JPH0574701B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an engine rotation speed control device, particularly to an engine rotation speed control device during idling and auto-cruise.

(Prior art) In automobile engines, the number of revolutions during idling is suppressed as much as possible to improve fuel efficiency and exhaust performance, and the number of revolutions is increased when warming up at startup or when an external load such as a cooler is applied. Automatic control of idling rotation is performed to accelerate the engine or prevent engine stalling. On the other hand, in recent years, automobiles have been put into practical use that are equipped with an auto-cruise function that controls the engine speed to maintain the vehicle speed at a constant speed specified by the driver.

By the way, in the past, the above-mentioned idling control and auto-cruise control were performed separately, but these both control the rotation speed by adjusting the amount of air flowing into the engine. , it is possible to integrate both control systems, and as an example of this, for example, JP-A-57-
There is an invention disclosed in Publication No. 110748. This invention includes one actuator that is used in common for idling control and auto-cruise control, and this actuator controls the opening and closing of a throttle valve to adjust the rotational speed according to external load, engine warm-up state, etc. during idling. The amount of air flowing into the engine is adjusted so that the rotational speed maintains a constant vehicle speed during autocruise. According to this, idling control and auto-cruise control can be performed with one actuator, and when both functions are provided, the structure of the engine is simplified and costs are reduced. However, this invention has the following drawbacks because idling control is performed by opening and closing a throttle valve. In other words, the idling control is performed at an extremely low rotation speed.
Since the idling speed is increased or decreased, the control range is narrow and precise control is required. However, the throttle valve is difficult to delicately control the opening, and it is difficult to control the air inflow amount in response to changes in the opening. The rate of change is large, especially near the fully closed position, where a slight increase or decrease in the degree of opening causes a large change in the amount of air inflow. This is because the idling speed cannot be accurately controlled by controlling the throttle valve.

(Object of the Invention) The present invention addresses the above-mentioned actual situation in engines that perform idling control and auto-cruise control, and specifically performs both of the above controls with a simple configuration without reducing the accuracy of idling control. The present invention aims to reduce the cost of an engine equipped with an idling control function and an auto-cruise function.

(Structure of the Invention) In order to achieve the above object, the engine rotation speed control device according to the present invention is characterized in that it is structured as follows.

That is, an air supply passage communicating with the downstream side of the throttle valve in the intake passage is provided with a control valve that opens and closes the supply passage to adjust the amount of air flowing into the intake passage downstream of the throttle valve. The idling control means controls the opening and closing of a valve to converge the idling speed to the target value, and the above-mentioned speed control means controls the actual vehicle speed to become the target vehicle speed by feedback control amount based on the deviation between the target vehicle speed and the actual vehicle speed. In an engine equipped with auto-cruise control means for adjusting a throttle valve, an actuator for driving the throttle valve and the control valve, and between the actuator and the throttle valve and between the actuator and the control valve. Each drive transmission path is turned on and off.
The actuator controls the transmission on/off mechanism that turns off and controls the control valve to open when the idling control means is activated, and opens the throttle valve when the auto cruise control means is activated. The invention is characterized by comprising a transmission control means that is operated to control the transmission. Therefore, idling control and auto-cruise control are performed by one actuator. In particular, since idling control is performed by a control valve provided in the air supply path, the air inflow amount or idling rotational speed can be controlled with high precision.

(Example) Hereinafter, an example of the present invention shown in the drawings will be described.

FIG. 1 shows a control system for engine speed control, in which an intake passage 5 is connected to a combustion chamber 2 of an engine 1 via intake and exhaust valves 3 and 4.
and an exhaust passage 6 are communicated with each other. An air cleaner 7, a fuel injection nozzle 8, and a throttle valve 9 are installed in the intake passage 5 from the upstream side, and fuel is introduced from a fuel tank 10 to the fuel injection nozzle 8 via a pump 11 and a pressure regulator 12. A fuel supply pipe 13 is connected to the combustion chamber 2, and a spark plug 14 is installed in the combustion chamber 2. Further, a bypass passage 15 is provided between the upstream side and the downstream side of the throttle valve 9 in the intake passage 5, and a bypass passage 15 is provided on the passage 15, and a bypass passage 15 is provided on the intake passage 5 between the upstream side and the downstream side of the throttle valve 9. A control valve 16 is installed to adjust the amount of air flowing into the tank. The control valve 16, the throttle valve 9, and the drive device 17 operate the control valve 16, and the drive device 17 has the following configuration. That is, as shown in Figure 2,
The drive device 17 includes one stepping motor 18 as an actuator, an idling electromagnetic clutch 21 to which rotation is input by the motor 18 through first and second reduction gear mechanisms 19 and 20, and an auto cruise clutch. The output circuit of the idling clutch 21 causes the control valve 16 to move linearly via the pinion 23 and the rack 24, and the output rotation of the autocruise clutch 22 causes the lever to move in a straight line. 25 and a wire 26 to rotate the throttle valve 9. Here, the rack 24 is provided with a protrusion 27, and a full-close switch is provided that comes into contact with the protrusion 27 when the control valve 16 is fully closed and fully opened to detect whether the valve 16 is forwardly closed or fully open, respectively. 28 and a full open switch 29 are provided.

However, the motor 18 in this drive device 17
The clutches 21 and 22 for idling and autocruise, the fuel injection nozzle 8, and the spark plug lug 14 are each controlled by a control unit 30. That is, as shown in FIG. 1, the direction and amount of rotation of the motor 18 are controlled by a forward/reverse signal A and a control amount (rotation amount) signal B sent from a control unit 30, and the clutches 21 and 22 are controlled by a clutch signal C. , D, the injection timing and injection amount of the fuel injection nozzle 8 are controlled by the injection signal E, and the ignition timing of the spark plug 14 is controlled by the ignition signal F.

The control unit 30 outputs these signals A to F to perform fuel control, ignition control, idling control, and auto cruise control.
The following information is input from various sensors and switches that detect the state of the engine or vehicle. That is, for fuel control, a negative pressure signal G is sent from a negative pressure sensor 31 installed on the downstream side of the throttle valve in the intake passage 5, and from a pair of crank angle sensors 33, 33 installed around the crankshaft 32. Crank angle signal H, H
and was installed in the exhaust passage 6 for injection amount correction.
The O ₂ signal I from the O ₂ sensor 34, the intake air temperature signal J from the intake air temperature sensor 35 installed at the upstream part of the intake passage 5 for correcting the injection amount, and the intake air temperature signal J for increasing the injection amount at startup. A cranking signal K from the starter switch 36 that detects engine cranking is input, and for ignition control,
The above crank angle signals H and H are used.

The control unit 30 also receives the crank angle signals H, H for detecting the idling state of the engine 1, and a throttle opening signal L from a throttle opening sensor 37 for detecting the opening of the throttle valve 9. At the same time, the water temperature signal M from the water temperature sensor 39 installed in the water jacket 38 of the engine 1 for idling control, the air conditioner compressor, power steering pump, lights, etc. installed in the vehicle are read. Load signals N, O, and P from an air conditioner switch 40, a power steering switch 41, and a light switch 42, which negatively detect the effects of external loads, are input. Further, in order to detect whether the control valve 16 is fully closed or fully open during this idling control, control valve position signals Q and Q' from a fully closed switch 28 and a fully open switch 29 shown in FIG. 2 are input.

Furthermore, the control unit 30 includes a vehicle speed signal R from a vehicle speed sensor 43 that detects the vehicle speed of the vehicle, a set switch 44, a coast switch 45, and a register operated by the driver during auto cruise operation for auto cruise control. Instruction signals S, T, and U from the user switch 46, a neutral signal V from the inhibitor switch 47 (in the case of a manual transmission, a clutch switch indicating clutch disengagement) indicating the neutral or parking state of the automatic transmission, and the brake. A brake signal W from the brake switch 48 that detects the depression of
is now entered. Here, the set switch 44 is set within a constant vehicle speed range (for example, 40 to
The coast switch 45 is used to set the vehicle to auto-cruise operation when the desired speed is reached while driving at a speed of 100 km/h).The coast switch 45 is used to decelerate during auto-cruise operation. The switch 46 is used to restore the previously set speed after the autocruise operation is canceled for reasons other than the operation of the autocruise main switch (not shown).

Next, the operation of the above embodiment will be explained with reference to the flowchart of FIG. 3 showing the operation of the control unit 30.

First, when the engine is started using the ignition key, the control unit 30
In step _X1 , various data are initialized, and in step _X2 , each sensor and switch 28, 29, 31, 33-37, 39-48 is
Various input information is read based on signals GW from . Next, the control unit 30 executes the fuel control routine from step _X3 to step _X4 when a predetermined fuel control time comes. In this fuel control routine, a basic injection amount corresponding to the engine intake negative pressure and rotation speed indicated by the negative pressure signal G and crank angle signals H, H is set, and the basic injection amount is determined based on the _O2 signal I. The basic injection amount is corrected according to the lean/rich state of the air-fuel ratio and the air filling amount detected based on the intake temperature signal J, and a cranking signal K indicating starter operation is input. Sometimes, the injection amount is set to increase at startup. And in step x ₅ ,
The injection signal E is sent to the fuel injection nozzle 8 so that the fuel injection amount thus set is achieved.

Further, when the predetermined ignition control timing comes, the control unit 30 proceeds from step _X6 to step _X7.
The ignition control routine is executed to set the ignition timing according to the above-mentioned intake negative pressure and engine rotation speed, and the rotation angle of the crankshaft 32 indicated by the crank angle signals H and H becomes an angle corresponding to the set timing. At this time, an ignition signal F is sent to the spark plug 14 in step _X8 .

Next, the control unit 30
_Throttle opening signal L, crank angle signal H,
From H, it is determined whether the engine operating state is in idling mode or not, and if it is in idling mode, step _X for idling control is executed.
Run _X19 . That is, first, _{in step}
Clutch signals D and C are sent to both clutches 22, 22, respectively, to disengage the autocruise clutch 22 and connect the idling clutch 21 shown in the figure. Then, in step _X12 , a target rotational speed is set according to the above-mentioned cooling water temperature and external load condition, and in step _X13 , the difference between this target rotational speed and the actual rotational speed of the engine 1 is calculated. This difference is within a preset dead zone (for example, for a target rotation speed of 650 RPM under no load and warm conditions, ±
20RPM ₎ , _{to prevent} hunting, execute steps Determine whether the number is higher or lower than the target rotation speed. When the actual rotation speed is lower than the target rotation speed, in _step is set, and when the actual rotation speed is higher than the target rotation speed, _step
A reversal command is set in which the direction of rotation is the reverse direction, and a control amount for the motor 18 is set in accordance with the difference between the two rotational speeds. And step X ₁₉ and step X ₁₅ above,
Hold command set with either X ₁₇ or X ₁₈ ,
A forward rotation command or a reverse rotation command is sent to the motor 18 as a forward/reverse rotation signal A, and the control amount set in either step X ₁₇ or X ₁₈ is sent to the motor 18 as a control amount signal B. As a result, the motor 18 is stopped by a hold command when the difference between the target rotation speed and the actual rotation speed is within the dead zone, and when the actual rotation speed is lower than the target rotation speed, the motor 18 is rotated in the forward direction by an amount corresponding to the difference. Further, when the actual rotation speed is higher than the target rotation speed, the rotation speed is rotated in the reverse direction by an amount corresponding to the difference.

However, when the motor 18 is rotationally driven, since the idling clutch 21 is connected and the auto-cruise clutch 22 is disconnected in step _X11 , the first reduction gear mechanism shown in FIG. 19. The control valve 16 on the bypass passage 15 is linearly moved via the idling clutch 21, pinion 23, and rack 24, so that when the motor 18 rotates forward, the opening degree of the control valve 16 increases, and the motor When 18 is reversed, the opening degree decreases. Along with this, bypass passage 1
The amount of air flowing from the upstream side of the throttle valve to the downstream side of the intake passage 5 through the throttle valve 5 is increased or decreased. As a result, when the actual rotational speed of the engine 1 is lower than the target rotational speed, the rotational speed is increased according to the difference, and when the actual rotational speed is higher than the target rotational speed, the rotational speed is similarly decreased, and the engine 1 is idled. The actual rotational speed at the time is controlled to converge to the target rotational speed or within its dead zone depending on the cooling water temperature and external load condition. In that case, this idling speed control is performed by bypass passage 1 with a small flow passage cross-sectional area.
Since this is done by increasing or decreasing the amount of air passing through the air filter 5 using a control valve that operates linearly, it can be done precisely and accurately.

On the other hand, if the engine is not in an idling state, the control unit 30 performs the above steps.
Step ₂₀ is executed from _X9 to send a clutch signal C to disconnect the idling clutch 21. Then, in _step
100Km/h), and if the mode is not in the auto cruise mode, in _step Send signal D. On the other hand, if the vehicle is in the auto cruise mode, the clutch signal D is sent to connect the auto cruise clutch 22 at step _X23 .
At the same time, at steps _X24 and _X25 , the brake signal W and neutral signal V indicate that the brake is not depressed and the transmission is not in a neutral state (or the clutch is not disengaged).
After confirming, read the input information necessary for auto cruise in step X ₂₆ , and then proceed to _step
Executes the auto cruise control routine. In this auto cruise control routine, the driver operates the set switch 44 and the coast switch 4.
5, resume switch 46, etc., the throttle valve 9 and its opening are set to maintain the designated vehicle speed, decelerate it, or return to the set vehicle speed. Then, in step _X28 , a forward/reverse rotation signal A and a control amount signal B are sent to the motor 18 so that the throttle valve opening degree is set. At this time, the idling clutch 21 is disconnected at step X ₂₀ , and the auto-cruise clutch ₂₂ is connected at step The throttle valve 9 is opened and closed via the clutch 22, lever 25, and wire 26, thereby increasing the amount of air inflow or the engine rotation speed necessary to maintain or restore the set vehicle speed. will be controlled by. Even if you are in auto cruise mode, if the brake is depressed or the transmission is operated in neutral, the above steps will not be executed.
Step _X22 is executed from _X24 and _X25 to cancel auto cruise control.

(Effects of the Invention) As described above, according to the present invention, idling control and auto-cruise control in an automobile engine are performed by one actuator, and the cost of an engine equipped with both of these control functions is reduced. In particular, according to the present invention, idling control is performed by adjusting the air inflow amount by operating a control valve on an air supply path (bias path) provided separately from the throttle valve. This will be done precisely and with high precision.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a control system diagram, FIG. 2 is a schematic configuration diagram of a drive device, and FIG. 3 is a flowchart diagram showing the operation. 5...Intake passage, 9...Throttle valve, 1
5... Air supply path (bypass passage), 16... Control valve, 18... Actuator (motor), 21,
22...Transmission on/off mechanism (idling clutch, auto cruise clutch), 30...
Idling control means, auto cruise control means, transmission control means (control unit).

Claims (1)

[Claims] 1. A control valve is provided in an air supply passage communicating with the downstream side of the throttle valve in the intake passage, and the control valve opens and closes the supply passage to adjust the amount of air flowing into the intake passage downstream of the throttle valve. An idling control means which performs opening/closing control to converge the idling rotation speed to a target value, and the above-mentioned throttle which controls the actual vehicle speed to become the target vehicle speed by feedback of a control amount based on the deviation between the target vehicle speed and the actual vehicle speed. The engine speed control device is equipped with an auto-cruise control means for adjusting valves, and includes one actuator for driving the throttle valve and the control valve, and an actuator for driving the throttle valve and the control valve; a transmission on/off mechanism provided between the actuator and the control valve to turn on and off each drive transmission path;
A transmission control means that operates these transmission on/off mechanisms by the actuator so that the control valve is controlled to open when the idling control means is activated, and the throttle valve is controlled to be opened when the auto cruise control means is activated. An engine rotation speed control device characterized by being provided with.