JPH05272348A - Supercharger controller - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent unnecessary start / stop operation of the mechanical turbocharger to improve drivability, fuel efficiency, and durability of the turbocharger clutch. [Structure] Counter CT when in supercharger operating range
1 is increased by a predetermined amount a (steps 110 and 115),
If there is not, decrease by a predetermined amount b (step 11
0, 120). In the supercharger, the counter CT1 has a predetermined value CT2.
It is operated at the above times, but is not operated at CT2 and below (steps 145 and 165). As a result, the delay time of the supercharger start / stop operation changes according to the period of operation in each of the supercharger operating region and the non-operating region, so that unnecessary supercharger start / stop operation is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a supercharger mechanically driven from an engine output shaft (hereinafter referred to as "mechanical supercharger").
The present invention relates to a supercharging control device using.

[0002]

2. Description of the Related Art In an engine having a mechanical supercharger, the supercharger is driven from an engine output shaft via a clutch, and the clutch is turned on (connected) or turned off (released) according to the load condition of the engine. The supercharger is operating and stopping.
That is, the clutch is turned on when the engine is under high load operation.
The turbocharger is operated to increase the engine output due to supercharging, and the clutch is turned off to stop the turbocharger during low load operation that does not require supercharging. It is preventing the deterioration.

In such a supercharger, generally, in order to prevent the ON / OFF of the clutch from being repeated due to a temporary change in load condition, a delay time is provided in the OFF operation of the clutch to change the operating frequency of the clutch. It is being reduced to improve the durability of the clutch. An example of such a supercharging control device is disclosed in Japanese Patent Laid-Open No. 61-294135. The device disclosed in the publication has a clutch ON.
It is characterized in that the delay time when performing the clutch-off operation from the state is set to be shorter as the engine speed is lower.

By setting the delay time as described above, the delay time becomes long when the engine speed is high,
The clutch durability can be improved by decreasing the clutch operation frequency, and the delay time can be shortened when the engine speed is low, so that the fuel consumption can be improved by decreasing the supercharger operation time.

[0005]

Conventionally, the ON / OFF control of the clutch of the mechanical supercharger is carried out only on the basis of the engine load conditions such as the engine speed and the load. History is not considered. In the device disclosed in Japanese Patent Laid-Open No. 67-294135, the delay time at the clutch OFF operation is changed according to the engine speed, but the history of the engine operating state is not considered and the engine speed is the same. If so, the delay time is always set to be constant. Further, when the clutch is turned on, no delay time is provided, and if the condition is satisfied, the clutch is immediately connected and the supercharger operates. Therefore, for example, when the accelerator is temporarily returned while traveling on a long uphill road, the turbocharger will stop immediately if the engine speed is low, and the drive torque will drop and the accelerator will be depressed again. However, if the accelerator is temporarily depressed while driving on a long downhill road, the supercharger will start immediately, resulting in unnecessary use of the supercharger. There was a problem that the durability and fuel consumption of the clutch might deteriorate due to the stoppage.

Even in the apparatus disclosed in Japanese Patent Laid-Open No. 61-294135, if the delay time is set even when the clutch is turned on and the delay times for both ON and OFF are set to be long as a whole, the above problem is solved to some extent. Although it is possible, if the delay time is set to be long uniformly, there arises a problem that the time delay in operating the supercharger according to the load condition becomes large during normal traveling.

In view of the above problems, the present invention provides a supercharging control device capable of preventing unnecessary start / stop of a supercharger and preventing deterioration of drivability and fuel consumption and deterioration of clutch durability. Has a purpose.

[0008]

According to the present invention, a supercharger C driven from an output shaft of an engine A through a clutch B and a load of the engine A, as shown in the diagram of the invention of FIG. Operation determining means D for determining whether or not it is in the condition supercharger operating region, and control means for controlling the operation of the supercharger C by connecting or releasing the clutch B according to the determination result of the operation determining means D. G, a comparison unit E for comparing a period in which the operation determining unit D determines that the load condition of the engine A is in the supercharger operating region and a period in which the operation determining unit D determines that the load condition is not in the supercharger operating region, and the comparison result. Based on the connection of the clutch B of the control means G,
There is provided a supercharging control device having a delay time setting means F for setting a delay time of a releasing operation.

[0009]

The delay time setting means F sets a longer delay time for the clutch OFF (release) operation of the control means G as the engine load condition is in the supercharger operating region for a longer period. The longer the period in the non-operation area, the longer the delay time of the clutch ON (connection) operation of the control means G is set.

