JPH0310017B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to an engine rotation control device that detects the current or voltage of a field coil of a generator and controls the engine rotation speed in accordance with an increase in electrical load.

BACKGROUND ART In general, a generator for an automobile is equipped with a generator having optimal performance so that a battery can be charged when using a predetermined electrical load even when the engine is idling. Normally, a generator is equipped with a voltage regulator, which controls the amount of charge according to the discharge state of the battery and prevents the battery from overcharging. It changes depending on the usage status of the load, and the output of the engine that drives the generator also changes in proportion to it. This change does not pose a particular problem under normal engine operating conditions, but during light load operation such as idling, the engine rotational speed increases due to the engine's own friction and the increased power consumption for driving auxiliary equipment. This can lead to engine malfunction.

Also, if a relatively large load from an auxiliary device (such as a compressor) is applied during idling, the engine speed will drop depending on the size of the load, and due to the characteristics of the alternator near idling speed, the engine speed will drop. In this case, the output current of the generator also decreases. In this case, in order to supply the current required to drive the engine and sufficient current for other electrical loads (including battery charging current), it is necessary to increase the conductivity of the constant voltage regulator to increase the power generated by the generator. However, this also increases the engine load, and as a result, does it stabilize when the engine speed decreases from the initial setting? (Actually, as the engine speed decreases, the generated torque also decreases, so from the engine side. The load on the generator becomes overloaded and stabilizes when it drops further from the initial setting), and the rotation also fluctuates, which may even lead to the engine stopping.

As a countermeasure, the conventional method is to use sensors to detect the application status of all electrical and mechanical loads connected to the engine load for each load, and to forcibly increase the engine's idle speed when the load is applied. I try to take it. However, taking such a measure creates manufacturing complexity such as sensors for each load, their mounting members, and wiring, and also increases or decreases in engine friction due to auxiliary equipment, etc., and increases or decreases over time. There are various drawbacks such as not being able to obtain the specified engine speed due to changes in the engine speed, shortening the life of the battery as it increases the amount of power generated by the generator regardless of the battery status, and further worsening fuel efficiency. It's becoming something.

Purpose The present invention was made in consideration of the above points, and
Either the generator output changes uniquely in response to electrical load fluctuations, or the engine speed decreases when the mechanical load increases, so that the generator output approaches the limit output at that reduced speed. By monitoring the increase in excitation current, the system indirectly detects engine load fluctuations and ensures optimal engine rotation according to electrical and mechanical loads. The purpose of the present invention is to provide an engine rotation control device that can perform the following functions.

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

In the engine rotation control device according to the present invention, as shown in FIG. 1, as a power source for a load 1,
battery 2 and connected in parallel to the battery 2,
In an engine power supply system consisting of a generator 4 driven by an engine 3 and a constant voltage regulator 5 that adjusts the voltage by adjusting the excitation depending on the output of the generator 4, the constant voltage regulator is used. Field voltage V _F of generator 4 whose conduction is controlled by
is detected by the D/A converter (f/V converter) 6, and the load condition is determined by the judgment circuit 7 according to the change in the field voltage _VF , and the engine rotation is determined based on the judgment result. The control unit 9 is provided with a control unit 9 which appropriately gives a drive command to the actuator 8 which adjusts the number of actuators.

FIG. 2 shows an example of the configuration of the actuator 8, in which the first and second stage solenoid valves 13 and 14 are driven by a drive command given from the judgment circuit 7, and the diaphragm 15 is Negative pressure is applied to the first chamber 151 and the second chamber 152, and the opening degree of the engine throttle 16 is changed in stages via the output shaft of the diaphragm 15. Note that P _B in the figure indicates a negative pressure source.

The operation of the engine rotation control device configured as described above will be described below when the engine rotation speed is controlled to be changed in two stages in response to load fluctuations.

Assume now that the field voltage V _F of the generator 4 detected by the D/A converter 6 in the control unit 9 changes as shown in FIG. 3 depending on the load condition.

