JPH02201067A - Exhaust gas recirculation device of engine - Google Patents

Abstract

PURPOSE:To reduce the pumping loss and enhance the rate of fuel consumption without causing the driver to feel troublesome by increasing the EGR amount of engine by a certain amount when a constant speed running device is actuated, and thereby combining EGR with constant speed running. CONSTITUTION:An EGR amount adjusting means B adjusts the EGR amount of an engine C on the basis of control by an EGR amount control means A under certain conditions. Therein a constant speed run sensing means D senses whether or not a constant speed running device is actuated. If so, the EGR amount by EGR amount adjusting means B is increased by an amount increasing means E from under abovementioned specific conditions. Thus the EGR and constant speed running are combined together, whereby the driver is free of troublesome feeling, and a reduced pumping loss will enhance the rate of fuel consumption.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to an exhaust gas recirculation device for an engine.

(Prior art) Conventionally, as a means of reducing engine NOx emissions,
For example, as shown in Japanese Unexamined Patent Publication No. 58-47148, there is exhaust gas recirculation (ERG) in which a part of the exhaust gas is returned to the intake system of the engine, and as a means for driving the vehicle while maintaining a constant speed. It is generally known that constant speed traveling devices exist.

Incidentally, in recent years, there has been a strong desire to improve fuel efficiency. One possible solution to this problem is to increase the ERG amount and at the same time, to compensate for the deterioration in driving performance, depress the accelerator pedal more deeply to ensure a predetermined amount of intake air. According to this, the opening degree of the throttle valve increases, and accordingly, the pumping loss is reduced and fuel efficiency is improved.

(Problems to be Solved by the Invention) However, in the above case, the driver must depress the accelerator pedal more deeply in order to secure a predetermined amount of intake air, which is unbearable.

In view of the above circumstances, the present invention was made by combining ERG and constant speed driving technology, and its purpose is to reduce pumping loss and improve fuel efficiency without causing any inconvenience to the driver. There is a particular thing.

(Means and effects for solving the problem) In order to achieve the above object, in the present invention, the ERG amount adjusting means adjusts the ERG amount based on control under predetermined conditions by the ERG amount controlling means. an exhaust gas recirculation system for an engine, comprising: a constant speed running detection means for detecting an operation of a constant speed running device; The present invention is configured to include: an increase means for increasing the amount of ERG;

With the configuration described in L, when the constant speed traveling device is in operation,
Even if the amount of ERG is increased, the constant speed running device will automatically increase the opening of the throttle valve by the amount commensurate with the increased amount in order to keep the vehicle speed constant, and the driver will be able to improve driving performance. There is no longer a need to press the gas pedal deeper to compensate for the deterioration. Therefore, by increasing the opening degree of the throttle valve, the pumping loss is significantly reduced and fuel efficiency is improved, while the driver is not bothered at all.

(Example) Embodiments of the present invention will be described below based on the drawings.

In FIG. 1, reference numeral 1 is an engine body, and intake air is supplied to an air cleaner 2, an air flow chamber 3, a throttle valve body 4. It is supplied to the combustion chamber 9 in which the spark plugs P are arranged through the surge tank 5, the intake manifold 6, and the intake boat 8 which is opened and closed by the intake valve 7. The path from the air cleaner 2 to the intake boat 8 is the intake passage 10. It consists of The amount of intake air flowing through this intake passage 10 is controlled by a throttle valve 11 driven by a motor M, and is measured by an air flow meter 12. are now mixed.

On the other hand, exhaust gas from the combustion chamber 9 passes through an exhaust passage 16 connected to an exhaust boat 15 that is opened and closed by an exhaust valve 14.
Emitted into the atmosphere.

The intake passage 10 and the exhaust passage 16 are the EGR passage 1.
7, and this EGR passage 17 has an E
A GR valve 18 is interposed. This EGR valve 1
Reference numeral 8 is an electromagnetic type, and the flow rate is adjusted according to the lift position of the valve body in this EGR valve 18.

