JPH04339156A - Control device for engine - Google Patents

Abstract

PURPOSE:To secure the control accuracy of an engine about as usual even when the intermittent abnormality of a signal generator occurs in the case where a control means controls the engine on the output of the signal generator provided on a crank shaft. CONSTITUTION:A cam shaft is provided with a signal generator 39. A comparison means 56 compares a signal generator 49 provided on a crank shaft with a signal generator 39 provided on a cam shaft on the frequency of the occurrence of an output signal in a set term. When a difference between the above frequencies of occurrence becomes above a set value, namely the signal generator 49 on the side of the crank shaft is judged to be in the state of intermittent abnormality, a compensating means 57 functions to make a control means 55 execute the control of an engine such as ignition timing or the like through another signal generator 39 provided on the above cam shaft. Thus the control accuracy of the engine can be secured about as usual.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in an engine control device that controls engine ignition timing and fuel injection amount, and more particularly to measures to be taken when a sensor that detects the engine rotational speed is abnormal.

0002

2. Description of the Related Art Conventionally, engine control, for example, setting of ignition timing, has been done by transmitting a rotation signal at every predetermined rotation angle according to the rotation of a crankshaft, as disclosed in Japanese Patent Laid-Open No. 57-59032. A rotation sensor is provided, and the ignition timing is set in accordance with the engine rotation based on an engine rotation signal from the rotation sensor.

0003

[Problems to be Solved by the Invention] In the above-mentioned rotation sensor, the rotating part is usually arranged at the end of the camshaft of the engine, and the detecting part for detecting the rotation of the rotating part is installed in the distributor. Often built-in. In this case, since the camshaft is driven by the crankshaft via a pulley, etc., the rotations of the camshaft and crankshaft do not correspond exactly, so the ignition timing can be set accurately. I can't do it. For this reason, one of the joint applicants has previously filed the patent application No.
In the specification and drawings of 253090, it is proposed that a rotation sensor is placed directly on the crankshaft to more accurately detect the rotation of the crankshaft, thereby appropriately setting and controlling the ignition timing of the engine with high precision.

However, when the rotation sensor is disposed on the crankshaft as described above, since the crankshaft is located at a relatively low height of the engine, scattered objects such as pebbles may fall onto the rotation sensor when the vehicle is running. As a result, the teeth of the rotating disk for signal generation built into the rotation sensor may become chipped, causing an error in the detection accuracy of the engine rotation speed. There is a regret that it is not possible to control the engine with high precision such as timing.

The present invention has been made in view of the above, and its purpose is to control the ignition timing of the air-fuel mixture even in an abnormal situation where the signal generator installed on the crankshaft is out of order. The objective is to ensure accurate control of the engine.

[0006]

[Means for Solving the Problems] In order to achieve the above object, in the present invention, a signal generator is provided on the camshaft in addition to the signal generator provided on the crankshaft, and a signal generator for the camshaft is generated. This system actively detects a tooth loss abnormality in the signal generator installed on the crankshaft, and when this abnormality is detected, the signal generator installed on the camshaft is used to continue controlling the engine.

That is, as shown in FIG. 1, the specific solution of the present invention includes a signal generator 49 that is provided on the crankshaft and generates a signal at each set crank angle period, and a The present invention is directed to an engine control device including a control means 55 that controls engine ignition timing and the like based on a signal. Then, another signal generator 39 is provided for the camshaft to generate a signal at each set cam angle period, and a comparison is made to compare the number of times the signals of both signal generators 49, 39 are generated within the set period. Upon receiving the outputs of the means 56 and the comparing means 56, when the difference in the number of times the signal is generated within the set period is greater than or equal to the set value, the engine is controlled based on the signal from another signal generator 39 provided on the camshaft. The configuration is such that a compensating means 57 is provided which is controlled by a control means 55.

[0008]

[Operation] With the above configuration, in the present invention, when the signal generator 49 provided on the crankshaft is normal, engine control such as the ignition timing of the air-fuel mixture is controlled based on the signal from the signal generator 49. This is done by means 55.

