JPH0454258A - Controller of engine - Google Patents

Abstract

PURPOSE:To stop a controller, prevent deterioration of a catalyser and improve emission in the case when a control time of ignition time control or fuel injection control exceeds a specific time by measuring the control time of the ignition time control or the fuel injection control to prevent slipping. CONSTITUTION:A controller stop means C to stop ignition time control or fuel injection control in the case when a control time of the ignition time control or the fuel injection control exceeds a specific time by way of measuring the control time of the ignition time control or the fuel injection control is provided in a controller provided with a slip prevention means B to carry out the ignition time control to prevent slipping by way of controlling an ignition time of an engine or the fuel injection control to prevent slipping by way of controlling a fuel injection amount of the engine in the case when a detection means A to detect slipping of a wheel detects slipping of the wheel. By this constitution, it is possible to avoid an exhaust air temperature from rising higher for a long period of time or a catalyser bed temperature from rising higher so as to improve emission by way of preventing deterioration of a catalyser.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention controls engine ignition timing and stops fuel injection to adjust engine torque and prevent wheel slip and drift. The present invention relates to an engine control device that prevents

(Prior Art) FIG. 7 is a flowchart showing fuel cut control of a conventional engine control device, which performs a kind of speed limiter control.

In this flowchart, first, in step S1, various signals such as the engine rotational speed N and vehicle speed vsr are read, and in the subsequent step S2, it is determined whether or not the shift gear of the transmission is in reverse gear. Step 8 if
If the vehicle is in the forward gear, the process proceeds to the backward gear control of step 3 or less, and if the vehicle is located in the forward gear, the process advances to the forward gear control of step 38 or less.

In reverse gear control step S3, a fuel cut rotational speed NMAXI for reversing is set, and in the subsequent step S4, a fuel cut vehicle speed VSPMAXI for reversing is set. Next, in step S5, it is determined whether or not the detected rotational speed N exceeds the fuel cut rotational speed N11AXl during reversing. If it does, the process jumps to step S7 and fuel injection to the engine is performed unconditionally. On the other hand, if the detected rotation speed N does not exceed the fuel cut rotation speed N when reversing, the process proceeds to step S6, and the detected vehicle speed vsp is set to the fuel cut vehicle speed V when reversing.
It is determined whether or not the P engineering AXII is exceeded, and if it is exceeded, the process proceeds to step S7 and the fuel is cut.
If the detected vehicle speed V does not exceed the fuel cut vehicle speed (d) during reversing, the process branches to step 512 and fuel injection control is continued.

Forward gear control 1 In step S8, the fuel cut rotational speed N and IAX during forward movement are set, and in the subsequent step S9, the fuel cut vehicle speed vsrxAx during forward movement is set. Here, the fuel cut rotational speed NMAX when moving forward and the fuel cut vehicle speed V,
, , □ are the fuel cut rotational speed NWA when reversing, respectively.
XII and fuel cut vehicle speed V1FNA-.

Next, in step SIO, it is determined whether or not the detected rotational speed N exceeds the fuel cut rotational speed NMAx during forward movement, and if it does, the process branches to step S7 and fuel injection to the engine is performed unconditionally. On the other hand, the detected rotational speed N is the fuel cut rotational speed N6. during forward movement. If the detected vehicle speed vsr does not exceed V5PIIIAX, the process proceeds to step Sll, and it is determined whether or not the detected vehicle speed vsr exceeds the fuel cut vehicle speed V5PIIIAX when moving forward. If it does, the process branches to step S7 to cut the fuel On the other hand, if the detected vehicle speed V3F does not exceed the forward fuel cut vehicle speed vsrx□, the process branches to step 512 and fuel injection control is continued.

According to this kind of control, when moving forward and backward,
When an engine overspeed condition (overrev) or a condition exceeding the maximum vehicle speed (180 km) stipulated by law occurs, the fuel can be cut (fuel cut) to avoid the condition.

