JPS63297744A - Idle revolution speed control for engine and device thereof - Google Patents

Abstract

PURPOSE:To permit the idle revolution speed control with high precision by controlling the generated electric power of an alternator according to the control instruction value which is formed by adding the correction instruction value with the average generated electric power control instruction value for holding the battery voltage at a prescribed value, when idle revolution is detected. CONSTITUTION:An alternator 14 all-water-rectifies the three-phase ac generated in a stator coil 18 by a rectifier 20 and supplied said electric current into a battery 12 and an electric load 10. In this case, one edge of the rotor coil 16 of the alternator 14 and the anode of a diode 17 are connected with the collector of a transistor 1 which is turned-ON/OFF according to the output of the pulse width modulation circuit 22 of an exciting current setting means 24. When the idle state is detected by an idle state detecting means 40, the output of an adder 30 which adds the signal after the integration processing 32 of the output of a battery voltage comparing circuit 28 and a revolution speed correction instruction signal supplied from a deviation detecting circuit 36 is selected by a selecting switch 26 and input into the exciting current setting means 24.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an engine idle rotation speed control method and apparatus, and more particularly to an engine idle rotation speed control method and apparatus for stabilizing the idle rotation speed at a substantially constant speed. related to

[Conventional technology]

As a rotational speed control device for keeping the idle rotational speed of the engine constant, a device for controlling the amount of air in a bypass passage that bypasses the throttle valve, a device for controlling the amount of fuel injection, etc. have been proposed. The fuel control system disclosed in Japanese Patent No. 201936 corrects the fuel injection amount for each cylinder so that the engine rotation speed for each cylinder approaches the average rotation speed for all cylinders. However, with such devices that control the fuel or air amount, although the results appear after controlling the fuel or air, there is a delay in the processes such as suction, compression, and explosion, resulting in a lack of quick response and insufficient The problem is that it does not have a significant stability effect.

On the other hand, as a device other than an engine idle speed control device that controls the amount of air and an engine idle speed control device that controls fuel, there is a device that controls the engine that controls the alternator, as shown in Japanese Patent Laid-Open No. 61-104130. Idle rotation speed @ There is a control device.

This is designed to prevent a momentary drop in engine speed caused by the alternator when an electrical load is applied during idling operation. It was intended to maintain the permissible limit value for a predetermined period of time.

[Problem that the invention seeks to solve]

However, although this device is effective in preventing rotation fluctuations when an electrical load is applied, it does not take into account irregular rotation fluctuations or rotation fluctuations that are on the verge of overshooting when transitioning from racing to idle. Therefore, it cannot be said that the idle stability is sufficient.

The present invention has been made in view of the above points, and an object of the present invention is to provide an engine idle rotation speed control method and apparatus that have excellent idle stability against rotation fluctuations.

[Means for Solving the Problems] (Part 1) To achieve the above object, the first invention provides an engine equipped with an engine-driven alternator that supplies power to an electrical load or charges a battery. In order to control the idle rotation speed of the engine, the engine rotation speed is detected and the idle operating state of the engine is detected, and the rotation speed signal is set to the average generated power control command value that maintains the battery voltage at a predetermined value when the idle state is detected. The present invention is characterized in that the power generated by the alternator is controlled by adding a rotational speed correction command value determined so as to reach a target rotational speed.

[Means for Solving the Problems] (Part 2) To achieve the above object, the second invention provides an engine equipped with an engine-driven alternator that supplies power to an electrical load or charges a battery. The idle rotation speed control device includes a rotation speed detection means for detecting the rotation speed of the engine, an idle state detection means for detecting the idle operating state of the engine, and a battery when the idle state detection means detects the idle state. The average generated power that maintains the voltage at a predetermined value is determined by adding a rotational speed correction command value determined such that the rotational speed signal detected by the rotational speed detection means becomes the target rotational speed to the control command value, and the alternator generates electricity. A generated power control means for controlling electric power is provided.

