JPH03136928A - Constant speed running device for vehicle - Google Patents

Abstract

PURPOSE:To soften change in engine output by providing a means which prohibits outputting a throttle valve open signal for the specified period of time by a constant speed running device upon receiving the throttle valve fully close signal of an idle switch. CONSTITUTION:When an idle switch 7 is turned off, the controller 1 of a constant speed running device (a means to prohibit outputting the open signal of a throttle valve 3 for the specified period of time) outputs throttle open/close signals to an actuator 5 so that constant speed running control is assumed. When the controller 1 detects that the switch 7 is turned on, it is judged whether or not a timer time set in advance has elapsed since this point of time. During the aforesaid period of the timer time, it is prohibited that the throttle open signal is outputted to the actuator 5 of the controller 1. After the timer time has elapsed while the timer time is counted up, the throttle open signal is allowed to be outputted again so that the timer is cleared up. Namely, even if the switch 7 is turned on and off during the period of the timer time, cut in fuel supply is kept on so that frequency in recovery is thereby lessened.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a vehicle constant-speed running system installed in a vehicle, and particularly to a vehicle constant-speed running system that is combined with an electronic engine control system. Related to constant speed traveling device.

(Prior Art) Some recent vehicles are equipped with a constant speed traveling device that automatically drives the vehicle at a constant speed. In such a vehicle, the driver accelerates until the desired speed is reached, looks at the speedometer, and when the desired speed is reached, sets the vehicle speed using the vehicle speed setting button, etc., and then the actual vehicle speed and the set vehicle speed are set. The opening degree of the throttle valve or the opening degree of the carburetor is adjusted so that the deviation from the actual vehicle speed becomes zero, and the speed is controlled so that the actual vehicle speed becomes the set vehicle speed. Such a constant speed traveling device is known, for example, from Japanese Patent Application Laid-open No. 59-58134, and when driving at a constant speed on a highway, it is not necessary for the driver to keep the accelerator pedal pressed all the time. This is convenient because when you press the clutch or brake pedal, the constant speed driving function is canceled and you can use the accelerator pedal to accelerate beyond the set speed, and when you stop operating the accelerator pedal, the engine brake decelerates and then returns to the set speed. It is designed to run at a constant speed.

On the other hand, some recent vehicles use electronic control units to control their engines. In such vehicles,
In order to reduce fuel consumption and reduce emissions, the throttle switch (known as the idle switch) recognizes when the throttle valve is fully closed while the vehicle is running, cuts off the fuel supply to the engine (Fuel Cut), and then opens the throttle valve again. Many of them are designed to sometimes restart the fuel supply (fuel cut recovery).

(Problem to be Solved by the Invention) However, in the combination of such a conventional constant speed traveling device and an electronic engine control device, it is difficult to fully open the throttle valve when traveling at a constant speed on a gentle downhill slope. If you try to maintain constant speed near the closed position, you will have to repeat engine fuel cut and fuel cut recovery. That is, when the vehicle speed increases or decreases due to a change in the downhill slope, the constant speed traveling device repeats the opening/closing signal of the throttle valve in response to this, and the idle switch detects this every time the throttle valve is fully closed.

Since this engine fuel cut and its recovery are performed simultaneously on all cylinders, the engine output torque suddenly changes, resulting in a longitudinal acceleration called a fuel cut surge (
G) occurs frequently. Therefore, there is a possibility that the passenger may feel uncomfortable. .

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a constant speed driving device for a vehicle that can reduce the frequency of fuel cut and fuel recovery, and can soften changes in engine output.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention provides a constant speed cruise control device that controls the vehicle speed to a constant set speed by adjusting the opening degree of a throttle valve. , an idle switch that detects a fully closed state of the throttle valve, and an engine electronic control device that receives an output signal from the idle switch and controls fuel cut to the engine and fuel cut recovery, the throttle valve of the idle switch Means is provided for inhibiting the output of the throttle valve open signal by the constant speed traveling device for a predetermined period of time when the valve fully closed signal is received.

Further, in the present invention, when performing fuel cut recovery, #11 is performed so that it is performed for each predetermined number of cylinders at predetermined time intervals.

Further, a constant speed driving control device that controls the vehicle speed to a constant set speed by adjusting the opening degree of the throttle valve, and an idle switch that detects a fully closed state of the throttle valve;
an engine electronic control device that controls fuel cut and fuel cut recovery to the engine in response to the output signal of the idle switch; The configuration is such that the control is performed at predetermined time intervals.

(Function) According to the above configuration, when the throttle valve becomes fully closed during constant speed driving and the idle switch detects this,
Since the constant speed cruise control device prohibits the output of the throttle opening signal for a predetermined period of time and then allows it, the frequency of fuel cut and fuel cut recovery is reduced.

In general, the engine electronic control unit performs engine fuel cut recovery for each predetermined number of cylinders at predetermined time intervals.
As a result, changes in engine output during fuel cut recovery become smoother, and fuel cut surges are softened.

(Example) Embodiments of the present invention will be described below based on the drawings.

The vehicle of this embodiment includes a constant speed traveling device controller 1 of a constant speed traveling control device A, and a constant speed traveling device controller 1 of a constant speed traveling control device A.
a constant speed traveling device actuator 5 that adjusts the opening degree of the throttle valve 3 in response to an output signal from the throttle valve 3; and an idle switch 7 that detects the fully closed state of the throttle valve 3;
The engine electronic control controller 11 controls the supply of fuel to the injector 9 of the engine.

The constant speed traveling device controller 1 and the engine electronic control controller 11 are both configured using microcomputers, and read necessary information according to a program stored in a ROM, perform predetermined processing, and issue output signals. It is something.

An idle switch 7 is connected to the input side port of the constant speed traveling device controller 1, and a constant speed traveling device actuator 5 and an engine electronic control controller 11 are connected to the output side port.

The input side boat of the engine electronic controller 11 includes a constant speed running device controller 1 and an idle switch 7.
is connected, and an engine injector 9 is connected to the output side port.

The idle switch 7 is turned on when the throttle valve 3 is fully closed, and inputs a throttle close signal to the constant speed traveling device controller 1 and the engine electronic controller 11.

Next, the operation of this embodiment will be explained using the flowcharts of FIGS. 2 and 3.

When the vehicle is running at a constant speed, the constant speed running device controller 1 outputs a throttle opening/closing signal to the constant speed running device actuator 5 to perform constant speed running control, as shown in FIG. is output to the engine electronic controller 11 (step Sl). Then, it is determined whether the idle switch 7 is ON or not (step S2
). This determination is to determine whether or not the throttle valve 3 is fully closed. When the throttle valve is fully closed, the idle switch 7 is turned on. At this point, the idle switch 7 is turned OFF.
At this time, the constant speed traveling device controller 1 outputs a throttle opening/closing signal to the actuator 5 to perform constant speed traveling control (swipe S3), and the constant speed traveling device controller 1
When detecting that the idle switch 7 is turned on, it is determined whether a preset timer time has elapsed since the time when this was detected (swipe S4).

During this timer time (for example, 10-odd seconds), the output of the throttle opening signal to the actuator 5 of the constant speed traveling device controller 1 is prohibited (step S9), and after the timer time has elapsed due to timer count-up (step 510). The output of the throttle open signal is allowed again (step S5), and the timer is cleared (step S6). With this configuration, the idle switch 7 remains in the fuel cut state even if it is ON or 0FFt during the timer time, and the opening degree of the fuel cut recovery can be reduced. Therefore, changes in engine output can be softened, and riding comfort can be significantly improved.

Then, when the timer is cleared, the process moves to step S3, where a throttle opening/closing signal is output to the actuator 5, and constant speed driving control is performed.

During the constant speed traveling control described above, while the constant speed traveling device controller 1 is prohibited from outputting the throttle opening signal,
That is, during the timer period during which the throttle is held in the closed state, the vehicle speed may be significantly reduced due to changes in the road surface slope, etc.

Therefore, the constant speed traveling device controller 1 compares the actual vehicle speed and the set vehicle speed during the timer time, and determines whether the actual vehicle speed difference has fallen by more than 2 km/h than the set vehicle speed ( Step S7) This judgment is YES
If so, the constant speed traveling device controller 1 outputs a set vehicle speed -2 km/h signal to the engine electronic controller 11 indicating that the actual vehicle speed has significantly decreased (step S8), and also allows the output of the throttle open signal. (Step S5). Then, the timer is cleared (step S6), and a throttle opening/closing signal is output (step S6).
3) Constant speed running control is performed. Therefore, even if a gentle downward slope suddenly becomes a slight upward slope, constant speed traveling can be maintained.

In addition, in step S7, even if the actual vehicle speed falls below the set vehicle speed, the output of the throttle open signal is prohibited as described above until the timer time elapses when the difference is less than 2 km/h (step S9). ).