Here, the detailed operation of the fuel injection control in step S12 of FIG. 7 will be explained. The intake air flow rate detection signal Q from the air flow meter and the rotation speed detection signal N from the crank angle sensor that detects the rotation speed of the engine are used. , the basic injection amount T, (=K・Q/N 8 K is a constant), and calculate the fuel injection amount T1 using the basic injection amount Tr and the following formula, and then calculate the fuel injection amount T! outputs an injection pulse signal corresponding to the fuel injection valve of each cylinder.

Ti-TFX (1+Ktm+Kas+Ka++ Ka
ec + Ksic) X Kyc+ T*However, K7
8 is a water temperature increase correction coefficient during warm-up, I (ms is an increase correction coefficient for starting and after starting, Kal is an increase correction coefficient after idling,) (ace is an acceleration correction coefficient for increasing the amount during acceleration operation, I'( etc is a deceleration correction coefficient for correcting weight loss during deceleration driving, KFc is a fuel cut correction coefficient, and T3 is a correction bone based on battery voltage.

Next, to explain the detailed operation of ignition timing control, first, it is determined whether or not the throttle valve is fully closed, and if it is fully closed (idle state 1), the ignition timing control is Search the ignition timing (advance value before compression top dead center) from a map of ignition advance characteristic A, which is a function of engine rotational speed N,
On the other hand, when the throttle valve is not fully closed, the basic ignition timing SAS when the operating state detected by the engine speed N and the basic fuel injection amount T is a steady condition is
Search from a three-dimensional map as shown in the figure. In either case, when engine knocking is detected, the ignition timing is corrected to the retarded side.

Traxibon Control (T) is effective for avoiding slips on snowy roads and drifting when cornering.
e3) A device is disclosed in, for example, Japanese Patent Application Laid-Open No. 63-309744, and in this device, the ratio of the difference between the driving wheel speed ■ and the driven wheel speed v (-(Vo@Vptm) /
Vrsm) is calculated as a slip rate, and when this slip rate exceeds a predetermined value, the ignition timing of each cylinder is retarded or the number of cylinders to which fuel is cut is increased or decreased according to the slip rate. .

According to this, it is possible to reduce the torque generated by the engine and prevent slips and drifts.

According to Japanese Patent Application Laid-Open No. 61-60331, a technique is disclosed in which the intake air flow rate is restricted by a throttle valve to reduce the torque generated by the engine. and drift can be prevented.

(Problems to be Solved by the Invention) However, in the above-mentioned conventional engine control device, the configuration is such that, depending on the slip ratio, the ignition timing of each cylinder is retarded, and the number of fuel-cut cylinders is increased or decreased. Therefore, in ■, the exhaust temperature rises and the catalyst deteriorates, and in ■, the fresh air from the cylinder where fuel was cut and the exhaust gas from the cylinder where fuel was not cut mix in the catalyst. As a result, the catalyst bed temperature increases and the catalyst deteriorates, resulting in problems in terms of deterioration of emissions, such as an increase in harmful exhaust components.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide an engine control device that can be used in conjunction with traction control without causing deterioration of emissions.

(Means for Solving the Problems) In order to achieve the above object, the present invention has a detecting means for detecting wheel slip, as shown in FIG.
slip prevention means that performs ignition timing control to prevent slip by controlling the ignition timing of the engine or fuel injection control to prevent slip by controlling the fuel injection amount of the engine when the detection means detects wheel slip; , a control stopping means for measuring the control time of the ignition timing control or the fuel injection control and stopping the ignition timing control or the fuel injection control when a predetermined time is exceeded.

(Function) In the present invention, when slip occurrence is detected by the detection means, ignition timing control or fuel injection control is performed until a predetermined time, and when the predetermined time is exceeded, it is forcibly stopped by the control stop means. .

Therefore, the exhaust gas temperature is prevented from increasing over a long period of time, or the catalyst bed temperature is prevented from increasing, thereby preventing deterioration of the catalyst and improving emissions.

(Embodiment) FIG. 2 is a diagram showing an embodiment of an engine control device according to the present invention.

