JPH07123797A - Number-of-revolution change controller - Google Patents

Abstract

PURPOSE:To obtain a number-of-revolution change controller in which a decrease in the number of revolutions of an engine can be suppressed even if an electric load increases during idling, and low speed operating, waste of a battery, uncomfortable vibration, and increase of cost are suppressed. CONSTITUTION:The number-of-revolutions change controller comprises an electric load in which a rectified output from a generator 10 is supplied as required, a battery 12 to be changed by the rectified output from the generator, a regulator 10R for so controlling a field current IF of the generator that a battery voltage VB becomes a set value VA, a target voltage calculator 21 for calculating a target voltage VR of the battery based on an operating state of an engine, and field current limiting means 15A for limiting a field current of the generator in response to a voltage deviation DELTAV of the battery voltage from the target voltage. A generating amount is limited separately from control of the number of revolutions of idling due to feedback to a suction system having a bypass air passage.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotation fluctuation control device for a gasoline engine automobile or the like in which a generator is driven by an internal combustion engine (engine), and does not particularly cause an increase in cost, and during idle operation and low speed operation. In particular, the present invention relates to a rotation fluctuation control device that does not cause unpleasant vibration or the like even when an electric load increases sharply.

[0002]

2. Description of the Related Art Generally, a gasoline engine vehicle is equipped with an alternator (generator) that is driven to rotate by the engine and outputs generated power. The power generated by the alternator while the engine is rotating is required. In addition to being supplied to various electric loads, the in-vehicle battery is charged with surplus power.

FIG. 12 is a schematic view of a drive system of a general rotation fluctuation control device. In the figure, 1 is an engine, 2 is an intake pipe for supplying an air-fuel mixture to the engine 1,
Reference numeral 3 is an air cleaner provided at the upstream end of the intake pipe 2 for purifying intake air, 4 is a throttle valve provided in the middle of the intake pipe 2 for adjusting the amount of intake air to the engine 1, and 5 is all throttle valves 4. It is an idle switch that detects an idle state by a closed state.

Reference numeral 6 is a bypass air passage provided in the intake pipe 2 so as to bypass the throttle valve 4, reference numeral 7 is a compression coil spring provided in the bypass air passage 6 and biasing the bypass air passage 6 toward the closing side. 8 is a compression coil spring 7
A needle valve provided at the tip of the valve 9 is a solenoid that drives the needle valve 8 to control the opening and closing of the bypass air passage 6.

Reference numeral 10 is a generator that is driven by the engine 1 and outputs generated power, that is, an alternator, 11 is an electric load connected to an output terminal of the alternator 10, and 12 is a battery charged by the alternator 11.

Reference numeral 13 is a distributor for supplying electric power to each cylinder of the engine 1 to determine ignition timing for each cylinder, and reference numeral 14 is a crank angle sensor for generating a crank angle signal θ synchronized with rotation of a crank shaft driven by the engine 1. Is. In this case, the crank angle sensor 14 is provided in the distributor 13.

Reference numeral 15 denotes an electronic control unit composed of a microcomputer, which calculates various control parameters and the like based on various sensor signals indicating the operating state of the engine 1 to control various control devices. The electronic control unit 15 takes in, for example, an idle detection signal A from the idle switch 5, a crank angle signal θ from a crank angle sensor, etc., and generates a control signal C, etc. for the solenoid 9 for idle speed control (ISC).

As shown in FIG. 12, air is sent to the engine 1 from an air cleaner 3 through an intake pipe 3, and at this time, a throttle valve 4 provided in the middle of the intake pipe 2.
Is opened and closed in conjunction with an accelerator pedal (not shown). The throttle valve 4 is fully closed during idle operation, and the fully closed state (idle operation state) of the throttle valve 4 is detected by the idle switch 5.

The bypass air passage 6 connects the upstream side and the downstream side of the intake pipe 2 so as to bypass the throttle valve 4. A needle valve (bypass valve) 8 biased by a compression coil spring 7 is provided in the bypass air passage 6, and a solenoid 9 is duty-driven by a control signal C from an electronic control unit 15, The needle valve 8 is driven to open / close the bypass air passage 6.

On the other hand, the alternator 10 is rotationally driven by the engine 1 to generate electric power, supply electric power to the electric load 11 and charge the battery 12 with the surplus electric power. The battery 12 supplies electric power to the electric load 11 when the electric power generated by the alternator 10 is insufficient or when electric power is not generated.

FIG. 13 is a block diagram showing an electric system of a drive system of a conventional rotation fluctuation control device, and 10 and 12 are the same as those described above. The alternator 10 has the following 1
The main components are 0F, 10S, 10D and 10R.

10F is a field coil which is rotated by the engine 1 and excited by the field current IF,
Reference numeral 10S is a three-phase stator coil arranged to face the field coil 10F.
Constitutes the power generation section of the alternator 10. Reference numeral 10D is a full-wave rectifier composed of a three-phase diode bridge connected to the output terminal of the stator coil 10S.

Reference numeral 10R is a regulator for controlling the field current IF, which is an output voltage (generated voltage) of the full-wave rectifier 10D.
That is, the field current IF is controlled to be turned on / off in accordance with the terminal voltage VB of the battery 12 (hereinafter, referred to as battery voltage) and the capacity of the electric load 11 used, so that the electric power generated by the power generation units 10F and 10S is adjusted. .

S is a voltage detection terminal for detecting the battery voltage VB, and VA is a set value of the terminal voltage of the battery 12 set according to the temperature of the regulator 10R (about 14.5V which is a substantially constant value), 30 Is a comparator that compares the set value VA with the actual battery voltage VB to generate an output signal according to these voltage deviations, and 31 is a comparator 30.
Is a power transistor that is controlled to be turned on / off in accordance with the output signal of (1) and determines the field current IF.

Although not shown in FIG. 13, various electric loads 11 mounted on the vehicle are connected to the output terminal of the full-wave rectifier 10D.

The regulator 10R has a field current IF when the battery voltage VB detected from the voltage detection terminal S decreases or the capacity of the electric load 11 used increases.
The duty ratio of is increased to increase the generated current. On the contrary, when the capacity of the electric load 11 is reduced, the duty ratio of the field current IF is reduced to reduce the generated current.

Further, when the electric potential of the voltage adjusting terminal (not shown) of the regulator 10R is grounded via the control unit (not shown) by a command from the electronic control unit 15, for example, a field flowing in the field coil 10F. The magnetic current IF becomes zero and the generated current becomes zero, so that the alternator 10 stops generating power.

Next, the specific operation of the conventional rotation fluctuation control device will be described with reference to FIGS. In the alternator 10, when the rotor having the field coil 10F is rotated, a three-phase alternating current is generated in the stator coil 10S provided on the stator. This three-phase alternating current is rectified by the full-wave rectifier 10D formed of a three-phase bridge composed of six diodes, for example, and is output as a direct current voltage.

At this time, the voltage generated by the alternator 10 is the rotational speed of the rotor corresponding to the rotation of the engine 1 and the field current IF for excitation that flows in the field coil 10F.
Proportional to the size of. This power generation voltage needs to be kept constant in order to supply various electric loads 11 and charge the battery 12, and when the rotor rotation speed becomes high and the power generation voltage is about to exceed the specified value, as described above. The field current IF is adjusted by the regulator 10R to suppress the generated voltage.

The regulator 10R adjusts the value of the field current IF flowing in the field coil 10F in the alternator 10 according to the current supplied to the electric load 11. In the case of the transistor type, the power transistor 31 is turned on and off. The energization amount is controlled by increasing or decreasing the duty ratio of the field current IF. In this way, the regulator 10R adjusts the power generation voltage of the alternator 10 to prevent overcharge and overdischarge of the battery 12.

The regulator 10R has a field coil 1 in the alternator 10 when the electric load 11 increases.
When the field current IF flowing in 0F is increased and the electric load 11 is decreased, the field current IF is decreased. Therefore,
The torque required to drive the alternator 10 to rotate is large when the electric load 11 is large, and is small when the electric load 11 is small.

Further, the comparator 30 in the regulator 10R
Compares the battery voltage VB with the set value VA and drives the power transistor 31 based on the comparison result to control the output voltage from the stator coil 10S,
Set the battery voltage VB to the set value VA (for example, 14.5
V).

For example, when the battery voltage VB is the set value VA
In the above case, by making the comparison output L level, the power transistor 31 is turned off to stop the power generation of the alternator 10, and the battery voltage VB is set to the set value VA.
If it is smaller than the above, the power output of the alternator 10 is executed by turning on the power transistor 31 by setting the comparison output to the H level.

By the way, the engine 1 of the automobile is in an idle operation (for example, the rotation speed of the engine 1 is 700 rpm).
When the electric load 11 suddenly increases during the low speed operation (about 1000 rpm) and the field current IF flowing in the field coil 10F in the alternator 10 increases,
The torque that rotationally drives the alternator 10 rapidly increases, and the rotation speed of the engine 1 decreases. As a result, in some cases, the rotation of the engine 1 becomes unstable, which gives an unpleasant vibration to the driver.

For example, when the battery voltage VB drops as the power consumption increases due to turning on the air conditioner, the comparator 30 in the regulator 10R causes the power transistor 3 to operate.
1 is driven to increase the output voltage of the alternator 10. However, since the torque applied to the engine 1 increases due to the energization of the field coil 10F, the rotation speed of the engine 1 decreases.

As described above, the torque generated by the engine 1 is small during the idle operation and the low speed operation, and particularly in the device in which the idle rotation speed is set low for the purpose of reducing fuel consumption, the unpleasant vibration as described above occurs. This can happen.

On the other hand, during the idle operation and the reduced operation, the driver does not perform any special operation and the vehicle interior noise is low. Therefore, the driver is sensitive to the sound generated by the engine 1 and the rotation fluctuation. Has become. Therefore,
In this state, turn on the car cooler, etc.
When the (power consumption) is increased, the rotation speed of the engine 1 decreases, and this decrease in rotation speed is felt by the driver.

In general, when a driver feels a decrease in the number of revolutions of the engine 1, he or she is likely to feel uncomfortable or feel uncomfortable, and further, when the engine 1 vibrates, the driver feels uneasy or uncomfortable. Pleasure increases. In fact, in a low rotation speed operating state, in the worst case, the engine 1 will stall.

In order to solve such a problem, the specification “WO91 / 08612” disclosed in the international publication has hitherto been used.
Although a technique for suppressing the field current IF as described in 1) has been proposed, in this case, it is necessary to provide the alternator 10 with an FR terminal for inputting a field coil control signal. Therefore, it is necessary to provide extra wiring between the electronic control unit 15 and the alternator 10, and it is necessary to provide a counter circuit or the like for detecting the control duty of the FR terminal in the electronic control unit 15. Will lead to higher costs.

[0030]

As described above, the conventional rotation fluctuation control device has the comparator 30 in the regulator 10R.
Since the power generation voltage is controlled only by turning on / off the power transistor 31 based on the output signal of the engine 1, when the electric load 11 is turned on during the idle operation and the low speed operation, a decrease in the rotation speed of the engine 1 and vibration occur. There is a problem that the driver feels anxious and uncomfortable.

When controlling the voltage applied to the voltage adjustment terminal of the regulator 10R, the battery voltage VB
Since the generated voltage is controlled only by turning on / off the power transistor 31 without changing the target voltage of 1, the engine 1 is reduced in rotation speed or vibrated similarly to the above, thereby giving the driver anxiety or discomfort. There was a problem.

Further, when the alternator 10 is provided with the FR terminal in order to suppress the field current IF of the field coil 10F, various circuit elements are required, which causes a problem of cost increase. .

The present invention has been made to solve the above-mentioned problems, and it is possible to limit the amount of drop in the engine speed even if the electric load increases suddenly during idle operation and low speed operation. By doing so, an object of the present invention is to obtain a rotation fluctuation control device that suppresses battery exhaustion and unpleasant vibrations without increasing costs.

[0034]

A rotation fluctuation control device according to claim 1 of the present invention comprises a generator driven by an engine, an electric load to which a rectified output from the generator is supplied as necessary, A battery that is charged by the rectified output from the generator, a regulator that controls the field current of the generator so that the terminal voltage of the battery is a set value, and a target voltage of the battery is calculated based on the operating state of the engine. A target voltage calculation unit and field current limiting means for limiting the field current of the generator according to the voltage deviation between the target voltage and the terminal voltage of the battery are provided.

According to a second aspect of the present invention, there is provided the rotation fluctuation control device according to the first aspect, wherein the field current limiting means is
The PID calculation according to the voltage deviation determines the limit value of the field current.

According to a third aspect of the present invention, there is provided the rotation fluctuation control device according to the second aspect, wherein the field current limiting means is
The field current is limited based on the duty control signal according to the limit value.

Further, according to a fourth aspect of the present invention, in the rotation fluctuation control device according to the second or third aspect, the field current limiting means has a voltage deviation when the terminal voltage of the battery is lower than the target voltage. When the terminal voltage of the battery is equal to or higher than the target voltage, the limit value is determined by reducing the integral value by the PID calculation by a predetermined value every predetermined time.

According to a fifth aspect of the present invention, in the rotation fluctuation control device according to any one of the first to fourth aspects, the field current limiting means sets the terminal voltage of the battery based on the limit value. The field current is limited by changing the value.

According to a sixth aspect of the present invention, in the rotation fluctuation control device according to the fifth aspect, the field current limiting means is
A set value switching unit for switching the set value between the normal first set value and the second set value lower than the first set value is included.

Further, a rotation fluctuation control device according to a seventh aspect of the present invention is the throttle fluctuation control device according to any one of the first to sixth aspects, which is provided in an intake pipe of the engine and adjusts an intake air amount to the engine. A valve, a bypass air passage that bypasses the throttle valve, and an idle air amount control unit that controls the opening area of the bypass air passage to control the idle speed of the engine. It adjusts the idle air volume.

[0041]

According to the first aspect of the present invention, the alternator-generated electric energy is limited using the deviation between the battery voltage and the target voltage as a parameter, in addition to the idle speed control by feedback to the intake system including the bypass air passage.
As a result, even if the electric load increases during idle rotation and low speed operation, the amount of power generation is limited and the reduction in rotation speed is suppressed to a small level.

Further, according to the second aspect of the present invention, the limit value of the generated current is determined by the PID control using the voltage deviation as a parameter. As a result, the target value of the generated current output from the stator coil is slowly raised, and even if the electric load increases during idle rotation and low speed operation, the amount of power generation is limited and the reduction in rotation speed is suppressed to a small level. At this time, the limit value of the field current corresponding to the power generation amount is not always constant during the idle operation and gradually increases due to the PID control, so that the battery is not discharged due to over-discharge of the battery. When the limit value is gradually increased during idling, the rotation speed does not drastically decrease even if the electric load increases.

Further, according to the third aspect of the present invention, the set value of the battery voltage is substantially set on average small (that is, low) by controlling the duty of the voltage adjusting terminal of the regulator.

Further, according to the fourth aspect of the present invention, in order to prevent the generated current from rapidly increasing when the electric load is turned on again, the integral value of the PID calculation is reduced by a predetermined value when the battery voltage is stable.

According to the fifth aspect of the present invention, the set value serving as the comparison reference in the regulator is changed according to the limit value to limit the field current.

According to the sixth aspect of the present invention, in response to the limit value, the normal set value is switched to the L level (predetermined level) set value.

Further, according to claim 7 of the present invention, based on the voltage deviation, the field current is limited to slowly raise the target generated current, and feedback control to the intake system is performed to reduce the idle speed. To prevent.

[0048]

EXAMPLES Example 1. Hereinafter, a first embodiment of the present invention (corresponding to claims 1 to 3 and claim 7) will be described with reference to the drawings. 1 is a configuration diagram showing an electric system of a drive system of Embodiment 1 of the present invention, and FIG. 2 is a block diagram showing a functional configuration of FIG. In each figure, 5, 9, 10, 10S, 10
F, 10D, 10R, 12, 14, 30 and 31 are the same as those described above, and 15A corresponds to the electronic control unit 15. The overall configuration of the rotation fluctuation control device of the present invention is as shown in FIG.

Reference numeral 16 denotes a control unit composed of, for example, an external transistor, which is an electronic control unit 15A.
ON / OFF control is performed by the duty control signal Cd from the device, and the ground potential is applied to the voltage adjustment terminal G of the regulator 10R with a duty ratio as necessary. The voltage adjustment terminal G is connected to the base of the power transistor 31.

Reference numeral 17 is an ignition switch which is turned on when the engine 1 is started. Reference numeral 18 is a charge lamp for displaying the charge state of the battery 12, one end of which is connected to the battery 12 via the ignition switch 17 and the other end of which is connected to the input terminal L of the regulator 10R.

Reference numeral 19 is a T / M select switch indicating the transmission position (for example, parking, N range, D range, etc.) of the automatic vehicle, and 20 is a clutch switch provided in the manual transmission switching vehicle. The switch signals from the switches 19 and 20 are input to the electronic control unit 15A as various sensor signals together with other parameter signals.

In this case, the electronic control unit 15A includes the following functional blocks 21 to 25. Reference numeral 21 is a target voltage calculation unit that calculates a target voltage VR of the battery 12 based on parameter input signals from various sensors, 22 is a subtraction unit that calculates a voltage deviation ΔV between the battery voltage VB and the target voltage VR, and 23 is a voltage deviation. A PID calculator that calculates a target generated current Ia by PID control according to ΔV, 24 is an Ia / If converter that converts the target generated current Ia into a target field current If based on a parameter input signal indicating an operating state,
Reference numeral 25 is a duty conversion unit that converts the target field current If into a duty control signal Cd for the control unit 16.

The electronic control unit 15A cooperates with the control unit 16 and the regulator 10R to form field current limiting means for limiting the field current IF of the alternator 10. Further, the electronic control unit 15A is
A control signal C for the solenoid 9 according to the voltage deviation ΔV
And a solenoid (9) that cooperates with the solenoid 9 to form idle air amount control means.

When the battery voltage VB is lower than the target voltage VR, the field current limiting means determines the limit value by PID control according to the voltage deviation ΔV. Further, in Example 3 described later, the field current limiting means determines the limit value by reducing the integral gain of the PID control by a predetermined value every predetermined time when the battery VB voltage is equal to or higher than the target voltage VR. .

The basic technique according to the first embodiment of the present invention will be described below with reference to FIGS. Figure 3-
FIG. 5 shows the grounding (ground potential) duty [%] of the G terminal (voltage adjusting terminal G) and the power generation rate of the alternator 10 (ratio of the actual power generation to the full power generation), that is, the drive duty of the field coil 10F [. %] Is a characteristic diagram showing the relationship with FIG.
When the power generation rate of 0% is permitted, FIG. 4 shows the case where the regulator 10R limits the power generation rate to 50%, and FIG. 5 shows the case where the regulator 10R limits the power generation rate to 25%. .

As is apparent from FIG. 3, when the field current IF actually flowing in the field coil 10F is continuous (when the G terminal grounding duty is 0%), the field coil driving duty is 100. %, And when the G terminal grounding duty is 100% and no field current IF is flowing in the field coil 10F, the field coil drive duty is 0%.

The drive duty of the field coil 10F is proportional to the power generation rate of the alternator 10. Further, the G terminal grounding duty indicates a ratio of grounding the G terminal. When the G terminal is continuously grounded, the G terminal grounding duty becomes 100%, and when the G terminal is not grounded at all, the G terminal grounding duty is 0%. Becomes Therefore, if the G terminal is grounded, regardless of the control state of the regulator 10R,
Power generation is forcibly cut.

In FIG. 3, the regulator 10R generates 100 power.
% When the G terminal grounding duty is 0
When it is decreased to%, the field coil drive duty (power generation rate) increases to 100%. Further, FIG. 4 shows a case where the regulator 10R permits 50% of power generation, and even if the G terminal grounding duty is 50% or less, the field coil drive duty does not become 50% or more. Further, in FIG. 5, the regulator 10R generates 25% of electric power.
This is the case when the G terminal grounding duty is 75
%, The field coil drive duty is 2
It does not exceed 5%.

From the above, the G terminal ground duty,
Alternatively, it can be seen that by controlling the G terminal non-grounding duty opposite to this, the maximum value of the drive duty (power generation rate) of the field coil 10F can be controlled, that is, the limit value of the power generation amount can be set.

FIG. 6 shows the field coil drive duty (power generation rate) and alternator drive torque (alternator 1).
Drive torque required to rotate 0) [Kg-m]
FIG. 6 is a characteristic diagram showing the relationship between the field coil drive duty and the alternator drive torque in a one-to-one relationship.

From the above conclusions obtained from FIGS. 3 to 6,
You can see the following. That is, in general, the electric load 11
Is increased, the regulator 10R increases the power generation rate, and when the power generation rate is increased, the alternator drive torque is increased (see FIG. 6). As a result, the rotational speed of the engine 1 is reduced during idle operation, causing unpleasant vibrations. Cause.

However, if the power generation rate is limited by the G grounding duty or the G terminal non-grounding duty during idle operation (see FIGS. 3 to 5) and the alternator drive torque is limited, the engine 1 will rotate at a certain rotational speed. It is possible to prevent the occurrence of unpleasant vibration without causing the following.

Furthermore, if the limit value is set strictly,
Even if the electric load 11 rapidly increases during idling, the engine speed of the engine 1 hardly decreases, and the driver does not notice the decrease of the engine speed. If the power generation rate is limited, the electric power to the suddenly increased electric load 11 will be insufficient, but this shortage can be covered by the battery 12.

Here, a specific operation of the regulator 10R by the duty control signal Cd will be described. For example, when the duty control signal Cd is on, the control unit 16 is in the on state, and the L level ground potential is applied to the voltage adjustment terminal G. At this time, the power transistor 31 in the regulator 10R is turned off regardless of the comparison output from the comparator 30, and the field current IF does not flow, so that the generated power from the stator coil 10S becomes zero.

On the contrary, when the duty control signal Cd is off, the control unit 16 is off. At this time, the power transistor 31 in the regulator 10R
Operates according to the comparison output from the comparator 30, whereby the field current IF flows. Therefore, the battery voltage VB is controlled to the set value VA by the control operation of the regulator 10R, and the target value of generated power is obtained from the stator coil 10S.

The regulator 10R is the required electrical load 1
When the power consumption increases due to the input of 1, the power transistor 31 is turned on to increase the power generation voltage from the stator coil 10S, as described above. At this time, if the engine 1 is not in the idle operation state, the control unit 16 is turned off so that the field current limiting means does not perform the field current limiting operation.

On the other hand, during the idle operation, the duty control signal Cd for suppressing the generated voltage is generated and the voltage adjustment terminal G is turned on by turning on / off the control unit 16.
The L level voltage is intermittently input.

At this time, the comparator 30 determines that the battery voltage V
Power transistor 3 so that B matches the set value VA
Generate a high-level comparison output to drive 1
Since the L-level voltage is intermittently input from the voltage adjusting terminal G, the on-time of the power transistor 31 is limited, and the amount of electricity (field current IF) of the field coil 10F is substantially limited. Therefore, the upper limit is given to the power generation amount of the stator coil 10S as follows.

First, as described above, the electronic control unit 15
A is the target voltage VR and the battery voltage V according to the operating state
The target power generation current Ia is calculated by performing the PID calculation of the equation (1) for the voltage deviation ΔV from B. However, since the control gain of the PID calculation is suppressed to a low value, the target power generation current Ia is also suppressed to a small value. There is.

From the target generated current Ia thus obtained,
The target field current If is determined according to the operating state, the duty is further converted, and the control unit 16 is driven to apply an intermittent earth potential corresponding to the duty value to the voltage adjustment terminal G of the regulator 10R.

That is, the control unit 16
The field current IF is limited to the target field current If by turning on / off the power transistor 31 by intermittently connecting the comparison output of the comparator 30 via the voltage adjustment terminal G. Then, by causing the stator coil 10S to generate power only up to the target generated current Ia, it is possible to prevent a large torque from being suddenly applied to the engine 1 and prevent the rotation speed from decreasing.

However, in the control by the target generated current Ia, the battery voltage VB does not reach the target voltage VR, so that the voltage deviation ΔV between the battery voltage VB and the target voltage VR still exists. . Therefore, the electronic control unit 15 calculates a new target generated current Ia based on the calculated voltage deviation ΔV,
The new duty control signal Cd operates to control the voltage applied to the voltage adjustment terminal G.

That is, the battery voltage VB and the target voltage V
As long as the voltage deviation ΔV from R exists, the target generated current Ia gradually increases by repeating the above operation, and eventually the battery voltage VB and the target voltage VR match. Since the limit value is set for the amount of power generation in this way, even if the electric load 11 suddenly increases during low-speed operation, the torque required to rotate the alternator 10 does not suddenly increase, and the rotational speed does not decrease much. Therefore, the unpleasant vibration of the engine 1 does not occur.

1 and 2 with reference to the flow chart of FIG. 7 and the characteristic diagram of FIG. 8 and FIG.
A specific operation of the first embodiment of the present invention shown in FIG.

The processing routine shown in FIG. 7 is started by an interruption of the constant time timer or a pulse interruption of the crank angle signal θ synchronized with the rotation of the engine 1, and the field current limiting means, ie, electronic control, which is the control center of the present invention. Control device 1
5A. Further, FIG. 8 shows the relationship between the load current fluctuation amount ΔI and the voltage deviation ΔV, and it can be seen that the two are in a proportional relationship. Note that the load current fluctuation amount ΔI in FIG.
Corresponds to the amount of fluctuation of the required target generated current Ia.

In FIG. 7, first, the idle switch 5
With the idle detection signal A from the input information as input information, it is determined whether or not the current operating state is idle operation (step S
1) If the idle operation is not being performed (that is, NO), the duty control signal Cd is turned off.
This turns off the control unit 16,
The voltage adjusting terminal G is turned off (step S2), and FIG.
Ends the process.

On the other hand, if it is determined in step S1 that the engine is idle (that is, YES), the actual battery voltage VB is read (step S3).
Input of various parameters indicating the operating state in the target voltage calculation unit 21 (information such as intake air temperature and vehicle speed, acceleration / deceleration, etc.)
Based on, the target voltage VR of the battery voltage VB is calculated (step S4).

Here, the reason for referring to the intake air temperature or the like is that the impedance (charging characteristic) of the battery 12 changes according to the liquid temperature of the battery 12, so that the target voltage VR is calculated in consideration of this. For example, at the time of deceleration, the target voltage VR is set high so that the battery 1 can be efficiently used.
2 is charged, and the charge / discharge balance of the battery 12 is maintained. Further, in the same manner as described above, the regulator 10
Based on the temperature of R, the set value VA (14.
About 5V).

Subsequently, the subtracting unit 22 calculates the voltage deviation ΔV between the actual battery voltage VB and the target voltage VR (step S5), and the PID calculating unit 23 performs the PID control based on the voltage deviation ΔV to obtain the target voltage. The target generated current Ia considered necessary to achieve VR is calculated using the following formula (step S6).

Ia = KP · ΔV + KI · ΣΔV + KD · (dΔV / dt) (1)

However, in the equation (1), KP is a proportional gain, KI is an integral gain, and KD is a differential gain. The gains KP, KI, and KD are set to relatively small values so that the power generation voltage output from the stator coil 10S in the alternator 10 gradually changes.

Here, the required generated current (target generated current Ia
It is known from the experimental results that there is a proportional relationship between the increase amount ΔI and the voltage deviation ΔV as shown in FIG. Therefore, some set gains KP, KI and KD
If the generated current is feedback-controlled so as to obtain the target generated current Ia according to the voltage deviation ΔV, the actual generated current is always converged to the target generated current Ia of the equation (1).

That is, if the target generated current Ia is smaller than the actually required current value, the actual battery voltage VB becomes smaller than the target voltage VR (VR> VB), and the voltage deviation ΔV does not become zero. Therefore, the integrated value (KI · Σ
By correcting ΔV) to the increasing side, the target generated current Ia obtained from the equation (1) gradually increases and finally converges.

By properly selecting the control gain, the target generated current Ia gradually increases without a sudden increase corresponding to the fluctuation of the electric load 11, and the torque load is gradually applied to the engine 1. As a result, it is possible to suppress the rotation fluctuation in response to the increase in the rotation speed (increase in torque) due to the increase in the air amount. As the control gain, for example, the proportional gain KP is about 10 [ampere / volt],
About 0.25 [ampere / volt] is suitable for the integral gain KI.

Next, the Ia / If converter 24 determines the target field current If from the target generated current Ia according to the operating state (input of various parameters) (step S7).
At this time, the generated current of the alternator 10 is the field current I.
Even if F is the same, the target field current If is calculated so as to become the target generated current Ia according to the operating state at that time, because it varies depending on the rotation speed of the engine 1 and the battery voltage VB.

Next, the field current IF is the target field current If.
The drive duty (for example, the ground duty) of the voltage adjustment terminal G is set so as to match with, and the duty control signal Cd is output (step S8).

Further, during the above control, since the engine is in the idle operation state, the target generated current Ia corresponding to the voltage deviation ΔV is obtained.
The drive torque for obtaining the above must be applied to the alternator 10 by idle speed control. Therefore,
The intake air amount of the engine 1 is calculated so that the engine speed corresponding to the drive torque is obtained, and the control signal C to the solenoid 9 for idle speed control is generated (step S9).

Through the above steps S3 to S9, the rotation fluctuation control process during idling is completed, and the routine proceeds to the next routine.

Example 2. In the first embodiment, the potential of the voltage adjustment terminal G is directly applied to the power transistor 31, and the power generation is completely stopped when the ground potential (L level potential) is applied to the power transistor 31. In response to the application of the L level potential to the voltage adjustment terminal G, the set value VA may be switched from the normal value (14.5V) to a predetermined voltage value (for example, about 12.5V).

In this case, the field current limiting means including the electronic control unit 15A limits the field current IF by limiting the set value VA of the battery voltage VB, and duty-controls the set value VA. Limit the current IF.
FIG. 9 is a block diagram showing the essential parts of a second embodiment (corresponding to claim 5 and claim 6) of the present invention.
5A, 16, 30, and 31 are the same as described above.

Reference numeral 32 denotes a set value switching section for switching the set value VA according to the voltage applied to the voltage adjusting terminal G. When the voltage adjusting terminal G is in the off state, the set value VA is set to the normal 14.5.
When the voltage adjustment terminal G is in the ON state and the applied voltage is at the L level, the set value VA is lower than the normal value 1
The voltage is switched to 2.5 V (e.g., a lower limit value for preventing over-discharge of the battery 12).

FIG. 10 is a circuit diagram showing a concrete example of the configuration of the set value switching unit 32 in FIG. 9. Reference numerals 32a to 32c are voltage dividing resistors connected in series between the battery voltage VB and the ground potential. is there. Battery side voltage dividing resistors 32a and 32
The connection point of b outputs the set value VA, the connection points of the ground side voltage dividing resistors 32b and 32c are connected to the voltage adjusting terminal G, and the ground side voltage dividing resistor 32c is connected to the potential of the voltage adjusting terminal G. Inserted or shorted by. Therefore, the set value VA is H level (14.5%) when the voltage dividing resistor 32c is inserted (the control unit 16 is turned off).
V), when the voltage dividing resistor 32c is short-circuited (control unit 16 is turned on), it becomes L level (12.5V).

In this case, similarly to the first embodiment, the target generated current Ia is slowly raised to prevent a large torque from being suddenly applied to the engine 1, and the battery 12
If the battery voltage VB is abnormally low due to excessive discharge (lower than the L level set value of 12.5 V),
The battery 12 can be charged with priority over the suppression control of the field current IF.

It is assumed that the battery voltage VB is controlled to the target voltage (for example, 14V) calculated by the target voltage calculation unit 21 and is stable. At this time, the target voltage VR lower than the set value 14.5V which is the reference of the comparator 30.
In order to control the duty to (14V), a pulse of a predetermined duty control signal Cd is input to the voltage adjustment terminal G.

By turning on the air conditioner,
A case where the battery voltage VB drops to 13V will be described. At this time, the battery voltage VB (13V) is H
It is expressed as follows using the level set value VA (= 14.5 V) and the L level set value VA (= 12.5 V).

14.5V> VB> 12.5V

That is, when the control unit 16 is turned on by the duty control signal Cd, the set value VA is 12.5V, so the comparator 30 determines that the battery voltage VB (13V) is higher than 12.5V. Then, the power transistor 31 is turned off to prohibit power generation.

On the contrary, when the control unit 16 is turned off, the set value VA returns to the H level (14.5 V), so that the comparator 30 causes the battery voltage VB (13
It is determined that V) is smaller than the set value VA (= 14.5V). Therefore, the comparison output is turned on, the power transistor 31 is turned on, and power is generated. That is, the alternator 1 is driven by the pulse of the duty control signal Cd.
The presence or absence of zero power generation is determined.

Next, a description will be given of a case where the battery voltage VB abnormally drops to 10V when the air conditioner is on during the idle operation while the battery 12 is being discharged.

At this time, the battery voltage VB becomes lower regardless of whether the set value VA selected by turning on / off the control unit 16 is 14.5V or 12.5V. Therefore, regardless of the duty pulse of the voltage signal input from the voltage adjustment terminal G, the comparator 30
The output of is turned on, and power is constantly generated. Thereby, the battery 12 can be protected from over discharge.

When the battery 12 is thus charged and the battery voltage VB eventually exceeds 12.5 V, the presence or absence of power generation is determined depending on the duty of the voltage signal from the voltage adjusting terminal G, as described above.

Thus, 14.5V>VB> 12.5
In the case of V, the presence or absence of power generation is controlled depending on the duty of the voltage applied to the voltage adjustment terminal G. That is, when the control unit 16 is on, the set value VA is 12.
Since it becomes 5V, VB ≧ VA and power generation is performed. When the control unit 16 is off, the set value VA becomes 14.5V, so VB <VA and power generation is stopped. The drive torque of the alternator 10 at this time is
It is determined only by the presence or absence of power generation, and does not change suddenly as in the first embodiment.

If VB <12.5V, the battery 12 may be over-discharged if left as it is, and it is necessary to charge the battery 12 prioritizing suppression of rotation fluctuation. Power generation is always performed regardless of the duty of the adjustment terminal G. However, in reality, there are few opportunities to encounter such an over-discharged state.

On the other hand, when the battery voltage VB becomes 14.5V or higher, the battery voltage VB is higher than the set value VA even if the control unit 16 is turned off and the set value VA is 14.5V. , The output of the comparator 30 remains off. Therefore, regardless of the duty of the voltage applied to the voltage adjustment terminal G, the regulator 10R does not work at all and power generation is not performed.

Example 3. Next, a third embodiment (corresponding to claim 4) of the present invention will be described. Embodiment 3 of the present invention
In the state where the battery voltage VB is in balance with the target voltage VR with the electric load 11 turned on, even if the electric load 11 is turned off and then turned on again, a sudden increase in the generated current is prevented, and This is to prevent a sudden torque application.

That is, in the first embodiment, the fact that the battery voltage VB is higher than the target voltage VR means that the target generated current Ia calculated by the PID calculator 23 is not sufficiently small. . Therefore, in such a case, from the previous integrated value to the predetermined value α
The target generated current Ia calculated by the PID calculator 23 is reduced more quickly by subtracting
It is desirable to prepare for re-input of 1.

In the second embodiment, the battery voltage VB becomes higher than the target voltage VR when the electric load 11 that has been turned on is cut off, but the comparator 3
When 0 turns off the power transistor 31, the battery voltage VB is controlled to the target voltage VR. Therefore, the electronic control unit 15A determines that VB = VR and Δ
Since V = 0, the target generated current Ia is equal to the electric load 1
The value will be kept as it was when the value of 1 was input.

In order to address this, the third embodiment of the present invention
In the above, even if the battery voltage VB is equal to the target generated current Ia and VB = VR, the target generated current Ia calculated by the PID calculator 23 is reduced by subtracting the predetermined value α from the previous value of the integrated value. is doing.

As a result, the target power generation current Ia gradually decreases, and eventually the alternator 10 has a target power generation current value sufficient to generate the target voltage VR with the electric load 11 cut off. Generated current I
a converges.

FIG. 11 is a flowchart showing the operation of the third embodiment of the present invention, and S1 to S9 are the same steps as described above. In this case, following the target voltage calculation step S4, it is determined whether or not VB <VR by comparing the actual battery voltage VB with the target voltage VR (step S11).

If battery voltage VB ≧ target voltage VR
If it is determined to be NO (that is, NO), the current value KI · ΣΔV (n) of the integrated value of the PID calculation is changed to the previous value predetermined value KI ·
A predetermined value α is subtracted from ΣΔV (n−1) to gradually reduce it (step S12). Hereinafter, the PID calculation is performed by proceeding to the voltage deviation calculation step S5 and the PID calculation step S6 described above.

As a result, the target generated current Ia calculated from the equation (1) decreases, the ground duty of the voltage adjusting terminal G increases (the non-ground duty decreases) by the duty control signal Cd, and finally the field The drive duty of the magnetic current IF coincides with the non-ground duty of the voltage adjustment terminal G and settles down. This is because if the drive duty of the field current IF becomes larger than the non-ground duty of the voltage adjustment terminal G,
This is because the actual battery voltage VB decreases.

As described above, if the drive duty of the field current IF and the non-ground duty of the voltage adjustment terminal G are kept in a standby state, even if the electric load 11 is turned on again, the generated current suddenly increases. Increase is suppressed. on the other hand,
If it is determined in step S11 that the battery voltage VB <the target voltage VR (that is, YES), the process directly proceeds to step S5 and thereafter, as in the case of the first embodiment.

When the third embodiment of the present invention is applied to the first embodiment, the integral gain KI is subtracted by a predetermined value until the actual battery voltage VB becomes lower than the target voltage VR. The decrease rate can be made faster. Therefore, the target generated current Ia corresponding to the target voltage VR of the battery 12 can be promptly obtained.

Similarly, when the third embodiment of the present invention is applied to the second embodiment, the integral gain KI is subtracted by a predetermined value until the actual battery voltage VB becomes lower than the target voltage VR, and the integral value is reduced. Since KI · ΣΔV is subtracted by the predetermined value α, the calculated value of the target generated current Ia drops to a value corresponding to the target voltage VR without being fixed to a constant value. As a result, even if the electric load 11 is turned on again, the target generated current Ia is limited,
Torque is not suddenly applied to the engine 1, and rotation fluctuation is prevented.

Particularly, in the second embodiment, since the field coil 10F is independently controlled by the regulator 10R, the drive duty of the field current IF is balanced with a duty sufficiently smaller than the non-ground duty of the voltage adjusting terminal G, The battery voltage VB may be stable. However, as in step S12, the battery voltage V
From the stable state of B, the non-ground duty of the voltage adjustment terminal G is reduced by the integrated value of the PID calculation by α every predetermined time (time when the routine of FIG. 11 is executed). It is possible to suppress the sudden increase of the generated current when the electric load 11 is turned on by approaching the drive duty of.

In each of the above-mentioned embodiments, the PID control is performed slowly in the case where the engine 1 is in the idle operation state. However, the PID control is not limited to the idle operation state. It is needless to say that the same effect can be obtained by being applicable even when the vehicle rotates at a low speed, or when driving at a low speed such as traveling in a traffic jam.

In this case, the step S1 for determining whether or not the engine is idling may be replaced with a step for determining whether or not the engine speed is equal to or lower than a predetermined speed. Alternatively, step S1 for determining the idling operation and step S2 for turning off the voltage adjustment terminal G may be deleted.

Example 4. In each of the above embodiments, the regulator 10R is provided in the alternator 10 and the control voltage is applied from the external electronic control unit 15A and the control unit 16 to the voltage adjusting terminal G. However, the regulator 10R is connected to the electronic control unit 15A. It may be provided inside and the regulator function may be realized by a program.

In this case, the drive duty of the field coil 10F can be directly controlled by the electronic control unit 15A.

[0121]

As described above, according to the first aspect of the present invention, the generator driven by the engine, the electric load supplied with the rectified output from the generator as needed, and the generator load A battery charged by the rectified output, a regulator that controls the field current of the generator so that the terminal voltage of the battery becomes a set value, and a target voltage calculation unit that calculates the target voltage of the battery based on the operating state of the engine. And field current limiting means for limiting the field current of the generator according to the voltage deviation between the target voltage and the terminal voltage of the battery, and idle speed control by feedback to the intake system including the bypass air passage, Since the amount of power generation is limited separately, it is possible to suppress the decrease in engine speed even if the electric load increases during idle rotation and low speed operation.
There is an effect that a rotation fluctuation control device that suppresses the occurrence of battery exhaustion and unpleasant vibrations can be obtained without inviting cost increase.

According to a second aspect of the present invention, in the first aspect, the field current limiting means determines the limit value of the field current by PID calculation according to the voltage deviation, and the target value of the generated current. Is started slowly, and even if the electric load increases during idle operation and low speed operation, the amount of power generation is limited to suppress the decrease in rotation speed to a small amount, so the electric load is reduced during idle rotation and low speed operation. Even if the number of rotations increases, it is possible to suppress a decrease in the engine speed, and it is possible to obtain a rotation fluctuation control device that suppresses battery exhaustion and unpleasant vibrations without increasing costs.

According to a third aspect of the present invention, in the second aspect, the field current limiting means limits the field current based on the duty control signal according to the limit value, and substantially the battery voltage. Since the setting value of is set to be small on average, it is possible to suppress the decrease in engine speed even if the electric load increases during idle rotation and low speed operation, and to increase battery life without increasing cost. There is an effect that a rotation fluctuation control device that suppresses the occurrence of unpleasant vibration and the like can be obtained.

Further, according to claim 4 of the present invention, in claim 2 or claim 3, the field current limiting means determines the PID according to the voltage deviation when the terminal voltage of the battery is lower than the target voltage. The limit value is determined by calculation, and if the terminal voltage of the battery is equal to or higher than the target voltage, PI is set every predetermined time.
Since the limit value is determined by reducing the integral value by the D calculation by a predetermined value, it is possible to prevent a sudden increase in the generated current when the electric load is turned on again, and to prevent the cost from increasing and the battery to run down or an unpleasant vibration. There is an effect that a rotation fluctuation control device that suppresses the occurrence of the above is obtained.

According to claim 5 of the present invention, in any one of claims 1 to 4, the field current limiting means changes the set value of the terminal voltage of the battery based on the limit value. As a result, the field current is limited, so that even if the electric load increases suddenly during idle operation or low speed operation, the amount of engine speed drop is limited, and the battery exhaustion and unpleasantness are avoided without increasing costs. There is an effect that a rotation fluctuation control device that suppresses the occurrence of various vibrations is obtained.

According to the sixth aspect of the present invention, in the fifth aspect, the field current limiting means sets the set value to the normal first set value and the second set value lower than the first set value. Since the setting value switching unit for switching to the value is included and the setting value is switched to the second setting value at the L level in response to the limit value, the engine speed is increased even when the electric load is rapidly increased during idle operation or low speed operation. There is an effect that a rotation fluctuation control device can be obtained in which the number of drops is limited and the occurrence of battery exhaustion and unpleasant vibrations is suppressed without increasing costs.

According to claim 7 of the present invention, in any one of claims 1 to 6, a throttle valve provided in an intake pipe of the engine for adjusting an intake air amount to the engine, and a throttle valve A bypass air passage for bypassing the valve and an idle air amount control means for controlling the opening area of the bypass air passage to control the idle speed of the engine are provided, and the air amount control means is configured to adjust the idle air amount according to the voltage deviation. The feedback control to the intake system is carried out to prevent the idling speed from decreasing, so even if the electric load suddenly increases during idling or low speed operation, the amount of engine speed drop It is possible to obtain a rotation fluctuation control device that can limit the battery exhaustion and unpleasant vibration without increasing the cost. There is an effect.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an electric system according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a functional configuration of a main part of the first embodiment of the present invention.

FIG. 3 is a characteristic diagram showing the relationship between the ground duty and the power generation rate for explaining the operation of the first embodiment of the present invention.

FIG. 4 is a characteristic diagram showing a relationship between a ground duty and a power generation rate for explaining the operation of the first embodiment of the present invention.

FIG. 5 is a characteristic diagram showing the relationship between the ground duty and the power generation rate for explaining the operation of the first embodiment of the present invention.

FIG. 6 is a characteristic diagram showing the relationship between the power generation rate and the alternator drive torque for explaining the operation of the first embodiment of the present invention.

FIG. 7 is a flowchart showing the operation of the first embodiment of the present invention.

FIG. 8 is a characteristic diagram showing the relationship between the load current fluctuation amount and the voltage deviation for explaining the operation of the first embodiment of the present invention.

FIG. 9 is a block diagram showing a functional configuration of a second embodiment of the present invention.

10 is a circuit diagram showing a specific configuration example of a set value switching unit in FIG.

FIG. 11 is a flowchart showing the operation of the third embodiment of the present invention.

FIG. 12 is a configuration diagram showing a general rotation fluctuation control device.

FIG. 13 is a block diagram showing a functional configuration of a conventional rotation fluctuation control device.

[Explanation of symbols]

1 engine 2 intake pipe 4 throttle valve 6 bypass air passage 9 solenoid 10 alternator (generator) 10D full-wave rectifier 10F field coil 10R regulator 10S stator coil 11 electric load 12 battery 15A electronic controller (field current limiting means) 21 target Voltage calculation unit 23 PID calculation unit 25 Duty conversion unit 32 Set value switching unit Cd Duty control signal IF Field current Ia Target generated current α Predetermined value VA Set value VB Battery voltage VR Target voltage ΔV Voltage deviation S1 Judging the idle operation state Step S4 Step of calculating the target voltage S5 Step of calculating the voltage deviation S6 Step of executing the PID calculation S8 Step of executing the duty calculation based on the PID calculation result S9 Calculate the idle air amount The step of subtracting the step S12 the integral value comparing step S11 the battery voltage and the target voltage

Claims (7)

[Claims] 1. A generator driven by an engine, an electric load to which a rectified output from the generator is supplied as necessary, a battery charged by the rectified output from the generator, and a battery A regulator that controls the field current of the generator so that the terminal voltage becomes a set value, a target voltage calculation unit that calculates a target voltage of the battery based on an operating state of the engine, the target voltage and the battery And a field current limiting means for limiting a field current of the generator according to a voltage deviation from the terminal voltage of the rotation fluctuation control device. 2. The rotation fluctuation control device according to claim 1, wherein the field current limiting means determines the limit value of the field current by a PID calculation according to the voltage deviation. 3. The rotation fluctuation control device according to claim 2, wherein the field current limiting unit limits the field current based on a duty control signal according to the limit value. 4. The field current limiting means determines the limit value by a PID calculation according to the voltage deviation when the terminal voltage of the battery is lower than the target voltage, and the terminal voltage of the battery is 4. The rotation fluctuation control device according to claim 2, wherein when the voltage is equal to or higher than the target voltage, the limit value is determined by reducing an integral value by the PID calculation by a predetermined value every predetermined time. 5. The field current limiting means limits the field current by changing a set value of a terminal voltage of the battery based on the limit value. Any of the rotation fluctuation control devices up to 4. 6. The field current limiting means sets the set value to a normal first set value and a second set value lower than the first set value.
6. The rotation fluctuation control device according to claim 5, further comprising a set value switching unit for switching to the set value of. 7. A throttle valve provided in an intake pipe of the engine for adjusting an intake air amount to the engine, a bypass air passage bypassing the throttle valve, and an opening area of the bypass air passage being controlled. 7. An idle air amount control means for controlling an idle speed of the engine, wherein the air amount control means adjusts the idle air amount according to the voltage deviation. Rotation fluctuation control device.