JPS6263152A - Idle controller for engine - Google Patents

Abstract

PURPOSE:To improve the fuel consumption idling by varying the increase quantity of the idle number of revolution according to the outside-air temperature and increasing the increase quantity of the idle number of revolution when the outside-air temperature is high, thus suppressing the unnecessary increase of revolution without deteriorating the operation of a cooler. CONSTITUTION:An idle controller 1 controls the idle number revolution by adjusting the quantity of air which bypasses a throttle valve 5 installed into an intake passage 4 for supplying intake into the combustion chamber 3 of an engine 2. In other words, a bypass valve 7 for opening and closing a bypass air passage 6 is operated by an actuator 8. In this case, into a control unit 11 for controlling the actuator 8, each signal of an idle switch 12, an engine speed sensor 13, a compressor 10 for cooler, an outside-air temperature sensor 14, and a temperature setting device 15 is input. When the cooler is used in idling, bypass air is controlled so that the engine speed increases as the difference between the outside-air temperature and the set temperature becomes larger.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an engine idle control device that controls the idle rotation speed associated with the use of a cooler.

(Prior art) Conventionally, when an external load is applied by driving a cooler compressor while the engine is idling, the idle speed has been reduced in order to improve the drop in engine speed and increase the cooling capacity of the cooler. There are known idle control devices in which the idle height is increased (for example, Japanese Patent Laid-Open No. 1983-1999)
56645).

However, if the idle speed is increased by a uniform amount when using the cooler, as in the preceding example,
This will unnecessarily increase the idle speed and reduce fuel efficiency during idle.

That is, when the cooler is used when the outside air temperature is not so high, a sufficient cooling capacity of the cooler can be obtained even with a relatively small increase in engine speed.

(Object of the Invention) In view of the above circumstances, the present invention aims to improve fuel efficiency during idling by avoiding unnecessary increases in rotation speed without impairing the performance of the cooler, while increasing the idling speed when using a cooler. It is an object of the present invention to provide an engine idle control device as described above.

(Structure of the Invention) The idle control device of the present invention increases the idle rotation speed when driving a cooler compressor, and changes this rotation speed increase depending on the outside air humidity, so that the higher the outside air temperature is, the higher the idle rotation speed is. It is characterized by having been set.

(Effects of the Invention) According to the present invention, by changing the point at which the idle speed increases when the cooler is used according to the outside air temperature, the idle speed increases unnecessarily when the outside air temperature is relatively low. It is possible to improve the fuel efficiency during idling while ensuring a good level of noise without causing excessive noise. Furthermore, when the outside air temperature is high, it is possible to increase the idle speed as much as possible to obtain a high cooling capacity commensurate with the outside air temperature.

(Example) Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 1 shows the overall schematic configuration.

The idle control device @1 controls the idle speed by adjusting a bypass air valve that bypasses a throttle valve 5 installed in an intake passage 4 that supplies intake air to a combustion chamber 3 of an engine 2.

That is, a bypass air passage 6 is provided that bypasses the throttle valve 5, a bypass valve 7 is provided that opens and closes the bypass air passage 6 to adjust the bypass air volume (intake amount), and the opening degree of the bypass valve 7 is linearly adjusted. Actuator 8
It is operated by.

Furthermore, a cooler compressor 10 is attached to the crankshaft 9 of the engine 1, and is driven by the rotational force of the crankshaft 9.
are linked.

The intake air m is controlled by adjusting the opening of the bypass valve 7 in conjunction with the operation of the linear actuator 8, using a control signal from the control unit 11. The control unit 11 receives a signal from an idle switch 12 to detect the idle operating state, a signal from a rotation sensor 13 to detect the engine speed,
An outside temperature sensor 1 receives a signal indicating the operating state of the cooler compressor 10 and detects outside air temperature.
4 outputs, temperature setting device 1 where the user sets the desired temperature
The signals from 5 are respectively input.

Then, the control unit 11 controls the intake air amount by bypass air control when using the cooler during idling, based on the difference between the outside air temperature and the set temperature, so that the larger the difference between the two, the higher the engine rotation speed. It is something.

That is, as shown in FIG. 2, the control unit 11 receives the set temperature Tu of the temperature setting device 15, in which the desired temperature is set by the user, and the outside air temperature TO detected by the outside air temperature sensor 14, and adjusts both of them. Based on the difference, the target idle rotation speed calculation section 11Δ calculates the target rotation speed Nt, and outputs the calculation result to the intake air amount control section 11B. In this intake air amount control unit 11B, the current engine rotation speed N and the target rotation speed Nt associated with the drive of the cooler compressor 10 are controlled.
By comparison, the bypass air control is performed according to the difference between the two so that the engine rotation speed N becomes the target rotation speed Nt.

Target rotation speed N in the target idle rotation speed calculation section 11A
The calculation of t is performed based on the characteristics shown in FIG. 3, for example. This characteristic is the difference ΔT between the set temperature Tu and the outside temperature TO.
= When TO-TIJ is 0°C or less, the cooler compressor 10 is not driven and the target rotation speed N is 6 as the lower limit.
00 ppm, and when the humidity difference ΔT is 20°C or more, the target rotation speed Nt is set to 1400 as the upper limit of the idle rotation speed.
rpm and set the target rotation speed to 600 between 0 and 20℃.
The setting is such that the speed gradually increases from rpm to 1400 rpm.

The operation of the control unit 11 will be explained based on flowchart 1 in FIG. 4. This flowchart shows only the main parts. When the user sets the desired temperature Tu using the temperature setting device 15 in step S1, it is determined in step S2 whether the cooler compressor 10 is in a driving state and in idle operation. When the determination in step $2 is YES, the temperature TO detected by the outside air temperature sensor 14 is read in step S3.

Then, in step S4, a target idle rotation speed Nt is calculated based on the characteristics shown in FIG. 3, corresponding to the difference ΔT between the set temperature TO and the outside temperature TO, and then step S
Then, the intake air d is feedback-controlled so that the engine rotational speed N becomes the target rotational speed Nt.

According to the embodiment described above, the idle rotation speed when the cooler is activated is set according to the difference between the outside temperature and the set temperature, and the cooler compressor is driven according to the required cooling capacity. This suppresses the necessary increase in idle speed.

In the above embodiment, the target idle rotation speed is determined according to the outside air temperature and the temperature set by the user, but it may be determined simply according to the outside air temperature.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of an engine equipped with an idle control device according to an embodiment of the present invention, FIG. 2 is a block diagram of the idle control device, and FIG. 3 is a characteristic diagram showing the calculation characteristics of the target idle rotation speed. FIG. 4 is a flowchart for explaining the operation of the control unit. 1... Idle control device 2... Engine 10... Cooler compressor 11...
...Control unit 11A...Target idle rotation speed calculating section 11B...Intake air amount control section 14...Outside temperature sensor 15...Temperature setting device Figure 3 Figure 4

Claims (1)

[Claims] (1) An engine idle control device that increases the idle rotation speed by a predetermined value when a cooler compressor is driven, which changes the amount of increase in the rotation speed according to the outside air temperature, and increases the increase as the outside air temperature increases. An engine idle control device characterized in that the engine idle control device is set so that: