JPH0790721B2 - Car constant speed running device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a constant-speed traveling device for an automobile, which keeps the vehicle speed at a desired set value for constant-speed traveling.

(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. When the vehicle speed reaches a desired vehicle speed, this constant speed traveling device sets the vehicle speed as a target value for constant speed traveling by a set operation by the driving vehicle, and thereafter compares the set vehicle speed with the actual vehicle speed. Then, when a difference occurs between the two, the actual vehicle speed is made to match the set vehicle speed by controlling the slot valve of the engine according to the difference. As such a constant speed traveling device, for example,
Some are disclosed in 57-164228.

The operation of such a constant speed traveling device is performed by operating a switch or the like by a driving vehicle while traveling, and after starting the constant speed traveling control by this operation, normally, in order to cancel this control, A switch that operates simultaneously with the operation of the brake pedal, the clutch pedal, etc. is provided, and the switch is used to cancel the constant speed running. In such a case, for example, when the switch fails and constant-speed running is not released even when the brake pedal is depressed, when the foot is released from the brake pedal, the vehicle accelerates to the set vehicle speed again, which is dangerous for running. There is.

From this, for example, in JP-A-55-29016,
In addition to a brake switch that operates in conjunction with the operation of a brake pedal to release constant-speed traveling control, a device that releases constant-speed traveling when the vehicle speed drops below a predetermined value is disclosed.

If such a device is used, even if the brake switch fails, the constant speed traveling control can be released and the safety in traveling can be improved, but the vehicle speed must drop below a predetermined value. If the vehicle speed does not drop significantly even if the brake pedal is operated, there is a problem that the constant speed running cannot be released.

(Object of the invention) The present invention has been made in view of such a problem, and even if the brake switch as a switch for releasing the constant speed traveling control fails, the constant speed is immediately applied when the brake is operated. It is an object of the present invention to provide a constant speed traveling device for an automobile capable of canceling traveling control.

(Structure of the Invention) The structure of the constant speed traveling device of the present invention will be described based on the claim correspondence diagram of FIG. The constant speed traveling device of the present invention compares the actual vehicle speed detected by the vehicle speed detection means B1 with the set vehicle speed in the vehicle speed control means B2, and outputs an operation signal from the vehicle speed control means B2 to the fuel supply means B3 to supply the fuel. The means B3 controls the amount of fuel supplied to the engine by opening and closing the throttle valve, etc., so that the actual vehicle speed is maintained at a substantially set vehicle speed.On the other hand, the engine speed detecting means for detecting a change in the engine speed. B4 is provided, the constant speed traveling system releasing means B5 determines whether or not the reduction rate of the engine speed detected by the engine rotation detecting means B4 is larger than a predetermined value, and when the reduction rate is larger than a predetermined value, It is characterized in that the constant speed traveling system canceling means B5 cancels the constant speed traveling control by the vehicle speed control means B2.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, the constant speed traveling device has a controller 5 connected via a main switch 4 to a power supply circuit 3 guided from an electric power supply 1 via an ignition switch 2, and the controller 5 has a vehicle speed. The signals from the accelerator switch 6, the coast switch 7 and the resume switch 8 as setting means and the signal from the vehicle speed sensor 9 are input, and the controller 5 outputs signals to the solenoids 11a, 12a, 13a of the actuator 10. It has become so. Here, the controller 5 plays a role as a vehicle speed control means and a constant speed traveling system releasing means, is constituted by a microcomputer, and has various arithmetic processing units (CPU) and a read-only memory (ROM) containing a control program. It also includes a random access memory (RAM) for temporarily storing various data.

The accelerator switch 6, the coast switch 7 and the resume switch 8 are connected between the controller 5 and the ground. Among these switches, the accelerator switch 6 is a switch that also has the function of a set switch. The vehicle speed indicated by the signal is, for example, 40 to 100k
By turning on when the desired vehicle speed is reached within the range of m / h, the vehicle speed setting function that sets the vehicle speed at that time as the set vehicle speed for constant speed traveling, and by holding the ON state, During this period, the set vehicle speed is increased, and when the set vehicle speed is turned off, the acceleration function is provided to perform constant speed running at the increased vehicle speed. Further, the coast switch 7 is used when decelerating during constant speed running, and the set vehicle speed decreases during ON operation. Further, when the constant speed traveling control is released due to a cause other than the OFF operation of the main switch 4, the resume switch 8 is turned on to restore the set vehicle speed before the release. Then, based on the signal from the operation of these switches 6, 7 and 8 and the signal from the vehicle speed sensor 9, the controller 5 causes the solenoids 11a, 12a and 13 of the actuator 10 to operate.
The operation signal is output to a to maintain the vehicle speed, accelerate, decelerate, or restore.

