JPH04133700A - Idling speed controller for vehicle - Google Patents

Abstract

PURPOSE:To suppress fluctuation of idling speed, when an intermittent electric load is operating, by setting the time, required for varying the conduction rate to a target value, longer than the ON time of the intermittent electric load. CONSTITUTION:Upon battery voltage drop due to turn ON of an intermittent electric load, conduction rate of a switching element 18 is increased. Increasing rate of the conduction rate is limited by a gradual varying means 21. Consequently, only 2/5 of target conduction rate is reached even at a time point when the intermittent electric load is turned OFF. On the other hand, when the conduction rate exceeds over the target range, a speed varying means 24 outputs a signal for increasing the idling speed. But since the increasing rate of the conduction rate is limited by the gradual varying means 21, the idling speed increasing signal is provided only a little during ON interval of the intermittent electric load. Consequently, the idling speed increases only a little during ON interval of the intermittent electric load.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an idle rotation speed control device for a vehicle that controls the idle rotation speed of an engine when the engine is idling to maintain the charging capacity of a battery.

U Prior Art] When the electrical load increases or the battery charging capacity decreases, the generator regulator adjusts the energization rate of the excitation coil, as is clear from the relationship between the energization rate and the generator output in Figure 4. It is designed to increase the power generation capacity and prevent the battery from dying. Conversely, when the electrical load decreases or the battery charging capacity increases, the energization rate of the excitation coil is reduced to reduce the generated power and prevent overcharging of the battery.

Furthermore, in recent years, vehicle idle speed control devices have been devised for the purpose of improving engine fuel efficiency. This control device suppresses excess engine rotation during idling, and maintains an energization rate as close to 100% as possible.
tle is desirable. Specifically, when the energization rate of the excitation coil is higher than the target range, for example 100%, and current is also taken out from the battery, the idle rotation speed is increased to increase the output of the generator. , prevents the battery from dying due to over-discharge of the battery. Further, when the energization rate of the excitation coil is lower than the target range, the idle rotation speed is lowered to prevent deterioration of fuel efficiency due to excessive idle rotation.

[Problems to be Solved by the Invention] The problems of the prior art will be explained using the time chart shown in FIG.

In the conventional technology, when an intermittent electrical load of a vehicle such as a direction indicator light or an intermittent wiper is activated, the intermittent electrical load periodically repeats on and off as shown by a solid line A.

When the intermittent electric load is turned on, the regulator increases the energization rate of the excitation coil, as shown by the broken line, to prevent the battery voltage from decreasing due to power consumption of the intermittent electric load. When the energization rate of the excitation coil increases and the energization rate becomes higher than the target range, the vehicle idle rotation speed control device increases the idle rotation speed and lowers the energization rate of the excitation coil, as shown by the broken line E. Be within target range.

Conversely, when the intermittent electric load is turned off, the regulator lowers the energization rate of the excitation coil to prevent overcharging of the battery, as shown by the broken line. When the energization rate becomes lower than the target range due to a decrease in the energization rate of the excitation coil, the broken line E
As shown in , the vehicle idle rotation speed control device lowers the idle rotation speed to bring the energization rate of the excitation coil within the target range.

Then, when the intermittent electric load is activated, the above steps are repeated. In other words, when operating an intermittent electric load, the idle rotation speed is
It fluctuates greatly each time the intermittent electrical load is turned on and off.

Incidentally, when the fluctuation range of the idle rotation speed is large, the rate of change in engine sound and the rate of change in engine vibration are large, which has the problem of causing discomfort to vehicle occupants.

SUMMARY OF THE INVENTION An object of the present invention is to provide an idle rotation speed control device for a vehicle that suppresses fluctuations in idle rotation speed during operation of an intermittent electric load and provides excellent vehicle comfort.

[Means for Solving the Problems] In order to achieve the above object, the vehicle idle rotation speed control device of the present invention employs the technical means shown in FIG. 1.