On the other hand, as shown in FIG. 3, during engine control (step 511
), it is determined whether the fuel is being cut (step 1).
2). Here, if the fuel is not being cut, it is determined whether or not the idle switch 7 is ON (step 813).
), when the idle switch 7 is ON, that is, when the throttle is fully closed, the fuel is immediately cut off (step 514). Therefore, on a slope with a gentle downward slope,
When trying to maintain constant speed driving with the throttle fully closed, cutting the fuel can improve fuel efficiency and emissions. Further, when the idle switch 7 is OFF in step S13, the process returns to step S11.

If the fuel is being cut in step S12, it is determined whether the idle switch 7 is OFF (step 515). Here, when the idle switch 7 is ON, the process moves to step S14 and the fuel cut is continued.
When the idle switch 7 is OFF, it is determined whether a constant speed driving control signal is input (step 5).
16).

When the constant speed driving control signal is input,
Constant speed driving control is performed according to the flow shown in Figure 2.
The throttle open signal is inhibited until the timer period has elapsed. Then, it is determined whether or not the set vehicle speed -2 km/h signal is input (step 517), and here, even if the actual vehicle speed is lower than the set vehicle speed, the difference is 2 km/h.
If the speed does not exceed m/h, set vehicle speed - 2km/h.
If the h signal is not input and the timer time of the constant speed traveling device controller 1 has elapsed, a throttle opening/closing signal is output to the actuator 3 (step S3),
When the throttle valve 3 is opened, for example in the case of a four-cylinder engine, injector #1. #4. #2. Fuel cut recovery is performed for each cylinder in the order of #3 at intervals of about 1 second (step 518). By performing recovery at intervals of one cylinder at a time in this manner, it is possible to smooth the change in engine output during recovery and soften the longitudinal G called fuel cut surge.

Further, in step S16, the actual vehicle speed decreases significantly and when the constant speed driving control signal is not input, and in step S17, the actual vehicle speed decreases significantly by 2 times the set vehicle speed.
When the km/h signal is being input, the process moves to step S19 and recovery is performed simultaneously for the cylinders.

By recovering all cylinders simultaneously in this manner, deceleration of vehicle speed can be kept to a minimum.

By performing constant speed control as described above, the frequency of fuel cut and fuel cut cut recovery is reduced, and the change in engine output during recovery becomes smoother, making it possible to soften fuel cut surges. .

Furthermore, deceleration of the actual vehicle speed relative to the set vehicle speed can be minimized during constant speed driving.

Note that fuel cut recovery is not limited to each cylinder, but can be performed at predetermined time intervals for every two cylinders in the case of a dispersed cylinder, for example, four cylinders.

[Effects of the Invention] As is clear from the above description, according to the configuration of the present invention, it is possible to smooth the change in engine output during fuel cut and fuel cut recovery, and to soften the fuel cut surge. Therefore, it is possible to eliminate the discomfort of the occupants.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a constant speed traveling device for a vehicle according to an embodiment of the present invention, FIG. 2 is a flowchart showing the control action of the constant speed traveling device controller, and FIG. 3 is a flowchart showing the control action of the engine electronic controller. FIG. A...Constant speed traveling control device B...Engine electronic control device 1...Constant speed traveling device controller (means for prohibiting the output of the throttle valve open signal for a predetermined time) 3...Throttle valve 7... idle switch

Claims (3)

[Claims] (1) A constant speed cruise control device that controls the vehicle speed to a constant set speed by adjusting the opening degree of the throttle valve, an idle switch that detects the fully closed state of the throttle valve, and an idle switch that receives the output signal of the idle switch. and an electronic engine control device that controls fuel cut to the engine and fuel cut recovery, and prohibits the output of the throttle valve open signal by the constant speed traveling device for a predetermined period of time when the throttle valve fully closed signal from the idle switch is received. A constant speed traveling device for a vehicle, characterized in that it is provided with means for. (2) The constant speed running system for a vehicle according to claim 1, wherein the engine electronic control device controls the fuel cut recovery to be performed at predetermined time intervals for each predetermined number of cylinders. (3) a constant speed cruise control device that controls the vehicle speed to a constant set speed by adjusting the opening degree of the throttle valve; an idle switch that detects the fully closed state of the throttle valve; and an idle switch that receives the output signal of the idle switch. and an engine electronic control device that controls fuel cut to the engine and fuel cut recovery, and the engine electronic control device controls the fuel cut recovery to be performed for each predetermined number of cylinders at predetermined time intervals. A constant speed traveling device for a vehicle characterized by the following.