JPH02275048A - Engine controller - Google Patents

Abstract

PURPOSE:To enable accurate fuel injection control and ignition timing control by installing both fuel H and ignition H maps conformed to an opened state of a selector valve changing intake charging efficiency according to an engine driving state, and other fuel L and ignition L maps conformed to the closed state, respectively. CONSTITUTION:This variable intake system being installed at the upstream side of an intake passage 12 of a rotary piston engine 11 has a selector valve 15 of slide passage structure, making this valve 15 contact or separate to or from an upstream opening part 12a of the intake passage 12 by drive of a DC motor with a reduction gear via wires 30, 31. With this constitution, intake pipe length is adjusted to be shortened or lengthened, thereby changing the extent of natural frequency in the intake passage 12. Then, fuel injection time and ignition timing are found by a specified map stored in a read-only memory in an electronic controller, namely, both fuel H and ignition H maps conformed to a high-speed mode for open of the selector valve 15, and other fuel L and ignition L maps conformed to a low-speed mode for close of the selector valve 15.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an engine control device that performs map control of fuel injection amount and ignition timing in accordance with changes in the natural frequency of an intake system, for example.

(Prior art) Conventionally, in an engine control device that map-controls the fuel injection amount and ignition timing in response to the throttle valve opening and engine speed as engine loads, the natural vibration of the intake system is When a variable intake system that switches the number of intakes is provided, it is conceivable to map control the fuel injection amount and ignition timing using a single map in response to the above-mentioned throttle valve opening and engine speed.

However, with the control using the single map described above, when changing the switching point of the variable intake system, complex corrections of the fuel injection amount and ignition timing are required, and precise adjustments are made in response to changes in the natural frequency of the intake system. Fuel control and ignition control are difficult, and there is a problem in that a drop in engine torque, a so-called torque valley, occurs at the above-mentioned switching points.

(Object of the Invention) A first aspect of the present invention is to perform precise fuel injection control and ignition timing control in accordance with changes in intake air filling efficiency by providing a plurality of maps according to switching states of a variable system. The purpose is to provide an engine control device that can perform

A second aspect of the present invention is an engine control capable of improving torque in the switching region of the variable system and eliminating torque valleys by changing and controlling the switching point of the variable system according to the engine operating state. The purpose is to provide equipment.

A third aspect of the present invention aims to provide an engine control device that can protect the engine by, for example, avoiding high loads and high rotations by performing fixed control on a specific map when a variable system fails. .

(Structure of the Invention) A first aspect of the present invention is an engine control device that map-controls at least one of a fuel injection amount and ignition timing according to an engine load and an engine speed, A variable system is provided to change the filling efficiency of the intake air accordingly, and at least:
A map corresponding to the first switching of the fuel injection amount or ignition timing according to the first switching state of the variable system, and a map corresponding to the second switching of the fuel injection amount or ignition timing according to the second switching state of the variable system. It is an engine control device equipped with a map and controls changes.

A second aspect of the present invention, in addition to the configuration of the first aspect, is an engine control device that changes and controls the switching point of the variable system according to the operating state of the engine.

A third aspect of the present invention, in addition to the configuration of the first aspect, is an engine control device that performs fixed control on a specific map among the plurality of maps when the variable system fails. do.

(Effects of the Invention) According to the first aspect of the present invention, since a plurality of maps are provided according to each switching state of the variable system, when the intake air filling efficiency is changed by switching the variable system, the corresponding side By using the map, it is possible to perform precise fuel injection control and ignition timing control in response to the change in charging efficiency.

According to the second aspect of the present invention, in addition to the effects of the first aspect, the switching point of the variable system is changed and controlled according to the operating state of the engine, so that the torque in the switching region of the variable system is improved. This has the effect of eliminating torque valleys.

According to the third aspect of the present invention, in addition to the effects of the first aspect, when the variable system fails, the control is fixed to a specific map, so that it is possible to avoid high load and high rotation when the variable system fails. As a result, there is an effect that the engine can be protected.