Now, when pebbles or the like are scattered while the vehicle is running, these scattered objects are likely to collide with the signal generator 49 located at a low position, that is, the signal generator 49 provided on the crankshaft. In this case, the teeth of the signal generator 49 provided on the crankshaft are chipped, resulting in a tooth-missing state. When this tooth-missing abnormality occurs, the number of times the signal is generated within the set period decreases. The difference between the number of signal generation times of the signal generator 39 provided at As a result, the compensating means 57 determines that the signal generator 49 provided on the crankshaft has a tooth missing abnormality, and the control means 55 controls the engine such as ignition timing based on the signal from the signal generator 39 provided on the camshaft. Let it be done.

Here, the signal generation accuracy of the signal generator 39 provided on the camshaft is as follows:
Although the signal generation accuracy is slightly lower than that under normal conditions, the signal generation accuracy is higher than that of the signal generator 49 on the crankshaft side with missing teeth, so the accuracy of engine control such as ignition timing is maintained as high as usual. be done.

[0011]

As explained above, according to the engine control device of the present invention, even when the signal generator provided on the crankshaft has an abnormality, the air-fuel mixture can be controlled with almost normal control accuracy. Since engine control such as ignition timing can be continued,
It is possible to ensure the normal running performance of the vehicle.

0012

Embodiments Hereinafter, embodiments of the present invention will be described with reference to FIG. 2 and subsequent drawings.

FIGS. 2 and 3 illustrate the present invention in a DOHC type 6
An example applied to a cylinder V-type engine will be shown. In the figure, an engine body 10 consisting of a cylinder block 7 on which a crankshaft 15 is disposed, and cylinder heads 8, 9,
The order of the explosion stroke is the first, third and fifth cylinders 1, 3, 5.
A first cylinder bank 11 is provided with cylinders 2, 4, and 6 having a second, fourth, and sixth cylinder in the order of explosion stroke. cylinders 1 to 6
A branch intake passage portion 13 forming a downstream portion of the intake passage is connected to each of the branch intake passage portions 13, and each branch intake passage portion 13 faces fuel injection valves 14a to 14f.

[0014] On the side of the end face 10a of the engine main body 10 in the first cylinder bank 11, a cam pump is provided at one end.
A camshaft 16 on the exhaust side to which a pulley 21 is attached, and a camshaft 17 on the intake side to which a cam pulley 22 is attached to one end are disposed, and an end surface of the engine body 10 in the second cylinder bank 12 is provided. On the part 10a side, an intake side camshaft 18 has a cam pulley 23 attached to one end, and an exhaust side camshaft 19 has a cam pulley 24 attached to one end.
is installed. Further, a crank pulley 25 is attached to one end of the crankshaft 15 protruding toward the end surface 10a of the engine body 10 so as to create a predetermined rotational phase difference between the crank pulley 25 and the cam pulleys 21 to 24. ing.

Idlers 20a, 20b, 2 are provided between the cam pulleys 21 to 24 and the crank pulley 25.
A timing belt 26 that is in contact with 0c is installed. The timing belt 26 transmits the rotation of the crankshaft 15, which is rotationally driven in the direction shown by the arrow in FIG. do. In addition, the engine body 10
A belt cover 27 that covers the cam pulleys 21 to 24 and the timing belt 26 is attached to the end face 10a side. In addition to the crank pulley 25, a plurality of auxiliary drive pulleys 28 are also attached to one end of the crankshaft 15.

Crank pulley 25 of the crankshaft 15
A rotating disk 40 with the crankshaft 15 as its rotational axis is attached to a portion located between the auxiliary drive pulley 28 and the rotating disk 40. Three teeth are formed at equal angular intervals and are formed by rectangular notches extending toward the bottom. Each tooth becomes a detected portion 41b of the rotating disk 40.

