JPH0342208B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a vehicle speed control device that can automatically control vehicle speed to a target vehicle speed.

Prior Art and Problems Vehicle speed control devices that can automatically control vehicle speed to a target vehicle speed without operating an accelerator pedal have been proposed in the past. Conventional vehicle speed control devices are equipped with an actuator that adjusts the opening degree of the throttle valve, and control the actuator based on the difference between the actual vehicle speed and a predetermined target vehicle speed. This method controls the opening degree of the throttle valve so that it becomes zero, but it has the following drawbacks. That is, it is necessary to provide an actuator with a complicated structure that can arbitrarily adjust the opening degree of the throttle valve, which has the drawback of making the device expensive. Moreover, it was completely useless when the vehicle speed was not controlled.

Purpose of the Invention In order to improve the above-mentioned drawbacks, the present invention shares an actuator for vehicle speed control and an actuator for idle control, and its purpose is to provide automatic vehicle speed control with an economical configuration. The goal is to provide equipment.

Structure of the Invention The present invention provides a bypass passage that bypasses upstream and downstream of a throttle valve, first and second branch passages provided in the bypass passage, and first and second branch passages of the bypass passage. A first solenoid valve provided at the confluence of the two and a second solenoid valve provided at either the first or second branch road determine whether or not the vehicle speed is being controlled. a first determination means, a second determination means for determining whether or not the vehicle is in an idling state, and when the first determination determines that the vehicle speed is being controlled, the second solenoid valve is fully opened;
If it is determined that it is not during vehicle speed control, the second
a first control means that fully closes the solenoid valve; and when the first determination means determines that the vehicle speed is being controlled, the first control means controls the first solenoid valve based on the target vehicle speed and the actual vehicle speed; and a second control means for controlling the opening degree of the first solenoid valve, and when the second determination means determines that the opening is in the idling state, the opening of the first solenoid valve is controlled based on the target engine speed and the actual engine speed. The present invention is characterized by comprising a third control means for controlling the opening degree.

That is, the present invention controls the amount of air taken into the engine in vehicle speed control by the amount of air in the bypass passage that bypasses the throttle valve, and also controls the valve for vehicle speed control and the valve for idling control by the first control valve. It was designed so that it can be used for both purposes.

However, idling control requires precise control of a small amount of intake air, and vehicle speed control requires controlling the amount of intake air over a wide range. Therefore, in order to control both with one valve, the amount of change in the intake air amount is large, and an expensive valve that can perform precise control is required.
The cost will increase.

Therefore, in the present invention, the bypass path is configured with two branch paths, and one of the branch paths is provided with a second solenoid valve, so that the opening/closing amount of the first control valve is controlled during vehicle speed control and idling control. The characteristics of the amount of intake air are changed.

That is, during vehicle speed control, the second solenoid valve is fully opened and intake air is supplied from both of the two branched paths via the first solenoid valve, thereby increasing the apparent diameter of the bypass path. This increases the change in the amount of intake air depending on the degree of opening and closing of the first electromagnetic valve, making it possible to supply a large amount of intake air.

Also, during idling control, the second solenoid valve is fully closed to supply intake air from either of the two branched paths via the first solenoid valve, reducing the apparent diameter of the bypass path. do.
This makes it possible to reduce the change in the amount of intake air depending on the degree of opening and closing of the second solenoid valve, thereby making it possible to precisely change the small amount of intake air.

Embodiment of the Invention FIG. 1 is a block diagram of an embodiment of the invention, in which 1 is a microprocessor, 2 is a data output section, 3 is a data input section, 4 is a memory, 5 is a drive circuit, and 6 is a pulse Generation circuit, 7 is cooler switch,
8 is a gear switch, 9 is a target speed setting section, 10 is an internal combustion engine, 11 is an air cleaner, 12 is an air flow meter, 13 is a throttle valve, 14 is a bypass passage that bypasses the upstream and downstream of the throttle valve 13, 15 and 16 are A branch path provided in the bypass passage 14, 17 and 18 are electromagnets, 19 and 20 are movable parts, 21 and 22 are springs, 23 is a bellows, and 24
25 is a vehicle speed sensor, and 26 is a crank angle sensor.

