JP3477754B2 - Engine control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] BACKGROUND OF THE INVENTION The present invention relates to a multi-cylinder engine.
The present invention relates to an engine control device to be used. [0002] 2. Description of the Related Art This type of fuel injection, particularly independent injection, is performed.
In the engine control unit, it is indispensable to determine the cylinder of the engine.
Yes, the reference position is detected when the engine starts rotating
Fuel injection (independent injection) until cylinder discrimination by
Can not do. Therefore, it has been proposed
The engine control device that operates after the start of rotation of the engine
Fuel injection is not performed until the first cylinder discrimination is performed.
Device to start independent injection after another, and start of engine rotation
Pre-injection for all cylinders in synchronization with
It can be broadly divided into devices that shift to independent injection. What
The latter control device is an improvement of the former control device.
For example, Japanese Patent Application Laid-Open No. 1-170735 has been proposed.
And JP-A-3-54337 are known.
You. [0003] Hereinafter, the control operation of the conventional engine control device will be described.
FIG. 1 shows the operation immediately after the start of engine rotation.
This will be described with reference to the timing chart of FIG. FIG.
4 shows an example of a 4-cycle 6-cylinder engine, and the first cylinder
(# 1) to sixth cylinder (# 6) are # 1 → # 2 → # 3 → # 4
It is ignited in the order of # 5 → # 6 → # 1. Crank angle signal
NE is output every 30 ° CA, and the reference position signals G1, G
2 is output immediately before TDC of the fourth cylinder and the first cylinder, respectively.
It is. [0004] The rotation of the engine starts at time t11.
Then, the crank angle signal NE and the reference position signal G1,
Mask period for preventing erroneous detection of G2 (time t11 to t11)
12), at time t13, the first reference position signal G1
Is detected. At this time, based on the reference position signal G1,
The fourth cylinder is determined. And at time t14,
Has an intake stroke after time t13 when the cylinder is determined
A fuel injection signal is sent to the cylinder, and after that, # 2 → # 3
→ Independent injection is performed in the cylinder order of # 4. In addition, all cylinders are synchronized with the start of rotation of the engine.
When the preliminary injection is performed for
As shown, at time t11, fuel injection is performed simultaneously for all cylinders.
Thereafter, the operation is shifted to the independent injection at time t14. On the other hand, the first point after the start of rotation of the engine
The fire signal is set after the first cylinder discrimination at time t13.
You. In other words, when the ignition timing is TDC of each cylinder,
At the falling edge of the ignition signal at time t15, the first spark
(At this time, the first ignition cylinder in FIG.
Cylinder). And thereafter, # 5 → # 6 → # 1 ...
The ignition is performed in the cylinder order. [0007] SUMMARY OF THE INVENTION
The engine control device has the following problems. Destination
Before the cylinder discrimination (before time t13 in FIG. 14).
When no firing is performed, time t14 (TD of the fourth cylinder)
Independent injection is started in C), and the first injection cylinder at this time
Is the second cylinder. Then, it was sucked into this second cylinder
The fuel is ignited at time t16, which is the TDC of the second cylinder.
It is. That is, the first explosion (first explosion) occurs at time t16.
Will be. In other words, during the period from time t13 to t16
Is to ignite the fifth, sixth, and first cylinders.
Cylinders can get the first explosion because fuel has not been inhaled.
It is a wasteful fire. As a result, after the engine starts rotating,
Two revolutions (period t11 to t16) have no first explosion,
There is a problem that the startability of the engine is deteriorated. At the start of engine rotation, all cylinders
When the preliminary injection is performed by the preliminary injection at the time t15,
The first explosion occurs due to the ignition of the intake fuel, and the subsequent
6, Explosion also occurs in the first cylinder due to intake fuel from preliminary injection
This. Therefore, compared to the former case, the engine
Startability is significantly improved. But in this case, reserve
Intake fuel of the second, third, and fourth cylinders among all cylinders to be injected
The fuel is exhausted without being ignited, and unburned gas
The problem of the emission of heat occurs. The present invention has been made in view of the above problems.
The purpose is to discharge unburned gas.
And to improve the startability of the engine
It is an object of the present invention to provide an engine control device that can perform the following. [0010] [MEANS FOR SOLVING THE PROBLEMS] To achieve the above object
Meanwhile, the engine control device of the present invention is configured as shown in FIG.
Used in an engine M1 having a plurality of cylinders
And detects the crank angle of the engine M1.