The idle rotation speed control device includes an excitation coil 1a that is energized to form a magnetic field, and an armature coil 1b that generates an electromotive force by a change in the magnetic field generated by the excitation coil 1a. Alternatively, a generator 1 in which the change in the magnetic field is applied to the armature coil 1b by driving the armature coil 1b, a battery 3 charged by the power generated by the generator 1, and the power generator 8! 11 generated electricity,
Alternatively, an intermittent electric load 4 operated by the electric power charged in the battery 3 and a switching element 5a that intermittents the current flowing through the excitation coil 1a are provided, and the energization rate of the switching element 5a is determined according to the state of charge of the battery 3. a regulator 5 that changes the charging capacity of the battery 3 to keep it within a predetermined range, a rotation speed variable means 6 that changes the idle rotation speed of the engine 2, and detects the energization rate of the switching element 5a to control the switching. A control circuit 7 is provided to control the rotational speed variable means 6 so that the energization rate of the element 5a falls within a preset target range.

The regulator 5 includes a switching element 5a.
A gradual change means 5b is provided for gradually changing the energization rate when changing the energization rate. Note that this gradual change means 5b
The rate of change in the energization rate is set such that the time required to change the energization rate to the target energization rate is longer than the ON time when the intermittent electric load 4 is operated.

[Function] When the intermittent electric load of the vehicle is activated, the energization rate of the switching element changes as the intermittent electric load switches between on and off. Specifically, when the intermittent electrical load is switched from off to on, the regulator increases the energization rate of the switching element to 8! to supply the power consumed by the electrical load. Increases the power generation amount of the child coil. When increasing the energization rate of the switching element, the energization rate is gradually increased by the gradual change means of the regulator.

The rate of change of the energization rate is set such that the time for changing the energization rate to the target energization rate is longer than the ON time of the intermittent electric load.

Therefore, even when the intermittent electric load is turned on, the energization rate of the excitation coil gradually increases, and even when the intermittent electric load is turned off and turned off, the amount of increase in the energization rate is small. In other words, the range of change in the energization rate due to intermittent electrical loads can be reduced by providing a gradual change means, and the change in the output of the rotation speed variable means that changes in response to the energization rate of the regulator is also small, and the idle rotation speed can be reduced. The fluctuation range can be reduced compared to the conventional method.

U Effects of the Invention As shown in the above-mentioned effects, the present invention can reduce the fluctuation range of the idle rotational speed when operating an intermittent electrical load compared to the conventional method. Fluctuations in engine noise and engine vibration are suppressed. As a result, the comfort of the vehicle can be improved.

[Example] Next, the vehicle idle rotation speed control device of the present invention is
An explanation will be given based on an example shown in the figure.

(Refinement of the Embodiment) FIGS. 2 to 5 show an embodiment of the present invention, and FIG. 2 shows a schematic block diagram of a control device for a vehicle idle rotation speed.

The automobile includes various electrical loads 10. The electrical loads 10 include electrical loads whose power consumption is approximately constant, such as side lights, headlamps, and radios, as well as electrical loads such as direction indicators and intermittent wipers.
It consists of an intermittent electrical load whose power consumption changes periodically. The automobile is equipped with a battery 11 that supplies power to the electric load 10.

This battery 11 is charged by a generator 13 that is driven by a vehicle running engine 12 to generate electricity.

The generator 13 includes an excitation coil 1 that is energized to form a magnetic field.
4, and an armature coil 15 that generates an electromotive force by a change in the magnetic field generated by the excitation coil 14, and one of the excitation coil 14 and the armature coil 15 is connected to the engine 12.
Rotationally driven by. Note that the alternating current generated by the armature coil 15 is converted into direct current by the rectifier circuit 16 and then output to the electric load 10 and battery 11 .

The amount of power generated by the generator 13, that is, the amount of power generated by the armature coil 15, is determined by the rotational drive speed of the generator 13 and the amount of current applied to the exciting coil 14. The amount of current supplied to this exciting coil 14 is controlled by a regulator 17.

The regulator 11 includes a switching element 18 that switches on and off the current supplied to the excitation coil 14. The switching element 18 of this embodiment uses a semiconductor such as a FET or a bipolar transistor, and the switching element 18 switches between 0N-OFFL and the exciting coil 14 depending on the energization state of the gate and base.
It controls the current supplied to the

The regulator 17 detects the voltage of the battery 11,
Comparing means 20 is provided for comparing the detected battery voltage with a reference voltage set by reference voltage generating means 19 and generating a signal for increasing the energization rate of switching element 18 if the battery voltage is lower than the reference voltage. .