Furthermore, the end face portion 10 of the cylinder block 7
A detector 4 is located close to the rotating disk 40 at point a.
4 is installed. The detector 44 has a main body portion 44a having a substantially U-shaped cross section and a mounting portion 44b. The mounting portion 44b of the detector 44 is attached to the cylinder block 7 with the facing pieces of the main body portion 44a sandwiching the outer peripheral edge portion of the rotating disk 40 where the detected portion 41b is located at a predetermined interval. There is. An electromagnet 4 is provided on one side of the main body portion 44a, and faces the detected portion 41b of the rotating disk 40 as the rotating disk 40 rotates.
A Hall element 48 is provided on the other side at a position opposite to the electromagnet 47, and the intensity of the magnetic field generated by the electromagnet 47 acting on the Hall element 48 is You can get output depending on the situation. Therefore, crankshaft 1
When the rotating disk 40 rotates with the rotation of the detector 44, the plurality of detected parts 41b are connected to the electromagnet 47 of the main body part 44a of the detector 44.
and the Hall element 48, and the output generated by the Hall element 48 is changed in accordance with the passage of the detected portion 41b. The detector 44 detects the output generated by the Hall element 48 and generates an engine rotation speed signal Ne corresponding to the pulse signal shown in FIG. 4(b).

With the above configuration, the detected portion 41b is provided on the crankshaft 15 and includes the electromagnet 47 and the Hall element 48.
A signal generator 49 is configured to generate an engine rotational speed signal Ne at every set crank angle period that passes between.

On the other hand, at one end of the exhaust camshaft 19 in the second cylinder bank 12, a rotating distributor 30 having a casing portion 30a fixed to a support portion 27a provided on a belt cover 27 is connected. A shaft 30b is coupled. The distributor 30 incorporates another signal generator 39 consisting of a rotating disk 32 having its rotation axis 30b as its rotation axis and a detector 34.

The rotating disk 32 has six teeth formed at equal angular intervals, each consisting of a rectangular notch extending from the outer peripheral edge toward the center. This becomes the detected portion 33 on the plate 32. On the other hand, the detection unit 34
The main body portion 34a and the mounting portion 34 have a U-shaped cross section.
b, and the opposing piece of the main body portion 34a is the rotating disk 3
Attachment part 3 with the outer circumference of part 2 sandwiched between the parts.
4b is attached to the casing 30a of the distributor 30. Then, the main body portion 34a of the detector 34
A light emitter 35 is provided on one side of the frame, and a light receiver 36 is provided on the other side facing the light emitter 35. The light receiver 36 receives the light from the light emitter 35. You can get output according to the reception. Therefore, when the rotating disk 32 rotates with the rotation of the camshaft 19, the detector 34 is activated as shown in FIG.
), six pulse signals SGT are generated per revolution of the camshaft.

Signals Ne and SGT output from the detectors 34 and 44 are input to a control unit 60.

In addition to the above-mentioned output signals Ne and SGT, the control unit 60 also receives an intake air amount signal Sa obtained from an air flow sensor 51 provided in the intake passage.
In addition to the starter status signal Ss obtained from the starter switch 52, other detection signals Sx necessary for controlling the engine are also input.

Furthermore, the control unit 60 individually sends drive pulse signals PJ to the fuel injection valves 14a to 14f.
1 to PJ6 respectively, and each fuel injection valve 14a to 14
f to perform the fuel injection operation.

The control unit 60 then shapes the engine rotation signal Ne corresponding to the pulse signal of the detector 44 shown in FIG. 4(b) into a waveform as shown in FIG. It has a function of creating a signal equal to the pulse signal SGT of .

Next, engine ignition timing control based on the signal from the signal generator 49 provided on the crankshaft 15 is shown in FIG.
This will be explained based on the control flow.

After starting, in step Si1, the engine rotational speed signal Ne obtained by shaping the output of the signal generator 49 into the waveform shown in FIG. 4(c) is measured and the engine rotational speed is read.
After reading the intake air amount and other input information from the air flow sensor 51 in step Si2, in step Si3, the ignition time Ta of the air-fuel mixture and the spark plug are determined based on the engine speed and intake air amount read above. energization start time T
Calculate b.