[Effect]

According to the present invention, when the engine is determined to be in an idle state by the idle state detection means, the generated power control means of the alternator determines that the rotation speed signal detected by the rotation speed detection means becomes the target rotation speed. A generated power control command value that determines an increase or decrease in the generated power of the alternator is determined based on the rotational speed correction command value, and generated power control is performed in accordance with this control command value. Therefore, by controlling the power generated by the alternator, the engine load can be controlled, and engine rotation fluctuations can be controlled.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a block diagram of an engine idle speed control device according to a first embodiment. As shown in the figure, one end of vehicle electrical equipment (electrical load) 10 and battery 1
The second anode is connected to the output terminal B of the alternator 14. This alternator 14 is the rotor coil 1 of the rotor.
Magnetic flux is generated in the rotor by applying an excitation current to the stator coil 18, and as the rotor is rotated based on the rotational speed of the engine, a power generation action occurs in the stator coil 18, generating three-phase alternating current. This three-phase alternating current is full-wave rectified by a rectifier 20 and output to an output terminal B.

One end of the rotor coil 16 is connected to the output contact B and also to the cathode of the diode 170. The other end of the rotor coil 16 and the anode of the diode 17 are connected to the collector of a transistor T,1 which is turned on and off in response to the output of the pulse width modulation circuit 22. The emitter of the transistor T,1 is grounded and the base is connected to the pulse width modulation circuit 22.

This pulse width modulation circuit 22 and the transistors T, 1- constitute excitation current setting means 24, and the duty ratio of the transistors T, 1 is controlled by the pulse width modulation circuit 22.

A contact C of a changeover switch 26 having contacts c, b, and a is connected to the input side of the excitation current setting means 24. Contact a of this changeover switch 26 is connected to the battery voltage comparison circuit 28.
The anode of the battery 12 is connected to the anode of the battery 12 via the anode.

This battery voltage comparison circuit 28 outputs an L (Low) signal when the voltage of the battery 12 is higher than a specified value (adjusted voltage), and outputs an H (High) signal when the voltage of the battery 12 is lower than the specified value. The control command signal ■ is output to contact a.

A contact point of the changeover switch 26 is connected to an adder 30. This adder 30 is connected via an integrator 332 to a connection line between the battery voltage comparator circuit 28 and contact a.

Therefore, the HSL signal from the battery voltage comparator circuit 2B is converted into a DC voltage by the integrator 32, and a control command signal that brings the voltage of the battery 12 to a specified value is input to the adder 30.

Further, a deviation detection circuit 36 is connected to the adder 30 via a gain adjuster 34. The deviation detection circuit 36 is connected to an engine rotational speed detection means 38 . Therefore, a rotational speed signal synchronized with the crank angle from the engine rotational speed detection means 38 is input to the deviation detection circuit 36, and the rotational speed signal and the target rotational speed of the idle rotational speed set in advance by the deviation detection circuit 36 are input. This deviation signal is subjected to PID control by a gain adjuster 34, and a rotational speed correction command signal is input to an adder 30.

Therefore, the adder 30 synthesizes the input control command signal and the rotational speed correction command signal and outputs the control command signal (2) to the contact. This control command signal ■ is an analog voltage,
The higher this voltage is, the higher the duty ratio, that is, the transistor T
Control is performed to lengthen the on-time of ri, and the excitation current is controlled.

Further, the changeover switch 26 is linked to an idle state detection means 40, so that when the state is other than the idle state, the contact C is connected to the contact a, and when the state is idle, the contact C is connected to the contact A. It has become.

The operation of the engine idle rotation speed control device of the first embodiment configured as described above will be explained.

When the idle state detecting means 40 detects that the vehicle is not in the idle state, the contact C of the changeover switch 26 is connected to the contact a. Then, the excitation current setting means 24 is controlled by the control command signal I.

That is, the excitation current setting means 24 is controlled based on the t(, L signal from the battery voltage comparison circuit 2B, and transistors T and l are turned off while the battery voltage is above the adjustment voltage, and conversely, when the battery voltage is below the adjustment voltage During this time, the transistors T and 1 are turned on.As described above, in operating states other than idling, the alternator 14 acts as a power supply means by a known voltage regulation function.

On the other hand, when the idle state detection means 40 detects the idle state, the contact C of the changeover switch 26 is connected to the contact S. Then, the excitation current setting means 24 is controlled by the control command signal ■. In other words, the excitation mt is generated by the control command signal ■ which is a combination of a control command signal such that the battery voltage becomes the regulated voltage by the adder 30, and a deviation signal between the rotation speed signal from the rotation speed detection means 38 and the target rotation speed.
The generated power is controlled by controlling the duty ratio of the transistors T, 1 of the current setting means 24. That is, when the idle rotational speed is faster than the target rotational speed, the alternator generates electricity while the battery voltage is maintained at the regulated voltage, increasing the mechanical load on the engine. Then, the idle rotation speed is controlled to become slower and reach the target rotation speed. Furthermore, when the idle rotation speed is lower than the target rotation speed, the battery voltage is maintained at the regulated voltage and the power generation of the alternator is reduced to reduce the mechanical load on the engine.

