JPS6056640A - Car-speed controller - Google Patents

Abstract

PURPOSE:To permit the efficient car-speed control by eliminating the variation of the actuator driving force caused by the variation of the negative pressure of a negative pressure source by varying the output signal of an arithmetic means, in order to eliminate the influence of the variation of the negative pressure onto the adjusted pressure of the actuator. CONSTITUTION:A reckless-operation detecting circuit 20 is connected to the reset board of a CPU, and a lead switch SW2 for detecting car-speed, clutch switch SW3, stop switch SW4, set switch SW5, resume switch SW6, and a vacuum switch SW7 are connected to an outside interruption input port IRQ and input ports K2, K3, K0, and K1 through interface circuits IF1-IF6 respectively. In constant-speed routine, a release solenoid SL2 is turned ON, and it is judged that SW7 is turned ON or not. When the negative pressure is less than a prescribed value, speed deviation gain is increased. The duty value is calculated on the basis of the obtained speed deviation gain, and a control solenoid SL1 is duty- controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vehicle speed control device, and more particularly to a vehicle speed control device in which a throttle is driven by a vacuum actuator powered by negative pressure generated in an intake manifold.

Generally, this type of vehicle speed control device includes a vehicle speed detecting means, a vehicle speed storing means, a calculation means for comparing the current vehicle speed detected by the vehicle speed detecting means and the stored vehicle speed and generating an actuator control signal, and a negative pressure based on the control signal. It consists of an actuator means that regulates the negative pressure from the source and uses this as power to open and close the vehicle's throttle valve. However, in vehicles using a carburetor brake, when the load becomes large, the negative pressure generated in the intake manifold becomes small. Become. For this reason, a vacuum switch is used to detect a decrease in negative pressure, and the vacuum pump is activated accordingly to ensure the necessary negative pressure.

However, the negative pressure generated by the vacuum pump is lower than the negative pressure generated by the intake manifold, and with the same control as normal, the actuator does not generate enough force to drive the throttle I, and the deviation from the vehicle speed is There is a problem with it getting bigger. In addition, there is no other way to increase the negative pressure of the vacuum pump other than increasing the dimensions of the vacuum pump, which is not desirable in terms of vehicle manufacturing.

Therefore, an object of the present invention is to eliminate the actuator driving force change due to the fluctuation of the negative pressure due to the above-mentioned mismatch. Negative pressure detecting means for detecting pressure changes, and No. 46 from the negative pressure detecting means are input to the calculating means, and the calculating means outputs a signal so as to eliminate the influence on the actuator negative pressure due to the negative pressure change of the negative pressure source. It is characterized in that it includes means for changing.

The arithmetic means and the means for changing the output No. 46 are constituted by, for example, a one-chip microcomputer, and a program for Ilj speed 1 control is executed within this microcomputer. The pressure of the actuator is adjusted, for example, by controlling the duty of the arithmetic means output signal, and when the negative pressure generated in the intake manifold decreases, the gain of this duty is increased.

Therefore, the actuator negative pressure increases and the throttle can be pulled with a sufficiently large force. In some cases, a vacuum pump may be added, but this pump may have a relatively small capacity.

Here's the drawing #! K (Examples of the present invention will now be described.

FIG. 1 shows an electric circuit with a vehicle speed control device according to an embodiment.

This will be explained with reference to FIG. In this example, the electronic control device 10 is a single-chip microcontroller/computer CPU.
It is composed mainly of. CPU reset boat R
A runaway detection circuit 2o is connected to ESET, and 2. 3, K
O and Kl each have an interface circuit IF.
Through I, IF2, IF3, IF4, Etota, and IFC, reed switch SW2 for vehicle speed detection,
Kura Nchisui Nchi SW3, St Npusuichi SW
4, set switch SW5, resume switch S
Connect w6 and vacuum switch 5ll17.

A permanent magnet connected to a speedometer cable (not shown) is arranged near the vehicle speed detection reed switch SW2, and when the vehicle moves and the permanent magnet rotates, the contacts of SW2 open and close accordingly. When the contact of SW2 changes from closed to open, the output level of the interface circuit IFI becomes low level L, and the microcomputer CPυ
An interrupt request is made.

The clutch switch SW3 opens and closes in conjunction with the clutch pedal of the vehicle, and the stop switch SW4 opens and closes in conjunction with the brake pedal of the 11-car vehicle. A stop lamp is connected to the switch SW4 and the switch SW4.
When 4 is turned on (closed), the stop lamp lights up.

Set switch SW5 and resume switch are set.

The vacuum switch SW7 is, for example, a diaphragm type, and is arranged at the intake pipe negative pressure introduction part. When the negative pressure decreases, the vacuum switch SW7 closes, the output of the interface circuit IF8 becomes low level, and a low level signal is sent to the input port RO. is applied.

The output port 00 of the microcomputer CPU is connected to the runaway detection circuit 20, and the output ports 02 and 03 are connected to the runaway detection circuit 20.
are connected to drivers DVI and DV2, respectively. A control solenoid SLI for controlling a negative pressure actuator, which will be described later, is connected to the dry/<ov l output, and a release solenoid SL2 is connected to the output of the driver DV2.