The crank angle detection means M2 and a predetermined crank angle
A reference position detecting means M3 for detecting the determined reference position;
The reference position detecting means after the start of rotation of the engine M1
At the first reference position detected by M3, the fuel injection control
First engine control means M4 for starting control and ignition control
Based on the detection result by the crank angle detecting means M2.
The crank angle when the rotation of the engine M1 is stopped
Stop crank angle detection means M5 for detectingPredetermined
The map is divided into regions for each predetermined crank angle.
On the basis of,Detected by the stop crank angle detecting means M5.
The output stop crank angle and the stop crank angle
Between the next reference position and the cylinder that is in the early stage of the intake stroke
Pre-injection cylinder discriminating means M6 for discriminating as pre-injection cylinder
And detecting the reference position from the start of rotation of the engine M1.
Until the detection of the first reference position by the means M3,
For the pre-injection cylinder by the pre-injection cylinder discriminating means M6
And second engine control means M7 for injecting fuel.
The gist of this is. [0011] According to the above construction, the crank angle detecting means M2
Detects the crank angle of the engine M1 and detects the reference position.
Means M3 is a reference position set at a predetermined crank angle.
To detect. The first engine control means M4 includes an engine M
1 is detected by the reference position detecting means M3 after the start of rotation.
Fuel injection control and ignition control at the first reference position
Start. Further, the stop crank angle detecting means M5 includes:
Based on the detection result by the crank angle detection means M2,
The crank angle when the rotation of the engine M1 is stopped is detected.
The preliminary injection cylinder discriminating means M6 includes:A predetermined, predetermined
Based on a map in which areas are separated for each rank angleAnd stop
Stop crank detected by crank angle detecting means M5
And the next reference position following the stop crank angle
The cylinder at the beginning of the intake stroke during
Determine. Furthermore, the second engine control means M7
From the start of rotation of the engine M1 by the reference position detecting means M3.
Until the first reference position is detected, the preliminary injection cylinder
Fuel is injected into the pre-injection cylinder by the stage M6. [0013] 【Example】 (First Embodiment) Hereinafter, the engine control device of the present invention will be described.
The first embodied in a flower-ignition four-cycle six-cylinder engine
Embodiments will be described with reference to the drawings. FIG. 1 shows an engine control device according to this embodiment.
FIG. 2 is a diagram schematically showing the configuration of the device. In FIG.
The rank angle sensor 1 is fixed to the crankshaft of the engine.
Crank angle rotor 2 and magnetic pickup
3. Outside of crank angle rotor 2
The teeth 2a are provided on the circumference every 10 ° CA (crank angle).
Part of which has two missing teeth 2a.
b is provided. In the present embodiment, the
The crank angle sensor 1 constitutes a crank angle detecting means.
I have. Further, the cam angle sensor 4 is used to
A cam fixed to a camshaft that rotates one half of one turn
Square rotor 5 and magnetic pickup coil 6
It is composed of One protrusion is provided on the outer circumference of the cam angle rotor 5.
A key 5a is provided. Note that, in this embodiment,
A reference position detecting means is constituted by the camera angle sensor 4.
You. The crank angle sensor 1 and the cam angle sensor 4
Is connected to a waveform shaping circuit 7.
The output signals of both sensors 1 and 4 are set to predetermined values as shown in FIG.
The waveform is shaped by the threshold value to generate a binary pulse signal.
That is, the waveform shaping circuit 7 outputs the output signal of the crank angle sensor 1.
10 ° CA (excluding the missing tooth 2b)
Generates the crank angle signal NE,
Generates a reference position signal G for each 720 ° CA according to the output signal
To achieve. The waveform shaping circuit 7 includes a microcomputer.
(Hereinafter abbreviated as microcomputer) 8 is connected to the
The microcomputer 8 receives the crank angle signal NE from the waveform shaping circuit 7.
And the reference position signal G is input and the reference position is set every 360 ° CA.
Position is detected. The microcomputer 8 includes a CPU (central processing unit).
Location), ROM (read only memory), RAM (lander
Access memory), backup RAM, input / output (I
/ O) is a well-known logical operation circuit including a port and the like. So
Then, the microcomputer 8 executes the air-conditioning based on the crank angle signal NE.
The engine speed is detected. The microcomputer 8 has a sensor group.
9 is input. This sensor group 9
Is composed of an intake pressure sensor 10, a water temperature sensor 11, etc.
The icon 8 is based on the detection signal from each sensor,
Detect water temperature, etc. On the other hand, the first cylinder (# 1) to the sixth cylinder (#
6) Intake pipes (not shown) have injectors 12A to 12A.