Further, in this constant speed traveling device, a clutch switch 14 as constant speed traveling canceling means for canceling the constant speed traveling control and a brake switch 15 are arranged in parallel between the power supply circuit 3 and the controller 5. And these switches 1
4 and 15 are turned on when the clutch is disengaged and the brake is actuated to input a release signal to the controller 5 to release the constant speed traveling control by the controller 5.

The controller 5 is also connected to an engine rotation sensor 30 that detects the number of revolutions of the engine.
The decrease rate of the engine speed is obtained based on the engine speed information sent from the controller 30 to the controller 5, and it is determined whether or not the decrease rate is equal to or more than a predetermined value. It acts as a traveling system releasing means to release the constant speed traveling control.

Next, the structure of the actuator 10 will be described.
As shown in the figure, the actuator 10 is a negative pressure diaphragm type actuator, and the inside of the casing 16 is a negative pressure chamber 18 that is made airtight by a rubber diaphragm 17 to the outside and a through hole 19 to the outside. Atmospheric chamber 20 communicated with
And urging the diaphragm 17 toward the atmosphere chamber 20 by a spring 21 arranged in the negative pressure chamber 18, and applying a negative pressure to the negative pressure chamber 18 on the end surface of the casing 16. A negative pressure introduction solenoid valve 11 for controlling the introduction and first and second atmosphere introduction solenoid valves 12 and 13 (the second atmosphere introduction solenoid valve 13 is not shown) are provided. The rod 22 connected to the diaphragm 17 penetrates the atmosphere chamber 20 in a state of being slidably held by the bearing portion 23 provided in the casing 16 and is projected to the outside, and the wire 24 is attached to the outside. The throttle valve 25 is connected to the throttle valve 25 provided in the intake passage of the engine via the throttle valve 25, and the throttle valve 25 is operated in the opening direction when the diaphragm 17 moves in the direction A (the negative pressure chamber 18 side).

Further, the negative pressure introducing solenoid valve 11 has a valve body 11c which opens a passage 11b having one end connected to the negative pressure introducing pipe 26 led from a negative pressure source and the other end communicating with the negative pressure chamber 18. The valve body 11c is urged by a spring 11d so as to shut off the passage 11b and opens the passage 11b against the spring 11d when the solenoid 11a is energized. Be moved to. Similarly, the first atmosphere-introducing solenoid valve 12 (the same applies to the second atmosphere-introducing solenoid valve 13) also has a valve body having a passage 12b whose one end is open to the atmosphere and whose other end is in communication with the negative pressure chamber 18. The valve body 12c is configured to be opened and closed by 12c, and the valve body 12c is urged by a spring 12d so as to open the passage 12b, and also cuts off the passage 12b against the spring 12d when the solenoid 12a is energized. It has become. Then, the solenoids 11a, 12a in these solenoid valves 11, 12, 13
The negative pressure in the negative pressure chamber 18 of the actuator 10 is controlled and the diaphragm 17 is displaced according to the negative pressure by controlling the energization of 12a by the signal from the controller 5 shown in FIG. Thus, the opening of the throttle valve 25 is controlled.

Next, the specific operation of the actuator will be described.

When the vehicle speed is in the range of 40 to 100 km / h during normal traveling, if the accelerator switch 6 connected to the control device 5 of the constant speed traveling device is turned on, the signal from the vehicle speed sensor 9 indicates that time. The vehicle speed is set in the controller 5 as a set vehicle speed, and thereafter, the controller 5 is made to match the actual vehicle speed with the set vehicle speed while comparing the set vehicle speed with the actual vehicle speed indicated by the signal from the vehicle speed sensor 9. A signal is output to the actuator 10.

That is, when the actual vehicle speed becomes lower than the set vehicle speed, the controller 5 causes the negative pressure introducing solenoid valve 11 in the actuator 10 and the solenoid 11 of the atmosphere introducing solenoid valve 12 to operate.
An energization signal is output to a and 12a, the negative pressure introducing solenoid valve 11 is opened, and the first atmosphere introducing solenoid valve 12 is closed.
Therefore, a negative pressure is introduced into the negative pressure chamber 18 of the actuator 10 to displace the diaphragm 17 in the A direction, and along with this, the throttle valve 25 is operated in the opening direction via the rod 22 and the wire 24 to the engine. Fuel supply increases. As a result, the actual vehicle speed rises and matches the set vehicle speed. On the other hand, when the actual vehicle speed is higher than the set vehicle speed, the solenoids 11a and 12a are not energized, so that the negative pressure introducing solenoid valve 11 is closed and the first atmosphere introducing solenoid valve 12 is opened, so that the negative pressure is increased. Room
The negative pressure in 18 is reduced. Therefore, the above diaphragm
17 is displaced in the anti-A direction and the throttle valve 25 is actuated in the closing direction to reduce the fuel supply amount to the engine, whereby the actual vehicle speed is reduced to match the set vehicle speed.
During such a constant speed traveling control, the solenoid 13a of the second atmosphere introducing solenoid valve 13 is always energized, and the valve 13 is kept closed. Further, when the clutch switch 14 or the brake switch 15 as the means for releasing the constant speed traveling control is turned on, the solenoids 11 mentioned above are released.
The energization to a, 12a, 13a is all stopped, the negative pressure introducing solenoid valve 11 is closed, and the first and second atmosphere introducing solenoid valves 12, 13 are opened to release the negative pressure chamber 18 to the atmosphere. By doing so, the operation of the actuator 10 is completely stopped, and the throttle valve 25 of the engine is operated by operating the accelerator pedal.

Further, when it is determined that the rate of decrease in the engine speed detected by the engine speed sensor 30 is equal to or higher than the predetermined value, the controller 5 causes the solenoids 11a, 12a,
The energization of 13a is all stopped, the constant speed traveling control is released, and the throttle valve 25 is activated in response to the operation of the accelerator pedal.

The control contents of the controller 5 in the constant speed traveling device described above will be described with reference to the flowchart of FIG.

This control starting from step S1 starts with step S2
In, constant speed traveling control is performed. As described above, this constant speed traveling control compares the set vehicle speed with the actual vehicle speed, and when the actual vehicle speed is lower than the set vehicle speed, increases the opening of the throttle valve, and conversely when the actual vehicle speed is higher than the set vehicle speed. In this system, the operation of the actuator is controlled so that the opening degree of the throttle valve is made small so that the actual vehicle speed substantially matches the set vehicle speed. Next, in step S3, the engine rotation sensor
The engine speed is detected by 30. Thereafter, in step S4, the engine speed reduction rate dN / dt is calculated, and it is determined whether or not the engine reduction rate dN / dt is larger than a predetermined value K. When dN / dt ≦ K, the process returns to step S2 to continue the constant speed running, while when dN / dt> K,
After proceeding to step S5 to release the constant speed traveling control, proceeding to step S6, the present flow is ended. It should be noted that in this control, instead of detecting the rate of decrease in vehicle speed, the rate of decrease in engine speed, which has a relatively large change, is detected, so it is easy to determine whether the rate of decrease exceeds a predetermined value. . In addition, since the rate of decrease is detected instead of the amount of decrease, it is determined whether or not constant speed running needs to be released immediately after the engine speed starts to decrease due to brake operation, and the constant speed running control is released. Can be made.

(Effects of the Invention) As described above, according to the present invention, in the constant speed traveling device that controls the amount of fuel supplied to the engine to perform constant speed traveling, the rate of decrease in engine rotation exceeds a predetermined value. In this case, the constant speed running control is released, so even if the brake switch fails and the constant speed running control release signal is not output from this brake switch even if the brake pedal is depressed. Also, when the engine speed is reduced by the brake operation, the constant speed traveling control can be immediately released, and the runaway of the vehicle due to the failure of the brake switch can be prevented.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a constant speed traveling device according to the present invention, FIG. 2 is a sectional view of an actuator in the device, FIG. 3 is a block diagram showing a configuration of the device, and FIG. 4 is a constant speed by the device. It is a flowchart which shows the content of traveling control. 5 ... Controller, 6 ... Accelerator switch 7 ... Coast switch, 8 ... Resume switch 10 ... Actuator, 25 ... Throttle valve 30 ... Engine rotation sensor

Claims (1)

[Claims] 1. A vehicle speed detecting means for detecting an actual vehicle speed, a fuel supplying means for controlling an amount of fuel supplied to an engine, and an actual vehicle speed detected by the vehicle speed detecting means are compared with a preset vehicle speed. A vehicle speed control means for controlling the operation of the fuel supply means so as to run at a constant speed while maintaining the actual vehicle speed substantially at the set vehicle speed; an engine speed detection means for detecting a change in the engine speed; A constant speed traveling system releasing means for releasing the constant speed traveling control by the vehicle speed control means when the rate of decrease of the engine speed detected by the rotation detecting means is larger than a predetermined decreasing rate. A constant-speed running device for automobiles.