Then, the idle rotation speed increases and is controlled to reach the target rotation speed. As a result, rotational speed control is performed to maintain the idle rotational speed at the target value while maintaining a predetermined battery voltage.

FIG. 2 shows a block diagram of an engine idle speed control device according to a second embodiment.

As shown in the figure, the output terminal B of the alternator 14 is connected to the collector of the transistor T, 2 of an output current setting means 50 consisting of the transistor T, 2 and the pulse width modulation circuit 22. The emitter of the transistor T,2 is connected to the anode of the battery 12 and the electrical load 10, and the base is connected to the pulse width modulation circuit 22. A relay 52 is connected in parallel to this transistor T,2.

The duty ratio of the transistors T, 2 is controlled by the pulse width modulation circuit 22, and the control command is given using an analog voltage. Here, control is performed such that the higher the voltage, the longer the duty ratio, that is, the on-time of the transistors T and 2.

On the other hand, one end of the rotor coil 16 of the alternator 14 is connected to the output terminal B and also to the cathode of the diode 17. The other end of rotor coil 16 and the anode of diode 17 are connected to the collector of transistor T,1. The emitter of the transistor T,1 is grounded, and the base is connected to a contact C of a changeover switch 26 with contacts c, b, and a.

Contact a of the changeover switch 26 is connected to the battery 1 via a resistor R.
The contact point is connected to the anode of battery voltage comparator circuit 2.
8 to the anode of the battery 12. An integrator 3 is connected to the connection line between the contact and the battery voltage comparison circuit 28.
An adder 30 is connected via 2. Further, to this adder 3o, a rotation speed detection means 38 is connected via a gain adjuster 34 and a deviation detection circuit 36, and a contact e of a changeover switch 54 having contacts eS f and d is connected. There is. A contact r of the changeover switch 54 is grounded, and a contact d is connected to the pulse width modulation circuit 22.

The relay 52 and the changeover switches 26 and 54 are linked to the idle state detection means 40, and when the state is other than the idle state, the contact g of the relay 52 is connected to the contact point G, and the contact point C of the changeover switch 26 is connected to the contact point 40. are connected, and contacts d and f of the changeover switch 54 are connected. In addition, in the case of an idle state, the contact g and the contact of the relay 52 are opened, and the contact C of the changeover switch 26 is opened.
and contact a are connected, and contacts d and e of the changeover switch 54 are connected.

The operation of the engine idle rotation speed control device of the second embodiment configured as above will be explained.

When it is detected that the idle state is not in the idle state by the idle state detection means 40, the contacts g and 2 of the relay 52 connected in parallel to the transistors T, 2 of the output current setting means 50 are connected. Changeover switch 5
Contacts d and f of No. 4 are connected. Therefore, the transistors T and 2 are turned off, and the output current from the alternator 14 is passed through the relay 52 to the battery 12 and the electric load 1o.
flows to

Furthermore, the contact point C and the contact point of the selector switch 26 connected to the base of the transistor T,1 are connected. Therefore, the signal from the battery voltage comparison circuit 28 controls the transistor T,1.

That is, the battery voltage comparison circuit 28 outputs an L (Low) signal when the battery voltage is higher than the adjustment voltage, and outputs an H (H3gh) signal when the battery voltage is lower than the adjustment voltage. 1 turns off when the battery voltage is higher than the regulated voltage, and turns on when the battery voltage is lower than the regulated voltage. In this manner, in operating states other than idling, the alternator 14 acts as a power supply means by a known voltage regulation function.

On the other hand, when the idle state detecting means 40 detects that the vehicle is in the idle state, the contact C and the contact a of the changeover switch 26 connected to the bases of the transistors T and 1 are connected. Therefore, the transistor T,1 is turned on and the excitation current reaches its maximum excitation state. Further, the contact g and contact e of the relay 52 connected in parallel to the output current setting means 50 are opened, and at the same time, the contact dt and the contact e of the changeover switch 54 are connected, and the signal from the adder 30 causes the output to be output. Current setting means 50 is controlled. Therefore, the output current from the alternator 14 flows to the battery 12 and the electric load 10 via the output current setting means 50.