Reference numeral 19 in FIG. 2 is a control unit consisting of a microcomputer, and to the control unit 19, an ON-OFF signal is sent from an auto cruise switch 20 that operates a constant speed traveling device (not shown), and an ON/OFF signal is sent from a rotation speed sensor 21. The engine rotation speed, the load signal from the load detection sensor 22, and the vehicle speed from the vehicle speed sensor 23 are respectively input.

On the other hand, from the control unit 19, the EGR valve 1
8, a motor M, and a spark plug P via an igniter and a destroyer (not shown).

To explain the outline of the control content of the control unit 19, the control unit 19 is designed to increase the amount of EGR when the vehicle is traveling at a constant speed. As a result, even if the EGR amount is increased during constant speed driving, the constant speed driving device automatically increases the opening degree of the throttle valve 11 via the motor M to keep the vehicle speed constant, and the EGR amount is increased. By increasing the amount of intake air, the insufficient amount of intake air is compensated for, and the driver does not have to press the accelerator pedal deeper to compensate for the deterioration in driving performance. Therefore, by increasing the opening degree of the throttle valve 11, the pumping loss is significantly reduced and fuel efficiency is improved, while the driver is not bothered at all.

In addition, in this case, the ignition timing is advanced in synchronization with the increase in the amount of EGR, which improves the output and
It is possible to instantaneously deal with a decrease in output due to an increase in the amount of GR.

The details of the control by the control unit 19 described above will be explained in detail with reference to the flowchart shown in FIG.

Of course, control knee) 19 is basically the CPU,
In addition to ROM, RAM, and CLOCK, it also has an A/D or D/A converter and an input/output interface, but since these are known configurations when using a microcomputer, their explanation will be omitted. Note that in the following explanation, P indicates a step.

First, at Pl, the ON-OFF signal from the auto cruise switch 20, engine speed, load condition, vehicle speed, etc. are read. Then, at P2, the valve body of the ERG valve 18 is changed according to the M rotation state. Basic lift amount F
T is set, and at P3, basic ignition timing θB is set according to the operating state.

In the next step P4, it is determined whether or not the vehicle is traveling at a constant speed (auto cruise). The determination of P4 is determined by the ON/OFF state of the auto cruise switch 20. When P4 is YES, a lift increase lPc during constant speed running is set in P5, PC in P5 and one valve in P2 are added, and the EGR valve 18 is feedback-controlled toward this. This P5. The PC is provided to increase the amount of EGRil during constant speed driving.

Next, at P7, advance angle increase θC during constant speed driving
is set, the θC is added to the θB of P3 in P8, and ignition is performed based on it. This P8
1 is provided to improve the output by advancing the ignition timing and instantly compensate for the decrease in output due to the increase in the amount of EGR. , the vehicle speed deviation is calculated, the operating amount of the throttle valve 11 is calculated based on it in PIO, and the throttle valve 11 is driven by motor M based on the operating amount of PIO in FIL. With this P9~pH, even if the EGR amount is increased in the PC, the opening degree of the throttle valve 11 will be automatically increased by an amount corresponding to the increased amount. Therefore, pumping loss can be reduced and fuel efficiency can be improved without requiring the driver to press the accelerator pedal to compensate for the deterioration in driving performance.

When P4 is No, it is during non-constant speed driving, and at this time, as usual, the EGR valve 18 is feedback-controlled in Pl2 for every one of P2, and Pl
3, ignition is performed based on the basic ignition timing θB.

(Effects of the Invention) As described above, the present invention can reduce pumping loss and improve fuel efficiency without causing any inconvenience to the driver.

[Brief explanation of the drawing]

FIG. 1 is an overall system diagram showing one embodiment of the present invention. FIG. 2 is a flowchart showing a control example of the present invention, and FIG. 3 is an overall configuration diagram of the present invention. 18: ERG valve 19: Control unit 20: Auto cruise switch

Claims (1)

[Claims] (1) In an engine exhaust gas recirculation system in which the ERG amount adjustment means adjusts the ERG amount based on control under predetermined conditions by the ERG amount control means, constant speed running detection means detects the operation of the constant speed running device. and an increase means for increasing the ERG amount by the ERG amount adjusting means when the constant speed traveling device is activated than under the predetermined conditions. Gas reflux device.