JPH01219335A - Idling speed controller for internal combustion engine - Google Patents

Abstract

PURPOSE:To aim at the stabilization of idling speed with a simple structure by making a duty ratio larger through a variation in battery voltage due to a current consumer at the time of controlling a solenoid valve installed in a bypass passage bypassing a throttle valve. CONSTITUTION:A solenoid valve 20 is installed in an intake passage 4 bypassing a throttle valve, performing duty control by a control part 22, and an intake air quantity for an engine 10 is adjusted according to a vacuum state at the time of idling speed, whereby engine speed is controlled for feedback. In addition, one end of a battery 28 is connected to the control part 22, and a variation in battery voltage due to a current consumer is detected, and thereby a current consumer state is judged, and a duty ratio in the solenoid valve 20 is made larger. Consequently, since the current consumer state is judgeable only by detecting the variation of the battery voltage, a controller is simplified, while a drop and variation in the idling speed can be controlled.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to an idle speed control device for an internal combustion engine,
In particular, the present invention relates to an idle speed control device for an internal combustion engine that controls a solenoid valve according to an electrical load, adjusts the amount of intake air into the engine, and controls the idle speed.

[Conventional technology]

In internal combustion engines, the idle speed is sometimes set low in order to purify exhaust gas and reduce fuel consumption. When the idling speed is low as described above, the engine speed decreases due to a slight increase in load, resulting in an inconvenient engine malfunction.

For example, an increase in electrical load due to the lighting of headlights, etc. lowers the engine speed, causing engine malfunction.

Alternatively, when engine cooling water is circulated through the heat exchanger in order to use the heater in cold weather, there is an inconvenience that warm-up operation becomes insufficient because the engine rotation speed is low.

In order to solve this problem, an idle speed control device for an internal combustion engine has been proposed that compensates for the reduction in engine speed when the above-mentioned electrical load is applied.

This internal combustion engine idle speed control device generally adjusts the amount of intake air into the engine when the engine is running at idle;
Feedback control is performed to bring the idle speed to the target idle speed.

Then, the idle speed is set to a target idle speed according to variations in the engine and changes in electrical load, and control is performed to improve the stability of the idle speed.

In addition, there is an engine idle speed control device disclosed in Japanese Patent Laid-Open No. 61-96155, which detects battery voltage and calculates an average value, and uses this average value to calculate the average value. The energization time to the electromagnetic means is corrected to compensate for fluctuations in battery voltage, and the delay in the rise of the pulse is compensated for to ensure substantially the same desired duty ratio, thereby stabilizing the idle rotation speed.

[Problem that the invention seeks to solve]

By the way, in a conventional internal combustion engine idle speed control device, when controlling the idle speed to a predetermined value by feedback control, the headlight switch 202, cooling fan switch 204, heater fan switch 20
6. Defogger switch 208, wiper switch 210
, an electrical load is generated by the ON operation of various switches such as the air conditioner switch 212, and as shown by the broken line in FIG. There is an inconvenience that this may occur.

For this reason, as shown in FIG. 6, it is necessary to connect each of the above-mentioned switches to the control section 214, and to input an electric load signal into the control section 214 when the various switches are turned on to perform correction control of the idle rotation speed. be. That is, when the various switches are turned on, the duty ratio of the solenoid valve 216 is increased by a certain amount α (%), and the opening and closing of the solenoid valve 216 is controlled to suppress a decrease in engine speed.

However, there are many input signals to the control unit 214, and the duty ratio is increased by a certain amount α (%) depending on the signal, and the rate of decrease in engine speed varies depending on the size of the electrical load. In the case of a light electrical load, there is a problem in that an increase in the constant amount α (%) causes the engine speed to increase.

Furthermore, if the duty ratio correction value is set respectively according to the electrical load signals of the various switches input to the control section, it is possible to prevent unnecessary increases in the engine speed, but the control section There are disadvantages in that the configuration becomes complicated and the cost becomes large, which is economically disadvantageous.

[Purpose of the invention]

SUMMARY OF THE INVENTION In order to eliminate the above-mentioned disadvantages, an object of the present invention is to provide a bypass passage that bypasses the throttle valve in the intake passage of the idle speed control device of an internal combustion engine, provide a solenoid valve in the middle of this bypass passage, and By installing a control unit that detects changes in battery voltage caused by an electrical load, sets the duty ratio of the solenoid valve to be large, and controls the idle rotation speed, the solenoid valve changes when the battery voltage changes due to an electrical load. By setting a large duty ratio and controlling the solenoid valve using this duty ratio, it is possible to suppress the drop and fluctuation of the idle rotation speed, and the electrical load state can be determined simply by detecting changes in battery voltage.
An object of the present invention is to realize an idle speed control device for an internal combustion engine that has a simple configuration and can reduce costs.

[Means for solving problems]

In order to achieve this object, the present invention provides an idle speed control device for an internal combustion engine that adjusts the intake air amount to the engine according to the load condition during idle speed and provides feedback control of the engine speed. A bypass passage that bypasses the valve is provided, and a solenoid valve is provided in the middle of this bypass passage, and a battery is connected to detect changes in battery voltage caused by an electrical load to increase the duty ratio of the solenoid valve (by setting the idle rotation speed). The present invention is characterized in that it is provided with a control section that controls.

(Function) With the above-mentioned configuration, when the battery voltage changes due to the electrical load caused by the on-operation of various switches, the duty ratio of the solenoid valve is increased (set), and the solenoid valve is controlled by this duty ratio. In addition to suppressing decreases and fluctuations in idle rotation speed, the electrical load state can be determined simply by detecting changes in battery voltage, simplifying the device configuration and reducing costs.

〔Example〕

Embodiments of the present invention will be described in detail below based on the drawings.

1 to 5 show embodiments of this invention. Second
In the figure, 2 is an internal combustion engine idle speed control device;
4 is an intake passage, 6 is a throttle valve, 8 is an intake valve, 1
0 is an engine, 12 is a combustion chamber, 14 is an exhaust valve, and 16 is an exhaust passage. A bypass passage 18 that bypasses the throttle valve 6 in the intake passage 4 of the idle speed control device 2 is provided. That is, one end 18 of the bypass passage 18
a is the intake passage 4-1 on the upstream side of the throttle valve 6
The other end 18b is opened to the throttle valve 6.
The bypass passage 18 is provided to open into the intake passage 4-2 on the downstream side.

A solenoid valve 20 for stabilization correction advance angle (ISO) in a normally closed state is provided in the middle of the bypass passage 18 and is controlled to open and close by a control section 22 to be described later.

Furthermore, a fuel injection valve 24 whose fuel injection amount is controlled by a control section 22 is provided in the intake passage 4-2 downstream of the other end 18b of the bypass passage 18.

Further, a distributor 26 is connected to the control unit 22, and one end of a battery 28 is connected to the controller 22.
The other end of the battery 28 is installed.

The control unit 22 controls changes in the battery voltage of the battery 28 due to electrical loads caused by the ON operations of various switches (not shown) such as a headlight switch, a cooling fan switch, a heater fan switch, a defogger switch, a wiper switch, and an air conditioner switch. Detected,
In order to increase the duty ratio A (%) of the solenoid valve 20,
For example, the duty ratio is set to A+α (%), and the solenoid valve 20 is opened and closed using this large duty ratio A+α (%) to control the idle rotation speed.

Specifically, as shown in FIG. 5, the battery voltage of the battery 28 is equal to the reference battery voltage drop level V (V).
From this reference battery voltage drop level V (V), the battery voltage drop level due to the electrical load is ΔV+(
When the duty ratio A (%) as shown in FIG. 3 changes by V), the duty ratio A (%) as shown in FIG. 3 is set larger by α (%) as shown in FIG.

Note that reference numeral 30 is a throttle opening sensor that detects the throttle opening of the throttle valve 6.

The operation will be explained along with the flowchart of the idle rotation speed control program of the idle rotation speed control device 2 of the internal combustion engine shown in FIG.

First, start the engine 10 of the idle speed control device 2 and start the idle speed control program (1
00)

Then, the engine rotation speed Nε signal and the throttle opening signal from the throttle opening sensor 30 are inputted to the control unit 22 (102), and it is determined whether the idle switch (not shown) has been turned on (104). I do.

If this judgment (104) is NO, the idle speed control device 2 of the internal combustion engine is controlled by normal feedback control, and if the above judgment (104) is YES, the headlight switch (not shown) or Cooling fan switch, heater fan switch, defogger switch,
Determining whether an electrical load is generated due to the on operation of various switches such as wiper switches and air conditioner switches, for example, whether a load switch (not shown) is turned on (
106).