Thereafter, in step Si4, it is determined whether or not the waveform-shaped engine rotation signal Ne is interrupted, and at the time of interruption, the ignition timer TA calculated above is set to the ignition time Ta in step Si5, and the ignition time Ta calculated above is set in step Si6.
The above calculated energization start time Tb is set to the ignition time timer TB.
Set.

After setting as above, the ignition timing timer TA is decremented by "1" in step Si7.
In step Si8, the value of the ignition timing timer TA is determined, and the value of the ignition timing timer TA is determined.
When A=0, the current flowing to the ignition coil is cut off in step Si9, and the ignition plug starts igniting the air-fuel mixture. Thereafter, in step Si10, the ignition time timer T
B is subtracted by "1", the value of the ignition time timer TB is determined in step Si11, and when TB=0, the energization to the ignition coil is restarted in step Si12, and the process ends.

Therefore, according to the control flow shown in FIG. 5, the engine rotational speed signal Ne of the signal generator 49 on the crankshaft side is
control means 55 for controlling engine ignition timing, etc. based on
It consists of

Next, a description will be given of how the control unit 60 determines whether the signal generator 49 on the crankshaft side is out of gear or not, based on the determination flowcharts shown in FIGS. 6 and 7.

Starting in FIG. 6, step S1
to set the engine speed to the set value (e.g. 500r.p.m.)
It is determined whether or not the following cranking is in progress, and only if cranking is in progress, it is determined in step S2 whether or not the signal generator 49 on the crankshaft side is missing a tooth. This determination is made when the counter csgtin for the number of SGT signals is equal to the set value KSGTIN, and the counter cneles for the number of pulse-shaped frequency-divided engine rotational speed signals Ne is equal to the set value KSNEL.
This is done by determining whether it is less than or equal to S. Here, the set value KSG
TIN is the number of SGT signals within a predetermined set period to, and the set value KSNELS is the number of SGT signals within a predetermined set period to.
This is a value determined according to o.

If it is determined that the signal generator 49 on the crankshaft side is in a toothless state, a flag xnelef indicating a toothless state is set to xnelef=1 in step S3. After that, in step S4, the number of SGT signals cs
Determine the value of gtin, csgtin=KSGTIN(
KSGTIN is a predetermined setting value),
In step S5, the counter csgtin,cneles=
Initialize to 0.

[0033] After that, as described above, if cranking is not in progress, if it is not determined that the tooth is missing, or if csgti
In the case of n≠KSGTIN, it is determined again in step S6 whether or not cranking is in progress, and in step S7 it is determined whether or not the engine is stopped (engine stalled). , in step S8, the counter csgtin for the number of SGT signals is set to "1".
'' and continues counting the number of objects. Otherwise, the counter csgtin is initialized to 0 in step S9.

Similarly, the pulsed engine speed signal N
The measurement of the number of e is performed by interrupting the above main flow by input interruption by the engine rotational speed signal Ne and performing the flow shown in FIG.
In step Sn1, it is determined whether the engine is stalled, and in step Sn2, it is determined whether or not it is cranking.If the engine is not stalled and cranking is in progress, the engine rotation speed signal Ne is determined in step Sn3. number counter c
"1" is added to neles to continue counting the number, while in other cases, the counter cneles is initialized to 0 in step Sn4.

Next, FIG. 8 shows switching control of signals used for engine control when the signal generator 49 on the crankshaft side is in a normal state and in an abnormal state. In the same figure, in step Ss1, S
The value of the selection flag xsftsel of the GT signal is determined. Here, this selection flag xsgtsel is set to "1" in the following situations.

(1) When the signal generator 49 on the crankshaft side fails (2)
When the signal generator 39 on the camshaft side is normal, and in any of the following cases ■ The engine speed is below the set value (for example, 5
00r. p. m) In the following cases: (1) When determining whether the signal generator 49 on the crankshaft side is missing (when xnelf = 1) Then, if xsgtsel = 0 in step Ss1, the signal generator 49 on the crankshaft side It is determined that it is normal, and in step Ss2, the engine ignition timing is controlled as usual using the engine rotational speed signal Ne from the signal generator 49 on the crankshaft side.