Intake air is supplied to the internal combustion engine 1 from an air cleaner 11 via an air flow meter 12 and a throttle valve 13.
0 cylinders, and fuel is injected from the injector 24. The flow of intake air is controlled by a throttle valve 13 that is linked to the accelerator pedal, but the throttle valve 13 is almost closed during idling. During idling, intake air is guided upstream of the throttle valve 13 via the bypass passage 14, the branch passage 15, and the movable part 19 movable in the direction of the arrow. Furthermore, the movable part 19
By changing the duty ratio of the pulse signal applied from the pulse generating circuit 6 to the electromagnet 17, its position changes and the amount of air flowing through the branch path 15 is controlled. Further, the branch path 16 is closed by the movable part 20 during idling and normal running. This adjusts the air flow rate required during idle.

Further, FIG. 2 is a flowchart showing the processing contents of the microprocessor 1, and the operation of FIG. 1 will be explained below with reference to FIG.

The microprocessor 1 determines whether or not it is in an idling state based on the state of the gear switch 8 (step S1). If it is determined that the microprocessor 1 is in the idling state, the microprocessor 1 determines whether the cooler switch 7 is on (step S2). Next, the microprocessor 1 determines the target rotational speed NF of the internal combustion engine 10 based on the determination result. That is, the judgment result in step S2 is YES.
In this case, NF=NF1 is set (step S3), and when the judgment result is NO, NF=NF1+α is set (step S4). Next, the microprocessor 1 determines the actual rotation speed NE based on the rotation angle position signal output from the crank angle sensor 26 (step S
5) Next, the difference ΔE=NF-NE between the target rotational speed NF and the actual rotational speed NE is determined (step S6).
Next, the microprocessor 1 calculates the difference ΔE using the following formula:
It is determined which of (1) to (3) is satisfied (step S7).

ΔN＞0 ...(1) ΔN=0 ...(2) ΔN<0 ...(3) If it is determined that formula (1) is satisfied, the duty ratio obtained in the previous processing cycle is The value obtained by adding the constant β to D is set as the new duty ratio D (step S8), and if it is determined that equation (2) is satisfied, the duty ratio D obtained in the previous processing cycle is set as the new duty ratio. The duty ratio D is set as D (step S9), and if it is determined that formula (3) is satisfied, the duty ratio D obtained in the previous processing cycle is set.
The value obtained by subtracting the constant β from is the new duty ratio D
(Step S10). Next, the microprocessor 1 applies a control signal created based on the new duty ratio D obtained in steps S8 to S10 to the pulse generation circuit 6 via the data output section 2 (step S11).

As a result, the pulse generation circuit 6 goes to step S8.
A pulse signal with the duty ratio D determined in steps S10 to S10 is applied to the electromagnet 17, the movable part 19 moves to a position corresponding to the duty ratio, and the amount of air flowing through the branch path 15 is controlled. And microprocessor 1
After the process of step S11 is completed, the program moves to the next control program in step S12.

If it is determined in step S1 that the vehicle is not in an idling state, the microprocessor 1 determines whether or not a setting switch (not shown) provided in the target speed setting section 9 is turned on (step S13). ). If it is determined that the setting switch is on, the microprocessor 1 sets the signal α applied to the drive circuit 5 via the data output section 2 to "1" (step S14). As a result, the drive circuit 5 excites the electromagnet 18, the movable part 20 moves in the direction of the arrow, and the branch path 16 becomes fully open.
Further, if it is determined that the setting switch is off, the microprocessor 1 sets the output signal α of the data output section 2 to "0" (step S15), and thereby the drive circuit 5 turns off the excitation of the electromagnet 18. The movable portion 20 is in the illustrated state, and the branch path 16 is in the fully closed state.

When the signal α is set to "1" in step S14, the microprocessor 1 reads the target vehicle speed SF set in the target vehicle speed setting section 9 (step S16), and then determines the actual speed based on the detection result of the vehicle speed sensor 25. Find the vehicle speed SV of (step S17),
Next, the difference between target vehicle speed SF and vehicle speed SV ΔS=SF−SV
(Step S18). Next, the microprocessor 1 determines which of the following equations (4) to (6) the difference .DELTA.S satisfies (step S19).