F is provided, and the microcomputer 8 detects the various sensors.
Based on the output result, the fuel generated by the injectors 12A to 12F
The fuel injection amount is calculated, and the calculation signal (fuel injection signal)
The injectors 12A to 12F are driven. This allows
The injectors 12A to 12F are arranged in a predetermined cylinder order (# 1 → #
2 → # 3 → # 4 → # 5 → # 6 → # 1)
Execute. The igniter 13 is a spark plug for each cylinder.
(Not shown), and the microcomputer 8
Calculate ignition signal IGT based on detection results of various sensors
Output to the igniter 13. This allows the ignition plug
A predetermined cylinder order (injection) is performed based on the ignition signal IGT.
In the same order as in the above), and a spark is generated. A key switch 15 is connected to the microcomputer 8.
The battery 14 is connected via the battery. Key switch 1
5 is the switching position of "OFF", "ON", "START"
have. The key switch 15 is not shown.
Switch from “OFF” position to “ON” position by key
Power is supplied from the battery 14 to the microcomputer 8
And the microcomputer 8 is activated, and the CPU in the microcomputer 8
Executes various control programs in the OM. Also, Kissui
When the switch 15 is switched to the “START” position, the
In addition to supplying power to the icon 8, the battery 14
Power is supplied to the motor 16 and the
Initial rotation is given to the gin. In this embodiment, the microcomputer 8 controls the first
Engine control means, stop crank angle detection means, preliminary injection
A firing cylinder determining unit and a second engine controlling unit are configured;
ing. Next, the operation of the engine control device according to the present embodiment will be described.
Will be described with reference to FIGS. Note that FIG.
Control routines for independent injection processing and ignition processing for each cylinder
It is a flowchart shown, and the microcomputer 8 has the crank angle.
The routine in FIG. 3 is started every time the edge of the signal NE is detected.
4 and 5 are flowcharts showing the subroutine of FIG.
It is. FIGS. 6 and 7 show when the engine starts to rotate.
Showing a control routine related to the preliminary injection processing in FIG.
The microcomputer 8 operates at predetermined time intervals (for example,
The routine shown in FIGS. 6 and 7 is started every 100 ms). Sa
In addition, FIG. 8 is a reference where cylinder information for pre-injection is stored.
FIG. 9 is a table for explaining the reference table of FIG.
FIG. 10 is a diagram for explaining the control operation of the microcomputer 8.
It is an imaging chart. When the routine shown in FIG. 3 is started,
Icon 8 first updates the crank counter in step 100.
Execute new processing (this corresponds to the subroutine of FIG. 4)
Do). The crank counter is the engine rotation
Is counted up according to the crank angle accompanying
And the crank angle as shown in the subroutine of FIG.
The signal NE is updated once every three edges of the signal NE.
It is set to a predetermined value by the TDC of the cylinder and the fourth cylinder. More specifically, in FIG.
In step 200, the edge counter n is incremented by "1".
(The edge counter n outputs the crank angle signal NE).
(Each time an edge is detected.)
It is determined whether the counter n is equal to or greater than "3". If n ≧ 3, the microcomputer 8 sets
Proceed to step 220 to clear the edge counter n to “0”.
Then, the process proceeds to step 230. Step 23
At 0, the microcomputer 8 counts the count value of the crank counter.
Update to the incremented value of "1", and follow step 2
Move to 40. At this time, the counter of the crank counter
The default value is a two-digit hexadecimal number.
In the description of this count value is (xx)₁₆Write as
You. Therefore, the power of the crank counter is supplied to the microcomputer 8.
At the time of entry (00)₁₆If it is initialized to
The default value is (00) after the microcomputer 8 is started.₁₆, (01)₁₆,
(02)₁₆.. Are counted. On the other hand, if n <3 in step 210,
The microcomputer 8 proceeds directly to step 240. that's all
According to the processing of steps 200 to 230,
One for every three edges of the link angle signal NE (30 ° CA
Every 1 time) the crank counter is incremented
Will be. Thereafter, the microcomputer 8 executes the current
The existing crank angle is the missing tooth position (the missing crank angle rotor 2).
(The position of the tooth portion 2b) is determined. Specifically
Means that the microcomputer 8 determines the position between the edges of the crank angle signal NE.
Measure the required time Tn (see Fig. 2)
Compare required time Tn-1 with required time Tn between the current edge
I do. Then, the microcomputer 8 calculates, for example, Tn> 2.5 · T
If n-1 holds, it is assumed that the tooth
Step 240 is affirmatively determined, and the routine proceeds to step 250.