The signal from this adder 30 is the H%L signal from the battery voltage comparator circuit 2, which is converted into a DC voltage by passing it through an integrator 32, and a control command signal that makes the battery voltage the regulated voltage, and a rotation speed detection means. The rotational speed signal from 38 is input to the deviation detection circuit 36 to find the deviation from the target rotational speed, and this deviation signal is PID-controlled by the gain adjuster 34 to generate a rotational speed correction command signal. It is. That is, the generated power is controlled by turning on and off the transistors T and 2 of the output current setting means 50 using the control command signal (2). In other words, when the idle rotation speed is faster than the target rotation speed, the output current from the alternator is supplied to the battery and the electrical load while the battery voltage is maintained at the regulated voltage, increasing the alternator's electrical load (and reducing the engine speed). increase the mechanical load on the

Then, the idle rotation speed is controlled to become slower and reach the target rotation speed. In addition, when the idle rotation speed is lower than the target rotation speed, the battery voltage is maintained at the regulated voltage while the supply of output current from the alternator is reduced to reduce the electrical load on the alternator and reduce the mechanical load on the engine. Reduce the load. Then, the idle rotation speed increases and is controlled to reach the target rotation speed. As a result, rotation/speed control is performed to maintain the idle rotation speed at the target value while maintaining a predetermined battery voltage.

FIG. 3 shows a block diagram of an engine idle speed control device according to a third embodiment.

This third embodiment realizes the same functions as those of the first embodiment using an electronic control device composed of a microcomputer.

As shown in the figure, the output terminal B of the alternator 14 is connected to the anode of the battery 12 and one end of the vehicle electrical component (electric load) 10. Further, one end of the rotor coil 16 in the alternator 14 is connected to the output contact B and also to the cathode of the diode 170. The other end of the rotor coil 16 and the anode of the diode 17 are connected to the collector of the transistor T,1 which is turned on and off in response to the output of the pulse width modulation circuit 22.

The pulse width modulation circuit 22 and the transistor T,1 constitute excitation current setting means 24, and the duty ratio of the transistor T,1 is controlled by the pulse width modulation circuit 22. This duty ratio is controlled by an analog voltage, and its operation is such that the higher the voltage value, the longer the duty ratio, that is, the on-time of T,1.

A contact C of a changeover switch 26 including a contact C3b5a is connected to the input side of the excitation current setting means 24. Contact a of this changeover switch 26 is connected to the battery voltage comparison circuit 2.
8 to the anode of the battery 12.

This battery voltage comparison circuit 28 outputs an L (Low) signal when the voltage of the battery 12 is higher than a specified value (adjusted voltage), and conversely outputs an H (formerly GH) signal when the voltage of the battery 12 is lower than the specified value. , and a control command signal ■ is output to contact a.

Selector switch 26. The output of the electronic control bag M50, which is composed of a microcomputer, ie, the control command signal (2) is connected to the contact point (2).

The input side of the electronic control device 50 is connected to the anode of the battery 2, the rotation speed signal from the rotation speed means 38, and the output signal from the idle state detection means 40.

Further, the changeover switch 26 is linked to an idle state detection means 40, so that when the state is other than the idle state, the contact C is connected to the contact a, and when the state is idle, the contact C is connected to the contact A. It has become.

The operation of the engine idle speed control device of the third embodiment configured as above will be explained with reference to FIG. 4. FIG. 4 shows a control flowchart of the electronic control device 50.

When the idle state detecting means 40 detects that the vehicle is not in the idle state, the contact C of the changeover switch 26 is connected to the contact a. - Then, the excitation current setting means 24 is controlled by the control command signal I.

That is, the excitation current setting means is controlled based on the H1L signal from the battery voltage comparison circuit 28, and transistors T and 1 are turned off while the battery voltage is above the adjustment voltage, and conversely, the transistors T and 1 are turned off while the battery voltage is below the adjustment voltage. T,
Turn on 1.

On the other hand, the electronic control unit 50 determines whether or not the engine is idle in step lOo, and as a result, since the engine is in a state other than idle in this case, no calculation is performed to control the power generated by the alternator.

In this way, in operating states other than idle, alternator 1
4 acts as a power supply means by a known voltage regulation function.

On the other hand, when the idle state detection means 40 detects the idle state, the contact C of the changeover switch 26 is connected to the contact S. Then, the excitation current setting means 24 is controlled by the control command signal ■.