A fuel injection valve 2 is provided at each intake port of the engine 1, and an output shaft of the engine 1 is connected to a drive shaft of the vehicle via a transmission 3.

The control unit 4, which has the functions of slip detection means, slip prevention means, and control stop means, receives a detection signal from an air flow meter 5 that detects the intake air flow rate Qa taken in from the outside via the air cleaner 33, and a distribution rotor. A detection signal from a crank angle sensor 6a (see FIG. 3) that is built in and detects the engine 10 rotational speed N;
A detection signal from a vehicle speed sensor 7, which is provided on the output shaft of the transmission 3 and detects the vehicle speed VIF, and a detection signal from a reverse switch 8, which outputs an on signal when the shift gear of the transmission 3 is in the reverse gear. is input.

The control unit 4 also receives a detection signal from an oxygen sensor 9 that detects the oxygen concentration of gas discharged from the engine 1, a detection signal from a water temperature sensor 10 that detects the temperature T- of the cooling water in the radiator, and a detection signal from the engine 1. A detection signal (■) from a knock sensor 11 that detects knocking of the engine 1, and a throttle chamber 3 that controls the amount of fuel and air supplied to the engine 1.
A detection signal of the throttle valve switch 13 (also called an idle switch) that is turned on when the throttle valve 12 in 4 is fully closed, and a detection signal of the throttle valve switch 13 (also referred to as an idle switch) that is turned on when the throttle valve 12 in 4 is fully closed, and a 4 neutral that outputs an on signal when the shift stage of the transmission 3 is located in the neutral stage. A detection signal from the switch 14 is input.

The control unit 4 further receives a detection signal from a catalyst inlet temperature sensor 31 that detects the temperature at the inlet of the catalyst, and a detection signal from a catalyst bed temperature sensor 32 that detects the catalyst bed temperature. In addition, 18 is an auxiliary air control valve for correcting the amount of air supplied to the engine 1, 19 is an air regulator for making the amount of air supplied to the engine 1 constant, and 20 is an air conditioner for air conditioning and warm air. A solenoid valve, 21 is a negative pressure control valve, and 22 is a fuel pump.

Further, 50 is a driving wheel speed sensor that detects the speed VDW of the driving wheel, 51 is a driven wheel speed sensor that detects the speed V, □ of the driven wheel, and the driving wheel speed sensor 50 and the driven wheel speed sensor 51 each detect A signal is input to the control section 4. Note that the driving wheel speed sensor 50 and the driven wheel speed sensor 51 together with the control section 4 constitute a detection means.

The control unit 4 includes an air flow meter 5 as shown in FIG.
a multiplexer 41 for selectively taking in an intake air flow rate detection signal from the , a cooling water temperature signal from the water temperature sensor 10 , an oxygen concentration detection signal from the oxygen sensor 9 , a knocking level detection signal from the knock sensor 11 , and the like; , a timer 42 that outputs a control signal for the capture of the multiplexer 41 at a predetermined time, and A that converts each analog signal captured by the multiplexer 41 into a digital signal.
/D converter 43.

The control unit 4 also controls each reset signal from the timer 45.
A counter 46 that counts the digital rotation speed detection signal from the crank angle sensor 6a, a CPU (central processing unit) 44 that performs control as described later based on the various input signals, and stores execution programs and various data for the CPU 44. and an output circuit 48 for outputting various control signals to the fuel injection valve 2, spark plug 16, etc.

Note that the reference angle signal from the crank angle sensor 6 is also input to the output circuit 48, and when the ignition timing calculated by the CPU 44 and this reference angle signal match, the ignition signal is sent to the power transistor 15 to ignite. The signal is output to the coil 17 and ignites the spark plugs 16 in a predetermined cylinder order via the distributor.

As shown in FIG. 4, the memory 47 includes cylinder data for cutting fuel in accordance with drive wheel slip rate control levels CL, ~CL, , ignition timing data for cylinders to which fuel is not cut, and fifth As shown in the figure, ignition timing data corresponding to the rotational speed N and basic injection amount TP and a program for the CPU 44 as shown in FIG. 6 are stored.