If the determination in step 240 is negative,
Step 8 ends this routine as it is. In step 250, the microcomputer 8 sets the reference position
It is determined whether or not the edge of the placement signal G has been detected. Soshi
If the edge of the reference position signal G is detected,
Controller 8 sets the crank counter to (00) in step 260
₁₆After this is set, this routine ends. Also, reference position
If the edge of the placement signal G is not detected, the microcomputer 8
Sets the crank counter in step 270 to (10)₁₆N
After this, the routine ends. In short, the missing tooth position (the crank angle rotor 2
Toothless portion 2b) every 360 ° CA (of the first and fourth cylinders).
(Just before TDC) and the edge of the reference position signal G is 7
It is detected every 20 ° CA (immediately before TDC of the first cylinder).
Therefore, both steps 240 and 250 are determined to be affirmative.
As a result, the TDC of the first cylinder can be detected, and
Step 240 is affirmatively determined and step 250 is not.
The TDC of the fourth cylinder can be detected by the
it can. The TDC of the first cylinder and the TDC of the fourth cylinder are engine
It becomes the reference position with the rotation of the button. And T of the first cylinder
In DC and TDC of the fourth cylinder, the crank counter is always
(00)₁₆, (10)₁₆Will be set to
Between the count value of the rank counter and the actual crank angle
Deviation is prevented. Returning to the description of the routine of FIG.
After the processing of step 100, the icon 8 proceeds to step 110.
The process proceeds to determine whether the flag F is “0”. What
The flag F becomes "0" at the start of engine rotation,
First ignition process and fuel injection after engine rotation
It is set to "1" when the firing process ends.
You. If F = 1, the microcomputer 8 proceeds to step 1
20 and according to the subroutine of FIG.
An ignition process and a fuel injection process are executed. In the routine shown in FIG.
In step 300, the current crank angle is the TD of one of the cylinders.
C is determined, and TDC of any cylinder must be
If it is not the timing of execution of ignition processing and fuel injection processing
And terminate the routine. TD of any cylinder
C, the microcomputer 8 determines in step 310 that the ignition timing
In addition to making the settings, in step 320 the fuel injection amount is set.
Perform settings. The setting of the ignition timing and the fuel
Regarding the setting of the injection quantity, follow the well-known setting method.
Although the description is avoided, in short, in setting the ignition timing, for example,
The engine at that time uses an ignition timing map (not shown)
An ignition timing according to the rotation speed and the intake pressure is obtained. or,
In setting the fuel injection amount, for example, a fuel injection amount map (not shown) is used.
Depending on the engine speed and intake pressure at that time
The required fuel injection amount is determined. On the other hand, at step 110 in FIG.
If so, the microcomputer 8 proceeds to step 130, where the current
Whether or not the rank angle is the position of the missing tooth, that is, T of the first cylinder
DC or TDC of the fourth cylinder
Separate. Then, the microcomputer 8 makes a negative determination in step 130.
If determined, the routine is terminated as it is, and step 13
If "0" is determined positively, the routine proceeds to step 140, and the ignition timing
Make the settings for It should be noted that this is set in step 140
The ignition timing is the same as the ignition timing in step 120 described above.
The microcomputer 8 is different from the ATDC of the first cylinder or the fourth cylinder.
Set the ignition signal IGT so that a spark is generated at 10 ° CA.
Set. In other words, at the first ignition after the engine starts rotating
In the first cylinder or the fourth cylinder, TDC
Power supply is started and power supply is cut off at ATDC10 ° CA.
Will be. Thereafter, the microcomputer 8 executes the processing at step 150.
The current TDC is the TDC of the first cylinder, or
It is determined whether or not the TDC is a cylinder TDC. And T of the first cylinder
If it is DC, the microcomputer 8 proceeds to step 160 and
Inject fuel into four cylinders. In addition, even if it is TDC of the fourth cylinder
If this is the case, the microcomputer 8 proceeds to step 170 and burns to the first cylinder.
Inject the charge. Thereafter, the microcomputer 8 determines in step 180
The flag F is set to "1" and the routine ends. Next, the reserve at the start of rotation of the engine will be described.
The preliminary injection processing will be described with reference to FIGS. This
Here, the pre-injection processing is performed next time when the rotation of the engine is stopped.
Fuel injection cylinder at the start of engine rotation
Above, this is referred to as a specific cylinder).
At the start of engine rotation, fuel is injected only to the specified cylinder.
Is what you do. The information on the specific cylinder is RO
M is stored in advance in a reference table (FIG. 8) in M.
