JP3095854B2 - Control device for engine with auto cruise device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an engine equipped with an auto cruise device which does not change the output characteristics of the engine when the auto cruise device is operating.

[0002]

2. Description of the Related Art Conventionally, means for changing the length of an intake passage of an engine, the cross-sectional area of a passage of an intake port, the opening / closing timing of an intake valve, the boost pressure of intake air, and the like have been provided, and these have been changed to the operating state of the engine. The output characteristics of the engine are changed by controlling the switching so that the intake charge is increased at a high load where a high output is required, and the intake charge is reduced at a low load where a low output is not required. There are various known engine control techniques designed to achieve both output performance and fuel efficiency.

For example, Japanese Patent Application Laid-Open No. Hei 2-221634 discloses an air intake bypass passage which bypasses a supercharger provided in an air intake passage, and an air bypass valve which opens and closes the air intake bypass passage is provided in the air intake bypass passage. At high load, the air bypass valve is closed to supply pressurized air pressurized by the turbocharger to the engine, while at low load, the air bypass valve is opened to supply unpressurized air to the engine through the intake bypass passage. A means for varying the amount of intake air charged is disclosed.

[0004]

By the way, in the case of a vehicle in which an automatic cruise device is further mounted on an engine in which the output characteristic is switched by varying the amount of intake air as described above, the automatic cruise device is operated. When the running state of the engine changes from low load to high load, or vice versa, due to changes in running resistance during that time, the output characteristics of the engine are switched with the change. There has been a problem that a sudden change occurs, and this causes disturbance in constant speed traveling control of the vehicle by the auto cruise device.

The present invention has been made in view of such circumstances, and a purpose of the present invention is to provide a control device for an engine with an auto-cruise device in which the output characteristics of the engine are not changed when the auto-cruise device is operated. Is to provide.

[0006]

To achieve the above object of the Invention The invention according to claim 1, the auto-cruise device for controlling the throttle opening of the engine to keep the vehicle speed, selecting the vehicle speed, operation of the engine An intake air charge amount variable means other than a throttle device that changes the intake air charge amount according to the state;
When detecting the start of the auto-cruising device, the standing
The operation state of the intake air charging amount variable means at the time
And knowledge, d the operating state of the sensed intake air charging amount changing means
Fixing means for continuously and forcibly fixing the engine regardless of the operating state of the engine .

According to a second aspect of the present invention, the vehicle speed is set to a selected vehicle speed.
Auto to control engine throttle opening to keep
Cruise device and intake charging depending on engine operation status
A variable intake charge other than a throttle device that changes the amount
And when the start of the auto cruise device is detected
In response to the signal from the auto cruise system,
If the vehicle speed is higher than the preset supercharging necessity judgment vehicle speed
Means for changing the intake charge amount so as to increase the intake charge amount.
Operation is forcibly fixed and the selected vehicle speed is set in advance.
If the vehicle speed is lower than the
Force the operation of the intake charge variable means so as to eliminate
And fixing means for fixing the fixing means.

According to a third aspect, the first and second aspects are described.
In the above, the intake charging amount variable means may be constituted by a supercharger provided in an intake system of the engine and a supercharge limiting means for restricting supercharging by the supercharger according to an operation state of the engine. .

[0009] As set forth in claim 4, in claim 3,
The supercharging restricting means may be an intake bypass means including an intake bypass passage bypassing the turbocharger and an air bypass valve opening and closing the intake bypass passage.

[0010]

