JP3073517B2 - Engine control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical field to which the invention pertains) The present invention relates to a means for changing the size of an external load (such as an air conditioner or an alternator) on an engine in accordance with various conditions, and a method for changing the engine speed. And a means for variably controlling the output of the engine (VVT, VICS, etc.).

2. Description of the Related Art Conventionally, output variable means for variably controlling the output of an engine in accordance with the number of revolutions of the engine is disclosed in, for example,
There is a so-called VVT of an engine valve timing control device described in Japanese Patent No. 27711.

That is, the opening / closing timing of at least one of the intake valve and the exhaust valve is switched by the valve timing changing means, and at the time of high load, the overlap period of intake and exhaust is set to be longer than at the time of low load, so that the intake filling efficiency is improved. With the improvement, the output is increased and the overlap period between intake and exhaust is set small in consideration of the low intake flow rate at low load, suppressing the increase in the amount of residual burned gas and ensuring the flammability. This is an output variable means that is configured to be suitable.

On the other hand, as a load changing means for changing the magnitude of the external load on the engine in accordance with various conditions, for example, there is an alternator control circuit described in Japanese Patent Application Laid-Open No. Sho 60-106397.

That is, a deceleration detector is connected to one input terminal of an OR circuit (OR circuit), and an external load high-level detector is connected to the other input terminal, respectively, based on the logical sum of the deceleration signal and the electric load level signal. This is a device configured to increase the voltage generated by the alternator.

By the way, in the case where both the above-described output varying means and the load changing means are provided, the switching of the output varying means (for example, the variable valve timing device) is smoothly performed due to the difference in the operation state of the external load (for example, the alternator). There was a problem that could not be done.

 Hereinafter, this problem will be described in detail with reference to FIG.

The characteristic a in the figure indicates that the alternator generated voltage is low (12.8
V) and the torque characteristics when a low-speed cam is used.
Characteristic b is a torque characteristic when the alternator generated voltage is high (14.4V) and a low-speed cam is used, and characteristic c is a characteristic when the alternator generated voltage is low (12.8V) and a high-speed cam is used. The characteristic d is a torque characteristic when the alternator generated voltage is high (14.4 V) and a high-speed cam is used.

When the alternator generated voltage does not change, the characteristic a,
As shown by the switching point B, the characteristic c or the characteristic b, the switching point C, and the characteristic d, the switching can be smoothly performed without a torque step at the valley of the torque, while the alternator generated voltage changes. A → B → C → d 、 b →
Switching is performed in the order of C → B → c, c → B → C → b, d → C → B → a, and a discontinuous change in torque occurs at an operation switching point at a switching speed of 4000 rpm, and torque shock occurs. There was a problem that occurred.

(Problems to be Solved by the Invention) The invention according to claim 1 of the present invention inhibits the change of the magnitude of the external load in the vicinity of the switching speed of the output variable means, thereby smoothly switching the output variable means. It is an object of the present invention to provide an engine control device that can perform the control.

According to the second aspect of the present invention, the operating speed of the external load (the magnitude of the external load) is changed by changing the switching speed of the output variable means according to the change in the magnitude of the external load. Regardless, an object of the present invention is to provide an engine control device that can smoothly switch output variable means.

According to a third aspect of the present invention, in addition to the object of the first aspect, the change of the voltage generated by the alternator is prohibited in the vicinity of the switching speed of the output variable means. It is an object of the present invention to provide an engine control device capable of smoothly performing the control.

According to a fourth aspect of the present invention, in addition to the object of the second aspect, the switching speed of the output variable means is reduced.
An object of the present invention is to provide an engine control device capable of smoothly switching output variable means regardless of the operation state of an alternator by changing the output voltage according to the voltage generated by the alternator.

The invention described in claim 5 of the present invention is applicable to the above-mentioned claims 1, 2, 3
Or, in addition to the object of the invention described in 4, the valve timing changing device which changes the valve timing by changing the overlap period of the intake and exhaust by setting the output variable means to a valve timing changing device (so-called VVT). It is an object of the present invention to provide an engine control device capable of achieving the objects of the inventions of the above claims in an equipped engine.

(Means for Solving the Problems) The invention according to claim 1 of the present invention provides an external load driven by an engine, an external load changing means for changing the magnitude of the external load according to various conditions, and an engine. An engine control device comprising: an output variable unit that variably controls an output of the engine; and an output variable unit control unit that changes an operation state of the output variable unit when the engine speed reaches the switching speed. External load change prohibition area setting means for setting a predetermined rotation range for the switching speed as an external load change prohibition area for prohibiting a change in the magnitude of the external load,
Determining means for determining whether the engine speed is within the external load change prohibition area set by the external load change prohibition area setting means; and determining that the engine speed is within the external load change prohibition area by the determination means. When the determination is made, the control device is an engine control device including an external load change prohibiting unit that prohibits the external load changing unit from changing the magnitude of the external load.