The icon 8 selects a specific cylinder using a reference table. More specifically, in the reference table of FIG.
Two rotations of the engine with TDC of the first cylinder set to 0 ° CA
(720 ° CA) is divided into six equal parts, and each area is represented by “A” to “F”.
It is divided into. Then, when the engine stops rotating,
Corresponding to the area, depending on which area the link angle is in
The selected cylinder is selected as the specific cylinder (the selected cylinder
Is indicated by a circle). The specific cylinder selected according to FIG.
According to the positional relationship between each region and the intake stroke of each cylinder shown in FIG.
The crank angle at the start of engine rotation.
Between the input of the first reference position signal and the intake stroke
The cylinder is a specific cylinder. This allows one to three ki
One of the cylinders becomes a specific cylinder. For example, crank
When the angle is in the “A” area of FIG. 9, the next reference position signal
Input stroke (TDC of the fourth cylinder)
The cylinders are the fifth cylinder and the sixth cylinder, and this cylinder is selected.
It becomes a cylinder. The same applies to other areas. Obedience
Therefore, by using the reference table shown in FIG.
Required to explode explosion and prevent unburned gas emissions
The minimum number of injection cylinders
You. The microcomputer 8 is temporarily stored in the RAM.
Crank angle according to the count value of the crank counter
Degree, and select a specific cylinder from the count value at that time.
You. When the routine shown in FIG. 6 is started,
In the icon 8, the key switch 15 is set to "OF" in step 400.
It is determined whether or not it has reached the "F" position. And the microcomputer
In the case of No. 8, if the position is not the “OFF” position, the routine ends as it is
If the position is “OFF”, the process proceeds to step 410.
You. The microcomputer 8 proceeds to the routine of FIG.
Read the RAM value of the crank counter
Crank counter using the reference table of FIG.
Select a specific cylinder according to the RAM value of
Store it in the backup RAM. After that, the microcomputer 8
At step 420, the power switch in the microcomputer 8 is turned off.
To end the routine. With the processing in FIG.
Information can be obtained, and this information is
It will be retained after the termination. When the routine shown in FIG. 7 is started,
The controller 8 sets the key switch 15 to “STA” in step 500
It is determined whether or not the “RT” position has been reached. And maiko
If it is not the “START” position,
End, and if it is the “START” position, step 51
Move to 0. The microcomputer 8 described above in step 510
Backup the specific cylinder stored in the routine of FIG.
Read from RAM and inject fuel into that specific cylinder
A fuel injection signal is output in order to cause this. The process of FIG.
Thus, the stored specific cylinder is reliably ignited. Next, according to the timing chart of FIG.
The control operation after the start of rotation of the engine will be described.
You. The time t0 in FIG. 10 is the engine rotation start time and time.
t0 to t1 are mask periods of the signals NE and G, and time t2 is
Time when the first reference position is detected after the engine starts rotating
Is shown. The crank angle at the start of rotation of the engine
The degree “P1” (660 ° CA in the figure) is the previous engine
The crank angle “P2” when the rotation of the motor is stopped (69 in the figure)
0 ° CA) has been reversed by 30 ° CA
You. Also, when the engine stops rotating, the crank counter
Und value is (1A)₁₆(This is the “F” area in FIG. 8)
Area), the backup RAM has specific cylinder information
As the fourth, fifth, and sixth cylinders. Then, in FIG.
The rotation of the gin starts. That is, at time t0, the key switch
When the switch 15 is turned “ON” and “STAR”
Switch to the "T" position, and the starter motor 16 starts.
You. Also, at this time t0, step 500 in FIG. 7 is affirmative.
The fourth, fifth, and fifth discriminated and stored as the specific cylinder
Fuel is simultaneously injected into the sixth cylinder. Here, the time t0 to t1 corresponds to the crank angle signal.
Signal NE and the reference position signal G for a certain period (for example, 10
0 to 150 msec) and do not perform cylinder discrimination.
No. This is a magnetic pick-up as in this embodiment.
Crank angle sensor 1 and cam angle sensor 4
Is configured, a minute rotation range (for example, 20 rpm
m or less). Yo
In this embodiment, the predetermined time immediately after the start of the rotation of the engine
Is the mask period of the detection signal. The engine
Immediately after the start of rotation, voltage fluctuation of the battery 14 and starter
Due to the vibration caused by the activation of the motor 16, the signals NE and G
False detection may occur. And after the mask period
At time t1, the routine of FIG. 3 is started. Thereafter, the first cylinder discrimination is performed at time t2.