According to the first and second aspects of the present invention, when the auto-cruise system is started, the operation of the intake charge variable means other than the throttle device is forcibly fixed, and the engine output is changed by changing the intake charge. Since the characteristics cannot be changed, the engine output will not change even if the operating state of the engine changes from high load to low load or from high load to low load due to changes in running resistance during constant speed running control by the auto cruise device. The constant-speed running control by the auto-cruise device is performed smoothly without a sudden change. In particular,
In the invention according to claim 1, the auto cruise device is activated.
Operating state of the intake air amount variable means at
It is maintained and forcibly fixed.
State of the intake air charge variable means in synchronization with the start of cruise
To prevent sudden changes in output characteristics due to changes in
Can be. In the invention according to claim 2, the selected vehicle speed is
At high speeds, intake charge is variable with large intake charge
Since the means is fixed, high-speed followability is improved, and the selected vehicle speed
At low speeds, the intake charge can be reduced when the intake charge is small.
Since the changing means is fixed, fuel efficiency can be improved.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a schematic configuration diagram of a control device of an engine with an auto cruise device according to the present invention. In FIG. 1, reference numeral 2 denotes an engine, and an air flow meter 6, a throttle valve 8, and a mechanical supercharger 10 are arranged in an intake passage 4 of the engine 2 from the upstream side. The mechanical supercharged air 10 is driven by the rotational force of an engine output shaft 14 via a belt transmission device 12, and a pulley 12a on the engine output shaft 14 side is provided with an electromagnetic clutch mechanism (not shown). Is attached and its operation is ON-
It can be turned off. The intake passage 4 is provided with an S / C bypass passage 16 that branches off from the downstream side of the throttle valve 8 and bypasses the mechanical supercharger 10.
8 and the bypass passage 1 when the engine 2 is under a low load.
An air bypass valve (abbreviated ABV) 20 for opening the valve 6 is provided.

The actuator 18 has a diaphragm 2
One of the two working chambers 22a communicates with the downstream side of the ABV 20 in the bypass passage 16 through the chamber 24, and the other working chamber 22b communicates with the downstream side of the throttle valve 8 in the intake passage 4 and the atmosphere through a three-way solenoid valve 26. The communication is selectable. ABV20 is actuator 1
When the other working chamber 22b is communicated with the downstream side of the throttle valve 8, the two working chambers 22a, 22b are fully closed by the spring force of the spring 22c when the pressures of the two working chambers 22a, 22b are balanced, and the three-way solenoid valve 26 is opened to the atmosphere introduction side. Is opened by the pressure difference between the two working chambers 22a and 22b.

The three-way solenoid valve 26 for controlling the operation of the actuator 18 of the ABV 20, the throttle valve 8 and the electromagnetic clutch of the belt transmission 12 are controlled by a control unit 28 comprising a microcomputer in accordance with a control program incorporated therein. . The control unit 28 receives, as information for controlling them, an engine speed signal, a boost signal, a vehicle speed signal, an auto cruise switch signal, a target vehicle speed selection switch signal, and the like.

That is, when the auto cruise switch is turned on, the control unit 28 compares the selected vehicle speed V0 set by the target vehicle speed selection switch with the vehicle speed Va detected by the vehicle speed sensor, and determines the detected vehicle speed Va as the selected vehicle speed V0.
The operation of an actuator 8a such as a stepping motor attached to the throttle valve 8 is controlled so as to converge on the throttle valve 8, and is configured as a so-called auto cruise device. Also, the control unit 28
Detects the operating state of the engine 2 from the engine speed and the boost pressure, and controls the operation of the three-way solenoid valve 26 according to the operating state to open and close the ABV 20. The ABV2 is configured as a so-called intake charge variable means for changing the intake charge of the engine 2 by performing
The operation of the electromagnetic clutch of the belt transmission 12 is also controlled in synchronization with the opening and closing of 0.

Further, when the auto cruise switch is turned on, the control unit 28 forcibly fixes the operation of the intake air amount changing means and does not change the output characteristics of the engine 2 during the operation of the auto cruise device. It is configured as an operation fixing means of the intake air charging amount varying means.

FIG. 2 is a flowchart showing an outline of control by the control unit 28. As shown in the figure, first, the control unit 28 reads signals from various sensors (S10), determines whether the auto cruise switch is ON (S20), and if the auto cruise switch is OFF (S20, S20). (No) Then, it is determined from the boost pressure (P) and the rotational speed (Ne) whether or not the operating state of the engine 2 is within the supercharging region (S3).
0).

Here, this judgment is made based on the load (CE) and the rotational speed (Ne) stored in the ROM in advance.
In this map, a range in which the boost pressure (P) is equal to or higher than a predetermined value (AmmHg) is a supercharging region in which the ABV 20 is closed, and a range in which the boost pressure (P) is equal to or lower than the predetermined value (shaded area) is ABV20. Is open to a non-supercharged area.