A signal for increasing the energization rate of the comparison means 20 is input to the gradual change means 21. The gradual change means 21 gradually increases the energization rate of the switching element 18, and when it continues to receive a signal for increasing the energization rate from the comparison means 20, the gradual change means 21 changes the on-time of the intermittent electric load (for example, The energization rate of the switching element 18 is gradually increased to the target energization rate over a period of time, for example, 5 seconds, which is set longer than the target energization rate (within 2 seconds).

In this embodiment, when the battery voltage rises above the reference voltage and the comparison means 20 stops generating the signal for increasing the energization rate, the gradual change means 21 instantly changes the energization rate of the switching element 18 to the target energization rate. Here is an example of descending to
It may be provided so that the energization rate gradually decreases.

The vehicle also includes a vehicle idle rotation speed control device 22 that controls the idle rotation speed of the engine 12 according to the energization rate of the switching element 18 .

This control device 22 includes a control circuit 23 using a microcomputer, and a speed variable means 2 that changes the idle rotation speed of the engine 12 based on a signal from the control circuit 23.
It is composed of 4.

The control circuit 23 detects the energization rate of the switching element 18, and the detected energization rate falls within a target range (for example, 70% to 90% energization rate) set in advance by the target setting means 25.
) is provided (see FIG. 4). This comparison means 26 outputs a signal to increase the idle rotation speed when the detected energization rate is higher than the target range, and conversely outputs a signal to increase the idle rotation speed when the detected energization rate is lower than the target range. Outputs a signal to lower the

The control circuit 23 includes a drive circuit 27 that provides a drive signal to the speed variable means 24, and the output signal generated by the comparison means 26 is output to the drive circuit 27.

The speed variable means 24 has a well-known structure that uses an electromagnetic actuator to change the intake air amount of the engine 12 to change the idle rotation speed of the engine 12, and the electromagnetic actuator is controlled by the drive circuit 27. .

Next, an example of the operation of the comparison means 26 of this embodiment will be explained based on the flowchart of FIG.

First, in step S1, it is determined from the throttle opening degree, vehicle speed, etc. whether the engine 12 is in an idle state. If the result of this determination is NO, the process returns to step S1. Further, if the determination result is YES, step S2
In step S3, the energization rate of the switching element 18 is read, and in step S3, it is determined whether the energization rate of the switching element 18 is higher than 90%. If the determination result is YES, the energization rate of the switching element 18 is higher than the target range, so in step S4, a signal to increase the idle rotation speed by a predetermined amount (for example, 10 ppm) is output to the drive circuit, and the process returns.

If the determination result in step S3 is NO, step S5
In this step, it is determined whether the energization rate of the switching element 18 is lower than 70%. If the result of this judgment is YES, since the energization rate of the switching element 18 is lower than the target range, in step S6, a signal for lowering the idle rotation speed by a predetermined amount (for example, 10 rpm) is output to the drive circuit, and the process returns.

If the determination result in step S5 is NO, the energization rate of the switching element 18 is within the target range, so there is no need to change the idle rotation speed, and the process returns as is.

(Operation of Embodiment) The operation of the vehicle idle rotation speed control device 22 shown above will be explained using the time chart of FIG. 5.

When a certain intermittent electrical load operates, as shown by solid line A,
The intermittent electrical load is turned on for 2 seconds and turned off for 2 seconds, repeating the cycle.

When the battery voltage decreases due to the intermittent electrical load being turned on, the regulator 17 increases the energization rate of the switching element 18. The rate of increase in the energization rate at this time is suppressed by the gradual change means 21.

Therefore, as shown by solid line B, even when the intermittent electrical load is switched from on to off, the target energization rate is
15 can only reach so many places.

On the other hand, when the energization rate of the switching element 18 increases and the energization rate of the switching element 18 becomes higher than the target range, the control circuit 23 gives the speed variable means 24 a signal to increase the idle rotation speed.

However, since the increase in the energization rate of the switching element 180 is suppressed by the gradual change means 21, only a small amount of the signal for increasing the idle rotation speed is received during the on-time of the intermittent electric load. Therefore, as shown by solid line C,
While the intermittent electrical load is on, the idle rotation speed is too low.
Yu doesn't rise.