When the judgment (106) is No, the idle speed control device 2 of the internal combustion engine is controlled by normal idle feedback control, and when the above judgment (106) is YES, the battery is controlled by the electric load. The voltage drop level ΔV+(V) is the reference battery voltage drop level V (
V) Make a judgment (108) as to whether or not the value is greater than or equal to the value.

If this judgment (108) is YES, it indicates that the various switches are not turned on and no electrical load is generated, and the duty ratio is set to A (%) (110 ).

Further, if the determination (108) is NO, it indicates that an electrical load is generated due to the on operation of various switches,
As shown in FIG. 4, the duty ratio is set to A+α (%) (112).

After setting the duty ratio, the program for controlling the idle speed is transmitted to the control section 22 to control the engine speed N.
A routine is made to input the E signal and the throttle opening signal (102).

As a result, when an electrical load is generated due to the on-operation of various switches and the reference battery voltage drop level ■(V) changes to the battery voltage drop level ΔV+(V) due to the electrical load, the duty ratio A of the solenoid valve 20 is (%) to A
+α (%), and as shown by the solid line in Fig. 5(e), it is possible to control the solenoid valve 20 with this large duty ratio A + α (%) to suppress the drop and fluctuation of the idle speed. This makes it possible to stabilize the idle speed, which is advantageous in practice.

In addition, the electrical load state can be determined only by detecting changes in the battery voltage of the battery 28, and compared to the conventional system in which various switches are connected to the control unit 22, the configuration of the device is simplified and manufacturing is easier. This makes it possible to reduce costs,
This is economically advantageous and allows the device to be made smaller and lighter.

Note that the present invention is not limited to the above-described embodiments, and various modifications can be made.

For example, in the above-described embodiment, the present invention changes the duty ratio A (%) by changing the battery voltage due to the electrical load.
is set to a large value of A + α (%), and the solenoid valve is controlled by this large duty ratio A + α (%). It is also possible to set the above stages and control the electromagnetic valve according to any one of the plurality of duty ratios to suppress the decrease and fluctuation of the idle rotation speed.

〔Effect of the invention〕

As explained in detail above, according to the present invention, there is a bypass that bypasses the throttle valve in the intake passage of the idle speed control device of the internal combustion engine! A solenoid valve is installed in the middle of this bypass passage, and a battery is connected to detect changes in battery voltage caused by an electrical load to increase the duty ratio of the solenoid valve. Since this is provided, the duty ratio of the solenoid valve can be increased (set) when the battery voltage changes due to the electrical load, and the solenoid valve can be controlled using this duty ratio to suppress the drop and fluctuation of the idle speed. In addition, the electrical load status can be determined simply by detecting changes in battery voltage, and compared to conventional devices, the configuration of the device can be simplified, making manufacturing easier and reducing costs. This is economically advantageous.

[Brief explanation of the drawing]

1 to 5 show embodiments of the present invention, FIG. 1 is a flowchart of an idle rotation speed control program of an idle rotation speed control device for an internal combustion engine, and FIG. 2 is a schematic diagram of an idle rotation speed control device for an internal combustion engine. Figure 3 is a diagram showing the duty ratio when Δv1≧V, Figure 4 is a diagram showing the duty ratio when ΔVl<V, and Figure 5 is a time chart of the idle speed control device of an internal combustion engine. be. FIG. 6 is a schematic explanatory diagram of a connection state of an idle rotation speed control device for an internal combustion engine to a control section, showing the prior art of the present invention. In the figure, 2 is an idle speed control device, 4.4-L
4-2 is an intake passage, 6 is a throttle valve, 8 is an intake valve, 10 is an engine, 12 is a combustion chamber, 14 is an exhaust valve, 1
6 is an exhaust passage, 18 is a bypass passage, 18a is one end, 1
8b is the other end, 20 is a solenoid valve, 22 is a control unit, 24 is a fuel injection valve, 26 is a distributor, 28 is a battery,
30 is a throttle opening sensor. Patent Applicant: Lead Automobile Industry Co., Ltd. Agent: Patent Attorney Yoshimi Saigo Figure 1 Figure 3 Figure 4

Claims (1)

[Claims] 1. In an internal combustion engine idle speed control device that adjusts the intake air amount to the engine according to the load condition during idle speed and provides feedback control of the engine speed, a bypass passage that bypasses a throttle valve in the intake passage is provided. A solenoid valve is provided in the middle of the passage, and a control unit is provided that connects a battery, detects a change in battery voltage due to an electric load, sets the duty ratio of the solenoid valve to be large, and controls the idle rotation speed. Idle speed control device for internal combustion engines.