According to a second aspect of the present invention, there is provided an external load driven by an engine, an external load changing means for changing the magnitude of the external load according to various conditions, and an output variable means for variably controlling the output of the engine. And an output variable means control means for changing the operation state of the output variable means when the engine speed reaches the switching speed at which the engine torque becomes the same regardless of the operation state of the output variable means. An engine control device, wherein the switching speed of the output variable means control means is changed in accordance with the change in the magnitude of the external load, and the change in the engine torque curve is caused by the change in the magnitude of the external load. In addition, the present invention is characterized in that the control device is an engine control device provided with a switching speed changing means for changing the operation state of the output variable means at the speed at which the engine torque becomes the same.

According to a third aspect of the present invention, in addition to the configuration of the first aspect of the present invention, an alternator having a variable target generation voltage is used as the external load, and the external load change prohibiting means sets the target generation voltage. It is a control device for an engine that prohibits a change.

According to a fourth aspect of the present invention, in addition to the configuration of the second aspect of the present invention, an alternator is used as the external load, the engine speed is shifted from a low speed to a high speed, and the alternator generated voltage is low. When the engine speed changes from high to low, and when the engine speed changes from high speed to low speed, and when the alternator generated voltage changes from high to low pressure, the switching speed is set high and the engine speed changes from low to high. When the alternator shifts from high to low and the alternator generated voltage changes from high to low, and when the engine speed changes from high to low and the alternator generated voltage changes from low to high, the switching speed is set low. It is a control device of an engine provided with a setting means.

The invention described in claim 5 of the present invention is applicable to the above-mentioned claims 1, 2, 3
Alternatively, in combination with the configuration of the invention described in 4, the output variable means is an engine control device set in a valve timing changing device that changes a valve timing by changing an overlap period of intake and exhaust. It is characterized by.

According to the first aspect of the present invention, the external load change prohibiting means prohibits the change of the magnitude of the external load itself near the switching speed of the output variable means. This prohibits changes in the engine torque curve,
By prohibiting the change of the switching speed at which the engine torque becomes the same, the effect of preventing the occurrence of torque shock can be obtained.

According to the second aspect of the present invention, an engine torque curve that changes in response to a change in the magnitude of the external load;
According to the switching speed at which the engine torque becomes the same,
Since the above-mentioned switching speed changing means changes the switching speed, the output variable means can be switched at the engine speed at which the same engine torque is always obtained irrespective of the magnitude of the external load, and torque shock is generated. There is an effect that can be prevented.

According to the third aspect of the present invention, the external load change prohibiting means prohibits the change of the voltage generated by the alternator near the switching speed of the output variable means. Can be performed smoothly,
This has the effect of preventing the occurrence of torque shock at the switching speed.

According to the invention described in claim 4 of the present invention, the switching speed changing means changes the switching speed of the output variable means in accordance with the voltage generated by the alternator, so that regardless of the voltage generated by the alternator, The switching of the output variable means can be performed smoothly, and there is an effect that the occurrence of torque shock at the switching speed can be prevented.

According to the fifth aspect of the present invention, since the output varying means is set to the valve timing changing device (so-called VVT), the valve timing changing which changes the valve timing by changing the intake / exhaust overlap period. The effects of the above-described inventions can be exhibited in an engine provided with the device.

Embodiment An embodiment of the present invention will be described below in detail with reference to the drawings.

The drawing shows the control device of the engine, and in FIG.
An intake passage 2 communicating with an intake port 1 is provided. A throttle valve 3 and an injector 4 are provided in the intake passage 2, and an idle switch 5 and a throttle sensor 6 are mounted outside the throttle body.

Further, an O2 sensor 9 is attached to an exhaust passage 8 communicating with the exhaust port 7. On the other hand, a crank pulley 11 fitted to a crankshaft 10, a pump pulley 12 for driving a water pump, and an alternator pulley 14 for driving an alternator 13 are provided. A V-belt is provided between these pulleys 11, 14, 12.
When the engine 16 is driven, a variety of engine accessories are driven when the engine 15 is driven.

By the way, a predetermined terminal (see FIG. 2) of the alternator 13 is connected to the battery 17 via a line 18 and a regulator 19, and a generated voltage output terminal of the alternator 13 is connected via a line 20 and a current sensor 21. ing.

Further, the battery 17 is connected to ground (specifically, the vehicle body) via a line 22, a starter 23 and a starter switch 24, while an electric load 26 such as an air conditioner is connected to the battery 17 via a line 25.