If the determination in S30 is Yes and the operating state of the engine 2 is within the supercharging region, an ON signal is transmitted to the three-way solenoid valve 26 to close the ABV 20 (S40, S50), An ON signal is transmitted to the clutch to drive the mechanical supercharger 10 (S60).
If the determination in S30 is No and the operating state of the engine 2 is in the non-supercharging region, an OFF signal is transmitted to the three-way solenoid valve 26 to open the ABV 20 (S70,
At the same time as S80), an OFF signal is transmitted to the electromagnetic clutch to stop driving the mechanical supercharger 10 (S90). That is, the intake air charging amount varying means is appropriately operated in accordance with the operation state of the engine 2, and in a high load state where high output is required, supercharging is performed to increase the engine output. In a load state, supercharging is stopped to improve fuel efficiency.

On the other hand, if the judgment in S20 is Yes and the auto cruise switch is in the ON state, the process proceeds to an operation fixing control routine for forcibly fixing the operation of the intake air charging amount varying means.

As shown in FIG. 3, in this operation fixed control routine, a selected vehicle speed V0 input from a target vehicle speed selection switch is read (S100), and the selected vehicle speed V0 is set in advance to determine whether supercharging is necessary. It is determined whether the vehicle speed is equal to or higher than the determination vehicle speed Vs (S110). And this judgment is Y
If the selected vehicle speed V0 is higher than the supercharging necessity determination vehicle speed Vs in es, an ON signal is transmitted to the three-way solenoid valve 26 to close the ABV 20 (S120, S13).
At the same time, the mechanical supercharger 10 is driven by transmitting an ON signal to the electromagnetic clutch (S140). In addition, the determination in S110 is No, and the selected vehicle speed V0 is the supercharging necessity determination vehicle speed Vs.
In the case of the following low speed, the three-way solenoid valve 26
To send the OFF signal to open the ABV 20 (S150,
At the same time as S160), an OFF signal is transmitted to the electromagnetic clutch to stop driving the mechanical supercharger 10. That is, when the auto cruise device is started, regardless of the operating state of the engine 2 detected thereafter, if the selected vehicle speed V0 set by the target vehicle speed selecting switch is a high speed requiring a high output, it is excessive. The supercharging is stopped at a low speed that does not require high output.

FIG. 4 shows a modified embodiment of the operation fixing control routine. In the case of this operation fixing control routine, it is first determined whether or not the ABV 20 is currently open, and if the ABV 20 is open (S210, Yes),
An OFF signal is sent to the three-way solenoid valve 26 to keep the ABV 20 open (S220,
Along with S230), an OFF signal is also transmitted to the electromagnetic clutch (S240), and the driving of the mechanical supercharger 10 is kept stopped. If the determination in S210 is No, ABV2
If 0 is closed, an ON signal is sent to the three-way solenoid valve 26 as it is to keep the ABV 20 closed (250, S260), and an ON signal is also sent to the electromagnetic clutch to send the mechanical supercharger 10 Remain driven (S270). That is, in the case of the operation fixing control routine of this modification, the operation state of the intake air charge amount varying means at the time when the auto cruise device is started is maintained as it is and is forcibly fixed. It is suitable for use in an auto-cruise system of a type that does not have a vehicle speed selection switch and that sets the vehicle speed at the time of startup as it is as the target selection vehicle speed.

As shown in the operation fixing control routine of FIG. 5, when the auto cruise device is started, an OFF signal is immediately transmitted to the three-way solenoid valve 26 to execute the ABV operation.
20 is opened (S310, S320), and at the same time, an OFF signal is transmitted to the electromagnetic clutch to stop driving the mechanical supercharger 10 (S330). Alternatively, on the contrary, as shown in the operation fixing control routine of FIG.
As soon as the auto cruise device is started, an ON signal is transmitted to the three-way solenoid valve 26 to close the ABV 20 (S410, S420) and to turn on the electromagnetic clutch.
A signal is transmitted to drive the mechanical supercharger 10 (S43).
0), the constant speed traveling control by the auto cruise device may be performed in the supercharging state.