Incidentally, FIG. 5(a) shows the basic ignition timing ADV according to the rotational speed N and the basic injection amount Tr. FIG. 5(b) is a map showing 18% of the rotational speed N and the basic injection amount T.
This is a map showing the ignition timing ADV-, and Fig. 5(C)
is a map showing the -16% ignition timing ADV-Ih according to the rotational speed N and the basic injection amount T.

Next, referring to FIG. 6, we will explain the operation of the above embodiment, especially the CPU.
The operation of 44 will be explained.

First, in step P1, the intake air flow rate Qa detected by the air flow meter 5 is measured, in step P2 the rotational speed N detected by the crank angle sensor 6a is measured, and in step P3, the cooling water flow rate Qa detected by the water temperature sensor 10 is measured. Measure the temperature T-.

Similarly, in step P6, the vehicle speed VffP detected by the vehicle speed sensor 7 is measured, in step P7, the knock signal ■ detected by the knock sensor 11 is measured, and in step P8, the drive wheel detected by the drive wheel sensor 50 is measured. The wheel speed VDW is measured, and the driven wheel speed V detected by the driven wheel sensor 51 in step P9
, 1.1.

Next, in step PIO, the basic injection amount T is calculated using the intake air flow rate Qa, the rotational speed N, and the following formula (%), and in step pH, the driving wheel speed Calculate the slip rate SL.

In the following step P14, the basic ignition timing A is determined based on the rotational speed N, the basic injection amount Tp, and the map shown in FIG. 5(a).
DV, and similarly, in step P15,
The 18% ignition timing ADV- is calculated using the rotational speed N, the basic injection amount TP, and the map shown in FIG. ) According to the map shown in
Calculate 6.

After determining in step P17 whether or not there is knocking based on the knock signal ■, in the following step P18,
The slip ratio SL is ranked in 13 stages so that it corresponds to the control level CL, ~CL, etc. (Ranks SL, ~S
LIri.

Next, in step P19, the slip rate St is compared with the rank SL having the minimum slip rate, and the slip rate SL is determined.
If it is rank SL, or higher, it is determined that slip has occurred and the process branches to step P28, and in step P2B, rank SL is set, which is the control level CL shown in FIG. 4, and the fuel is cut for each cylinder. and traction control (Te3) by ignition timing control, followed by step P2.
9, the first TCS timer that counts the traction control (Te3) time is started, and the timer shown in FIG.
The process advances to step P30 shown in 2).

On the other hand, if the slip rate SL is not equal to or higher than rank SL, it is determined that no slip has occurred and the process proceeds to step P20.
, and compare the rotational speed N with the high-speed fuel cut-off rotational speed N, which is the high-speed limit of the engine, and the 0 rotational speed N is the high-speed rotation fuel cut-off rotational speed N. If it is larger than y, the process branches to step P22, and if it is smaller, the process branches to step P21.
Proceed to.

In step P21, the vehicle speed vsp is compared with the vehicle speed limit, for example, 180 to 1/h, and the vehicle speed ■3F is 180 to 17
If it is 1 or more, the process branches to step P22, and 180
If it is less than Km/h, proceed to step P23. In step P22, the fuel cut correction coefficient KFC is set to "0".
Set it to cut the fuel in the gold cylinder, and proceed to step P23.
Then, the fuel cut correction coefficient KFC is set to "1" and no fuel cut is performed for any cylinder.

In the following step P24, a knock signal ■ is generated. and its judgment value 5LEL, and if the knock signal V is larger than the judgment value 5LEL, in step P25, the basic ignition timing ADV @ is retarded by an angle β to set the ignition advance angle ADV, and the knock signal ■ is judged. If the value is less than or equal to 5LEL, the basic ignition timing ADV is determined in step P26. Ignition advance angle A
DV.

In the subsequent step P27, the fuel injection amount TL is calculated, and the process proceeds to step P38 shown in FIG. 6(2).