In the same figure, the field voltage V _F of generator 4 during no-load idling is set at the lower limit of 7.
When the engine 3 is stable at idling speed (V) and in the no-load idling speed range, when the first load is applied at time t ₁ , the field voltage V _F
increases, and when it reaches the upper limit setting value 12 (V) preset in the judgment circuit 7, the judgment circuit 7 issues a first-stage drive command to the actuator 8 at time _t2 , and as a result, The first stage of increasing the rotational speed of the engine 3 is executed. Note that the judgment circuit 7
Inside are the field voltage V _F and the lower limit setting voltage 7.
(V) and the upper limit set voltage 12 (V), respectively, and generate matching outputs, and each comparator output is held and each drive command for the first stage and second stage is given to the actuator 8. Two latches are provided, and at time t ₂ , as shown in FIG.
The output becomes “H” and it is the first stage latch A.
The output of the lower limit comparator B is "L" and the content of the latch B is "L".

Next, even when the first step of increasing the rotation speed is executed, the field voltage V _F does not immediately drop due to the response delay, and after it reaches the upper limit setting voltage 12 (V) or higher, the field voltage V _F gradually decreases, and at time t ₄ , the field voltage V _F is approximately 7.5 (V)
The rotational speed stably enters a rotational speed region that is balanced with the first load. Note that at this time, the field voltage V _F is
Since the overload state during the period _t2 to _t3 , which is at 12 (V) or more, is within the preset time T _D (for example, 1 second), the judgment circuit 7 determines that the overload state at that time is not a problem. It is judged as.

Next, at time t ₅ , a second load is further applied, and the field voltage V _F increases accordingly and reaches the upper limit set voltage 12 (V) at time t ₆ . A second drive command is issued, thereby increasing the engine 3's rotational speed to the second stage. At this time, the output of the upper limit limiting comparator A becomes "H" again, and this is held in the second stage latch B. Therefore, as in the previous case, the field voltage V _F
exceeds 12 (V) for a short period of time, then decreases, and t ₈
At this point, the voltage between the first load and the second stabilizes at approximately 8 (V).
The engine enters a rotational range in equilibrium with a load applied.

Next, at time t _{9 , when the first and second loads are removed and a no-load state occurs, the field voltage V F decreases .} Set lower limit setting value 7
(V), the second-stage drive command that had been issued to the actuator 8 from the determination circuit 7 is turned off, and the second-stage rotational speed up state is released. Note that at time _t10 , the output of lower limit comparator B has become "H" and the output of second stage latch B has become "L", and at this point the output of first stage latch A is still low. It is held at "H".

Next, after canceling the high rotational speed state in the second stage,
A certain period of time that is set in the judgment circuit 7 after the field voltage V _F reaches 7 (V) or less
When the voltage rises to 7 (V) again within T _D and becomes stable, the output of the first stage latch A in the judgment circuit 7 becomes "L" at the time t ₁₁ , when the time T _D has elapsed, and the output up to that point becomes "L". The first-stage rotational speed increase state is released, and the engine 3 is thereby maintained in an unloaded idling state. In addition, in that case, within a certain time T _D , 7
(V), and when the field voltage V _F rises after entering, it reaches 8 (V) or more as shown by the dotted line in the figure, and then it decreases again and t ₁₂ after T _D time has passed. When the voltage reaches 7 (V) at the time, the judgment circuit 7 immediately cancels the first stage rotational speed up state at the time _t12 .

Next, at time t ₁₃ , the third load is applied again,
As a result, when the field voltage V _F rises and reaches the upper limit set value 12 (V), the first stage of rotation up is executed at time _t14 in exactly the same manner as in the previous case. At this time, if the period of overload state in which the field voltage V _F increases to 12 (V) or more due to the inrush of the field voltage continues for more than the set time T _D , the judgment circuit 7 determines that the set time T _D has elapsed. At time ₁₅ , a second-stage drive command is given to the actuator 8, thereby causing the second-stage rotation speed increase to continue. Similarly, control of increasing and decreasing the rotational speed is performed in stages as the load changes.

In addition, in FIG. 3, the upper limit comparator A
is designed to produce an "H" level output from when the field voltage V _F reaches 12 (V) until it drops to 11 (V), and the lower limit comparator B is set so that the field voltage V _F is 7 (V). The "H" level output is generated from when the voltage reaches 8 (V) until it rises to 8 (V).

