and storing the first and second predetermined vehicle speeds V1 and V2, respectively.

The operation of the constant speed traveling system for a vehicle constructed as described above will be explained below with reference to the flowchart of FIG. 2 and the time chart of FIG. 3.

In a first step 41, the CPU 30 detects the current vehicle speed VS from the vehicle speed sensor 35 and the throttle sensor 33.
Various necessary signals such as throttle opening TVO are read from the controller.

Next, in a second step 42, the CPU 30 reads the current vehicle speed VS read in the first step 41 and the RAM.
38 and the first predetermined vehicle speed V1 stored in advance, and when VS<V1 (see time t1 in FIG. 3).
On the other hand, when VS>V1 (when the vehicle speed VS exceeds the first predetermined vehicle speed V1 due to the vehicle traveling downhill during the predetermined travel control), the next third step is performed. 43.

In the third step 43 described above, the CPU 30 compares the throttle opening TVO read in advance in the first step 41 with the throttle opening α close to the fully closed state, and when TVO>α (for example, When the driver depresses the accelerator even though constant speed driving control is in progress, the process is terminated, while when TVO<α (see time t2 in FIG. 3), the next fourth The process moves to step 44.

In the fourth step 44, the CPU 30 drives and controls the hydraulic control device 25 of the automatic transmission 18 to downshift the gear stage of the automatic transmission 18 from, for example, 4th speed to 3rd speed. In other words, the current vehicle speed VS exceeds the first predetermined vehicle speed V1 as the vehicle speed for downshift determination due to the downhill traveling of the vehicle during constant speed driving control, and the throttle opening TVO is set to the preset opening α. In the following cases, by downshifting from 4th gear to 3rd gear, the engine brake effect returns the vehicle to the set vehicle speed V0.

Next, in a fifth step 45, the CPU 30 compares the current vehicle speed VS with a second predetermined vehicle speed V2 as the vehicle speed for canceling constant speed driving control, and when VS<V2 (at time t3 in FIG. In the case of virtual line b), the process moves to the next sixth step 46, and when VS<V2, the process moves to another seventh step 47.

In the sixth step 46 described above, the CPU 30 performs constant speed driving control (corresponding to the difference between the current vehicle speed VS and the set vehicle speed V0, controls the throttle opening degree TVO so that the current vehicle speed VS becomes the set vehicle speed V0). control), while in the seventh step 47 described above, the CPU 30 compares the current vehicle speed VS and the first predetermined vehicle speed V1, and determines that VS>V
When it is 1, the process returns to the fifth step 45 described above, and VS
When <V1, the process moves to the next eighth step 48.

In the eighth step 48, the CPU 30 compares the throttle opening degree TVO with the throttle opening degree β for determining the end of a downhill slope stored in advance in the RAM 38, and determines the TVO.
>β (see time t4 in FIG. 3), the process moves to the next ninth step 49.

In the ninth step 49, the CPU 30 drives and controls the hydraulic control device 25 of the automatic transmission 18 to shift up the gear stage of the automatic transmission 18 from, for example, 3rd speed to 4th speed. In other words, the seventh step 47 mentioned above
Both the determination of the vehicle speed return in step 48 and the determination of the throttle opening degree in the eighth step 48 described above (in order to obtain the above-mentioned set vehicle speed V0 in 3rd gear, an opening degree greater than the throttle opening degree in 4th gear is required). Accordingly, the end of the downhill slope is determined, and the ninth step 49
to shift up.

In summary, the vehicle speed (second predetermined vehicle speed V2) for canceling constant speed driving control and this vehicle speed V2
When the current vehicle speed VS exceeds the first predetermined vehicle speed V1 described above (vehicle speed for canceling constant speed driving control), Since the above-mentioned downshift means (see the fourth step 44 in the flowchart of FIG. 2) executes a downshift when the vehicle speed does not reach V2, the vehicle speed can be returned to the set vehicle speed V0 by the engine braking effect. As a result, it is possible to effectively prevent the constant speed driving control from being frequently canceled on a downhill slope.

In the above embodiment, the throttle opening degree β for determining the end of a downhill slope is set, and the determination of the end of a downhill slope is made when the current throttle opening degree TVO becomes equal to or greater than the throttle opening degree β. However, this downhill end determination may be performed using a timer method in which the upshift is executed after a predetermined period of time (for example, 20 seconds) has elapsed after the current vehicle speed VS has returned to the set vehicle speed V0.

[0030] In the correspondence between the structure of the present invention and the above-described embodiment, the constant speed traveling means of the present invention has the CPU of the embodiment.
Similarly, the setting means corresponds to the RAM 38, the downshift means corresponds to the fourth step 44 under the control of the CPU 30, the canceling means corresponds to the sixth step 46 under the control of the CPU 30, and the downshift means corresponds to the sixth step 46 under the control of the CPU 30. The controlled amount is
Although the present invention corresponds to the throttle opening degree, the present invention is not limited to the configuration of the above-described embodiment.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing a constant speed traveling device for a vehicle according to the present invention.

FIG. 2 is a flowchart.

[Figure 3] Time chart.

[Explanation of symbols]

30... CPU (constant speed traveling means) 38... RAM (setting means) 44... Fourth step (shift down means) 46... Sixth step (cancelling means) V0... Set vehicle speed V1... First predetermined vehicle speed V2... Second Predetermined vehicle speed VS…Current vehicle speed

Claims (1)

[Claims] 1. A constant speed traveling device for a vehicle, comprising a constant speed traveling means in which an engine control amount is controlled so as to converge to a preset vehicle speed, the first vehicle speed being greater than the preset vehicle speed.
setting means for respectively setting a predetermined vehicle speed and a second predetermined vehicle speed greater than the first predetermined vehicle speed; and a downshifting means for performing a downshift when the current vehicle speed exceeds the first predetermined vehicle speed. and a release means for canceling constant speed travel control by the constant speed travel means when the current vehicle speed exceeds the second predetermined vehicle speed.