The circuit configuration of the alternator 13 and the regulator 19 is as shown in FIG.

That is, the alternator 13 is provided with a stator 27 having a star-connected stator coil, and a rotor 28 driven to rotate by the alternator pulley 14 (see FIG. 1) having a field coil. When the rotor 28 rotates, three-phase AC power is induced in the stator 27, and the three-phase AC power is rectified to DC by a rectifier circuit 29 including six diodes. After the pulsation is absorbed and the waveform is shaped, it is output from the B terminal (generated power output terminal).

A part of the three-phase AC power induced in the alternator 13 is rectified by the auxiliary
Supplied to

The regulator 19 is constantly supplied with a battery voltage from the battery 17 via an S terminal (battery sensing terminal), and is supplied with power from the battery 17 via an L terminal when the ignition switch 32 is turned on.

A check lamp 33 and an adjustment resistor 34 are provided between the L terminal and the ignition switch 32. The regulator 19 is connected to the collector of a first transistor T1 in the CPU 60 (see FIG. 6). G terminal (alternator voltage control terminal) and T connected to the plus side of the rotor 28
A terminal, an F terminal (field current terminal) connected to the negative side of the rotor 28, and an E terminal (earth terminal) connected to the ground are provided.

The regulator 19 includes second to fourth transistors T2, T3,
T4, first to fourth diodes D1, D2, D3, D4, and first to eighth resistors R1, R2, R3, R4, R5, R6, R7, R8. Are connected as shown to form an electric circuit, which receives a signal from the CPU 60 and switches the alternator voltage to high (hereinafter simply abbreviated to H) or low (hereinafter simply abbreviated to L). At the same time, alternator voltage control for reducing the alternator voltage when the battery is deteriorated is performed.

The above-described fourth transistor T4 is a two-stage transistor circuit, and the third diode D3 is a Zener diode.

Here, the operation of the regulator 19 in the above HL control will be described as follows.

That is, the above-described regulator 19 causes the alternator voltage to follow a target value by feedback control, and sets the target value to H (14.4 V) in accordance with a signal from the CPU 60.
Or switch to L (12.8V).

Basically, when the alternator voltage exceeds the target value, the fourth transistor T4 becomes non-conductive, no current flows through the rotor 28, and the alternator voltage decreases. When the voltage falls below the target value, the fourth transistor T4 is turned on, a current flows through the rotor 28, and the ON / OFF control is performed so that the alternator voltage increases.

Specifically, when the alternator voltage exceeds the target value, the Zener diode D3 conducts, a positive voltage applied through the third resistor R3 is applied to the base of the third transistor T3, and the third transistor T3 is turned on. And the fourth transistor T4 becomes non-conductive when the base voltage becomes 0,
No current flows through the rotor 28.

On the other hand, when the alternator voltage is lower than the target value, the zener diode D3 becomes non-conductive, so that the third transistor
T3 becomes non-conductive, the fourth transistor T4 becomes conductive accordingly, and current flows through the rotor 28.

Switching of the target value is basically performed by changing the ratio Vi / Vo between the voltage Vi (input voltage) between X and Z and the voltage Vo (output voltage) between YZ.

That is, the output voltage Vo is applied to the Zener diode D3, and when the output voltage Vo becomes equal to or higher than the break voltage, the Zener diode D3 conducts.

Therefore, as Vi / Vo is large, the Zener diode D3 becomes conductive at a high alternator voltage.By changing Vi / Vo, the target value can be freely changed. The target value is switched between H and L by switching Vo between large and small steps.

Specifically, when the H signal is applied to the base of the first transistor T1 of the CPU 60, the first transistor T1 conducts and the G terminal is grounded via the first transistor T1, so that the second transistor T2 The base voltage becomes 0 and becomes non-conductive. Therefore, a current flows through the fifth resistor R5, and at this time, the voltage ratio (Vi / Vo) is determined by the resistance ratio (series resistance value of R3, R4, R5) / (series resistance value of R4, R5). . In this case, since the resistance ratio is small, the target value is L (12.8 V).

On the other hand, when the L signal is applied to the base of the first transistor T1, the first transistor T1 is turned off and the second transistor T1 is turned off.
The transistor T2 is turned on when a positive voltage is applied to the base. Therefore, no current flows through the fifth resistor R5, and at this time, the voltage ratio (Vi / Vo) is determined by the resistance ratio (series resistance value of R3, R4, R5) / (resistance value of R4). in this case,
Since the resistance ratio is large, the target value is H (14.4 V).

Next, with reference to FIGS. 3 and 4, the configuration of a valve mechanism 36 provided in the cylinder head 35 and a so-called VVT as a valve timing changing device 37 as an output varying means will be described.

Camshaft 38 linked to crankshaft 10 of engine 16
Is disposed at the center of the cylinder head 35 in parallel with the crankshaft 10, and the exhaust valve 39 is provided via a roller follower 40 slidably in contact with an exhaust cam of a camshaft 38 and an exhaust rocker arm 42 pivotally mounted on a rocker shaft 41. Is driven to open and close.

Low-speed rocker arm 44 that opens and closes one intake valve 43
And a low-speed rocker arm that drives the other intake valve 43 to open and close.
45, and a high-speed rocker arm 46 for driving each of these rocker arms 44, 45, and each of these rocker arms 44, 45,
46 is pivoted to the lock shaft 47, and the low-speed rocker arm 4
The roller followers 44a and 45a of the camshaft 38 are in sliding contact with the low-speed cams of the camshaft 38, respectively.

On the side of the camshaft 38 opposite to the rocker shaft 47,
A pin hole 49 is formed between the high-speed rocker arm 46 and the low-speed rocker arm 44, and another pin hole 50 is formed between the high-speed rocker arm 46 and the low-speed rocker arm 45.
The pin 51 is formed in the pin hole 49 and the pin 52 is mounted in the pin hole 50 so as to be movable in the axial direction, and the pins 51 and 52 are formed by compression coil springs 53 and 54, respectively. The pin holes 49 and 50 are urged toward the high-speed rocker arm 46 side to communicate with each other in the high-speed rocker arm 46. The hydraulic oil chamber 55 at the ends of the pin holes 49 and 50 is connected to the electromagnetic switching valve 56 (the sixth When the pressurized oil in the hydraulic oil chamber 55 is discharged, the pair of pins 51 and 52 are driven by the spring force of the coil springs 53 and 54 to provide a high-speed rocker arm. It moves to the pin hole part in 46, and the intake valves 43 are each rocker arm for low speed
When they are driven by 44, 45 and pressurized oil is supplied to the hydraulic oil chamber 55, the pair of pins 51, 52 is switched to the position shown in FIG. Is driven through a low-speed rocker arm 44, and the other intake valve 43 is driven by a high-speed rocker arm 46 by a low-speed rocker arm 45.
Is driven through.

In other words, when the pressurized oil in the hydraulic oil chamber 55 is drained, the low speed cam of the camshaft 38 is selected to shorten the intake / exhaust overlap period as shown in FIG. Is selected so that the intake and exhaust overlap period becomes longer.

FIG. 6 shows a control circuit block diagram. The CPU 60 controls the engine speed Ne from the distributor 57, the intake air amount Q from the air flow meter 58, the consumption current I from the current sensor 21, and the air-fuel ratio A / F, starter switch 24
Signal from the electric load switch 59 which is turned on when the relatively heavy electric load 26 is operating.
N, OFF signal, idle signal from idle switch 5,
Based on the throttle opening tvo from the throttle sensor 6, the engine water temperature t from the water temperature sensor 61, and the battery voltage Vb from the battery 17, the injector 4, the first transistor T
1. The drive of the regulator 19, the alternator 13, and the electromagnetic switching valve 56 for VVT is controlled, and the RAM 63 stores necessary data.

Here, the above-described CPU 60 includes output variable means control means (refer to CPU 60 itself) for changing the operation of the valve timing changing device 37 (output variable means) when the engine speed Ne reaches the switching speed Nc. An external load change prohibition region α that prohibits a change in the magnitude of the external load within a predetermined rotation speed range with respect to the above-described switching rotation speed Nc.
External load change prohibition area setting means (refer to each of steps 75 and 96 in FIG. 7) which is set as the external load change prohibition area setting means (see FIG. 8). Determining means for determining whether or not the engine speed is within the prohibited area α (see steps 75 and 96 in FIG. 7); and when the determining means determines that the engine speed Ne is within the external load change prohibiting area α. And external load change prohibition means (see steps 75 and 96 in FIG. 7) for prohibiting the external load change means (see regulator 19) from changing the size of the external load (see oil generator 13). Doubles.

Further, the valve timing changing device 37 compares the switching speed Nc, for example, 4000 rpm, with the current engine speed Ne, and when Ne ≧ Nc, switches to the high-speed valve timing via the electromagnetic switching valve 56. At the same time, when Ne <Nc, the switching to the low-speed valve timing is controlled via the above-described electromagnetic switching valve 56.

The operation of the engine control device configured as described above will be described with reference to the flowchart of FIG. 7 and the characteristic diagram of FIG.

In a first step 71, the CPU 60 outputs the starter switch 24 output, the engine speed Ne, the electric load switch 59 output, the idle switch 5 output, the current sensor 21 output,
The reading of the throttle opening signal and the water temperature signal is executed.

Next, in a second step 72, the CPU 60 sets the starter switch 2
It is determined whether or not the engine has been started based on the four outputs. If the engine is being started, the process proceeds to the next third step 73, while after the engine has been started, the process proceeds to another fourth step 74.

In the above-described third step 73, the CPU 60 determines whether or not the voltage generated by the alternator 13 is the previous H control, and skips to the sixth step 76 during the previous L control, and proceeds to the next fifth step 75 during the previous H control. Transition.

In the fifth step 75, the CPU 60 determines whether or not the current engine speed Ne is outside the vicinity of the switching speed.

That is, as shown in FIG.
Set to 00 rpm, 3500 rp of ± 500 rpm for this 4000 rpm
The range from m to 4500 rpm is set near the switching speed (external load change prohibition region α), and the other ranges are set outside the switching speed, and the above-described determination is performed.

In other words, it is determined whether it is within the range α of 3500 rpm to 4500 rpm shown in FIG.

Then, in the region α near the switching speed of the valve timing changing device 37, the twelfth operation is performed in order to prevent the voltage generated by the alternator 13 from being changed from H to L.
While the process proceeds to step 82, if it is not near the switching speed, the process proceeds to the next sixth step 76.

In the sixth step 76, the CPU 60 controls the voltage generated by the alternator 13 to the L level of 12.8V.

Next, in a seventh step 77, the CPU 60 sets the timer operation flag F
After resetting t (Ft = 0), the process returns to the first step 71.

On the other hand, in the above-described fourth step 74, the CPU 60 determines whether or not the electric load switch 59 is ON. When the electric load switch 59 is ON, the CPU 60 skips to the next 25th step 95 as the alternator L control prohibition condition is satisfied. The process moves to the next eighth step 78.

In the eighth step 78, the CPU 60 determines whether or not the engine water temperature t is low (t ≦ 0 ° C.) and the activity of the battery 17 is reduced. When t ≦ 0 ° C., the above-mentioned 25th step 95
On the other hand, when t> 0 ° C., the flow shifts to the next ninth step 79.

In the ninth step 79, the CPU 60 determines whether or not the current consumption I is greater than a preset 10 amperes based on the output of the current sensor 21. If I ≧ 10A, the alternator L control inhibition condition is satisfied and the above-described 25th step is performed. Skip to 95, I <10
In the case of A, the process proceeds to the next tenth step 80.

In this tenth step 80, the CPU 60 determines whether or not the vehicle is in a deceleration state. When the vehicle decelerates, the process proceeds to the following eleventh step 81. When the vehicle is not decelerating, the process proceeds to the third step 73 described above.

In the above-described eleventh step 81, the CPU 60 determines whether the battery deterioration flag F is 1 or 0. When F = 0 (when NO is determined), the process proceeds to the next twelfth step 82, while F = 1 In the case of (when YES is determined), the flow shifts to another thirteenth step 83.

In the thirteenth step 83, the CPU 60 executes alternator control for battery deterioration.

That is, the target value of the alternator voltage is set to an appropriate value slightly higher than the battery voltage Vb under the operating conditions under which the H control is to be performed, so that useless charging of the alternator 13 to the battery 17 is prevented.

On the other hand, in the twelfth step 82, the CPU 60 controls the voltage generated by the alternator 13 to the H level.

Next, in a fourteenth step 84, the CPU 60 sets the alternator voltage V
a and the battery voltage Vb are read.

Next, in a fifteenth step 85, the CPU 60 determines that the voltage difference ΔV = Va−V
Calculate b.

Next, in a sixteenth step 86, the CPU 60 determines that the voltage difference ΔV is 0.4 V
If the voltage difference ΔV is less than 0.4 V,
It is considered that the battery voltage Vb is sufficiently increased following the alternator voltage Va, and the battery 17 is not deteriorated and has a high charge rate. Therefore, the voltage difference ΔV is 0.
If it is less than 4 V, it is determined that the battery 17 has not deteriorated.

As a result of the comparison in the sixteenth step 86, when ΔV <0.4 V (NO determination), the process proceeds to the seventh step 77, in which the CPU 60 resets the timer operation flag Ft. When (Ft = 0), the process returns to the first step 71.

On the other hand, as a result of the comparison in the above-mentioned sixteenth step 86, ΔV ≧ 0.
At 4 V (when YES is determined), it is determined that the battery 17 has deteriorated, and the routine shifts to the next seventeenth step 87.

In the seventeenth step 87, the CPU 60 sets the timer operation flag Ft
Is 1 or not.

This timer operation flag Ft is basically
In the 20th step 90 when the determination of the presence or absence of
Is set to, and when the judgment operation is completed, the seventh step 77
Is reset to 0.

If Ft = 0 as a result of the comparison in the above-described seventeenth step 87, the battery deterioration determination has been started from this time.
At step 88, the current voltage difference ΔV is stored as the reference voltage difference ΔVo. At the nineteenth step 89, the timer is set (started). At the twentieth step 90, the timer operation flag Ft is set (Ft = 1). It returns to the first step 71.

On the other hand, if Ft = 1 as a result of the comparison in the seventeenth step 87, since the timer is counting, the next twenty-first step 87
At 91, it is compared whether or not the time has elapsed, that is, whether or not 10 seconds have elapsed since the start of the battery deterioration determination. As a result of this comparison, if the time has not elapsed, the battery deterioration determination cannot be performed yet.
The program skips 4,97 and returns to the first step 71.

On the other hand, if the time is up as a result of the comparison in the 21st step 91, then in the next 22nd step 92, 0.1V ≧ ΔVo−ΔV ≧
It is compared whether it is 0 or not. As a result of this comparison, ΔVo−ΔV> 0.
At 1 V, the voltage difference ΔV decreases in 10 seconds, and it is considered that the charging rate is increasing. Therefore, the reason why the voltage difference ΔV is 0.4 V or more is simply a decrease in the charging rate. Thus, it is determined that the battery 17 has not deteriorated. Thereafter, in a seventh step 77, the timer operation flag Ft is reset to 0, and the process returns to the first step 71. If ΔVo−ΔV <0, it means that the charge rate of the battery 17 is decreasing even though the alternator 13 is generating power at a high voltage. In such a case, since the deterioration of the battery 17 cannot be determined, the process returns to the first step 71 via the seventh step 77.

On the other hand, as a result of the comparison in the 22nd step 92, 0.1V ≧ ΔVo−Δ
When V ≧ 0, since the battery voltage Vb has not recovered even though the battery has been charged, it is determined that the battery 17 has deteriorated, and the routine proceeds to the next twenty-third step 93, where In step 93, the CPU 60 sets the battery deterioration flag F (F = 1).

Next, in a twenty-fourth step 94, the CPU 60 issues an alarm indicating deterioration of the battery 17, and in a seventh step 77, the CPU 60 resets the timer operation flag Ft (Ft = 0),
Return to 71.

On the other hand, in the above-mentioned twenty-fifth step 95, the CPU 60 determines whether or not the voltage generated by the alternator 13 is the previous L control.
At the time of control, the flow shifts to the next 26th step 96.

In the twenty-sixth step 96, the CPU 60 determines whether or not the current engine speed Ne is out of the vicinity of the switching speed, and determines whether or not the area α (the eighth
If the voltage generated by the alternator 13 is L
The process shifts to the above-described sixth step 76 in order to prohibit the change from to H, while the process shifts to another eleventh step 81 when the rotation is outside the vicinity of the switching rotation.

As described above, in the vicinity of the switching speed of the valve timing changing device 37 (within the external load change prohibition region α), the above-described steps 75 and 96 (external load change prohibiting means) prohibit the change of the voltage generated by the alternator 13. The switching of the valve timing changing device 37 is smoothly performed in a state where there is no torque step as in the characteristic a, the switching point B, the characteristic c, or the characteristic b, the switching point C, the characteristic d in FIG. This has the effect of preventing the occurrence of torque shock at the switching points B and C corresponding to the engine speed of 4000 rpm.

That is, in the vicinity of the switching speed of the output variable means (see VVT), the above-mentioned external load change prohibiting means prohibits the change of the magnitude of the external load itself, thereby prohibiting the change of the engine torque curve, and It is intended to prevent torque shock by prohibiting a change in the same switching speed.

9 and 10 show another embodiment of the engine control device. 1 to 6 is the same as that of the previous embodiment, and the flow chart of the voltage generated by the alternator 13 is shown in FIG.
3,75,95,96 are removed.

In this embodiment, when the engine speed Ne reaches the switching speed at which the engine torque becomes the same irrespective of the difference in the operation state of the valve timing changing device 37 (output variable means), the CPU 60 sets the valve timing. Output variable means control means (CPU 6
0 itself) and changing the switching speed of the output variable means control means in accordance with the change in the magnitude of the external load, regardless of the change in the engine torque curve accompanying the change in the magnitude of the external load. The number of revolutions at which the engine torque is the same (3800rpm, 4100r in Fig. 10)
pm) to change the operating state of the valve timing changing device 37 (second step 102 in FIG. 9).
See).

Further, a map shown in the following table is stored in the RAM 63 as setting means.

Here, the above map shows that the engine speed Ne shifts from low to high and the alternator generated voltage is low
When the voltage changes from V to high voltage 14.4V, and when the engine speed changes from high speed to low speed and the alternator generated voltage changes from high voltage 14.4V to low pressure 12.8V, the above operation switching point
When Nc is set high, for example, at 4100 rpm, the engine speed Ne shifts from low to high, and the alternator generated voltage changes from high 14.4V to low 12.8V, and the engine speed Ne shifts from high to low. When the alternator generated voltage changes from low voltage 12.8V to high voltage 14.4V, the setting means sets the operation switching point Nc low (for example, at 3800 rpm).

The operation of the thus configured engine control device will be described with reference to the flowchart of FIG. 9 and the characteristic diagram of FIG.

In a first step 101, the CPU 60 reads various necessary signals such as the engine speed Ne, the changing direction of the engine speed, and the voltage generated by the alternator 13.

Next, in a second step 102, the CPU 60 uses the map stored in the RAM 63 to switch the rotation speed Nc corresponding to various conditions, that is, 4000
Call any of rpm, 4100rpm, 3800rpm.

Next, in a third step 103, the CPU 60 sets the called switching speed.
The engine speed Nc is compared with the current engine speed Ne. When Ne ≧ Nc, the process proceeds to the next fourth step 104, and when Ne <Nc, the process proceeds to another fifth step 105.

In the above-described fourth step 104, the CPU 60 switches the electromagnetic switching valve 56 to the oil supply position to supply pressurized oil to the hydraulic oil chamber 55,
Switch to high-speed valve timing. On the other hand, in the above-described fifth step 105, the CPU 60 switches the electromagnetic switching valve 56 to the oil discharge position to discharge the pressurized oil in the hydraulic oil chamber 55, and switches to the low-speed valve timing. Return to 101.

In other words, the next 8
The following embodiments are obtained.

When the engine speed Ne changes from a low speed to a high speed and the voltage generated by the alternator 13 remains unchanged at 12.8 V, the switching speed Nc is 4000 rpm and the switching is performed in the order of a → B → c. Can be switched smoothly.

When the engine speed Ne changes from a low speed to a high speed and the voltage generated by the alternator 13 changes from 12.8V to 14.4V, the switching speed Nc is 4100 rpm, and the switching is performed in the order of a → D → d. Switching of the changing device 37 can be performed smoothly.

When the engine speed Ne changes from low speed to high speed and the voltage generated by the alternator 13 remains unchanged at 14.4 V, the switching speed Nc is 4000 rpm, and the switching is performed in the order of b → C → d. Can be switched smoothly.

When the engine speed Ne changes from low speed to high speed and the voltage generated by the alternator 13 changes from 14.4 V to 12.8 V, the switching speed Nc is 3800 rpm, and the switching is performed in the order of b → A → c. Switching of the changing device 37 can be performed smoothly.

When the engine speed Ne changes from high speed to low speed and the voltage generated by the alternator 13 remains unchanged at 12.8 V, the switching speed Nc is 4000 rpm, and the switching is performed in the order of c → B → a. Can be switched smoothly.

When the engine speed Ne changes from high speed to low speed and the voltage generated by the alternator 13 changes from 12.8V to 14.4V, the switching speed Nc is 3800rpm, and the switching is performed in the order of c → A → b, and the valve timing Switching of the changing device 37 can be performed smoothly.

When the engine speed Ne changes from high speed to low speed and the voltage generated by the alternator 13 remains unchanged at 14.4 V, the switching speed Nc is 4000 rpm and the switching is performed in the order of d → C → b. Can be switched smoothly.

When the engine speed Ne changes from high speed to low speed and the voltage generated by the alternator 13 changes from 14.4V to 12.8V, the switching speed Nc is 4100rpm, and the switching is performed in the order of d → D → a. Switching of the changing device 37 can be performed smoothly.

In short, according to the embodiment shown in FIGS. 9 and 10,
Since the second step 102 (switching speed changing means) under the control of the CPU 60 changes the switching speed Nc of the valve timing changing device 37 in accordance with the voltage generated by the alternator 13, the valve is independent of the voltage generated by the alternator 13. The switching of the timing changing device 37 can be performed smoothly, and there is an effect that the occurrence of torque shock can be prevented.

That is, the above-described switching speed changing means (see step 102) changes the switching speed in accordance with the engine torque curve which changes in accordance with the change in the magnitude of the external load and the switching speed in which the engine torque becomes the same. Therefore, regardless of the magnitude of the external load, the valve timing changing device 37 can be switched at the engine speed at which the same engine torque is always obtained, thereby preventing torque shock.

In the correspondence between the configuration of the present invention and the above-described embodiment, the external load of the present invention corresponds to the alternator 13 of the embodiment. Hereinafter, similarly, the load changing means corresponds to the regulator 19, and the output varying means corresponds to The variable output means control means corresponds to the CPU 60 itself. The external load change prohibition area setting means, the judgment means, and the external load change prohibition means correspond to the steps 75 and 96 ( The switching speed changing means corresponds to the second step 102 (see FIG. 9), and the setting means corresponds to the map stored in the RAM 63. However, the present invention is not limited only to the configuration of the embodiment.

For example, the external load may be an air conditioner with relatively large power consumption instead of the alternator 13 described above,
As the output variable means, the above-described valve timing changing device
It is needless to say that a variable intake device that changes the length of the intake passage, so-called VISC, may be used instead of 37.

Also, the change in the voltage generated by the alternator near the VVT operation switching point is small. For example, when switching from H control to L control, the voltage difference of L control is increased from 12.8V to 13.0V to reduce the voltage difference. Is also good.

[Brief description of the drawings]

1 is a system diagram showing an engine control device of the present invention, FIG. 2 is an electric circuit diagram of an alternator and a regulator, FIG. 3 is a longitudinal sectional view showing a valve mechanism, and FIG. 4 is a valve mechanism and valves. FIG. 5 is a characteristic diagram of a valve lift amount with respect to a crank angle, FIG. 6 is a control circuit block diagram, FIG. 7 is a flowchart, and FIG. 8 shows a torque change with respect to an engine speed. FIG. 9 is a flowchart, FIG. 10 is a characteristic diagram showing a change in torque with respect to the engine speed, and FIG. 11 is a characteristic diagram for explaining occurrence of a conventional torque shock. 13 Alternator (external load) 16 Engine 19 Regulator (load changing means) 37 Valve timing changing device (output variable means) 75, 96 Step (external load change prohibition area setting means,
Judgment means, external load change prohibition means) 102 Second step (switching speed change means)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI H02P 9/04 H02P 9/04 L (56) References JP-A-59-194058 (JP, A) JP-A-60-30444 ( JP, A) JP-A-61-200327 (JP, A) JP-A-59-113222 (JP, A) JP-A-4-109039 (JP, A) Full-open 1987-117232 (JP, U) Full-open 63-31212 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F02D 13/02-45/00 F02B 27/02 H02P 9/04

Claims (5)

(57) [Claims] An external load driven by an engine, external load changing means for changing the magnitude of the external load according to various conditions, output variable means for variably controlling the output of the engine, and An output variable control means for changing an operation state of the output variable means at the time of the switching speed, wherein an external load is set within a predetermined rotation speed range with respect to the switching speed. External load change prohibition area setting means for setting as an external load change prohibition area for prohibiting size change; and determining whether the engine speed is within an external load change prohibition area set by the external load change prohibition area setting means. Determining means for determining, and when the determining means determines that the engine speed is within the external load change prohibition region, the magnitude of the external load by the external load changing means is determined. An engine control device equipped with external load change prohibition means for prohibiting the change of the engine load. 2. An external load driven by an engine, an external load changing means for changing the magnitude of the external load according to various conditions, an output variable means for variably controlling an engine output, and an engine speed. An engine control device comprising: output variable means control means for changing an operation state of the output variable means when the engine torque reaches a switching speed at which the engine torque becomes the same regardless of a difference in an operation state of the output variable means. The switching speed of the output variable means control means is changed in accordance with the change in the magnitude of the external load, and the engine torque remains the same regardless of the change in the engine torque curve accompanying the change in the magnitude of the external load. An engine control device provided with a switching speed changing means for changing an operation state of an output variable means at a certain speed. 3. The engine control device according to claim 1, wherein an alternator having a variable target generated voltage is used as the external load, and the change of the target generated voltage is prohibited by the external load change prohibiting means. 4. An alternator is used as the external load, when the engine speed changes from low to high, and when the alternator generated voltage changes from low to high, and when the engine speed changes from high to low, And when the alternator generated voltage changes from high to low, the switching speed is set high, and when the engine speed shifts from low to high, and when the alternator generated voltage changes from high to low, 3. The engine control device according to claim 2, further comprising setting means for setting the switching speed low when the number shifts from high speed to low speed and the alternator generated voltage changes from low pressure to high pressure. 5. The engine according to claim 1, wherein said output varying means is set in a valve timing changing device for changing a valve timing by changing an overlap period of intake and exhaust. Control device.