Figure 4 shows the rotational speed N of the engine 3 and the field voltage V _F of the alternator 4 with respect to the load current.
Normally, the characteristics of N ₀ and V _F0 change to the characteristics of N ₁ and V _F1 due to the increase in the rotation speed of the engine 3 in the first stage. As the temperature increases, the characteristics gradually shift to those of N ₂ and V _F2 . Therefore, in the characteristics shown in Fig. 4, when the load current increases from point a to 10 (A) at point b, the first stage of rotation speed is increased at point b, so that V _F0 = 12 ( V) to V _F1 = 7.5 (V),
It will be switched from N ₀ = 560 (rpm) to N ₁ = 690 (rpm). In addition, when the rotation speed is increased in the first stage, the load current is = 16 (A).
When increasing to , V _F1 = 12 (V), N ₁ = 620 at point d
By increasing the rotational speed to the second stage (rpm), the switching is made to V _F2 =8 (V) and N ₂ =750 (rpm). Note that point a in the figure indicates the time of no-load idling. V _F0 = 7 (V), N ₀ =
It is set to 650 (rpm). Further, point c indicates the power generation limit point of the generator 4, and when a load current greater than or equal to point c is required, current is also supplied from the battery 2 to the load.

FIG. 5 shows a specific example of the circuit configuration of the control unit 9.
a first comparator 71 (corresponding to the above-mentioned comparator B) that compares the field voltage V _F of the generator 4 detected by the D/A converter 6 with a lower limit setting value (7V); A comparator section consisting of a second comparator 72 (corresponding to the above-mentioned comparator A) that compares the field voltage V _F and the upper limit set value (12V), and each of the comparators 71 and 7
A monostable multivibrator 73 that is triggered in response to the output of 2 and generates a control clock, and a timer 7 that delays the trigger output by a fixed time T _D
4. A clock control section consisting of a monostable multivibrator 75 triggered by the delayed output of the timer 74, and a negative signal of the output of the first comparator 71 as the D input, and a clock according to the clock from the clock control section. first and second flip-flops which hold the contents and drive a solenoid 81 for increasing the first stage rotation speed and a solenoid 82 for increasing the second stage rotation speed in the actuator 8 according to the held contents. 76 and 77 (corresponding to the aforementioned latches A and B). Note that the flip-flop 77 is not reset unless the Q output of the flip-flop 76 becomes "H", and the set input terminal of the flip-flop 77 is grounded so that the flip-flop 76 is set by its Q output. When the comparator 72 first generates an "H" level output, the flip-flop 76 first enters the operating state according to the clock from the clock control section, and the next comparator 72 enters the operating state first.
When the flip-flop 77 outputs a "H" level, the flip-flop 77 subsequently enters the operating state, and when the output of the comparator 71 reaches the "H" level, only the flip-flop 77 brings its Q output to the "L" level. There is. Further, the solenoid 81 for increasing the rotation speed of the first stage is energized according to the Q output of the flip-flop 76, and the solenoid 82 for increasing the rotation speed of the second stage is activated by the AND of the Q output of the flip-flop 76 and the Q output of the flip-flop 77. It is expected that it will be energized in anticipation of its establishment. Furthermore, the monostable multivibrator 73 in the clock control section receives the negation signal of the output of the comparator 71 and the output of the comparator 72.
It is designed to be triggered by an _OR signal with the output of A control clock is provided to the flip-flops 76 and 77. In the figure, 78 is a circuit for giving a set command to the monostable multivibrators 73, 75 and the timer 74 and a reset command to the flip-flops 76, 77 when the power is turned on. In addition, this judgment circuit 7 includes:
A circuit 79 is provided for forcibly deenergizing the second stage solenoid 82 in the actuator 8 when the gear position canceler switch SW1 is turned on and the idling state of the engine is released. Furthermore, the cancel switch SW in the fuel cut fully closed unit
A circuit 80 is provided for forcibly deenergizing each of the first and second stage solenoids 81 and 82 in the actuator 8 when the engine is turned on and the fuel supplied to the engine is cut off. ing.

Note that the engine rotation control device according to the present invention is not limited to the case where the two-stage rotation speed increase control is performed as described above, but can also be applied to changes in the field voltage of the generator 4 according to load fluctuations. Needless to say, it is also possible to similarly perform rotational speed increase control in n stages (n=1, 2, 3, . . . ).