Further, in the illustrated embodiment, the intake air amount changing means constituted by the mechanical supercharger and the intake bypass mechanism thereof is exemplified, but the present invention is not limited to this.
As the intake charging amount varying means, an intake passage length varying mechanism, an intake port passage sectional area varying mechanism, a valve timing variable mechanism of an intake valve, or the like can be adopted.

[0024]

As described in detail in the above embodiment, according to the control apparatus for an engine with an auto cruise device according to the present invention, when the auto cruise device is started, the intake air charging amount variable means other than the throttle device. The operation of the engine is forcibly fixed and the engine output characteristics cannot be changed by changing the intake air charge. Even when the load changes or the load changes from a high load to a low load, the constant speed traveling control by the auto cruise device is smoothly performed without a sudden change in the engine output. In particular, in the invention according to claim 1, the auto cruise
The operation of the intake air amount variable means at the time when the device is started
The moving state is maintained and it is forcibly fixed.
So that the intake charge is synchronized with the auto cruise start
Sudden change in output characteristics due to change in state of variable means
Can be prevented. In the invention according to claim 2,
If the selected vehicle speed is high,
High-speed followability is improved because the intake air amount variable means is fixed.
However, if the selected vehicle speed is low, the intake charge is small.
, The intake charge variable means is fixed, improving fuel efficiency.
I can do it.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of a control device for an engine with an auto cruise device according to the present invention.

FIG. 2 is a flowchart showing an outline of control contents in a control device of the engine with an auto-cruise device shown in FIG.

FIG. 3 is a flowchart showing the contents of an operation fixing control routine shown in FIG. 2;

FIG. 4 is a flowchart of a modified embodiment showing the contents of an operation fixing control routine shown in FIG. 2;

FIG. 5 is a flowchart of another modified embodiment showing the operation fixing control routine shown in FIG. 2;

FIG. 6 is a flowchart of a further modified embodiment showing the contents of the operation fixing control routine shown in FIG. 2;

[Explanation of symbols]

 2 Engine 4 Intake passage 6 Air flow meter 8 Throttle valve 8a Actuator 10 Mechanical supercharger 16 S / C bypass passage 18 Diaphragm actuator 20 Air bypass valve (ABV) 26 Three-way solenoid valve 28 Control unit

──────────────────────────────────────────────────続 き Continuation of front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F02D 29/00-29/06 B60K 31/00 F02B 33/00

Claims (4)

(57) [Claims] An automatic cruise control device for controlling a throttle opening degree of an engine so as to maintain a vehicle speed at a selected vehicle speed; an intake charge variable means other than a throttle device for changing an intake charge according to an operation state of the engine; when detecting the start of the auto-cruising device, the standing
The operation state of the intake air charging amount variable means at the time
And knowledge, d the operating state of the sensed intake air charging amount changing means
A control device for an engine with an auto cruise device, comprising: fixing means for continuously and forcibly fixing the engine regardless of the operation state of the engine. The engine is controlled to maintain the vehicle speed at a selected vehicle speed.
An auto cruise system that controls the throttle opening and a switch that changes the intake air charge according to the operating state of the engine
When the start-up of the auto cruise device and the intake air amount variable means other than the rottling device are detected,
The selected vehicle speed is preset in response to the signal from the cruise device
If the vehicle speed is higher than the required
The operation of the intake charge amount changing means is increased so that the charge amount is increased.
Supercharging required, forcibly fixed and preset vehicle speed is set
If the vehicle speed is lower than the no-judgment vehicle speed, the intake charge amount will decrease.
The operation of the intake air amount changing means is forcibly fixed as described above.
Controller of the auto-cruise device motorized, characterized in that it comprises a fastening means that, the. 3. The engine according to claim 1, wherein said intake air charging amount varying means includes an engine charging amount varying means.
The turbocharger provided in the intake system and the turbocharger
And supercharging limiting means for limiting according to the operating state of the gin.
The control device for an engine with an auto cruise device according to any one of claims 1 to 2, wherein: 4. The system according to claim 1 , wherein said supercharging restricting means bypasses said supercharger.
Opening and closing the intake bypass passage
Intake bypass means consisting of an air bypass valve
The control device for an engine with an auto cruise device according to claim 3 , wherein