JPH0361648A - Engine speed controller - Google Patents

Abstract

PURPOSE:To prevent the variation of the number of revolution in the load variation by feedback controlling the idle revolution speed when at least one of a throttle valve closure detecting switch and a throttle valve opening degree detecting means is normal and in idle state. CONSTITUTION:An electronic control unit 20 receives the signal supplied from a throttle opening degree sensor 8, idle switch 9, ignitor 13, and a car speed sensor 17, and judges the normalcy/anomaly of the throttle opening degree sensor 8 and the idle switch 9. When at least one of the idle switch 9 and the throttle opening degree sensor 8 is normal and in idle state, an air control valve 11 set in parallel to a throttle valve 7 is feedback-controlled so that the revolution speed of an engine 1 which is calculated by the signal supplied from the ignitor 13 becomes equal to an aimed idle revolution speed. Thus, the increase and reduction of the actual revolution speed in the load variation can be prevented.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an engine rotation speed control device, and in particular, an engine speed control device that performs idle control by detecting an idle state from a throttle opening value, an idle switch signal, etc. Regarding.

[Conventional technology]

Conventional engine speed control devices perform closed-loop feedback control of the engine speed when it is determined that the engine is in an idling state based on the operating state of the engine based on an on signal from an idle switch, etc., and the engine is determined to be in a non-idling state. In this case, oven loop control is performed to adjust the amount of air supplied to the engine and control the engine rotational speed.

The above-mentioned open loop control maintains the opening degree of the air control valve provided in the bypass conduit that bypasses the throttle valve of the engine regardless of the operating state of the engine.

The closed-loop control described above determines the target rotation speed and basic air amount based on the operating state of the engine, such as whether an electric load is applied, whether the automatic transmission is in the neutral range or drive range, and the engine cooling water temperature. A feedback correction amount that eliminates the deviation between the target rotation speed and the actual rotation speed is determined by learning, and the opening degree of the air control valve is controlled using the sum of the basic air amount and the feedback correction amount as the control amount.

Note that since the amount of fuel supplied to the engine is determined according to the amount of air supplied, the actual rotation speed can be controlled by controlling the amount of air supplied.

[Problem to be solved by the invention]

The conventional engine speed control device is as described above.
If the idle switch is malfunctioning, and the idle switch outputs an off signal when it should have output an on signal even in the idle state with the throttle valve closed, it will determine that it is not in the idle state and perform oven loop control. Put it away. Therefore, when a load change such as an electrical load occurs, the engine speed increases or decreases, and in the worst case, the engine stalls.

Furthermore, the same applies to the case where the idle state is detected based on the output signal of the throttle opening sensor that detects the opening of the throttle valve.

Furthermore, if the on-range of the idle switch is wide relative to the throttle opening, the on-range may exceed the limit of closed-loop control.

In this idle state, even if the air control valve is fully closed and the throttle valve then closes further for some reason and falls within the control limit of the closed loop, the rotation speed drop due to insufficient intake air volume will cause the throttle valve to close. Troop control caused problems such as the opening speed of the air control valve being relatively faster than the opening speed of the air control valve, resulting in a drop in engine speed and, in the worst case, engine stalling.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to obtain an engine speed control device that can prevent abnormal increases and decreases in engine speed.

[Means to solve the problem]

The engine rotation speed control device of the present invention is an apparatus equipped with a control means for performing feedback control of the rotation speed during an idle state, and includes a switch means for detecting that a throttle valve is closed and an opening degree detection device for detecting a throttle opening degree. The engine is equipped with a detection means for detecting that at least one of the means is normal and in an idle state, and feedback control of the rotational speed is performed in response to this detection signal.

[For production]

In the engine speed control device according to the present invention, even if one of the switch means and the opening detection means fails, the detecting means detects that the normal means is in an idling state, and performs feedback control of the rotation speed. Execute.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 is a configuration diagram showing an engine rotation speed control device etc. according to an embodiment of the present invention. In the figure, 1 is a well-known spark ignition engine mounted on, for example, a car.
Main air is taken in through an air cleaner 2, an intake pipe 3, and an intake branch pipe 4, and fuel is injected and supplied from a single electromagnetic fuel injection valve 5 provided in the intake pipe 3. This amount of fuel is determined by a fuel control system (not shown), for example, based on an output signal of a pressure sensor 6 that detects the pressure inside the intake pipe 3 in absolute pressure.

7 is a throttle valve that adjusts the main intake air amount of the engine 1 by the driver's arbitrary operation of the accelerator pedal (not shown); 8 is a throttle opening sensor that detects the opening of the throttle valve 7; 9 is a throttle valve The idle switch detects that the throttle valve 7 is almost closed, and if the idle opening value when the throttle valve 7 is fully closed is θIDL, it turns on when the actual throttle opening value θ is less than θIDL+β.

10 is a bypass conduit provided to bypass the throttle valve 7 on the downstream side of the electromagnetic fuel injection valve 5, and 11 is an air control valve provided between the bypass conduits 10. One end of the bypass conduit 10 is connected to an air inlet provided between the electromagnetic fuel injection valve 5 and the throttle valve 7, and
The other end of the bypass N pipe 10 is connected to an air outlet provided downstream of the throttle valve 7.

Air i! The 1m valve 11 is, for example, an electromagnetic control valve whose opening degree corresponds to the duty ratio of the applied drive signal,
The flow passage cross-sectional area of the bypass conduit IO is controlled in proportion to its duty ratio.

The ignition device of the engine 1 is connected to an ignition control system that forms an ignition signal from operating state parameters of the engine 1, and an igniter 13 and an ignition coil that control on/off the primary current of the ignition coil 12 according to this ignition signal. 12,
It consists of a distributor (not shown), a spark plug (not shown), etc.

Reference numeral 14 represents the temperature of the engine 1, for example, a cooling water temperature sensor that detects the cooling water temperature; 15, an electric load switch for turning on the load of auxiliary equipment such as an air conditioner; and 16, a torque converter signal for the automatic transmission. A signal line 17 is a vehicle speed sensor that outputs a pulse signal with a frequency proportional to the rotational speed of the axle and detects the vehicle speed. 18 is an exhaust pipe of the engine 1, and 19 is a catalyst, in which the air-fuel mixture combusted by the engine 1 is purified as exhaust gas and discharged to the outside.

20 is an electronic control unit that is operated by being supplied with power from a battery 21 via a key switch 22, and includes a throttle opening sensor 8, an idle switch 9, and an ignition coil 12.
From each output signal from the primary side of the vehicle speed sensor 17 and the
It is determined whether or not it is in the idle state, and depending on the result of this determination, the ignition is closed based on the ignition signal on the primary side of the ignition coil 12, the signal from the cooling water temperature sensor 14, the signal from the electric load switch 15 and the signal line 16. Air control valve 11 during troop control
The air control valve 11 is driven and controlled based on the control amount obtained during open loop control or the control amount during open loop control.

Next, the electronic control unit 20 will be explained with reference to FIG. 100 is a microcomputer, and a CP calculates the control amount of idle rotation, etc. according to a predetermined program.
U200, a 7-leaving counter 201 for measuring the rotation period of the engine l, a timer 202 for measuring the duty ratio of the drive signal applied to the air control valve 11,
An A/D converter 203 that converts an analog input signal into a digital signal, a human power boat 204 that inputs the digital signal as it is, a RAM 205 that serves as a work memory, and a program that stores the flows shown in Figures 3 to 6. It is composed of a ROM 206, an output port 207 for outputting M motion signals, a common bus 208, and the like. 1
01 is the first input interface circuit, and the ignition coil 12
The primary side ignition signal is waveform-shaped and input into the microcomputer 100 as an interrupt signal. When this interrupt signal is generated, the CPU 200 reads the value of the counter 201, calculates the cycle of the engine rotation speed from the difference from the previous value, and stores it in the RAM 205. 102 is a second human power interface circuit which removes noise from the output signals of the throttle opening sensor 8 and the cooling water temperature sensor 14, and converts them into A/D.
Output to converter 203. Reference numeral 103 denotes a third human power interface circuit, which outputs the on-signal of the idle switch 9, the on-signal of the electric load switch 15, the neutral safety signal from the signal line 16, and the pulse from the vehicle speed safe't 17 to predetermined levels to the input board 204. Output. 104 is an output interface circuit that amplifies the drive signal from the output port 207 and outputs it to the air control valve 11. 105
is a power supply circuit, and when the key switch 22 is turned on, the battery 2
The microcomputer 10 uses the voltage from 1 as a constant voltage.
0.

Next, the operation of this embodiment will be explained with reference mainly to FIGS. 3 to 6 among FIGS. 1 to 6.

3 and 6 show each process in a main routine (not shown), and the process shown in FIG. 3 is executed earlier than that shown in FIG. In FIG. 3, first, in step Sl, it is determined whether or not the idle switch 9 is normal or not. If normal, proceed to step S2, determine whether the idle switch 9 is on, and if it is on, proceed to step S3, step S
3, the throttle opening sensor failure determination process, the details of which are shown in FIG. 5, is performed, that is, it is determined whether the throttle opening sensor 8 is normal or not. If it is normal, the process advances to step S4, and as described later, in step S3, the second
The actual throttle opening value θ read through the human power interface circuit 102 and the A/D converter 203 is the minimum value θ.
Determine whether or not. This is done by comparing the actual throttle opening value θ with the value set as the idle opening value θIIIL when the throttle valve 7 is fully open.If the read actual throttle opening value θ is the minimum value, then In step S5, the actual throttle opening value θ is converted to the idle opening value θIDL.
Store the settings as θ,. , update.

After the processing in step S5, the process returns.

If it is determined that the idle switch 9 is abnormal in step S1, and if it is determined that the idle switch 9 is off in step S2, then the throttle opening sensor 8 is determined in step S3.
If it is determined that is abnormal, or if it is determined in step S4 that the actual throttle opening value θ is not the minimum value θin, the process returns. After returning, the process shown in FIG. 6 is executed, and then the process returns to step S1 to repeat the above operations.

Next, the processing for determining failure of the idle switch will be explained with reference to FIG. In step 3100, the sixth step 310 is to calculate the actual rotation speed Ne of the engine 1 based on the rotation period of the engine 1 calculated in an interrupt routine (not shown).
1, it is determined whether the idle switch 9 is on.

If it is on, the process proceeds to step 5102, where it is determined whether or not the actual rotational speed Ne is equal to or greater than a first predetermined value equivalent to, for example, 1500 rpm.If it is above, it is determined that the idle switch is abnormal, and if it is not, it is determined that the idle switch is normal.

If it is determined in step 5101 that it is off, step 510
Proceeding to step 3, it is determined whether or not the actual rotational speed Ne is equal to or less than a second predetermined value corresponding to, for example, 11000 rpm. If it is less than that, it is determined that the idle switch is abnormal, and if it is not less than that, it is determined that the idle switch is normal.

Next, a process for determining failure of the throttle opening sensor will be explained with reference to FIG. In step 5200, from the throttle opening sensor 8 to the second manual ink face circuit 102 and the A/
The actual throttle opening value θ is read through the D converter 203. Next, in step 3201, it is determined whether the actual throttle opening value θ is within a predetermined range that includes at least the range when the throttle valve 7 is normal. If it is within a predetermined range, the throttle opening sensor is determined to be normal, and if it is outside the predetermined range, it is determined that the throttle opening sensor is abnormal.

Next, the idle rotation speed control process will be explained with reference to FIG. First, in step S10, it is determined whether the vehicle speed sensor 17 is not generating a pulse, that is, whether the vehicle is stopped or not. If the vehicle is not stopped, the process proceeds to step S17, and if the vehicle is stopped, the process proceeds to step 311. It is determined whether the idle switch 9 is normal or not. This determination may be made by executing the process shown in FIG. 4, but in this embodiment, a flag (not shown in FIG. 4) is set according to the determination result obtained in step S1 of FIG. All you have to do is identify.

If the idle switch 9 is normal, the process proceeds to step 312, where it is determined whether the idle switch 9 is on or not. If it is off, the process proceeds to step SIT, and if it is on, the process proceeds to step 313, where it is determined whether the throttle opening sensor 8 is normal. Determine whether This determination may be made by executing the process shown in FIG. 5, but in this embodiment, a flag (not shown in FIG. 4, 8 If it is determined to be normal, the process proceeds to step 315, and if it is determined to be abnormal, the process proceeds to step 316.

On the other hand, if it is determined in step 311 that the idle switch 9 is abnormal, the process advances to step S14, and step S1
3, it is determined whether the throttle opening sensor 8 is normal or not. If abnormal, proceed to step 317; if normal, proceed to step 315.

In step 315, the actual throttle opening value θ is equal to or less than the throttle opening value eIDL+α for idle determination at which closed-loop control (described later) becomes effective (however, θ1□ is the idle opening value obtained in the process of FIG. 3, and α is With the throttle opening correction value for idle determination, it is determined whether 0, α, and β hold true. If it is below, the closed loop control is valid, so the process advances to step S16.

In step S16, the opening degree of the air control valve 11 is controlled by performing well-known closed loop control using the actual rotational speed Ne. During this closed loop control, each signal of the cooling water temperature sensor 14, electric load switch 15, and signal line 16 and the actual rotation speed N. Use. If not, the control limit of the closed loop control will be exceeded, that is, the air control valve 11 will be almost fully closed, so the process proceeds to step 317.

In step SIT, well-known oven loop control is performed to control the air control valve 11 to a predetermined opening degree.

After the processing in step 316 or step SIT, the return occurs, and after executing the processing in FIG. 3, the process returns to step SI.
Return to O and repeat the above operation.

In the above embodiment, when the actual throttle opening value θ is equal to the true idle opening value θIIIL, the actual rotation speed is Ne,
For example, it will be 800 rpm. When the actual throttle opening value θ is θIOL+β, which is the ON limit of the idle switch 9, the actual rotational speed Ne becomes Nez, for example, 1200 rpm. When the throttle opening sensor 8 is normal and the throttle opening sensor 8 is normal, θ
When it is determined that ≦θIDL+α, it is determined to be an idle state and closed-loop control is performed, within the control limits of closed-loop control.

FIG. 7 shows a main part of the flow of another embodiment, showing a part where the flow of FIG. 3 is incorporated into the flow of FIG. 6, and the same steps are given the same symbols.

The processing in steps S4 and S5 in FIG. 3 is the same as in step S13 in FIG. The process is the same as the process shown in FIG. 6 except that it is entered between YES in 314 and step S15. Step S1
3 or if it is determined in S14 that the throttle opening sensor 8 is normal, the process proceeds to step S4. In step S4, it is determined whether the actual throttle opening value θ is the minimum value θ1ain,
If it is the minimum value, the process proceeds to step S15 after storing and setting θ in θIDL in step S5, and if it is not the minimum value, the process jumps to step 315. Other processing operations have already been explained in FIG. 6, so their explanation will be omitted.

In the above embodiment, the key switch 22 is turned on and off.
related to off (supplying power to RAM 205 and
205 may be made non-volatile so that the idle opening values θ and L obtained from the actual throttle opening value are always stored.

〔Effect of the invention〕

As described above, according to the present invention, when at least one of the switch means for detecting that the throttle valve is closed and the opening detection means for detecting the throttle opening is in a normal and idle state, the feed bank of the idle rotation speed is detected. Since the control is performed, it is possible to prevent the actual rotational speed from decreasing or increasing when the load changes.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of the device according to an embodiment of the present invention, FIG. 2 is a block diagram showing the configuration of the electronic control unit, etc. in FIG. 1, and FIG. 3 is a flow diagram of the idle opening determination process. Fourth
The figure is a flow diagram of the idle switch failure determination process.
The figure is a flow diagram of the throttle opening sensor failure determination process.
FIG. 6 is a flowchart of the idle speed control process, and FIG. 7 is a partial flowchart showing the main part of the operation according to another embodiment of the present invention. In the figure, 1...engine, 3...intake pipe, 7...throttle valve, 8...throttle opening sensor, 9...
Idle switch, 10... Bypass conduit, 11...
- Air control valve, 12... Ignition coil, 13... Igniter, 17... Vehicle speed sensor, 20... Electronic control unit. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] Engine rotation speed control comprising a control means that performs feedback control of the idle rotation speed of the engine by controlling the intake air amount of the engine based on factors that determine the operating condition of the engine when the engine is in an idle state. The apparatus includes a detection means for detecting that at least one of a switch means for detecting that the throttle valve is closed and an opening degree detection means for detecting the opening degree of the throttle valve is normal and in an idle state, An engine rotation speed control device, characterized in that the control means performs feedback control of the idle rotation speed in response to a detection signal from the detection means.