Thus, the TDC of the fourth cylinder is detected. Also, this time t2
And the crank counter is (10)₁₆Set to the clan
The angle of rotation (“P2” → “P1”) or the mask period
And the actual crank angle
Is eliminated. Then, according to the routine of FIG.
To generate an ignition signal IGT at time t3 (A of the fourth cylinder).
(TDC10 ° CA) spark of 4th cylinder spark plug
Live. At this time, fuel is injected into the fourth cylinder by preliminary injection.
First explosion occurs because of inhalation. Then, the second time
After the ignition of, normal ignition control is performed.
Sparks occur. Further, after the time t2, the fuel injection is stopped as shown in FIG.
It is shifted to independent injection by the routine. At this time, independent injection
The first cylinder to fire is the first cylinder,
Is the first fuel at time t2 because the preliminary injection is not performed.
Inhalation will be performed. Then, # 1 → # 2 → #
Independent injection is performed in the order of 3. As described in detail above, the end of the first embodiment
In the gin control device, the crank angle is
Update the count value of the crank counter corresponding to the degree
(According to the routine of FIG. 4). And the rotation of the engine
The crank angle at stop is counted by the crank counter.
, And using the reference table of FIG.
Specific cylinder (injection air during preliminary injection)
6) and stored in the backup RAM (see FIG. 6).
). The specific cylinder selected according to FIG.
Crank angle when engine rotation stops and its crank angle
Cylinder with an intake stroke between the next reference position following
Was. When the engine starts rotating, the backup RA
The specific cylinder stored in M is read out, and the specific cylinder is read out.
Then, the preliminary injection was performed (according to the routine of FIG. 7).
Also, after detecting the first reference position after the start of engine rotation
Shifts fuel injection to independent injection for each cylinder,
The ignition process is started for each cylinder (see FIG. 3).
Depending on In short, according to the configuration of this embodiment, the end
Between the start of rotation of the gin and the detection of the first reference position.
In addition, by performing a preliminary injection corresponding to the intake stroke,
Pre-injection fuel injected into cylinders during intake stroke
It can be reliably burned in the subsequent ignition process.
Wear. As a result, emission of unburned gas can be suppressed.
You. Also, the ignition process is performed based on the first reference position.
When burning, the fuel sucked in the preliminary injection can be burned.
First explosion to improve engine startability
be able to. In the above case, the rotation of the engine
Only the case where the stop position is set to the “F” region in FIG. 8 has been described.
Achieves the object of the present invention even if the stop position is in another area
It goes without saying that you can do it. On the other hand, the method for selecting a specific cylinder is shown in FIG.
May be changed in addition to the reference table.
A body example will be illustrated. In the reference table of FIG.
Synchronizes the “A” to “F” regions with the TDC of each cylinder
Although it was divided, the reference table shown in FIG.
By changing a part of the area, a new "A '" to "F'" area
Are classified. That is, in the reference table of FIG.
The "A '" and "D'" areas are the "A" and "D" areas in FIG.
30 ° CA in the crank angle range on the retard side
Have been. The "B '" and "E'" areas in FIG.
30 ° CA only at the beginning of the “B” and “E” areas
Is set in the crank angle region on the retard side, and “C ′”,
The "F '" area is ending after the "C" and "F" areas in FIG.
Only in the crank angle range on the retard side by 30 ° CA
Have been. Then, a specific cylinder is selected with reference to FIG.
As a result, regarding the first, second, fourth, and fifth cylinders,
The engine rotation stop angle is 30 ° CA from the start of the intake stroke.
If the cylinder is in the range up to
You can choose. For example, if the engine stop position
In the case of 0 to 30 ° CA, only the fifth and sixth cylinders in FIG.
In contrast to the specific cylinder, FIG.
In addition to the above cylinders, the fourth cylinder is also a specific cylinder. That is,
The gin rotation start position is already at the beginning of the intake stroke
Since fuel intake is actually possible, spare
Perform injection. As a result, the first bomb can be expedited
You. In FIG. 11, the "B '" area is
The boundary angle with the "C '" region, and the "E'" region
The boundary angle with the “F ′” region is retarded with respect to the case of FIG.
Not displaced. In other words, the engine rotation stop position
(Memory angle) and rotation start position (actual angle)
If a deviation occurs, the reference immediately after the start of engine rotation
The position (TDC of the first and fourth cylinders) cannot be detected.
For this reason, only the area near the reference position
Does not retard the area. For example, "B '"
If the end angle of the area is set to 270 ° CA, this angle becomes the second angle.
