JP3441471B2 - Engine control device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine control apparatus provided with a pumping loss reducing means comprising a late intake port and an on-off valve for opening and closing the late intake port. About. 2. Description of the Related Art In an engine in which load control is performed by adjusting the amount of intake air using a throttle valve disposed in an intake passage, when the opening of the throttle valve is small, the intake pressure downstream of the throttle valve is negative. Because of the pressure, there is a problem that a so-called pumping loss occurs and fuel efficiency is deteriorated. For this reason, an intake late closing port that closes later than the basic intake port closing timing is conventionally provided downstream of the throttle valve of the engine, and a part of the air-fuel mixture in the combustion chamber is initially removed from the intake late closing port at the beginning of the compression stroke. There has been proposed a pumping loss reduction device that improves the fuel efficiency by reducing the amount of intake air by sending it to the outside, thereby allowing the throttle valve to open more widely. The above pumping loss reducing device is
When applied to a cylinder rotary piston engine, an intermediate housing that defines two cylinders is provided with a communication passage that connects the working chamber of one cylinder in the intake stroke and the working chamber of another cylinder in the compression stroke. There is also known a configuration in which an opening / closing valve whose opening is controlled in accordance with the engine speed and the throttle opening is provided in the communication path in addition to being provided as an intake late closing port (Japanese Patent Application Laid-Open No. Sho 63-163). 25
No. 3117). In an engine provided with an intake late closing port to reduce pumping loss, an on-off valve for controlling pumping loss reduction is operated from a fully closed state to a fully opened state. Then, even if the intake air amount is constant, the intake negative pressure (boost) changes as shown in FIG. Therefore, an engine equipped with a so-called D JETRO type electronically controlled fuel injection device that measures an intake air amount by detecting an intake pipe negative pressure and determines a fuel injection amount from the intake air amount and the engine speed. When the above-described pumping loss reduction device is applied to the above, it is necessary to correct the fuel injection amount according to the opening of the on-off valve for pumping loss reduction control. However, when a step motor or the like is used as an actuator for driving the on-off valve, a mechanical delay occurs in the on-off operation of the on-off valve. Therefore, simply correcting the fuel injection amount in accordance with the target opening degree of the on-off valve determined by the engine speed and the throttle opening degree causes a shift in the fuel injection amount due to the operation delay of the on-off valve. [0008] In view of the above circumstances, the present invention provides a pumping method.
In an engine having an on-off valve that opens and closes an intake late closing port for reducing loss, it is possible to prevent a shift in fuel injection amount due to a decrease in intake negative pressure when the on-off valve is opened, and to operate the on-off valve. It is an object of the present invention to provide a control device capable of preventing a difference in fuel injection amount due to a delay. SUMMARY OF THE INVENTION The present invention provides an intake late closing valve.
Opening and closing to change the ventilation rate of this intake late closing port
Valve and engine speed detection to detect engine speed
Means and a slot for detecting the throttle opening of the engine
Opening degree detecting means, the engine speed and the throttle
The target opening of the on-off valve is set according to the opening, and the target opening is set.
Opening control means for controlling the opening of the on-off valve based on the degree,
Depending on the engine speed and throttle opening, the target fuel
For setting the basic value of the target fuel injection amount to obtain the basic value of the fuel injection amount
And the fuel injection amount based on the target opening of the on-off valve.
Correction amount setting procedure for obtaining the first correction amount for the basic value of
Stage, opening detection means for detecting the actual opening of the on-off valve,
Based on the deviation between the target opening and the actual opening of the on-off valve,
A second supplement for obtaining a second correction amount for the basic value of the fuel injection amount
A positive amount setting means for setting the basic value of the fuel injection amount to the first
And control the fuel injector based on the value corrected by the second correction amount
And a fuel injection valve control means . The operation of the engine control apparatus according to the present invention is based on the target fuel in accordance with the engine speed and the throttle opening.
For setting the basic value of the target fuel injection amount to obtain the basic value of the fuel injection amount
It includes a stage, the fuel injection amount based on the target opening degree of the on-off valve
Correction amount setting procedure for obtaining the first correction amount for the basic value of
Based on the deviation between the target opening and the actual opening of the on- off valve
Obtains a second correction amount to the basic value of the upper Symbol fuel injection amount have
A second correction amount setting means for controlling the fuel injection valve control means.
And the basic value of the fuel injection amount is calculated using the first and second correction amounts.
Since the fuel injection valve is controlled based on the corrected value, when the pumping loss reduction control by the late intake closing is applied to the engine equipped with the D-JETRO type electronic fuel injection control device, In addition, even if the intake negative pressure changes according to the opening degree of the on-off valve, the fuel injection amount can be corrected in accordance with the change, and the deviation of the fuel injection amount due to a delay in the operation of the on-off valve is also prevented. Can be. Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an exploded schematic view showing a configuration in which the present invention is applied to a two-cylinder rotary piston engine, and FIG. 2 is a sectional view thereof. In FIG. 1, a rotary piston engine (hereinafter simply referred to as “engine”) 1 includes a casing 2.
It has. The casing 2 includes an intermediate housing 3 and two rotor housings 4 a and 4 disposed on both sides of the intermediate housing 3.
b, and two side housings 5a, 5b arranged outside these two rotor housings 4a, 4b. The inner peripheral surfaces of the rotor housings 4a and 4b form a trochoid surface, and two trochoid surfaces are formed by this trochoid surface, both side surfaces of the intermediate housing 3, and inner surfaces of the side housings 5a and 5b. Spaces 6a and 6b are formed. The two trochoid spaces 6a and 6b accommodate rotors 7a and 7b, respectively. The rotors 7a and 7b are supported by an eccentric shaft 8 and extend through the trochoid spaces 6a and 6b at an angle of 180 °. It is configured to perform planetary motion with a phase. Reference numeral 10 denotes an intake device. The intake device 10 includes a common intake passage 11, a throttle valve 12 provided in the common intake passage 11, and a surge tank formed at a downstream end of the common intake passage 11. 13 and independent intake passages 15a and 15b connecting the surge tank 13 and intake ports 14a and 14b of each cylinder. Each independent intake passage 15a, 15b has a fuel injection valve 16a,
16b is provided. A communication passage 17 is formed in the intermediate housing 3. As shown in FIG. 3 (a), the communication passage 17 is used to move the compression working chamber of one trochoid space 6a to the suction operation of the other trochoid space 6b in accordance with the rotation of the rotors 7a and 7b out of phase by 180 °. In order to alternately show a communication state in which the communication chamber communicates with the chamber and a communication state in which the compression working chamber of the other trochoid space 6b communicates with the intake working chamber of the one trochoid space 6a, as shown in FIG. The two ends of the communication passage 17 are opened to the trochoid spaces 6a, 6b as intake late closing ports 18a, 18b, respectively. The communication passage 17 is provided with an on-off valve 19 for adjusting the flow rate of the communication passage 17. The on / off valve 19 is controlled to open and close using a step motor 31 as an actuator. The step motor 31 is driven by a drive signal output from a controller 30 connected to a control circuit (ECU) 20 including a microcomputer. ing. Reference numerals 21a and 21b denote spark plugs, and reference numerals 22a and 22b denote rotor housings 4a and 4b.
The exhaust port formed in b is shown. Exhaust port 22a,
A common exhaust passage 23 is connected to the exhaust passage 22b.
3 is provided with an oxygen concentration sensor (O ₂ sensor) 24. In addition, a throttle opening sensor 25 for detecting the opening (TVO) of the throttle valve 12 is provided in the common intake passage 11, and the surge tank 13 has an intake negative pressure (boost).
Sensor 26 for detecting the intake air temperature and an intake air temperature sensor 27 for detecting the intake air temperature.
Is provided with a water temperature sensor 28. Further, an angle sensor 29 for detecting the rotation angle of the eccentric shaft 8 is provided,
The outputs of these sensors are all input to the control circuit 20. The control circuit 20 stores the fuel control up as shown in FIG. 4 in its memory, and this map sets a feedback area in an operation area corresponding to the engine speed and the load. ing. This feedback range is set between the two engine speeds with the predetermined intake pressure detected by the boost sensor 26 as the upper limit of the load and the detection value of the throttle opening sensor 25 as the lower limit. Then, the control circuit 20 outputs a fuel injection pulse having a pulse width calculated based on the output of the sensor to the fuel injection valves 16a and 16b, and in a feedback control region set on the fuel control map, ₂ The output of the sensor 24 is fed back to control the fuel injection amount. FIG. 5 is a block diagram showing a configuration of the control circuit 20 and the controller 30 of FIG. Control circuit 2
0 is a determination circuit 32, an on-off valve target opening storage circuit 33, an on-off valve target opening calculation circuit 34, an opening signal control circuit 35, a basic fuel injection amount calculation circuit 36, a first correction circuit 37, a comparison circuit 38, Second correction circuit 39 and fuel injection control circuit 40
It has. The controller 30 includes a step motor signal conversion circuit 41, a step motor drive circuit 42, and an actual step signal transmission circuit 43. On-off valve 1 for pumping loss reduction control
Opening the valve 9 lowers the temperature of the compressed air-fuel mixture and deteriorates the combustibility. Therefore, it is not preferable to open the on-off valve 19 particularly in a light load region. Therefore, the control circuit 20 determines whether the throttle opening degree sensor 25 and the angle sensor 2
9, the throttle opening TVO and the engine speed are detected to determine whether or not the current operation region is a region suitable for the pumping loss reduction control. In this embodiment, the fuel injection amount feedback control region shown in the map of FIG. 4 is set as the pumping loss reduction control region. The on-off valve target opening storage circuit 33 stores an on-off valve target opening map as shown in FIG. This map shows the target opening of the on-off valve 19 corresponding to the engine speed and the throttle opening TVO by the stepping motor 31.
Are shown by straight lines parallel to each other (parallel to the horizontal axis) representing the number of steps. In this case, the throttle opening TV
As is clear from FIG. 7 showing the relationship between the engine torque and O, the smaller the throttle opening TVO, the larger the torque change. Therefore, the mutually parallel straight lines representing the number of steps are dense in a region where the throttle opening TVO is small. In a region where the throttle opening TVO is large, sparseness is set to improve drivability. The opening / closing valve target opening calculating circuit 34 is a circuit for calculating the target opening of the opening / closing valve 19 from the throttle opening TVO and the engine speed using the map shown in FIG. The opening is output to the controller 30 via the opening signal control circuit 35. Further, in order to correct a change in the intake negative pressure (boost) according to the target opening of the opening / closing valve 19 (see FIG. 11), the fuel injection amount correction coefficient K ₁ corresponding to the target opening is determined by the first correction circuit 37. Is output to Next, in the basic fuel injection amount calculation circuit 36,
The basic pulse width of the fuel injection pulse applied to the fuel injection valves 16a and 16b is calculated from the intake negative pressure (boost), the engine speed, and the like. This basic pulse width is multiplied by the above-described correction coefficient K ₁ in the first correction circuit 37, and the fuel injection amount is corrected according to the target opening of the on-off valve 19. On the other hand, in the controller 30, the control circuit 2
The opening signal (target step signal) output from the opening signal control circuit 35 of 0 is converted into a step motor drive signal by a step motor signal conversion circuit 41, and this drive signal is transmitted to the step motor 31 through the step motor drive circuit 42. Is output. An actual step signal indicating the actual number of steps of the step motor 31 is transmitted from the transmission circuit 43 to the comparison circuit 38 of the control circuit 20. The actual number of steps is compared, and a fuel injection amount correction coefficient K ₂ according to the difference between the target number of steps and the actual number of steps is output from the comparison circuit 38 to the second correction circuit 39. In the second correction circuit 39, the pulse width of the fuel injection pulse previously corrected in the first correction circuit 37 is further multiplied by a correction coefficient K ₂ and further corrected. An injection pulse is output to the fuel injection valves 16a and 16b. FIGS. 8 and 9 are flowcharts of a fuel injection amount control routine executed by the control circuit 20. Note that S8 to S10 in FIG. First, the throttle opening TVO, the engine speed, and the intake negative pressure (boost) are read in S1 of FIG. 8, and in the next S2, the basic pulse width of the fuel injection pulse is obtained from the throttle opening TVO and the engine speed. Is calculated. Next, in S3, it is determined whether or not it is in the pumping loss reduction control area. If it is not in the pumping loss reduction control area, the process proceeds to S17 in FIG. 9 to perform fuel injection control with the basic injection pulse width. Next, when it is determined in S3 that it is in the pumping loss control area, the target opening of the on-off valve 19 is read from the map of FIG. in S6 calculates a correction coefficient K ₁ corresponding to the target opening, by multiplying the correction coefficient K ₁ to the basic pulse width of the fuel injection pulse in the next S7 performs first fuel correction. On the other hand, from the control circuit 20 to the controller 30
The opening / closing valve target opening signal sent to the controller is converted into a step motor drive signal in S8, and a drive signal is output to the step motor 31 in S9. Then, the actual step signal is transmitted to the control circuit 20 in S10. Next, in S11 of FIG.
