JPH06311799A - Control system for ac generator driven by internal combustion engine - Google Patents

Abstract

PURPOSE:To stabilize power performance of an internal combustion engine by always correcting a generated voltage command value in response to an operating state of the engine. CONSTITUTION:Pieces of information such as an engine speed Ne, an engine water temperature TW, a throttle opening theta, an engine intake air amount Q, etc, of parameters of an internal combustion engine are input to an arithmetic processor 8. An electric load state and a vehicle traveling state are load- identified from the conditions. Thereafter, a target generated voltage for controlling an output of a generator 3 is so set as to become optimum for a vehicle state according to the load identified state. These processes are calculated in the processor 8, and a generated voltage command value P corresponding to the target generated voltage is output to a field current controller 5, thereby controlling a storage battery voltage in the generator 3 to a target generated voltage. In this case, the processor 8 detects a voltage difference between the battery voltage and the target voltage, thereby correcting the value P by the difference.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control system for an AC generator driven by an internal combustion engine, and in particular, it is driven by an internal combustion engine which is rotatably driven by an internal combustion engine mounted on an automobile to generate electric power. The present invention relates to an AC generator control system.

[0002]

2. Description of the Related Art Conventionally, a control system for a vehicle alternator which is driven to rotate by an internal combustion engine mounted on an automobile to generate electric power is disclosed in, for example, Japanese Patent Laid-Open No. 60-16195.

This type of control system uses a microcomputer to comprehensively control the power generation operation of the generator in accordance with not only the onboard battery but also the state of the engine and the state of the electric load. Particularly, in the control system, an output signal from an air conditioner, a sensor that detects when the headlamp is turned on, or the like is taken in as an operating parameter of the internal combustion engine to detect an operating state or an electric load state. Then, the target generated voltage of the generator is selectively switched according to the detected operating state or electric load state.

On the other hand, in Japanese Patent Laid-Open No. 3-270700, when the load on the internal combustion engine changes, the type of the load change is discriminated, and power generation is performed according to a predetermined pattern determined corresponding to the discriminated load change type. Disclosed is a control system for an on-vehicle generator which controls a field current of a machine.

[0005]

In the former case of the above-mentioned prior art, since the power generation operation is comprehensively controlled by taking in the operating state and the electric load state, it is possible to perform better control. The method of controlling the power generation operation is simply switching the target voltage value with the control device.

Therefore, even if the effects of power performance and fuel efficiency of the internal combustion engine are sufficiently obtained, it is not possible to obtain a stable effect depending on the switching voltage value.

Further, in the latter prior art, since the circuit elements of the voltage adjusting circuit itself have a large variation, as a result, variations occur among products, and a stable and highly accurate voltage adjusting device cannot be obtained.

An object of the present invention is to provide a control system for an AC generator driven by an internal combustion engine, which can stabilize the power performance and fuel efficiency effects of the internal combustion engine.

[0009]

The present invention is directed to an internal combustion engine mounted on a vehicle, a generator rotatably driven by the internal combustion engine, a storage battery charged by the generated power of the generator, and a voltage of the storage battery. And a means for detecting the electric load state mounted on the vehicle, and corrects the generated voltage command value for controlling the output voltage of the generator according to the operating state and the electric load state of the internal combustion engine. It is achieved by

[0010]

The arithmetic processing circuit inputs information such as engine speed Ne, engine water temperature Tw, throttle opening θ, engine intake air amount Q, etc., which are parameters of the internal combustion engine, as a vehicle state signal, and the air conditioner operation is performed based on these conditions. Status detection,
The load at the electric load state and the vehicle running state is detected by detecting when the engine starts, detecting the running state of the vehicle, and detecting whether the electric load is on or off. After that, a target power generation voltage for controlling the output of the generator is set so as to be optimal for the vehicle state according to the load determination state.

By performing these processes inside the arithmetic processing circuit and outputting the generated voltage command value P corresponding to the target generated voltage to the field current control circuit, the storage battery voltage in the vehicle alternator is the target generated voltage. Controlled by voltage. Here, the arithmetic processing circuit detects the voltage difference between the storage battery voltage and the target power generation voltage, and corrects the power generation voltage command value P based on the voltage difference.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A control system for an AC generator driven by an internal combustion engine according to an embodiment of the present invention will be described below with reference to the drawings of the embodiments.