That is, for example, when the vehicle is traveling on a long uphill road in a supercharger operating state, the period in the supercharger operating region becomes longer, and accordingly the clutch O of the control means G is increased.
The FF operation delay time is set long. Therefore, when the accelerator is temporarily returned, the clutch is not turned off and the drivability is not deteriorated due to the torque reduction. Further, when the vehicle is traveling on a long downhill road in the non-supercharger operation state, the period in the non-supercharger operation area becomes longer, and accordingly the clutch ON operation delay time of the control means G becomes longer. Therefore, the clutch is not turned on by a temporary depression of the accelerator, and unnecessary supercharger start / stop does not occur.

[0011]

FIG. 2 shows the structure of a supercharging control device of the present invention.
In the figure, 1 is an engine, 2 is an intake pipe of the engine, and 8 is a throttle valve, which opens and closes an intake passage of the intake pipe 2 according to an operation of an accelerator pedal (not shown) by a driver. Reference numeral 3 is a mechanical supercharger provided in the intake pipe downstream of the throttle valve 8.

The supercharger 3 is mechanically driven by a belt or the like from a pulley 4 provided on the crankshaft of the engine 1 via a clutch 5 and is operated and stopped by the clutch 5 being disengaged. In this embodiment, an electromagnetic clutch that can be turned on / off by an electric signal is used as the clutch 5, and a positive displacement roots compressor is used as the supercharger 3. Reference numeral 6 in the drawing denotes an intake bypass passage that bypasses the supercharger 3 and connects the intake pipe on the downstream side of the throttle valve 8 and the intake pipe on the outlet side of the supercharger. A bypass control valve 7 is provided in the intake bypass passage 6, and the amount of air passing through the bypass passage 6 can be continuously adjusted by changing the opening degree of the bypass control valve 7 by an actuator 10 such as a stepper motor.

If the opening degree of the bypass control valve 7 is set to a large value, the amount of air flowing back from the discharge side of the supercharger 3 through the bypass passage 6 to the upstream side increases, and the compression ratio of the supercharger decreases, so Supply pressure is reduced. On the contrary, when the opening degree of the bypass control valve 7 is set to be small, the amount of the recirculated air is reduced and the supercharging pressure is increased. Therefore, even at the same supercharger speed, the supercharging pressure can be changed by changing the opening degree of the bypass control valve 7.

Reference numeral 20 in the drawing denotes a control circuit for carrying out supercharging control according to the present invention. In this embodiment, a known type of digital computer is used as the control circuit, and the control circuit 20 for performing the control of the present invention includes a throttle sensor 14 for detecting the opening of the throttle valve 8 and an engine speed. Outputs of a rotation speed sensor 12, a vehicle speed sensor 11 for detecting a vehicle traveling speed, an opening sensor 16 for detecting an opening degree of the bypass control valve 7, and an air flow meter 13 for detecting an intake air amount are respectively inputted.

The output port of the control circuit 20 is connected to the actuator 10 of the bypass control valve 7 and the electromagnetic clutch 5 of the supercharger 3 via a drive circuit (not shown), and controls the opening degree of the bypass control valve 7 respectively. The electromagnetic clutch 5 is connected and released. Next, FIG. 3 shows a flowchart of an embodiment of the supercharging control operation of the present invention. This routine is executed by the control circuit 20 at regular intervals (for example, every 0.5 seconds).

When the routine starts in the figure, in step 100, operating parameters such as the engine speed NE, the vehicle speed VS, the throttle valve opening TA, and the intake air amount Q are read from the corresponding sensors. Next, the throttle 105 determines whether the vehicle speed VS is higher than a predetermined value VSo. In this embodiment, VSo is set to about 5 km / h, and the counter CT1 is cleared when the state of VS ≦ VSo continues for a predetermined time as described later.

If VS> VSo, it is determined in step 110 whether the engine load condition is in the supercharger operation region. In the present embodiment, the determination of the supercharger operating region is performed using the engine load (throttle valve opening TA) and the engine speed NE. FIG. 4 shows an example of setting the supercharger operating region. As shown in FIG. 4, the load at which the supercharger operates (throttle valve opening TA) is set low in a region where the rotational speed NE is high. As the parameter indicating the load, the intake air amount Q / NE per engine revolution may be used instead of the throttle valve opening TA. In this embodiment, the control circuit 2
0 stores the function of FIG. 4 as a map and determines the supercharger operating region.

When it is judged in step 110 whether or not it is in the supercharger operating region, in steps 115 and 120 the counter CT1 is increased or decreased according to the judgment result.
That is, if it is in the operating region, the predetermined value a is added to CT1 (step 115). If it is not in the operating region, CT1 is added.
The predetermined value b is subtracted from. Then steps 125, 1
In step 30 and steps 135 and 140, CT1 is guarded by the upper limit value CT1max and the lower limit value CT1min, respectively.