Voltage from the vehicle battery is applied to the control solenoid SLI, the release solenoid FSL2, and the constant voltage power supply circuit 30 that generates the constant voltage Vcc via the ignition key switch SWI. The circuit 40 corresponds to the operation of the CPU when the brake is applied.
This is for disabling the stiff lease solenoid SL2.

FIG. 2 shows the configuration of the negative pressure actuator 100 controlled by the electric circuit shown in FIG. 1. See Figure 2! IC! and explain. The housing 101 has two parts 101a and 10
1b. The diaphragm 102 is held between the flange portions of two portions 101a and 101b.

The space surrounded by the diaphragm 102 and the housing 101a is a negative pressure chamber, and the diaphragm 102 and the housing 101a are
The space surrounded by OIb communicates with the atmosphere. 10
3 is a compression coil spring inserted between the housing l01a and the diaphragm 102, which pushes the diaphragm 102 back to the position of the imaginary line when the pressure in the negative pressure chamber is close to atmospheric pressure. A protrusion 104 fixed near the center of the diaphragm 102 is connected to a link of the slot I/reparve 105. The housing 101a is provided with a negative pressure intake port 107 communicating with an intake manifold 108, an atmospheric air intake port 108, and an air intake port 08.

110 is a negative pressure control valve, and 111 is an edible release valve, both of which are fixedly connected to the housing 101a, and the other end faces the control I/roll solenoid SLI. Both ends of the movable piece 112 function as valve bodies, and they open the negative pressure intake port 107, close the atmospheric air intake port 108 (as shown in the figure), or close the negative pressure several people in response to the activation and cancellation of the solenoid SLI. 107 blockage.

The air intake port 108 is opened.

Similarly to the negative pressure release valve 110, the i+J moving piece 114,
Although it has a tension coil spring 115 and a slide/id SL2, the movable piece 114 prevents the air intake 109 from being blocked (
condition shown) or open. Note that 1ift is the accelerator pedal, and 147 is the bow coil spring.

Figure 4, Figure 5, Figure 6, Figure 7, and Figure 8 [mtx
7fJ1 shows a schematic operation of the microcomputer CPU shown in FIG. The operation of the CPLI will be explained step by step without reference to each figure. Note that when the 11i is operated, the constant switch SW2 is repeatedly turned on and off, and each time SW2 is turned off, the microcomputer CPU executes external interrupt processing.

First, the program shown in FIG. 4 will be described.

When the power is turned on, initial settings are performed (St). That is, the output port is set to the initial level and the contents of the memory are cleared. Invert the output port 00 level. That is, if this boat 00 is set to a high level 1, that level is set to a low level L, and if it is set to a low level, it is set to a high level 11. This process is always executed at least once within a predetermined period of time if the CPU is operating normally, and as a result, a pulse signal with a substantially constant period is applied to the runaway detection circuit 20 from the CPU. . When a pulse signal is applied, the runaway detection circuit 20 sets the output level of the comparator CP to H, turns on the I transistor Q1, and sets the RESET terminal of the CPU to a high level 1.
Set to 1. However, when the CPU goes out of control and stops generating pulses on port 00, the output level of comparator CI) is reversed to L, transistor Q1 is turned off, and CP
A low level L is applied to the reset terminal RESET of I/.

When the reset terminal RESET becomes L, the CPU performs the same operation as when the power is turned on, so the runaway stops.

Next, in step S2, the current vehicle speed is set to the low speed limit (for example, 4
0 Km/h) or less. If NO, the stored vehicle speed is cleared in step S3, and the status flag S is set to 0 in step s4.

If the current vehicle speed is not lower than the low speed limit 7 at S2, it is determined at Step S5 whether the brake switch is turned on (closed). If any switch is turned off, the state 51, 4 . If S is set to 0 and none of the switches are turned on, it is determined in step s7 that the center switch SW4 is on, and if YES, that is, if it is turned on, the state s is set to 2 in step s8. be done. If the resume switch SW5 is turned on in step s8, the state S is set to 3 in step SIO.

In step S11, four routines 312-15 are branched depending on the status S 460-3.

In the standby state routine 512 (FIG. 6) with S=0, S2
5 and 92B, the roll solenoid sLi and the release solenoid SL2 are respectively turned off and the throttle control is canceled.

In the constant speed control state routine S with S=1]3 (Figure ffs6), in step S18, the release solenoid
2 It is turned on and the vacuum switch SW is turned on at S19.
7 is turned on. When NO, that is, when normal negative pressure is generated, maintain the speed deviation gain of 6 hats.When (520) is YES, that is, when the obtained negative pressure is lower than the predetermined value, the speed deviation gain is maintained. Increase (S21). In step S22, S20. S
The duty value is determined based on the speed deviation value obtained in step 21. This duty value is, for example, the speed deviation (
It is calculated from the formula: = memorized vehicle speed - current vehicle speed) x speed deviation gain constant + acceleration component duty. Next, control solenoid S is set using the tute value calculated in 323.
Duty control of LI.