In step P30 shown in FIG. 6(2), the fuel cut limit value Ln, that is, the time required for the catalyst to reach the limit temperature after the start of traction control, is calculated from the rotational speed N and the basic injection amount TP, and the following step P31 The count value of the first TCS timer is compared with the limit value Ln, and if the count value is larger than the limit value Ln, the process proceeds to step P32 and below, and if it is smaller, the process branches to step P36 and below.

In step P32, the first TCS timer is reset to stop traction control, and in step P33, a second TCS timer is activated to count the time during which traction control is not performed. That is, steps P29 to P32 constitute the stopping means 93 in FIG.

In step P34, the rotational speed N and the basic injection amount T are determined.

Accordingly, the limit value (2) for the time during which traction control is not performed is calculated, and then in step P35, the count value of the second TCS timer and the limit value (2) are compared. If the count value of the second TCS timer is larger than the limit value Lm, the process returns to step P19 shown in FIG. 6(1), the traction control becomes possible, and the second TCS timer
If the count value of the CS timer is less than the limit value Lw+, the process returns to step P20 shown in FIG. 6(1) and no traffic control is performed.

In step P36, the cylinders to which fuel is to be cut are calculated based on the control level CLII of the traffic control and the table shown in FIG. The fuel injection amount T1 is set in the register, and the ignition timing ADV is set in the register in step P39.

Therefore, the fuel injection amount T set in this register
, and ignition timing ADV are output from the output circuit 48 in FIG. 3, and the fuel injection valve 2 and spark plug 10 in FIG. 2 are controlled.

(Effects) As explained above, according to the present invention, there is provided a detection means for detecting wheel slip, and an ignition timing for controlling engine ignition timing to prevent slip when the detection means detects wheel slip. a slip prevention means that performs fuel injection control to prevent slip by controlling the fuel injection amount of the engine; and a slip prevention means that measures the control time of the ignition timing control or the fuel injection control, and when the control time of the ignition timing control or the fuel injection control is exceeded, the ignition is activated when a predetermined time is exceeded. and a control stop means for stopping the timing control or fuel injection control, it is possible to avoid an increase in the exhaust temperature for a long period of time or an increase in the catalyst bed temperature, and as a result, the catalyst It is possible to prevent deterioration and improve emission.

[Brief explanation of drawings]

FIG. 1 is a conceptual configuration diagram of the present invention, and FIGS. 2 to 6 are diagrams showing one embodiment of an engine control device according to the present invention.
Figure 3 is a block diagram of its control unit, Figure 4 is an explanatory diagram showing cylinder data for which fuel is cut according to the slip rate of the drive wheels and ignition timing data for cylinders to which fuel is not cut. , Fig. 5 is an explanatory diagram showing ignition timing data according to the rotation speed and basic injection amount, Fig. 6 is a flowchart for explaining the operation of the control section, and Figs.
The figures show a conventional example, and Fig. 7 is a flowchart for explaining its operation, Fig. 8 is a graph showing the ignition advance characteristic as a function of the engine rotational speed during idling, and Fig. 9 is an explanatory diagram showing the basic ignition timing. 1... Engine, 4... Control unit (detection means, slip prevention means, control stop means), 50... Drive wheel speed sensor (detection means), 51
....Followed wheel speed sensor (detection means).

Claims (4)

[Claims] (1) Detection means for detecting wheel slip; ignition timing control means for controlling engine ignition timing to prevent slip when the detection means detects wheel slip; and control of the ignition timing control means. 1. A control device for an engine, comprising: control stop means for measuring time and stopping control of the ignition timing control means when a predetermined time has been exceeded. (2) a detection means for detecting wheel slip; a fuel injection control means for controlling the fuel injection amount of the engine to prevent slip when the detection means detects wheel slip; 1. A control device for an engine, comprising: control stop means for measuring a control time and stopping control of the fuel injection control means when a predetermined time is exceeded. (3) The engine control device according to claim 1 or 2, wherein the predetermined time is set depending on the operating state of the engine. (4) The engine control device according to claim 1 or 2, characterized in that, after the control is stopped beyond the predetermined time, the control is not restarted until a specific time determined by engine conditions has elapsed.