On the other hand, if xsgtsel=1, it is determined that the signal generator 49 on the crankshaft side is in failure or missing a tooth, and in step Ss3 the signal generator 39 on the camshaft side is used to control the engine. ignition timing control. Note that the above switching of the signals used may be performed by an electronic circuit shown in FIG.

Accordingly, in step S2 of the control flow shown in FIG.
It constitutes a comparison means 56 for comparison within o. Further, in step S3 of the control flow shown in FIG. 6 and steps Ss1 and Ss2 of the switching control flow shown in FIG. When the difference is greater than or equal to the set value, the SGT signal selection flag xsgtsel is set to 1, and it is determined that the signal generator 49 provided on the crankshaft is abnormal. The compensating means 57 is configured to cause the control means 55 to control the ignition timing of the engine.

Therefore, in the above embodiment, when the signal generator 49 provided on the crankshaft 15 is normal, the engine rotational speed signal Ne corresponding to the pulse signal shown in FIG. The engine rotational speed signal Ne is converted into the engine rotational speed signal Ne whose waveform is shaped into a pulse wave shown in d), and the ignition timing control shown in FIG. 5 is performed every time each pulse of this rotational speed signal Ne is generated. Here, the signal generator 49 is connected to the crankshaft 15.
Since the engine rotational speed signal Ne is disposed at , the generation of the engine rotational speed signal Ne accurately follows the rotation of the crankshaft 15, and ignition timing control is performed with high accuracy.

On the other hand, if scattered objects such as pebbles occur when the vehicle is running, these scattered objects will be transmitted to the signal generator 39 on the camshaft side.
It is easy to collide with the signal generator 49 on the crankshaft side, which is lower in height than the signal generator 49 on the crankshaft side, and the teeth of the rotating disk 40 of the signal generator 49 on the crankshaft side (that is, the non-detecting portion 41b) are chipped, resulting in a toothless state. There are cases. However, in this case, as the number of pulses generated by the signal generator 49 on the crankshaft side decreases, the comparing means 56 determines that when csgtin=KSGTIN and cneles≦KSNELS, the signal generator 49 on the crankshaft side It is determined that there is a tooth missing abnormality, and the tooth missing flag xneles and the SGT signal selection flag xsgts are set.
Both el are set to "1" and the SGT signal of the signal generator 39 on the camshaft side is selected as the signal for engine control. Here, since the signal generator 39 that generates the SGT signal is provided on the camshaft 19, the SGT signal is generated with somewhat lower accuracy than the engine rotation speed signal Ne of the signal generator 49 on the crankshaft side. , the frequency-divided engine rotational speed signal N of the toothless signal generator 49 on the crankshaft side.
Since the generation accuracy is higher than that of e, the engine control can be maintained at almost normal control accuracy.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of the present invention.

FIG. 2 is a plan view of a six-cylinder V-type engine showing an embodiment of the present invention.

FIG. 3 is a front view of the same.

FIG. 4 is a diagram showing various signal waveforms.

FIG. 5 is a flowchart showing ignition timing control.

FIG. 6 is a flowchart showing a tooth missing determination of a signal generator provided on the crankshaft.

FIG. 7 is a flowchart showing counting of the number of engine rotation speed signals.

FIG. 8 is a flowchart showing switching control of signals used for engine control depending on whether or not there is an abnormality in a signal generator provided on the crankshaft.

FIG. 9 is an electronic circuit diagram showing the same control.

[Explanation of symbols]

10 Engine body 15
crankshaft 19
Camshaft 34 Detector 32 Rotating disk 39
Other signal generator 40
Rotating disk 44 detector

Claims (1)

[Claims] 1. An engine comprising: a signal generator installed on a crankshaft and generating a signal at every set crank angle cycle; and a control means controlling ignition timing, etc. of the engine based on the signal from the signal generator. A control device, which is installed on the camshaft and generates a signal at each set cam angle cycle, and controls the number of times the signals of the signal generator and the other signal generators are generated within a set period. When the difference in the number of signal occurrences within a set period is greater than or equal to the set value, the engine and compensation means for causing the control means to perform control of the engine.