(Example) An embodiment of the present invention will be described in detail below based on the drawings.

The drawing shows a control device for a multi-cylinder rotary piston engine. In FIG. 1, a working chamber 2 is formed inside the peritrochoid surface 1a of a rotor housing 1, while an intake boat 3 and An exhaust boat 4 is formed, and a trailing side spark plug 5T is installed on the other side.
and a leading side spark plug 5L are respectively provided.

In the rotor housing 1 described above, a rotor 8 is provided which moves eccentrically about an axis 7 by means of an eccentric shaft 6.

The rotor 8 has a trilobal inner envelope surface 9, and an apex seal 10 is attached to the apex of the rotor.

Multi-cylinder rotary piston engine 1 configured in this way
Each intake boat 3 of 1 has an intake passage 12.
. . , and each of these intake passages 12 . . . is provided with a throttle body 13 having a built-in throttle valve and a fuel injection valve 14, respectively.

A variable intake system is provided upstream of the above-mentioned intake passage 12 to change the natural frequency of the intake system depending on the engine operating state.

That is, switching valves 15.15 having a slide passage structure are provided corresponding to the upstream ends of each of the above-mentioned intake passages 12, and as shown in FIGS. 2 and 3, these switching valves 15.15 are By separating upward from the upstream openings 12a, 12a of the corresponding intake passages 12.12, the length of the intake pipes is shortened and the natural frequency of the intake passages is set high,
As shown in FIGS. 4 and 5, each of the above-mentioned switching valves 15.
15 to the upstream opening 12a of the intake passage 12.12.
, 12a, the length of the intake pipe is increased and the natural frequency of the intake passage is set to be low.

Here, the upstream opening 12a of the above-mentioned intake passage 12.12
A flange 16 is integrally formed on the outer side of , 12B, and a flange 18 is integrally formed on the outer side of the upper end of two air horns 17.17 for forming long pipes, and the corner portions of these upper and lower flanges 18.16 A total of four struts 19 stretched between each other allow the air horn 1 described above to
7.17 is fixedly supported and spaced upward from the upstream opening 12a of the intake passage 12.

The above-mentioned switching valve 15.15 has seal members 20.21 at both its upper and lower ends, and these seal members 20.21
By moving up and down along the outer periphery of the air horn 17, the natural frequency of the intake passage is changed.

Further, as shown in FIG. 6, bolts 23 and 24 are used to connect the guide ball 25 between the center part of the upper flange 18 and the ball support part 22 formed on the lower center surface of the lower flange 16. The above-mentioned switching valve 15.1 is connected to the guide ball 25 located outside the intake passage.
It is configured to guide the vertical sliding movement of 5.

That is, the two switching valves 15.15 are connected to the connecting member 2.
6.26, the valves are connected to each other by a connecting boss 27 at the center of the valve, and this connecting boss 27 is vertically slidably fitted to the above-mentioned guide ball 25 through a linear ball bearing 28, thereby forming a switching valve. 15.15 is constructed to prevent twisting.

Further, wire ends 29, 29 are disposed within the above-mentioned connecting boss 27 as a stop for the wire ends. Note that a retainer is fitted onto the outside of the wire ends 29, 29 to prevent the wire from falling off when the wire is cut. Then, the wires 30, 3], which are locked to these wire ends 29 and 29, are connected to a D
By operating the C motor 32, the above-mentioned switching valve 15.15 is configured to be switched to the high speed side (see Figs. 2 and 3) and the low speed side (see Figs. 4 and 5). .

The above-mentioned motor 32 is mounted on the base frame 3 as shown in FIG.
A driven plate 37 is fitted to the rotating shaft 36 of the motor 32, and one end of the above-mentioned one wire 30 is attached to the driven plate 37 via the wire end 38. , one end of the other wire 31 described above is attached to the driven plate 37 via a wire end 39.

Further, a spring 40 is biased to the above-mentioned driven plate 37,
This spring 40 biases the above-mentioned switching valve 15, 15 to the high speed side via the driven plate 37 and the wire 30 as shown in FIG.

FIG. 8 shows the control circuit of the engine control device, in which the CPU
Reference numeral 50 indicates a timer 43 and each of the first to fourth NPN type transistors TRI in accordance with a program stored in the ROM 42 based on various signals and interrupt signals from the analog-to-digital converter 41.

TR2, TR3, TR4, motor drive unit 44, variable intake system drive motor 32, fuel injection valve 14,
The igniter coil 45 and the spark plug 5 are driven and controlled, and the RAM 46 corresponds to fail judgment water temperature (FWT), fail judgment oil temperature (FOT), fail judgment engine rotation speed, sudden acceleration setting value (KΔRPM), and slow acceleration. Set rotation speed (KRPM) and set throttle opening (KTV
O), stores necessary data such as set rotation speed (KRPMS) and set throttle opening (KTVO3) corresponding to sudden acceleration.

The frequency/voltage converter 47 connected to the input side of the CPU 50 performs F-V conversion on the crank angle signal and outputs an engine rotation speed signal to the analog/digital converter 41 described above.

Further, the above-mentioned analog-to-digital converter 41 receives a throttle opening (TV O') signal and an opening (INTVO) signal of the switching valve 15 from a position sensor (not shown) that detects the rotational position of the motor 32. be done.

Furthermore, the above-mentioned ROM 42 stores a fuel injection amount map (fuel L map) and an ignition timing map (ignition L map) corresponding to the first switching state of the variable intake system, that is, the low speed mode when the switching valve 15 is closed, and the variable intake system. A map of fuel injection amount (fuel H map) and a map of ignition timing (ignition H map) corresponding to the second switching state of the system, that is, the high speed mode of opening of the switching valve 15 are stored.

The operation of the control device for the multi-cylinder rotary piston engine configured as described above will be explained with reference to the flowcharts shown in FIGS. 9 and 10.

In the first step 51, the CPU 50 controls the engine rotational speed (R
PM), throttle opening (TvO), switching valve 15
opening (INTVO), water temperature (WT), oil temperature (OT)
Load.

Next, in a second step 52, the CPU 50 compares the read water/oil temperature (WT) with the fail judgment water temperature (FWT), and also compares the read oil temperature (OT) with the fail judgment oil temperature (FO
If the engine parameters are abnormal (WT>FWT or OT>FOT), the process moves to the next third step 53.

In this third step 53, the CPU 50 makes the first transistor TRI conductive and outputs a control signal to the motor drive unit 44 to drive the motor 32 at low speed (XSPEED=O).

Next, in a fourth step 54, the CPU 50 makes the second transistor TR2 conductive, and sends a control signal (XO
PEN=O) is output, the motor 32 is driven at the above-mentioned low speed in the switching valve closing direction, the switching valve 15 is closed, the variable intake system is set to a low-speed mode, and the engine output is reduced when the above-mentioned engine parameters are abnormal. let me,
In this way, the engine is protected.

Next, in a fifth step 55, the CPU 50 fixes the map read from the ROM 42 to the low-speed fuel L map and ignition map, and calculates the fuel injection time (Ti) and ignition timing (Ig) from each of these low-speed maps. ), the process returns to the first step 51 described above.

On the other hand, in the second step 52 described above, water oil (WT), oil temperature (
OT) If the CPU 50 determines that both are normal, the process moves to the next sixth step 56.

In this sixth step 56, the CPU 50 determines whether the current engine speed (RPM) is smaller than the fail judgment engine speed, for example, 1o rpm, and determines whether RPM>10rpm.
When 1llll, the process moves to the next seventh step 57, while when RPM<10+pm, for example, when the engine is stopped, the process moves to another eighth step 58.

In the eighth step 58, the CPU 50 makes the first transistor TR1 non-conductive and outputs a control signal to the motor drive unit 44 to drive the motor 32 at high speed (XSPEED=1).

Next, in a ninth step 59, the CPU 50 makes the second transistor TR2 non-conductive and sends a control signal (X
OPEN=1) is output, the motor 32 is driven at the above-mentioned high speed in the switching valve opening direction, and the switching valve 15 is
The seal member 21 is opened to protect the seal member 21 and to facilitate maintenance.

In the seventh step 57 described above, the CPU 50 sets Q, 5s in advance.
Switching valve open/close signal (XOPEN) monitored for each ec
) and the opening degree (INTVO) of the switching valve 15, when the valve opening/closing signal is open and the valve opening is fully closed, which is unmatched, and when the valve opening/closing signal is closed, and the valve opening is fully open, it is unmatched. Furthermore, if the valve opening degree (INTVO) is the same value twice in a row when the valve opening degree is not fully closed or fully open, it is considered as a failure of the variable intake system, and the third to fifth steps 53 and 54 degrees described above are performed. 55, a specific map among the plurality of maps, that is, the fuel L map for low speed, is ignited and fixed to the map to avoid high load and high rotation, thereby protecting the engine.

On the other hand, when the CPU 50 determines in the seventh step 57 that the variable intake system is normal, the next 10th step 57
The process moves to step 60.

In this tenth step 60, the CPU 50 controls the rotational change rate (
ΔRPM) is calculated, and the process moves to the next eleventh step 61.

In the above-mentioned 11th step 61, the CPU 50 compares the rotational change rate (ΔRPM) with the rapid acceleration set value (KΔRPM), and moves to the 12th step 62 when the vehicle is rapidly accelerating, while at the time of slow acceleration or steady running, it compares the rotation rate of change (ΔRPM) with the rapid acceleration setting value (KΔRPM). The process moves to the thirteenth step 63.

In other words, based on the determination in the eleventh step 61 described above, C
The PU 50 changes and controls the switching point of the variable intake system depending on the operating state of the engine.

During slow acceleration, the set rotation speed (KRPM) is, for example, 7500.
rpm, set throttle opening (KTVO)
The switching point (first switching point) is the engine operating state corresponding to, for example, 80%, and when the set rotation speed (KRPMS) is set to, for example, 72Q Q tpm during sudden acceleration, the set throttle opening (KTVO8)>(corresponds to, for example, 75%). By setting the operating state of the engine as a switching point (second switching point), the torque in the switching region of the variable intake system is improved and control is performed to eliminate the torque valley.

That is, at the time of sudden acceleration, in the above-mentioned twelfth step 62,
CPU50 indicates that the engine operating status is RPM > KRPMS.
Then, it is determined whether or not the second switching point of TvO>KTvO8 has been reached, and when the second switching point is reached, the switching valve 15 is opened at high speed by the processing of the above-mentioned eighth and ninth steps 58 and 59, and then, Next 14th step 6
4, and in the fourteenth step 64, the CPU 50 indexes the fuel injection time (Ti) and ignition timing (Ig) from the high-speed fuel H map and ignition H map.

On the other hand, during slow acceleration, the CP is
For U50, the engine operating state is RPM>KRPM and T.
It is determined whether the first switching point of vO>KT■0 has been reached, and when the first switching point is reached, the next 15th switching point is reached.
The process moves to step 65, and in this 15th step 65, C
The PU 50 conducts the first transistor TRI to cause the motor drive unit 44 to heat the motor 32 at low heat (xs
A control signal to be driven at PEED=0) is output.

Next, in a sixteenth step 66, the CPU 50 makes the second transistor TR2 non-conductive and sends a control signal (X
OPEN=1) is output, the motor 32 is driven at the above-mentioned low speed in the switching valve opening direction, and the switching valve 15 is
After opening at low speed, the process moves to the fourteenth step 64 described above.

In this way, the switching valve 15 is opened quickly during sudden acceleration, and the switching valve 15 is opened slowly during slow acceleration, thereby optimizing the valve opening degree.

By the way, when an interrupt signal is input from the crank angle sensor, the CPU 50 executes processing based on the interrupt routine shown in FIG.

It should be noted that the above-mentioned interrupt signals are generated sequentially at the rising edge of the signal for each revolution of the engine.

In the first step 71, the CPU 50 determines whether or not the switching valve opening/closing signal (XOPEN) has changed since the previous interrupt. The process moves to step 2 72.

In this second step 72, the CPU 50 determines whether the switching valve 15 has been switched from closed to open or from open to closed, and if the switching valve 15 has been switched from open to closed, it executes the next third step. 73, and in this third step 73, the valve open flag (SOPEN) is set to O, while if the switching valve 15 is switched from closed to open, the process moves to another fourth step 74, and the valve open flag (SOPEN) is set to O. In step 74, the valve open flag (SOPEN) is set to 1.

In the third step 73 described above, the valve open flag is set to 0.
After setting the value to 20, the CPU 50 sets the count value of the built-in counter to 20 in the next fifth step 75.

Further, after setting the valve open flag to 1 in the fourth step 74 described above, in the next sixth step 76, the CPU 50
indicates that the motor drive speed control signal (XSPEED) is 1 or 0 (
3rd, 8th, and 15th steps 53, 58, and 65), and if X5PEED=O, the process moves to the next seventh step 77.
sets the count value of the built-in counter to 30 corresponding to the low speed switching of the valve, while if X5PEED=1, the process moves to another eighth step 78;
Then, the CPU 50 sets the count value of the built-in counter to 20 in response to the high-speed valve switching.

Next, in a ninth step 79, the CPU 50 determines whether the count value has become zero or not, and if COUNT≠0, the process proceeds to the next tenth step 80.

At this tenth step 80, the CPU 50 executes subtraction of the count value set by the process described above.

Next, in an eleventh step 81, the CPU 50 determines whether the valve open flag (SOP E N) is 1 or 0, and
When OPEN=1, the process moves to the twelfth step 82.

At this twelfth step 82, the CPU 50 determines whether the count value is 29 or not, and moves to the next thirteenth step 83 only during the initial control to open the switching valve 15 at a low speed when C0TJNT=29.

In this thirteenth step 83, the CPU 50 sets the fuel injection time to Tixl, 05 to make the air-fuel ratio rich, and sets the ignition timing to a value (Ig) that does not cause retard or advance, and sets the ignition timing to a value (Ig) that does not cause retard or advance. 85
By creating a phase difference in the ignition timing,
Take measures against switching shock.

On the other hand, in the above-mentioned twelfth step 82, C0UNT≠29
If it is determined that this is the case, that is, during control after the initial control in which the switching valve 15 is opened at a low speed, or during control in which the switching valve 15 is opened at a high speed, the process moves to the next fourteenth step 84.

In this fourteenth step 84, the CPU 50 sets the fuel injection time to 'rtxt, 05 to make the air-fuel ratio richer, and retards the ignition timing by 5 degrees to match the operating time of the ~2 switching valve 15. The fuel injection time (Ti) and ignition timing (Ig) are corrected to optimize the air-fuel ratio during valve opening control.

The switching pulp 15 for which the CPU 50 has determined that the valve open flag 5 OPEN = 0 in the eleventh step 81 described above
During the closing control, the process moves to the next fifteenth step 85.

In this 15th step 85, the CPU 50 sets the fuel injection time to TixO,95 to make the air-fuel ratio lean, and advances the ignition timing by 5 degrees.
The fuel injection time commensurate with the operating time of the switching valve 15 (
Ti) and ignition timing (1g) are corrected,
Aim to optimize the air-fuel ratio during valve closing control.