FIG. 1 shows an embodiment of a control system for an AC generator driven by an internal combustion engine according to the present invention. The arithmetic processing circuit 8 for controlling the internal combustion engine 1 mounted on the vehicle has an engine speed Ne, which is a parameter of the internal combustion engine,
Information such as engine water temperature Tw, throttle opening θ, and engine intake air amount Q is input as a vehicle state signal, and from these conditions, air conditioner operating state detection, engine start detection, vehicle running state detection, electric load ON / OFF detection is performed to determine the load between the electric load state and the vehicle running state. After that, a target power generation voltage for controlling the output of the generator 3 is set so as to be optimum for the vehicle state according to the load determination state. These processes are arithmetically processed in the arithmetic processing circuit 8 and the generated voltage command value P corresponding to the target generated voltage is output to the field current control circuit 5, so that the storage battery voltage in the vehicle AC generator 3 is the target generated power. Controlled by voltage. Here, the arithmetic processing circuit 8 detects the voltage difference between the storage battery voltage and the target power generation voltage, and corrects the power generation voltage command value P based on the voltage difference.

FIG. 2 shows the overall configuration of a control system for an AC generator driven by the internal combustion engine of the present invention. In the figure, an internal combustion engine 1 mounted on a vehicle such as an automobile includes a crankshaft 11 that outputs a rotational torque. Although not shown, the crankshaft 11 is mechanically connected to the vehicle AC generator 3 via a pulley or a belt, and is rotationally driven. The vehicle alternator 3 is
Similar to a conventional generator, a rotor formed by winding a field winding 31 on the outer periphery, and a stator formed by winding three-phase windings 32a, 32b, 32c so as to face the outer peripheral surface of the rotor. It consists of In addition, the three-phase winding 32a of the generator 3,
A full-wave rectifier circuit 33 formed by connecting a plurality of pairs of diodes in parallel is connected to 32b and 32c, and the three-phase AC output of the generator 3 is rectified and supplied to the in-vehicle storage battery 4 for charging. Is configured. The generator 3 includes
A voltage adjusting device 5 that adjusts the output voltage while detecting the voltage of the vehicle-mounted storage battery 4 is provided in part.

In addition, the internal combustion engine 1, like the general vehicle, transmits its rotational torque to the drive wheels 6 via the transmission 2.
Have been communicated to. The embodiment of FIG. 2 is a multi-cylinder fuel injection (MPI) type four-cylinder internal combustion engine, which is provided with four injectors 51 and a drive device 52 for controlling the fuel supply amount for each cylinder. ing.

Also, an ignition plug 5 provided for each cylinder
3 sparks by the high voltage for ignition distributed from the distributor 54, which has a built-in ignition coil, in the order of the ignition cylinders, and explodes the fuel compressed in each cylinder. Then, the fuel injection device of the injector 51 and the ignition timing of the ignition plug 53 are controlled by the arithmetic processing circuit 8 which is a control device of the internal combustion engine 1. Also,
In FIG. 2, inside the fuel tank 7 for storing fuel,
A fuel pump 71 for pressurizing fuel and supplying it to the injector 51 is arranged. The operation of the fuel pump 71 is also controlled by the fuel pump control device 72 by the arithmetic processing circuit 8.
Controlled through.

The arithmetic processing circuit 8 for controlling the internal combustion engine 1 is composed of, for example, a microcomputer, and is used for the central processing unit (CPU) 81 for performing arithmetic in various controls, and for arithmetic. Random access memory (RAM) 82 for temporarily storing various data for storage and read-on memory (ROM) 83 for storing and storing data necessary for programs and calculations. Separately, an input / output hybrid integrated circuit (I / O LSI) 84 is provided. The I / O LSI 84 is the internal combustion engine 1
Is for taking in various parameters and data required for the control into the microcomputer, and for example, an A / D converter for converting an analog signal such as the storage battery voltage VB into a digital signal is also incorporated. . The I / O LSI 84 drives various actuators based on the calculation result of the microcomputer.
It is also configured to generate a generated voltage command value to be controlled.