FIG. 6 shows another configuration example of the control unit 9, in which the field voltage V _F of the generator 4 detected by the D/A converter 6 is compared with the upper limit set value (12V). A solenoid 12 for increasing the rotation speed of the actuator is activated by a driver 11 according to the matched output.
I'm trying to energize it. In addition, by applying an external load (for example, an air conditioner) signal, the output side of the comparator 10 is grounded, the solenoid 12 is forcibly energized, and the fuel cut fully closed unit is When the cancel signal is applied, the driver 11 is forcibly turned off and the solenoid 1 is turned off.
2 can be deactivated. Therefore, the rotation speed increase control in this case is a pumping control based only on the upper limit limit of the field voltage of the generator 4.

Effects As described above, the engine rotation control device according to the present invention includes a first means for detecting a field current or a field voltage in a generator having a regulator that controls charging of a battery, and a first means for detecting a field current or a field voltage in a generator having a regulator for controlling charging of a battery, and a first means for detecting a field current or a field voltage in a generator having a regulator for controlling charging of a battery. a second means for determining that the set value has been reached and issuing an engine rotation control command; and a third means for raising or lowering the engine speed by a certain amount, and in the second means, after the detected value temporarily reaches the upper limit or lower limit set value and the engine speed is raised or lowered to a predetermined value. , it is determined that the detected value has not yet fallen below the upper limit set value even after a preset time has elapsed, or that it has not stabilized at the lower limit set value, and when that time has elapsed, the next step is performed. to issue an engine rotation control command to cause the engine rotational speed to increase to a predetermined level in the next step, or to cause the engine rotational speed to decrease to a predetermined level at the next stage immediately after the detected value stabilizes at the lower limit set value. It is characterized by the fact that each load state is centrally monitored by looking at changes in the field voltage of the generator, instead of monitoring the application state of each load individually as in the past. It is possible to perform optimal engine idle up control according to fluctuations, increasing engine speed according to load conditions,
It is an excellent engine that can perform variable control of descent in multiple stages with high precision, and can perform variable control of engine speed according to load fluctuations quickly and appropriately without causing a response delay. It has advantages.

[Brief explanation of the drawing]

FIG. 1 is a circuit configuration diagram showing an embodiment of the idle up control system for a gasoline engine according to the present invention, FIG. 2 is a simplified diagram showing an example of the configuration of an actuator in the same embodiment, and FIG. 3 is a schematic diagram showing an example of the configuration of an actuator in the same embodiment. A time chart to explain engine idle up control operation in response to changes in alternator feed voltage. Figure 4 shows the engine speed and alternator feed voltage relative to load current when two-stage idle up control is implemented. FIG. 5 is a specific circuit diagram of a control unit for performing two-stage idle up control in the same embodiment, and FIG. 6 is a one-stage idle up control in the same embodiment. FIG. 2 is a specific circuit diagram of a control unit for performing the following steps. 1... Load, 2... Battery, 3... Engine, 4... Alternator, 5... Constant voltage regulator, 6... D/A converter, 7... Judgment circuit, 8
...Actuator, 9...Control unit.

Claims (1)

[Claims] 1. A first means for detecting field current or field voltage in a generator having a regulator that controls battery charging, and comparing the detected value with a preset upper or lower limit setting value to reach the set value. a second means that issues an engine rotation control command based on a determination that the engine speed has changed, and a third means that increases or decreases the engine rotation speed by a predetermined amount in multiple stages in response to the command; In the second means, after the detected value temporarily reaches the upper limit or lower limit set value and the engine speed is increased or decreased to a predetermined value, the detected value remains the upper limit set value even after a preset time has elapsed. It is determined that the engine speed is not below the lower limit set value, or that it is not stable at the lower limit set value, and when that time has elapsed, the engine speed is increased to a specified level in the next stage, or the detected value is the lower limit set value. 1. An engine rotation control device characterized in that, as soon as the engine rotation speed becomes stable at a set value, an engine rotation control command is issued to cause the engine rotation speed to decrease by a predetermined value in the next stage.