In the cent state routine S14 with S=2, the release slide/id is turned on in S30, and it is determined in S31 whether or not the set switch SW4 is on. If the answer is NO, that is, if the set switch that was once turned on is set to 1 and turned off, the current vehicle speed is stored in the memory vehicle speed memory in the CPU in step 933, and in S34, +lS is set to 1.
It is said that This enables constant speed control in the control state loop. If YES in step S31, that is, the set switch continues to be pressed, vehicle speed storage is not performed, control solenoid SLI is turned off in step S32, and the process returns.

In the resume state routine (S15) with S=3, S
After release slide/id SL2 is turned on at 35,
At 53B, it is determined whether the resume switch SW5 is on (closed). If NO, that is, if the Shuhm switch is once turned on or turned off by being released, t 8 S is set to 1 in step S37, after which the control state routine can be entered. Y in S38
At ES, that is, when the resume switch SW5 is still being pressed, it is determined at 538 whether 0.5 seconds or more has elapsed since the resume switch was turned on (closed).

When YES, that is, resume switch SW5 is set to 0.
If the button is held down for more than 5 seconds, the control solenoid is turned on in S39 to perform acceleration control iJ1, and the current tonne speed is newly memorized in S40. When the answer in S38 is NO, that is, if the resume switch SW5 is pressed within, for example, 0.5 seconds, S4
The duty is calculated by + (+l+ or 111).

Based on that 1st shift, Con! in S42!・Controls the low speed on and off to keep the vehicle at the target speed of 1j.
do.

The following programs are executed in the CPU, and one of the four modes can be achieved in response to the operation of the trigger switch, clutch switch, sense/r/nona, and resume switch.

For example, as shown in FIG. 3, when the negative pressure at the intake manifold falls below the vacuum switch setting due to an increase in load, the vacuum switch SW7 is turned on at time ti. Therefore, the duty value is increased in steps S22 and 22, thereby preventing a decrease in the actuator negative pressure, that is, the vehicle speed.

In FIG. 3, the dotted line portion of the curve showing vehicle speed and actuator negative pressure shows changes in the case without the control according to the present invention.

In step S22 of the above program, the duty value is calculated using a relatively complicated formula, but a constant may be added to the normal duty when the vacuum switch SW7 is turned on. Mata vacuum switch S-7
The condition for returning to Wakubatake's speed deviation gain (S20) may be that the speed deviation has become equal to or less than the setting 1α, or that the speed deviation is set to 1α or less. It may also mean that a certain amount of time has passed since ? was turned off.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the electrical circuit configuration of an embodiment of the vehicle speed control device of the present invention, and FIG. 2 is a longitudinal cross-sectional view showing a negative pressure actuator controlled by the inspiratory circuit of il. , 3rd IN is a time chart showing changes in vehicle speed, various negative pressures, and duty values corresponding to on/off of vacuum 4 inch Sw7. 4 to 8 are flowcharts showing programs executed within the CPU. 10: Electronic control device (electronic control means) 20: Runaway detection circuit 30: Stabilizing electric M circuit 100: Negative pressure actuator (throttle drive means) 101: Housing 102; Diaphragm 103; Compression coil spring 104; Projection 105 Ni Throttle valve 108: Intake manifold 107: Negative pressure intake 108, 10!3: Atmospheric intake 110: Negative pressure control valve Ill: Negative pressure release valve 112, 114: Movable piece 116: Accelerator pedal 117: Tension coil spring SWI: Ignition key Switch SW2 + Reed switch (vehicle speed detection means) SW3: Clutch switch SW4- Strap switch SW5: Set switch (first switch means) S
WI (: Resume switch (second switch means) S-7; Vacuum switch SLI: Control solenoid SL2 + Release solenoid CP [I: Microcomputer IFI, IF2, IF3, 1F4, 1F
5, IF6: Interface circuit []V1. []V2: s-dynamic circuit CP: Comparator applicant Aisin Seiki Co., Ltd. agent Force and buried soil Asa Kato Michi Ji5 Figure 7

Claims (2)

[Claims] (1) a vehicle speed detection means, a calculation means for generating an actuator control signal by comparing the current vehicle speed detected by the vehicle speed storage means and the vehicle speed detection means with the stored vehicle speed; XjI. In a vehicle speed control device comprising an actuator means that regulates the negative pressure from a negative pressure source based on a control signal and uses this as motive power to open and close a throttle valve of the vehicle, a negative pressure detection device that detects changes in negative pressure of the negative pressure source and means for manually inputting a signal from the negative pressure detection means to the calculation means to change the output signal of the calculation means so as to eliminate the influence on the actuator pressure regulation pressure due to a change in the negative pressure of the negative pressure source. A vehicle speed control device featuring: (2) The vehicle speed control device according to claim 1, wherein the pressure regulation control in the actuator is performed by duty control of a signal from a Wit calculation means.