In order to detect the parameters and data of the internal combustion engine necessary for the control by the arithmetic processing circuit 8 described above, for example, an air flow meter (for example, a hot wire type air flow sensor etc.) for detecting the intake air amount Q taken into the internal combustion engine. ) 10
1, a water temperature sensor 102 for detecting the water temperature TW of the cooling water, a throttle sensor 1 for detecting the opening θ of the throttle valve 1
03, an O ₂ sensor 104 for detecting the oxygen concentration O ₂ in the exhaust gas and controlling the air-fuel ratio (A / F) of the supplied fuel,
A crank angle sensor 105 for generating a pulse output n for each predetermined rotation angle (for example, 1 degree) of the crankshaft 11 for detecting the speed or rotation angle of the internal combustion engine, and a depression angle of an accelerator pedal or a throttle valve. An idle switch 106 for detecting the idle state SI of the engine from the angle, a starter switch 107 for detecting the start-up SS of the starter for starting the engine, and the like are provided. Furthermore,
The transmission 2 has a neutral state SN.
Neutral switch 1 for detecting whether or not
08 is provided.

In addition to the parameters and data of various operations of the internal combustion engine described above, the arithmetic processing circuit 8 supplies the storage battery voltage VB of the vehicle-mounted storage battery 4 and the load current supplied to the electric load 41 such as the headlamp. The output signal of the current sensor 42 that detects IL is input. The current sensor 42 is configured by using, for example, a Hall element or the like. Further, the arithmetic processing circuit 8 includes a compressor 9 for an air conditioner, and the crankshaft 1
The output signal A of the air conditioner load switch 92 for detecting the operation of the electromagnetic clutch 91 for connecting and disconnecting to 1 is also input, and the operation of the air conditioner can be determined by the signal.

In the configuration described above, the voltage adjusting device 5 detects the output voltage VB of the on-vehicle storage battery 4 and controls the field current IF with an output signal obtained by comparing the output voltage VB with a predetermined reference value. The power generation output of the generator 3 is controlled. On the other hand, the arithmetic processing circuit 8 performs a predetermined arithmetic operation by taking in the operating parameters of the internal combustion engine output from the sensors, switches, etc., controls various actuators based on the arithmetic operation result, and operates the internal combustion engine. Control.

According to the present invention, the arithmetic processing circuit 8 is
Not only the operation of the internal combustion engine 1 is controlled, but also the power generation output of the generator 3 is controlled. That is, the generated voltage command value P is output from the I / O LSI 84 of the arithmetic processing circuit 8 and input to the control circuit 50.

Here, the control circuit 50 is shown in FIG.
Will be explained. FIG. 3 shows a circuit block of the control circuit 50, which includes a transistor drive circuit 504.
Is the main control loop. Here, when the generated voltage command value P is input to the terminal C, the voltage conversion circuit 50
3 outputs the signal a and controls the transistor drive circuit 504. When no signal is input to the terminal C, the voltage input from the terminal S controls the generated voltage of the generator to be constant. The voltage control device 5 also includes an alarm circuit 501 that drives the warning light 502 via the terminal L.

The operation of the voltage conversion circuit 503 will be described with reference to FIGS. 4 and 5. FIG. 4 is a diagram showing a circuit configuration of the voltage conversion circuit 503, in which 503a is NOT.
Gates 503b and 503c are analog switches composed of C-MOS transfer gates, and 503.
d and 503f are resistors, and 503e and 503g are secondary filters that are capacitors.

Here, the input signal P which is the generated voltage command value
Is Hi level, analog switch 50
3c is turned on, the analog switch 503b is turned off, and the signal b is a predetermined reference voltage V0 (for example, 2.
4V). As a matter of course, the input signal P is low
If it is at the level, the signal b is grounded. For example, when the input signal P is a signal that repeats Hi / Low, the signal b repeats V0 (for example, 2.4V) / 0V. As described above, the output signal a is obtained by passing the secondary filter that outputs the signal b. Figure 5
As an example, the signal a becomes as shown in the figure by passing the generated voltage command value P having a cycle of t (for example, 6.4 msec) through the voltage conversion circuit 503. Here, a supplementary description of the generated voltage command value P is made by using a duty signal with a constant cycle.