Conversely, when an intermittent electrical load changes from an on state to an off state,
When the battery voltage increases, the regulator 17 lowers the energization rate of the switching element 18 and the excitation coil 14 to reduce the power generation of the generator 13, thereby preventing overcharging of the battery 11.

When the energization rate of this switching element 18 becomes low,
The energization rate of the switching element 18 is lowered to the target energization rate. When the energization rate of the switching element 18 becomes lower than the target range, the control circuit 23 gives a signal to the speed variable means 24 to lower the idle rotation speed, and the idle rotation speed is reduced to an appropriate rotation speed.

The above is then repeated during operation of the intermittent electrical load.

(Effects of Example) In this example, as shown in the above operation, even if the intermittent electric load is activated and repeatedly turns on and off, the idle rotation speed does not vary greatly. As a result, fluctuations in engine noise and engine vibration that occur during intermittent electric load operation are suppressed compared to conventional systems, and the comfort of the vehicle is improved.

Note that the rotation speed variable means 24 and this rotation speed variable means 2
In some cases, the circuit controlling 4 is provided with means for gradually changing the idle rotation speed in order to prevent the idle rotation from hunting. However, the rotational speed variable means 24 also serves as a boat fishing device and an air conditioner idle-up. Rotation speed variable means 24 and this rotation speed variable means 2
If the circuit controlling 4 is provided with means for gradually increasing the idle rotation speed over a period longer than the ON time of the intermittent electric load, which corresponds to the gradual change means 21 of the present invention, the responsiveness of idle up will deteriorate. If the idle-up response is poor, the electrical load increases rapidly during idle, and when the energization rate of the excitation coil suddenly increases and the generator drive torque increases rapidly, the idle rotation speed decreases and the engine This causes the inconvenience of stalling. For this reason, it is not possible to provide the rotational speed variable means 24 or the circuit that controls the rotational speed variable means 24 with a means for gradually increasing the idle rotational speed, which corresponds to the gradual change means 21 of the present invention.

Furthermore, the numerical values shown in the examples are for explanation purposes only, and the present invention is not limited to the numerical values in the examples.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an outline of the invention. 2 and 3 show an embodiment, in which FIG. 2 is a schematic block diagram of a vehicle idle rotation speed control device, and FIG. 3 is a flowchart 1-2 showing the operation of the control circuit. The figure is a graph showing the relationship between the generator output and the engine rotational speed and the energization rate of the excitation coil, and FIG. 5 is a time chart for explaining the operation. In the diagram 1a... Excitation coil 1b... Armature coil
1... Generator 2... Engine 3... Battery
4 ・Intermittent electric load 5a...Switching element 5
b...Gradual change means 5...Regulator 6.Rotation speed variable means 7...Control circuit Figure 1 1a Excitation coil/starter 3...Battery 5a/Switching element 5...Regulator 7 Control circuit 1b - Armature coil 2 - Engine 4 - Intermittent electric load 5b - Gradual change means 6 - Rotation speed variable means Fig. 3

Claims (1)

[Scope of Claims] 1) (a) An excitation coil that is energized to form a magnetic field, and an armature coil that generates an electromotive force by changes in the magnetic field generated by the excitation coil; (b) a battery that is charged by the power generated by the generator; (c) power generation by the generator; an intermittent electric load operated by the electric power charged in the excitation coil or the electric power charged in the battery; and (d) a switching element that intermittents the current flowing through the excitation coil, and the switching element operates according to the state of charge of the battery. a regulator that maintains the charging capacity of the battery within a predetermined range by changing the energization rate; (e) a rotation speed variable means that changes the idle rotation speed of the engine; (f) detecting the energization rate of the switching element; , a vehicle idle rotation speed control device comprising: a control circuit that controls the rotation speed variable means so that the energization rate of the switching element falls within a preset target range; (d-1) The regulator includes a gradual change means that gradually changes the conduction rate when changing the conduction rate of the switching element, and the rate of change of the conduction rate by the gradual change means is determined by the time required to change the conduction rate to the target conduction rate. is set to be longer than the ON time when the intermittent electric load is activated.