Next, in a sixteenth step 86, the CPU 50 uses the timer 43 to set the fuel injection time (Ti) and ignition timing (1g) preset in each step 83, 84, and 85 described above.
This timer 43 is set to the fuel injector 14 through the third and fourth transistors TR3 and TR4. The igniter coil 45 and the spark plug 5 are driven and controlled.

In summary, there are a plurality of maps depending on the open/close switching state of the variable intake system, that is, a fuel H map and an ignition H map depending on the open state of the switching valve 15, and a fuel L map depending on the closed state of the switching valve 15. , ignition map, and by using the map on the side that corresponds to opening or closing according to the change in the natural frequency due to switching of this variable intake system, precise control is provided in response to the change in the natural frequency. This has the effect of allowing fuel injection control and ignition timing control to be performed.

In addition, since the switching point of the variable intake system is changed and controlled depending on the engine operating condition, such as sudden acceleration or slow acceleration, it is possible to improve the torque in the switching region of the variable intake system and eliminate torque valleys. There is an effect that can be done.

Furthermore, when the variable intake system fails, control is fixed to the lower speed map (fuel L map, ignition map) among the multiple maps mentioned above, so high load rotation is avoided in the event of a failure, and the engine is protected. This has the effect of making it possible to achieve this goal.

In terms of the correspondence between the structure of the present invention and the embodiments described above, the engine of the present invention corresponds to the multi-cylinder rotary piston engine 11 of the embodiment, and similarly, the variable system is a variable intake system using the switching valve 15. The map corresponding to the first switching corresponds to the fuel L map and the ignition map, and the map corresponding to the second switching corresponds to the fuel H map and the ignition H map, and changes and controls the switching point of the variable system. The means are
The means for fixing control to a specific map when the variable system fails corresponds to the seventh step 57 and the fifth step 55 under the control of the CPU 50, which correspond to the 11th, 12th, and 13th steps 61, 62, and 63 under the control of the CPU 50. However, the present invention is not limited to the configuration of the above-described embodiment, but can also be applied to a reciprocating engine.

Further, the variable system described above may be a means for varying the intake air filling efficiency by changing the opening/closing timing of intake and exhaust valves in a reciprocating engine.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, Fig. 1 is an overall view showing the control device of a multi-cylinder rotary piston engine, Fig. 2 is an explanatory diagram when the switching valve is open, and Fig. 3 is a cross section when the switching valve is open. Figure 4 is an explanatory diagram when the switching valve is closed. Figure 5 is a sectional view when the switching valve is closed. Figure 6 is a sectional view taken along the VI-Vl line in Figure 2. Figure 7 is a switching valve drive. An enlarged view of the motor, Figure 8 is a control circuit diagram, Figure 9 is a flowchart showing the main routine, Figure 10 is a flowchart showing the main routine.
The figure is a flowchart showing the interrupt routine. 11...Multi-cylinder rotary piston engine 15...
Switching valve 50...CPU Fig. 2 15...Switching valve jl- ■2...#epulp/tJJ increase bulk' Fig. 4 15--...Lure No. 70 with cutting lees Blade Fig. 6 15・Killing valve

Claims (3)

[Claims] (1) An engine control device that performs map control on at least one of the fuel injection amount and ignition timing in response to engine load and engine speed, and that changes intake air filling efficiency in accordance with engine operating conditions. a map corresponding to the first switching of the fuel injection amount or ignition timing according to the first switching state of the variable system; and a map corresponding to the first switching of the fuel injection amount or ignition timing according to the second switching state of the variable system. An engine control device comprising a map corresponding to second switching of ignition timing. (2) The engine control device according to claim 1, which changes and controls the switching point of the variable system according to the operating state of the engine. (3) The engine control device according to claim 1, which performs fixed control to a specific map among the plurality of maps when the variable system fails.