JPH0536608B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to an air pump driven by an engine, a control valve that opens and closes a communication passage that bypasses the air pump, and a control valve located downstream of the intake passage from the communication passage. The present invention relates to a supercharging control device in an engine supercharging device provided with a throttle valve that throttles a passage during deceleration.

(Prior art) In this type of engine supercharging device equipped with an air pump, a control valve, and a throttle valve, the air pump is operated with the control valve closed in an operating range where the engine load is higher than a predetermined load. In operation ranges where the engine load is below a predetermined load, the air pump is stopped and the control valve is opened to perform non-supercharging operation (for example, (Refer to Publication No. 18519/1983).

In this known example of a supercharging control device, the operation timing (operation control load) of the air pump and control valve is fixed to a predetermined value, and therefore, for example, even when decelerating to obtain a sufficient engine braking effect, the engine load remains constant. When the air pressure drops to the predetermined value, the air pump is automatically stopped and the control valve is opened at the same time.

However, with such a configuration, during deceleration, for example, the drive resistance of the air pump that acts as a braking force is released before the deceleration is sufficiently achieved, so the engine braking effect is not sufficiently obtained and the deceleration performance is reduced. In addition, when re-accelerating after deceleration, the intake pressure has already dropped to near atmospheric pressure during deceleration, so when re-accelerating, this intake pressure is increased again to the specified boost pressure. It takes time to do this, and this results in the problem of poor acceleration response.

(Object of the Invention) In view of the above-mentioned problems, an object of the present invention is to provide an engine supercharging control device that can improve both the deceleration performance during deceleration and the acceleration performance during re-acceleration after deceleration. It was done for a purpose.

(Means for Achieving the Object) As a means for achieving the above object, the present invention provides an air pump that is installed in the middle of the intake system path and whose drive is turned on and off according to the engine load, and a suction side of the air pump. and a control valve that opens and closes the communication passage depending on the load of the engine, and a throttle valve that is provided on the intake downstream side of the communication passage and throttles the intake passage during deceleration, The air pump is turned off at low loads, including deceleration conditions, and turned on at high loads, while the control valve is opened at low loads and closed at high loads. The supply control device includes a deceleration detecting means for detecting a decelerating state of the engine, and a deceleration detecting means that receives an output from the decelerating detecting means to determine whether the air pump is in the driving on state and the control valve is decelerated when the air pump is in the driving on state. The present invention is characterized in that a deceleration control means is provided for maintaining the valve closed state for a predetermined period of time and delaying the drive-off of the air pump and the opening operation of the control valve from the closed state.

(Function) In the present invention, when the operating state of the engine shifts from a high-load operating state in which the air pump is driven on and the control valve is closed to a deceleration operating state in which the throttle valve is throttled, this load state Despite the change, the air pump is kept in the on state and the control valve is kept in the closed state for a predetermined period of time, and after the predetermined period of time the air pump is turned off and the control valve is opened (i.e., the air pump is turned off and the control valve is opened). (The driving off of the control valve and the opening of the control valve are delayed for a predetermined period of time). As a result, for a predetermined period after the shift to deceleration operation, the air pump and the discharge side passage are blocked by the throttle valve and control valve, so the discharge pressure of the air pump is high even though the air pump is operating. As a result, the driving resistance of the air pump applied to the engine increases, and the engine braking effect is further enhanced.

On the other hand, during re-acceleration after deceleration and within the predetermined time, the air pump's discharge pressure is already at a high pressure higher than the predetermined boost pressure, so a large amount of intake air is quickly generated at the same time as the throttle valve opens. It is introduced into the working chamber of the engine and provides good acceleration by rapidly increasing the output torque.

(Embodiments) Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

The drawing shows a system diagram of an automobile engine 1 equipped with a supercharging control device according to an embodiment of the present invention, and reference numeral 2 in the drawing represents an intake passage.

An air cleaner 3 is installed at the most upstream end of this intake passage 2.
and an air flow meter 4, and at the downstream end there is a throttle valve 5 (as defined in the claims) whose opening is adjusted according to the amount of depression of the accelerator pedal 15, and which is closed to narrow the passage when the engine is decelerating. ) and a fuel injector 6 are installed. Further, a vane type air pump 7 is installed in the intake passage 2 at an intermediate position between the air flow meter 4 and the throttle valve 5.
is installed. This air pump 7 is connected to the engine 1 via an electromagnetic clutch 9 that is controlled on and off by a controller 8, which will be described later. Or the drive is turned off.

Further, in addition to the air pump 7 in the intake passage 2,
The suction side and the discharge side of the air pump 7 are communicated with each other via a communication passage 10 that bypasses the air pump 7. A control valve 11 for controlling opening and closing of the communication passage 10 is attached to the communication passage 10. This control valve 11 is controlled to open and close by a pulse motor 12 whose operation is controlled by a controller 8, which will be described later.

The controller 8 receives an intake pressure signal C1 outputted from a pressure sensor 13 provided on the discharge side of the air pump 7 and a throttle opening signal C outputted from a throttle opening sensor 14 attached to the throttle valve 5.
2, and outputs a clutch signal C3 to the electromagnetic clutch 9 and an opening/closing signal C4 to the pulse motor 12, thereby controlling the operations of the air pump 7 and the control valve 11 as described later.

The control of the air pump 7 and the control valve 11 by the controller 8 will be explained below.