FIG. 6 shows the relationship between the power generation voltage command value P calculated by the calculation processing circuit 8 according to the operating state of the internal combustion engine and the target power generation voltage of the generator. In this figure, a range in which X is the lower limit value and Y is the upper limit value is the effective range of the generated voltage control, and only in the case of a signal in the effective range, the target generated voltage as shown in the figure can be controlled. Here, it is assumed that the duty ratio (DUTY) of the generated voltage command value P within the effective range and the target generated voltage have a proportional relationship. Also,
The conduction ratio outside the effective range of the generated voltage command value P is provided to prevent unstable operation due to signal mixing (noise).

Next, an example of the present invention will be described with reference to the flowchart of FIG. When the control task of the generator is started in step 701, the voltage VB of the in-vehicle storage battery is loaded in step 702, the cooling water temperature TW in the internal combustion engine is loaded in step 703, and the target power generation according to the operating state is loaded in step 704. A control command value VB1 corresponding to the voltage command value P is selected. The flowchart for selection will be described later. Thus, the control command value V
After selecting B1, in step 705, the control command value VB1
And a voltage difference ΔVB ΔVB = VB−VB1 from the voltage VB of the vehicle-mounted storage battery fetched in step 702 is calculated.

Here, a determination for stable control is made. First, in step 706, it is determined whether the operating state has changed, and if the operating state has changed, the correction process is not performed in step 710. If it is determined in step 706 that the operating state has not changed, it is determined in step 707 whether the ΔVB calculated in step 705 has converged. In this determination, if the ΔVB has not converged in spite of the correction processing, the control is stopped in step 713. Step 7
In the determination of 07, if the ΔVB has converged,
It is determined whether or not the correction processing is within the range. For example,
If ΔVB is within the range of 0.1V <ΔVB <0.8V, the correction process is performed in step 708, but if it is out of the range, the correction process is not performed in step 710. Here, a supplementary description of the correction processing in step 708 will be given. If the voltage difference ΔVB (OLD) at the time of performing the correction processing last time is used, ΔVB = ΔVB (OLD) + (α × ΔVB) (for example,
α = 1/10), and the correction process can be performed by adding the calculated ΔVB to the control command value VB1.
Thus, as a post-process of steps 709 and 710, it is determined in step 711 whether the internal combustion engine 1 is stopped. If not, the process returns to step 702, but is stopped in step 711. If it is determined that the voltage difference ΔVB is present, the voltage difference ΔVB is stored in the storage device 82 as ΔVB ′ (step 712). It is assumed that the stored voltage difference ΔVB ′ is held until the internal combustion engine 1 is started thereafter, and the control command value VB1 is corrected when the internal combustion engine 1 is started, and the process ends at step 713.

An example of the method of selecting the control command value VB1 in step 704 will be described with reference to FIG. First, when the task is started in step 801, the operating state is determined using information such as engine speed, intake air amount, throttle opening, air-fuel ratio, and electric load operation (step 802). When the determined operating state is accelerating (step 803), the control command value VB1 = 13.
The same applies when 0V (step 808) is set and the vehicle is in a steady running state (step 804). When the determined state is the idle operation state (step 805), the control command value VB1 = 14.4V. In cases other than these states, the control command value VB1 = 15.2 V is set, and in each case, the process ends in step 809.

Here, the correction operation will be described with reference to FIG. For example, if the storage battery voltage VB and the control command value VB1 are a voltage difference ΔVB1 as shown in FIG. 9, the control command value VB1 is changed at the timing a when the operating state changes, and therefore it is also shown in the figure. Thus, the storage battery voltage VB and the control command value VB1 change. However, since the correction is performed using the previous voltage difference ΔVB2 at the timing b at the time of the next operation state change, ΔVB2> ΔVB3 can be satisfied.

When the internal combustion engine is stopped,
Since the voltage difference ΔVB3 is held, when the internal combustion engine is started again, the vehicle-mounted storage battery voltage V
The voltage difference between B and the control command value VB1 can be reduced. In addition, in the above-described example, the voltage difference between the on-vehicle storage battery voltage VB and the control command value VB1 is corrected according to the operating state, but the arithmetic processing circuit 8 for controlling the driving operation of the internal combustion engine is incorporated. Timing (eg,
It is also possible to make a correction every 2 seconds. This is because the correction cycle is accelerated by reducing the voltage difference between the vehicle-mounted storage battery VB and the control command value VB1 and advancing the fetch timing. When the engine is stopped in this state, the voltage difference ΔVB3 is held and the voltage difference ΔVB3 is controlled when the engine is started again, as shown in the above-mentioned flowchart. The voltage difference can be reduced by performing the correction process. In the above-mentioned example, the voltage difference is corrected according to the change of the operating state,
The arithmetic processing circuit 8 for controlling the driving operation of the internal combustion engine 1 can also perform the correction processing every 2 seconds, for example, and the faster the correction processing, the better control can be performed.

Here, another embodiment will be described with reference to FIGS. Since the reference voltage V0 has a voltage change characteristic with respect to a temperature change, assuming that the reference voltage V0 has a characteristic as shown in FIG.
In, there is a proportional relationship. Therefore, it becomes possible to correct the control command value VB1 corresponding to the target generated voltage command value P by determining the temperature condition and the like in the internal combustion engine 1. Therefore, the relationship between the duty ratio (DUTY) of the power generation voltage command value P shown in FIG. 6 and the target power generation voltage is set in consideration of the temperature characteristic of the reference voltage V0 shown in FIG.
With reference to the temperature T0 (normal temperature) as shown in FIG. 1, when the temperature rises to T1, the reference voltage is that V0 drops to V1 and the target power generation voltage corresponding to ΔVT1 drops to normal temperature. Is equal to

On the contrary, if the temperature drops to T2, the reference voltage becomes equal to that V0 rises to V2 and the target generated voltage corresponding to ΔVT2 rises with respect to the room temperature.

As described above, when the reference voltage has the temperature characteristic, the variation of the target generated voltage with respect to the temperature change can be calculated as can be seen from FIG. Therefore, the correction processing can be performed by calculating the fluctuation amount of the reference voltage with respect to the temperature change in the calculation processing circuit 8 and calculating the control command value VB1 based on the fluctuation amount. Therefore, the liquid temperature of the vehicle-mounted battery, the temperature of the intake air, or the like can be used as the means for determining the temperature condition, but here, as will be described later, as an example of the control system, control using the cooling water temperature is performed. Will be described.

Here, if the operation relationship of the TR drive circuit 504 shown in FIG. 3 is supplementarily described based on the timing chart of FIG. 13, TR is driven by the voltage of the S terminal until the signal P is input. The generated voltage is kept constant. When the signal P is input at the timing x, the TR and FD connection terminal operations change as shown in the figure. Therefore, the field current IF increases and, as a result, the power generation voltage increases. Here, if the temperature rises to T1 at timing y, the reference voltage V0 drops to V1 as shown in FIG. 10, so that the TR and FD connection terminal operations change as shown in the figure. . Therefore, the field current IF decreases and the generated voltage also decreases.

FIG. 12 shows a flow chart of the control system using the cooling water temperature. When the control task of the generator is started in step 1201, the voltage VB of the on-vehicle battery is loaded in step 1202, the cooling water temperature TW in the internal combustion engine 1 is loaded in step 1203, and the operation of the internal combustion engine 1 is determined in step 1204. The operating state of the vehicle equipped with the internal combustion engine 1 is determined based on information such as engine speed, intake air amount, throttle opening, air-fuel ratio, and electric load operation. Therefore, in the arithmetic processing circuit 8, the control command value VB1 according to the operating state is selected (step 1205). Here, with respect to the operating state, for example, the operating state such as an accelerating state, a decelerating state, an idling state, or the like is determined based on information such as the throttle opening or the engine speed. Determine (FIG. 8).

Thus, after the control command value VB1 is selected, the temperature condition of the reference voltage V0 is determined from the cooling water temperature TW in step 1206, and the control command value VB1 is determined.
To correct. Here, a supplementary explanation of the correction process will be made. By using the coefficient β for converting the cooling water temperature TW into the temperature of the reference voltage V0, ΔVT = V1 + ΔV / ΔT × TW × β (ΔV = V2-V1, ΔT = T1-T2), and this value ΔVT is the control command value VB.
Correction can be performed by adding 1 to the value.

Next, in step 1207, it is judged whether or not the internal combustion engine is stopped, and if it is in operation, the process returns to step 1202, and if it is stopped, step 1208.
Ends in. In the present embodiment as well, when the reference voltage has a temperature characteristic, it is possible to perform stable and favorable control by determining the temperature condition and making a correction.

Here, another embodiment will be described with reference to FIG. For example, if the generated voltage of the vehicle alternator has a voltage change characteristic with respect to the load current IL and the number of revolutions and has the characteristic as shown in FIG. 13, for example, the vehicle alternator Assuming that the load current IL is A1 when the rotation speed is N1, the voltage generated by the vehicle AC generator is V1. In the vehicle alternator having such characteristics, if the electric load of the vehicle increases to A2, the generated voltage of the vehicle alternator becomes V2, and the voltage difference ΔV1 with respect to the previous state.
Cause

When the load current IL is A1, the number of revolutions of the vehicle alternator is N1, N2, N3.
The generated voltage of the vehicle alternator is V
1, V3, V4, and voltage differences ΔV2, ΔV3 are generated with respect to the previous states, respectively. Therefore, by calculating the voltage difference of the power generation voltage of the vehicle alternator due to the change of the load current IL and the number of revolutions in the arithmetic processing circuit 8 to perform the calculation with respect to the target power generation voltage command value VB1, Correction processing can be performed. However, in the vehicle AC generator, the maximum of the load current IL changes to A3, A4, A5 as the number of revolutions of the vehicle AC generator changes to N1, N2 and N3, and the load current IL changes. When IL is larger than the maximum value, the power generation voltage of the vehicle alternator further decreases. Therefore, it is necessary to understand the maximum value of the load current IL according to the rotation speed of the vehicle alternator in performing the correction process.

Therefore, as an example of the control system for performing the correction based on the characteristics of the vehicle AC generator described above, the correction process when the rotation speed of the vehicle AC generator is N1 will be described with reference to the flowchart of FIG. explain. When the control task is started in step 1401, step 140
In step 1403, the voltage VB of the on-vehicle battery is taken in, and in step 1403, the internal combustion engine 1 is operated by information such as engine speed, intake air amount, throttle opening, air-fuel ratio, and electric load operation as means for determining the operation. Determine the operating status of a vehicle equipped with an engine. Therefore, in the arithmetic processing circuit 8, the control command value VB1 according to the operating state is selected (step 1404). here,
Regarding the operating state, for example, the operating state such as an accelerating state, a decelerating state, an idling state, or the like is determined based on information such as the throttle opening degree and the engine speed ( (Figure 8). Thus, after selecting the control command value VB1, the load current IL is calculated from the information on the electric load operation, and when the load current IL is compared with the maximum value A3 of the load current IL (step 1405), the maximum value A3 is calculated. If is larger, the output of the control command value VB1 is stopped. (Step 1409) Further, in the step 1405, the maximum value A3
When the load current IL is smaller than that, the control command value VB1 is corrected using the voltage difference ΔV1 according to the change of the load current IL (step 1406). here,
A supplementary explanation of the correction processing will be given by referring to the control command value ΔV.
The correction is made by adding the voltage difference ΔV1 to B1. Next, when the voltage difference ΔVB ′ ΔVB ′ = VB−VB ′ between the on-vehicle battery voltage VB and the voltage VB ′ held in the storage device 82 is larger than a certain allowable value (for example, 0.5V), When it is determined that the control is abnormal, the output of the control command value VB1 is stopped in step 1409. The voltage difference Δ
If VB 'is smaller than the allowable value, the on-vehicle battery voltage VB is stored in the storage device 82 as VB' (step 1408). Next, step 141
At 0, it is determined whether or not the internal combustion engine 1 is stopped. If it is operating, the process returns to step 1402, and if it is stopped, the process ends in step 1411. Here, the processing in the state where the rotation speed of the vehicle alternator is N1 has been described, but step 1 is performed even when the rotation speed changes.
Since the operating state of the vehicle is determined using the engine speed in 403, similar control can be performed. In the present embodiment, stable and favorable control can be performed by determining and correcting the load state according to the characteristics of the vehicle alternator. In the present embodiment, the correction control is performed by the load current IL of the on-vehicle battery voltage VB and the voltage difference that changes depending on the rotation speed of the vehicle alternator, but the load current IL of the on-vehicle battery voltage VB and Similar control can be performed even with a voltage ratio that changes depending on the rotation speed of the vehicle alternator.

[0041]

According to the present invention, the power generation voltage command value is constantly corrected according to the operating state of the internal combustion engine, so that the power performance and fuel efficiency of the internal combustion engine can always be stably obtained.

[Brief description of drawings]

FIG. 1 is a functional diagram of a vehicle AC generator control system according to the present invention.

FIG. 2 is an overall block diagram of the system according to the present invention.

FIG. 3 is a functional diagram of a generator according to the present invention.

FIG. 4 is a block diagram of the same voltage conversion circuit.

FIG. 5 is an operation waveform diagram of the voltage conversion circuit.

FIG. 6 is a graph showing a relationship between a power generation voltage command value and a target power generation voltage.

FIG. 7 is a flowchart of voltage correction according to the present invention.

FIG. 8 is a flowchart of stable control regarding voltage correction.

FIG. 9 is an operation waveform diagram in the control system.

FIG. 10 is a temperature characteristic diagram with respect to a reference voltage.

FIG. 11 is a graph showing a relationship between a power generation voltage command value, a target power generation voltage, and temperature.

FIG. 12 is a flowchart of a control system that performs correction based on temperature.

FIG. 13 is a graph showing the voltage / current characteristics of the vehicle alternator.

FIG. 14 is a flowchart of a control system that corrects according to the characteristics of the vehicle alternator.

15 is an operation timing chart including the transistor drive circuit in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine, 3 ... AC generator for vehicles, 4 ... On-vehicle storage battery, 5 ... Power generation control device, 8 ... Arithmetic processing circuit, 11 ... Crank shaft, 31 ... Field winding.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuji Maeda 2520 Takaba, Takata, Ibaraki Prefecture Hitachi Automotive Systems Division (72) Inventor Masakatsu Fujishita 2520 Takaba, Katsuta, Ibaraki Hitachi, Ltd. Automotive Equipment Division (72) Inventor Masahiro Sato 2477 Kashima Yatsu, Katsuta-shi, Ibaraki Pref. 3 Hitachi Automotive Engineering Co., Ltd. (72) Inventor Seiichi Kawasaki Kashima Yatsu, Katsuta-shi, Ibaraki 2477 Address 3 Hitachi Automotive Engineering Co., Ltd. (72) Inventor Takayuki Ebisawa 2520 Takaba, Katsuta City, Ibaraki Hitachi Automotive Systems Division, Hitachi Ltd.

Claims (10)