That is, when the electronic control unit 50 determines that the vehicle is in an idle state in step 100, the following calculation is performed.

First, the battery voltage ■I is read in step 102, the deviation amount between the battery voltage V and the adjustment voltage Vast is determined in step 104, and step 106
Based on this deviation amount, an average generated power control command value is calculated so that the battery voltage becomes the regulated voltage. The other is that the engine rotation speed Ne is read in step 108, and the engine rotation speed Ne is read in step 110.
The amount of deviation between the engine speed and the target rotational speed N, . Step! In step 14, the generated power control command value is calculated by adding both command values, and in step 116, it is output as a control command signal ■.

This control command signal (2) is an analog voltage, and in response to this signal, the duty ratio of the transistors T and 1 of the excitation current setting means 24 is controlled, thereby controlling the generated power.

That is, when the idle rotation speed is faster than the m rotation speed, the battery voltage is not maintained at the regulated voltage, but the alternator generates electricity, increasing the mechanical load on the engine. Then, the idle rotation speed is controlled to become slower and reach the target rotation speed.Also, if the idle rotation speed is lower than the target rotation speed, the battery voltage is maintained at the regulated voltage and the power generation of the alternator is reduced. Reduce the mechanical load on the engine. Then, the engine rotation speed increases and is controlled to reach the target rotation speed.

As a result, rotation speed control is performed to maintain the idle rotation speed at the target value while maintaining a predetermined battery voltage.

As explained above, according to this embodiment, the alternator can perform rotational fluctuation absorption control to maintain the idle rotational speed at the target rotational speed without impairing the battery charging function, thereby realizing a stable idle operating state. can.

〔Effect of the invention〕

Specific effects of the present invention will be explained with reference to the drawings (FIGS. 5, 6, and 7).

FIG. 5 shows an example of the effect of improving engine idle stability. In this figure, engine stability is expressed in the form of the standard deviation of rotational speed fluctuations, and the smaller the standard deviation value, the more stable the engine is. According to this, it can be seen that the standard deviation value is small in both the first embodiment and the embodiment shown in FIG. 12, and the stability is improved.

Furthermore, FIG. 6 is an example showing the effect of suppressing periodic low-frequency idle rotation fluctuations, that is, hunting. This example was implemented using the configuration of the first example, and it can be seen that it is effective against hunting.

Furthermore, FIG. 7 shows the effect on rotational speed fluctuations on the verge of overshooting when the racing state shifts to the idling state. According to this, it can be seen that rotational fluctuations on the verge of overshooting are suppressed and the speed is quickly stabilized.

As explained above, according to the present invention, the idle rotation speed can be controlled even against irregular idle rotation speed fluctuations, hunting, and rotation speed fluctuations that are on the verge of overshooting when transitioning from racing to idle. The effect is that the speed can be stabilized at a constant speed.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an engine idle speed control device according to a first embodiment of the present invention, and FIG. 2 is a block diagram showing an engine idle speed control device according to a second embodiment of the present invention. 3 and 4 are block diagrams and control flowcharts showing an engine idle speed control device according to a third embodiment of the present invention, and FIGS. 5 to 7 specifically illustrate the effects of the present invention. This is a drawing showing the 12... Battery, 14... Alternator, 38... Rotation speed detection means, 24... Excitation current setting means.

Claims (2)

[Claims] (1) When controlling the idle speed of an engine equipped with an engine-driven alternator that supplies power to an electrical load or charges a battery, detects the engine speed and also detects the idle operating state of the engine. Then, the rotation speed correction command value determined so that the rotation speed signal becomes the target rotation speed is added to the average generated power control command value that maintains the battery voltage at a predetermined value when the idle state is detected, and the generated power of the alternator is adjusted. A method for controlling an idle rotation speed of an engine. (2) In an engine idle rotation speed control device equipped with an engine-driven alternator that supplies power to an electrical load or charges a battery, the engine idle speed detection means detects the engine rotation speed, and the engine idle Idle state detection means detects the operating state; and when the idle state detection means detects the idle state, the rotation detected by the rotation speed detection means is added to the average generated power control command value that maintains the battery voltage at a predetermined value. An idle rotational speed control device for an engine, comprising: power generation control means for controlling the power generated by the alternator by adding a rotational speed correction command value determined so that the speed signal becomes a target rotational speed.