ΔS＞0 ...(4) ΔS=0 ...(5) ΔS<0 ...(6) If it is determined that formula (4) is satisfied, the duty ratio obtained in the previous processing cycle is D1
The value obtained by adding the constant θ to the new duty ratio D1
(step S20), and if it is determined that equation (5) is satisfied, the duty ratio D1 in the previous processing cycle is set (step S21), and equation (6) is set.
If it is determined that the following is satisfied, the value obtained by subtracting the constant θ from the duty ratio D1 in the previous processing cycle is set as a new duty ratio D1 (step S22).

Next, the microprocessor 1 performs step S2.
A control signal created based on the duty ratio D1 determined in steps 0 to S22 is applied to the pulse generation circuit 6 (step S23). As a result, the pulse generating circuit 6 applies the pulse signal with the duty ratio D1 obtained in steps S20 to S22 to the electromagnet 17, the movable part 19 moves to the position corresponding to the duty ratio D1, and the air flowing through the branch paths 15 and 16 is moved to the position corresponding to the duty ratio D1. Amount controlled. When the process in step S23 is completed, the microprocessor 1 moves on to the next control program in step S12.

In this way, in this embodiment, the branch passage 16 is fully opened during automatic vehicle speed control to obtain the amount of air necessary for the vehicle to run. Therefore, an actuator is provided to control the opening degree of the throttle valve. The construction is economical compared to conventional devices that require

Although not explained in the embodiment, if an operation that cancels the automatic vehicle speed control (for example, a brake operation) is performed while performing steps S14 to S23, the microprocessor 1 is for moving to step S12. Although not explained in the embodiment, the differences ΔN and ΔS obtained in steps S6 and S18 are made to correspond one-to-one with the duty ratios D and D1, and the duty ratio is determined based on the differences ΔN and ΔS. Of course, D and D1 may also be determined.

Effects of the Invention As explained above, the present invention provides the first and second branch paths in the bypass passage, and the first and second branch paths.
A second solenoid valve (consisting of an electromagnet 18, a movable part 20, etc. in the embodiment) is provided on either one of the branch paths,
When controlling the speed of the vehicle, the second solenoid valve is fully opened to allow sufficient air to flow through the first solenoid valve (which in the embodiment consists of an electromagnet 17, a movable part 19, etc.) and is necessary for driving. In addition, since the first solenoid valve can be used in common with the idle control valve, there is an advantage that the structure can be made more economical compared to conventional devices that require an actuator to control the opening degree of the throttle valve. be.

Note that the second control valve only needs to be in two states, fully open and fully closed, and there is no need to control it to an intermediate value, so a relatively inexpensive valve can be used.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG.
The figure is a flowchart showing the processing contents of the microprocessor 1. 1 is a microprocessor, 2 is a data output section,
3 is a data input section, 4 is a memory, 5 is a drive circuit,
6 is a pulse generation circuit, 7 is a cooler switch, 8 is a gear switch, 9 is a target speed setting section, 10 is an internal combustion engine, 11 is an air cleaner, 12 is an air flow meter, 13 is a throttle valve, 14 is a bypass passage, 15 and 16 are Branching path, 17 and 18 are electromagnets,
19 and 20 are movable parts, 21 and 22 are springs, 23 is a bellows, 24 is an injector, 25 is a vehicle speed sensor, and 26 is a crank angle sensor.

Claims (1)

[Scope of Claims] 1. A bypass passage that bypasses upstream and downstream of the throttle valve; first and second branch passages provided in the bypass passage; and the first and second branch passages of the bypass passage. A first solenoid valve provided at the confluence of the roads; A second solenoid valve provided at either the first or second branch road; Determine whether or not vehicle speed control is in progress. a first determining means for determining whether or not the vehicle is in an idling state; and a second determining means for determining whether or not the vehicle is in an idling state.
determining means, and when the first determining means determines that the vehicle speed is being controlled, fully opening the second electromagnetic valve;
If it is determined that it is not during vehicle speed control, the second
a first control means that fully closes the solenoid valve; and when the first determination means determines that the vehicle speed is being controlled, the first control means controls the first solenoid valve based on the target vehicle speed and the actual vehicle speed; a second control means for controlling the opening degree of the first electromagnetic valve based on the target engine speed and the actual engine speed when the second judgment means determines that the valve is in an idling state; A vehicle speed control device comprising: third control means for controlling an opening degree.