[Claims] 1. A vehicle in which an output of an AC generator driven by an internal combustion engine is charged in a storage battery, and the output of the AC generator is controlled by a target generated voltage command value determined according to a load state of the internal combustion engine. A charging system for an AC generator driven by an internal combustion engine, characterized in that the generated voltage command value is constantly corrected by closed loop control according to a voltage difference between the storage battery voltage and a target generated voltage. Control system. 2. An internal combustion engine mounted on a vehicle, an AC generator driven by the internal combustion engine to generate electric power, a storage battery charged by the electric power generated by the generator, and a voltage of the storage battery are detected. A voltage adjustment circuit that adjusts the voltage value of the storage battery to the reference voltage by comparing it with a predetermined reference voltage, and a generated voltage for variably controlling the output voltage of the AC generator according to the state of the internal combustion engine. In a vehicle charging system including an arithmetic processing circuit that generates a command value, the arithmetic processing circuit takes in the generated voltage command value and the voltage value of the storage battery, performs a function process, and responds to a voltage value corresponding to the value. A control system for an alternator driven by an internal combustion engine, which corrects the generated voltage command value so that the voltage value of the storage battery approaches the target generated voltage value. 3. The arithmetic processing circuit fetches an electric load operation signal for detecting that the electric load of the vehicle is less than or equal to a preset usage amount, and the voltage command is issued only when the usage amount of the electrical load is small. By performing a storage process of the voltage difference between the target power generation voltage commanded by the circuit and the voltage of the storage means detected by the voltage detection circuit, and by adding or subtracting the voltage difference to or from the command of the voltage command circuit, 3. The voltage of the storage means is made substantially equal to the target power generation voltage commanded by the voltage command circuit.
A control system for an alternator driven by the internal combustion engine described. 4. The arithmetic processing circuit fetches an electric load operation signal for detecting that the electric load of the vehicle is equal to or less than a preset usage amount, and the voltage command is issued only when the usage amount of the electrical load is small. By performing a storage process of the target power generation voltage commanded by the circuit and the voltage ratio of the voltage of the storage means detected by the voltage detection circuit, and multiplying and dividing the voltage ratio by the command of the voltage command circuit, 3. The control system for an AC generator driven by an internal combustion engine according to claim 2, wherein the voltage of the storage means can be made substantially equal to the target power generation voltage commanded by the voltage command circuit. . 5. The arithmetic processing circuit performs storage processing of the voltage difference only when the voltage difference is smaller than a preset value, and adds or subtracts the voltage difference to or from a command of the voltage command circuit. 3. The control system for an AC generator driven by an internal combustion engine according to claim 2, wherein the voltage of the power storage means is always made substantially equal to the target power generation voltage commanded by the voltage command circuit. 6. The arithmetic processing circuit performs storage processing of the voltage ratio only when the voltage ratio is smaller than a preset value, and multiplies and divides the voltage ratio by a command of the voltage command circuit. 3. The control system for an AC generator driven by an internal combustion engine according to claim 2, wherein the voltage of the power storage means is always made substantially equal to the target power generation voltage commanded by the voltage command circuit. . 7. A control system provided with a reference voltage that causes a voltage change with respect to a change in ambient temperature, wherein the ambient temperature is stored in the arithmetic processing circuit, and the temperature change is performed in response to a command from the voltage command circuit. 3. The internal combustion engine according to claim 2, wherein the voltage of the storage means can be made substantially equal to the target power generation voltage commanded by the voltage command circuit by adding / subtracting the voltage change amount with respect to AC generator control system driven by. 8. When the generated voltage changes according to the number of revolutions and the electric load of the vehicle due to the characteristics of the generator, the arithmetic processing circuit is:
The voltage difference between the power generation voltage before the change and the power generation voltage after the change is stored, and the voltage difference is added to or subtracted from the command of the voltage command circuit, so that the voltage of the storage means is always the voltage. The control system for an AC generator driven by an internal combustion engine according to claim 2, wherein the target generation voltage commanded by the command circuit is made substantially equal. 9. When the generated voltage changes according to the number of revolutions or the electric load of the vehicle due to the characteristics of the generator, the arithmetic processing circuit is:
By performing a storage process of the voltage ratio between the generated voltage before the change and the generated voltage after the change, and multiplying and dividing the voltage ratio by the command of the voltage command circuit, the voltage of the storage means is always The control system for an AC generator driven by an internal combustion engine according to claim 2, wherein the target generation voltage commanded by the voltage command circuit is made substantially equal. 10. The arithmetic processing circuit comprises a storage device capable of retaining data even when the power supply is cut off.
A control system for an AC generator driven by the internal combustion engine according to any one of 7, 8, and 9.