Switching of the operating mode of the engine 1, that is, switching between supercharging operation and non-supercharging operation, is performed according to the throttle opening (that is, engine load). That is,
In a high-load operation region where the throttle opening is equal to or greater than a predetermined opening θ, the air pump 7 is turned on with the control valve 11 closed, and supercharging operation is performed (the state shown by the chain line in the drawing). On the other hand, in a low-load operation region including a deceleration operation region where the throttle opening is less than the predetermined opening θ, the control valve 11 is opened while the air pump 7 is off, and non-supercharging operation is performed. (Situation shown in solid line in the drawing).

On the other hand, if the engine 1 is decelerated while performing supercharging operation (i.e., the throttle opening is greater than or equal to the set opening θ) (for example, when the throttle opening is greater than or equal to the set opening θ), (if the throttle opening is suddenly closed over a predetermined opening width), even if the throttle opening is reduced to the above-mentioned set opening θ, the operating states of the air pump 7 and the control valve 11 will not be changed at the predetermined opening θ for a predetermined period of time. Leave the current state as it is, that is, drive on the air pump 7 and control valve 11.
Keep the valve closed.

Therefore, during deceleration operation, the air pump 7 performs the supercharging action with the control valve 11 closed and the throttle valve 5 throttled close to fully closed (normally considered fully closed). The pressure on the discharge side increases further than during normal supercharging, and the driving resistance of the air pump 7 that is loaded on the engine increases, and the engine braking effect is further enhanced, compared to when the driving resistance of the air pump 7 is not used. This will result in even higher deceleration performance.

On the other hand, during re-acceleration after deceleration (within the predetermined time period), when the throttle valve 5 is opened by depressing the accelerator pedal 15, the high pressure that was pressurized and sealed by the air pump 7 during deceleration is released. Since the intake air is quickly introduced into the working chamber of the engine 1 at high pressure, the output torque increases rapidly, and the vehicle is quickly shifted to acceleration in response to the depression of the accelerator pedal 15 (i.e., the acceleration response is improved). good quality).

As mentioned above, in order to improve the deceleration performance as well as the acceleration performance during re-acceleration after deceleration, it is good to increase the air pressure on the discharge side of the air pump 7, but if it becomes too high, the opposite will occur. Therefore, in order to protect the engine, in this embodiment, the air pressure is set to a predetermined pressure (for example, to prevent intake air from blowing back to the intake metering valve). control valve 11
Even within the predetermined time period during which the air pump 7 is kept closed, the control valve 11 is appropriately opened to allow a portion of the supercharging air to flow out to the upstream side of the air pump 7. 7 is kept in the driven state).

Furthermore, the effect of improving deceleration performance due to the containment of supercharged air as described above is highest during sudden deceleration when the pedal force on the accelerator pedal 15 is completely released and the throttle valve 5 is rapidly closed to the fully closed position. However, the effect can be sufficiently obtained even during slow deceleration, for example, when the throttle valve 5 closes only close to the half-open position.

Furthermore, although the above embodiment has been described with reference to a fuel injection type gasoline engine, the present invention is not limited to this, and may be applied to any engine in which a throttle valve is provided in the intake passage to throttle the passage during deceleration. For example, the present invention can be applied to a diesel engine in which the intake passage is throttled by a throttle valve provided in the intake passage during deceleration to prevent intake air from being blown back when the exhaust brake is activated.

(Effects of the Invention) As described above, according to the engine supercharging control device of the present invention, the throttle valve is throttled and deceleration operation is performed from a high-load operating state in which the air pump is turned on and the control valve is closed. , the air pump is maintained in the on-drive state and the control valve in the closed state for a predetermined period of time, and the discharge pressure of the air pump is increased by the throttle valve and the control valve, both of which are in the closed state. As a result, the driving resistance of the air pump applied to the engine increases, the engine braking effect is enhanced, and a higher level of deceleration performance is ensured.

Furthermore, when reaccelerating after deceleration and within the predetermined time, the air pump's discharge pressure is already at a high pressure higher than the predetermined boost pressure, so a large amount of intake air quickly flows into the engine at the same time as the throttle valve opens. It is introduced into the working chamber and provides good acceleration due to the rapid increase in output torque.

[Brief explanation of the drawing]

The drawing is an overall system diagram of an engine equipped with a supercharging control device according to an embodiment of the present invention. 1...Engine, 2...Intake system path (intake passage),
3...Air cleaner, 4...Air flow meter,
5... Throttle valve, 6... Fuel injector, 7... Air pump, 8... Controller,
9...Electromagnetic clutch, 10...Communication path, 11...
Control valve, 12... Pulse motor, 13... Pressure sensor, 14... Throttle opening sensor, 15...
Accelerator pedal.

Claims (1)

[Scope of Claims] 1. An air pump whose drive is turned on and off depending on the engine load is provided in the middle of the intake system path, a communication path that communicates the suction side and the discharge side of the air pump, and the communication path is connected to the engine. a control valve that opens and closes depending on the load; and a throttle valve that is provided on the intake downstream side of the communication passage and throttles the intake passage during deceleration, and the air pump turns off the control valve during low loads including deceleration states; In an engine supercharging control device, the control valve is turned on when the load is high, the control valve is opened when the load is low, and the control valve is closed when the load is high; , when the air pump is decelerated in the drive-on state in response to the output from the deceleration detecting means, the drive-on state of the air pump and the closed state of the control valve are maintained for a predetermined period of time, and the drive of the air pump is turned off. 1. A supercharging control device for an engine, comprising: deceleration control means for delaying opening operation of a control valve from a closed state.