The BTDC of four cylinders is 90 ° CA. And the memory angle
When the difference between the actual angle and the actual angle is large (90 ° CA or more)
), The TDC of the fourth cylinder cannot be detected and the point of the sixth cylinder
I can't fire. Therefore, the end angle of the “B ′” area is
6th in the range of 240 to 270 ° CA
When the preliminary injection is performed for the cylinder, the injection for the sixth cylinder is performed.
There is a possibility that the injected fuel is released as unburned gas. What
If you do not need to consider the above reasons
Shows all the areas "A '" to "F'" as "A" in FIG.
Shifting to the retard side with respect to the “F” region
Can also. As another example of realizing the reference table,
FIG. This corresponds to “A” to “F” in the reference table.
When the region and the intake stroke of each cylinder overlap,
This is to prevent the preliminary injection of the cylinder from being performed. Figure 9
For example, in the “A” region, this region is
The intake strokes of the third and fourth cylinders overlap. Therefore, this place
In this case, four cylinders other than the third and fourth cylinders are specified cylinders.
And the preliminary injection is performed. In FIG.
In the reference table, even in areas other than the “A” area,
Four cylinders are selected as specific cylinders. Second Embodiment Next, a second embodiment of the present invention will be described with reference to FIG.
13 will be described. In the first embodiment, a plurality of
Is selected for all specified cylinders simultaneously
In the second embodiment, the specific injection was performed.
Even if it is a preliminary injection without simultaneous injection when there are multiple cylinders
Independent injection is performed. More specifically, in the second embodiment, FIG.
In step 510, the crank of the backup RAM
Independent injection is performed by the counter. That is, for a specific cylinder
The start angle of the intake stroke to match the specific cylinder
Independent injection during exhaust stroke (60 ° CA before start of intake stroke)
Set the crank counter in advance. And d
When the engine starts to rotate, it is ignited first among the specified cylinders.
Inject fuel independently only to the cylinders
When the spark counter reaches the set count value, the next ignition
Inject fuel into the cylinder. FIG. 13 is a table for explaining the second embodiment.
It is an imaging chart. Note that in the second embodiment,
Unlike the first embodiment, when the microcomputer 8 is powered on,
Do not initialize the rank counter. That is, the rotation of the engine
Backup R value of crank counter at stop
AM and store it after the engine starts rotating.
Count up following the value stored in the backup RAM
Start. And the count value is (1B)₁₆Next
To (00)₁₆Has been updated. This gives the count value
And the actual crank angle. Now, referring to FIG.
At the start time t0, only the fourth cylinder among the specific cylinders
The preliminary injection is performed independently. Then, at time t1,
Update of rank counter is started and counts at time ta
Value is (00)₁₆become. That is, in FIG.
At t2, the count value of the crank counter and the actual crank
The angle is shifted by 60 ° CA. At time tb, the crank cow
Before the start of the intake stroke by the fifth cylinder
0 ° CA (actually, the starting angle of the intake stroke)
Pre-injection into the specific cylinder, cylinder 5, independently
Shooting is performed. The time tc is the same as the time tb.
Preliminary injection independently for the sixth cylinder at the start angle of the intake stroke
Is performed. Thus, the crankshaft updated in FIG.
Independent injection is sequentially performed according to the counter. In the case of FIG. 13, the actual engine
Crank angle and crank counter value are not 60 ° CA
The exhaust stroke (60 before the start of the intake stroke).
° CA)
The start angle of the intake stroke in the period tb, tc is obtained. But this
In the case of, sufficient fuel intake is possible in the corresponding intake stroke
There is no problem. Independent injection of specific cylinders
In this case, the injection angle is retarded more than
The angle can be the first half of the air stroke. The present invention is not limited to the above embodiment.
Instead, it can be embodied in the following manner. Up
In this embodiment, the reference position is set at every 360 ° CA (engine 1).
Once per rotation), but change this setting interval.
You can also. For example, a reference position is set every 120 ° CA.
So that one reference position is detected for each cylinder.
Is also good. In this case, the interval between the start of the intake stroke between each cylinder is
Since it is 120 ° CA, from the start of engine rotation
Cylinders with intake strokes before the first reference position is detected
Always one cylinder, backup RAM always one cylinder
Minute information will be stored. As a result,
While the area required for storage in the
The number of pre-injection cylinders has decreased, and it has shifted quickly to normal injection control.
Can be done. In each of the above embodiments, a six-cylinder engine is used.