The actual step signal transmitted from is read, and the actual step number is subtracted from the target step number in S12 to compare the two. In this case, as shown in the map of FIG.
When the value obtained by subtracting the actual number of steps from the target number of steps is positive, the on-off valve 19 has not been opened to the target opening degree.
Small drop in boost. Therefore, the air-fuel ratio is too rich if the fuel correction in S7 is left as it is, and this is corrected to the lean side. That is, smaller than 1 the value of the correction factor K ₂ at S13. On the other hand, when the value obtained by subtracting the actual number of steps from the target number of steps is negative, the on-off valve 19 is too open than the target opening, and the boost drop is large.
Therefore, the air-fuel ratio is too lean if the fuel correction in S7 is left as it is, and this is corrected to the rich side. That is,
Greater than 1 the value of the correction factor K ₂ at S14. If the target step number and the actual step number become equal, S15
And K ₂ = 1. As described above, the correction coefficient K ₂ based on FIG.
After calculating the performs final fuel correction by multiplying the correction coefficient K ₂ to the fuel injection pulse width is corrected in S7, S
The program proceeds to step 17, where fuel injection control is performed, and this control routine ends. As is apparent from the above description, in the engine control device according to the present invention, the fuel correction corresponding to the boost reduction caused by the opening of the on-off valve 19 and the on-off valve 19
Since fuel correction is performed in response to the operation delay of
Even during the pumping loss reduction control, it is possible to prevent the deviation of the fuel injection amount.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded schematic view showing a configuration of a two-cylinder rotary piston engine to which the present invention is applied. FIG. 2 is a sectional view of FIG. FIG. 4 is a map showing a feedback control region of a fuel injection amount. FIG. 5 is a block diagram showing a configuration of a control circuit and a controller of FIG. 1. FIG. 6 is a target opening map of an on-off valve. FIG. 8 is a first half of a flowchart showing a fuel injection control routine executed by the control circuit. FIG. 9 is a second half of the flowchart. FIG. 10 is a correction coefficient map. FIG. Graph showing the relationship between opening and boost [Description of References] 1 Rotary piston engine 3 Intermediate housings 4a, 4b Rotor housings 5a, 5b Side housings a, 6b trochoid space 7a, 7b the rotor 8 the eccentric shaft 10 intake device 12 throttle valve 16a, 16b fuel injection valve 17 communicating path 18a, 18b intake valve closing retardation port 19 closing valve 20 the control circuit 30 the controller 31 step motor

Continuation of the front page (56) References JP-A-63-253117 (JP, A) JP-A-2-248637 (JP, A) JP-A-3-1155741 (JP, A) (58) Fields investigated (Int) .Cl. ⁷ , DB name) F02B 53/06 F02D 13/02

Claims (1)

(57) Patent Claims 1. A inspiratory late closing port, an opening and closing valve for changing the airflow amount of the intake valve closing retardation port, an engine speed detecting means for detecting a rotational speed of the engine
And throttle opening detection that detects the throttle opening of the engine
Outlet means, and the above-mentioned opening in accordance with the above-mentioned engine speed and throttle opening.
Set a target opening for closing the valve, and open / close the valve based on the target opening.
Opening control means for controlling the opening of the engine, and a target fuel in accordance with the engine speed and the throttle opening.
For setting the basic value of the target fuel injection amount to obtain the basic value of the fuel injection amount
And the fuel injection amount based on the target opening of the on-off valve.
A first correction amount setting means for determining a first correction amount for the value, and opening detection means for detecting an actual opening degree of the on-off valve, the on the basis of the deviation between the target opening and the actual opening of the closing valve
A second supplement for obtaining a second correction amount for the basic value of the fuel injection amount
A positive amount setting means for supplementing the basic value of the fuel injection amount with the first and second correction amounts;
Fuel injection valve control that controls the fuel injection valve based on the corrected value
Control means for the engine.