Although a specific example has been shown, other multi-cylinder engines (of four
Cylinder, eight cylinders, etc.). In this case, the number of cylinders
And the reference table is changed and set according to the reference position.
You. In the above embodiment, the specific cylinder information is
The cylinder number is selected in the reference table of FIG.
Was stored in the backup RAM.
The count value of the counter may be stored and held.
In this case, a special injection
A constant cylinder will be selected. Further, in the above embodiment, the rotation of the engine
Although a certain mask period was set at the start,
By using a magnetic crank angle sensor that uses an element
Signal detection in the minute rotation range (around 0 rpm) becomes possible
The mask period can be omitted. Further, in the above embodiment, the cylinder is determined.
The engine control unit performs fuel injection independently for each cylinder.
This was embodied in the
It may be embodied by changing to a gin control device. [0061] According to the present invention, whether the rotation of the engine has started is determined.
Before the first reference position is detected.
By performing a pre-injection tailored to the initial reference position
To ensure that fuel is burned when ignition control is started.
Can be. As a result, the first explosion is expedited, and the engine startability is improved.
Can be improved. further,Predetermined,
The area is divided every predetermined crank angleBased on the map
Before the reference position is detected.
By performing pre-injection on cylinders, injection by pre-injection
Fuel is surely taken into the cylinder during the intake stroke, and the subsequent ignition
It will be surely burned in the processing. As a result, unburned
Gas emission can be suppressed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration diagram schematically showing an engine control device according to an embodiment of the present invention. FIG. 2 is a waveform diagram showing output signals of a crank angle sensor and a cam angle sensor. FIG. 3 is a flowchart showing a control routine of an independent injection process and an ignition process. FIG. 4 is a flowchart showing a subroutine of FIG. 3, showing a process of updating a crank counter. FIG. 5 is a flowchart showing a subroutine of FIG. 3, illustrating an ignition process and a fuel injection process during a normal operation. FIG. 6 is a flowchart showing a routine for storing a specific cylinder for preliminary injection. FIG. 7 is a flowchart illustrating a routine related to a preliminary injection process. FIG. 8 is a reference table storing cylinder information for preliminary injection. FIG. 9 is a relationship diagram between a crank angle and a cycle of each cylinder. FIG. 10 is a timing chart for explaining the operation of the microcomputer in the first embodiment. FIG. 11 is a reference table storing cylinder information for preliminary injection in another example of the first embodiment. FIG. 12 is also a reference table storing cylinder information for preliminary injection in another example of the first embodiment. FIG. 13 is a timing chart for explaining the operation of the microcomputer in the second embodiment. FIG. 14 is a timing chart for explaining conventional engine control. FIG. 15 is a block diagram showing components of the present invention. [Description of Signs] 1. Crank angle sensor as crank angle detection means,
4 ... Cam angle sensor as reference position detecting means, 8 ... First
Microcomputer as the engine control means, the stop crank angle detection means, the preliminary injection cylinder discriminating means, and the second engine control means.

Continuation of the front page (56) References JP-A-2-271073 (JP, A) JP-A-60-69247 (JP, A) JP-A-60-62665 (JP, A) JP-A-60-240875 (JP) , A) JP-A-59-138734 (JP, A) JP-A-5-332177 (JP, A) JP-A-7-501378 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB Name) F02M 39/00-71/04 F01N 3/00-3/38 F01N 9/00-11/00 F02P 1/00-3/12 F02P 5/145-5/155 F02P 7/00-7/10 F02P 9/00-17/12 F02D 9/00-11/10 F02D 13/00-28/00 F02D 41/00-41/40 F02D 43/00-45/00

Claims (1)

(57) [Claim 1] Used in an engine having a plurality of cylinders, a crank angle detecting means for detecting a crank angle of the engine, wherein the crank angle is set to a predetermined crank angle. Reference position detection means for detecting a reference position; first engine control means for starting fuel injection control and ignition control at an initial reference position detected by the reference position detection means after the start of rotation of the engine; Based on the detection result by the crank angle detection means,
A stop crank angle detecting means for detecting a crank angle at the time when the rotation of the engine is stopped, and an area divided for each predetermined crank angle.
Preliminary injection for discriminating, as a preliminary injection cylinder, a cylinder at the beginning of an intake stroke between a stop crank angle detected by the stop crank angle detection means and a next reference position following the stop crank angle based on the map. A second engine control for injecting fuel to the preliminary injection cylinder by the preliminary injection cylinder determining means during a period from the start of rotation of the engine to the detection of the first reference position by the reference position detecting means; And an engine control device.