Step 145 is a judgment as to whether or not the supercharger can be operated. In this embodiment, it is determined in step 110 whether or not the engine load condition is in the supercharger operating region, but depending on the result, the supercharger is not immediately started and stopped, and the counter C
The supercharger is started and stopped based on the value of T1. That is, when CT1 is larger than the predetermined value CT2 in step 145, the process proceeds to step 150, the electromagnetic clutch is turned on to operate the supercharger, and in step 155, the bypass control valve opening degree is set according to the load condition. Adjust the supply pressure. In this embodiment, the bypass control valve opening θb is set based on the throttle valve opening TA based on the map of FIG. 5, and the opening decreases and the boost pressure increases as the engine load (throttle valve opening TA) increases. It is like this. If CT1 is less than or equal to the predetermined value CT1 in step 145, step 1
At 60, the electromagnetic clutch is turned off to stop the supercharger, and at step 165, the bypass control valve is set to a predetermined opening (for example, fully open).

When the vehicle speed VS is equal to or lower than VSo in step 105, the vehicle speed is V in steps 170 and 175.
When the state of So or lower continues for a predetermined time To or longer, the value of CT1 is cleared. In this way, by controlling the operation of the supercharger based on the value of the counter CT1, it is possible to reflect the history of past operating states in the supercharge control.

That is, since the value of the counter CT1 is sufficiently increased in steps 110 to 130 when the vehicle is traveling on a long uphill road, step 120 is executed even if the accelerator is temporarily returned. Therefore, since CT1 ≦ CT2 is not immediately satisfied, the supercharger is not stopped and the drivability is not deteriorated. On the contrary, when traveling on a long downhill road, the value of CT1 is sufficiently small, so that even if the accelerator is temporarily depressed, CT1> CT2 does not immediately hold, which is unnecessary. Start / stop of the supercharger is prevented.

FIGS. 6A to 6D are diagrams showing the effects when the supercharging control of FIG. 3 is performed. 6 (A) to (D)
The horizontal axis represents time, and the vertical axis represents throttle valve opening TA (FIG. 6 (A), vehicle speed VS (FIG. 6 (B)), counter CT1 value (FIG. 6 (C)), electromagnetic clutch (overload). 6D shows the operating state of the feeder, the vehicle is in a stopped state in a section I in the drawing (FIG. 6B), and the counter CT1 is shown.
Is zero (step 175 in FIG. 3, FIG. 6).
(C)).

Therefore, in this state, when the accelerator is depressed and the engine is left empty (FIG. 6A, A).
Point), the turbocharger does not operate (solid line in FIG. 6D). Figure 6
(D) The dotted line shows the operation of the supercharger by the conventional control. Conventionally, even in such a case, unnecessary operation stop of the supercharger has been repeated (point A ′ in FIG. 6 (D)). Next, section II
Indicates that the vehicle is traveling on a long hill or is being accelerated slowly. (Fig. 6
(A), (B)). In this state, CT1 increases and becomes approximately equal to the guard value CT1max (FIG. 6).
(C)), therefore, even if the accelerator is temporarily returned (point B in FIG. 6A), CT1 immediately changes to CT.
It does not fall below 2 (FIG. 6C), and the turbocharger can only be stopped as in the conventional case (dotted line in FIG. 6D) (FIG. 6C).
(D) Solid line).

Similarly, in section III, the vehicle is in a slow deceleration state (Fig. 6 (A)).
(B)) In this case as well, according to the control of the present invention, the accelerator is temporarily depressed during deceleration (see FIG. 6).
Even at points (A) and (C), the turbocharger did not work immediately (Fig. 6).
(C), (D), unnecessary start / stop of the supercharger can be prevented. In this embodiment, CT1 upper limit value CT1max and lower limit value C
Although guarded at T1min (Fig. 3, step 13
0, 140), which prevents the delay in starting and stopping the supercharger from becoming excessive.

In this embodiment, the value of CT2 (step 145 in FIG. 3) is constant, but the value of CT2 depends on the load (throttle opening TA or intake air amount Q / NE per engine revolution). It may be changed, for example, in FIG.
If the value of CT2 is made smaller as the load becomes heavier, the supercharger can be operated more easily at the time of high load when supercharging is required.

Similarly, the increment a and the decrement b of the counter CT1 (steps 115 and 120 in FIG. 3) are not set to constant values but may be changed according to the vehicle speed VS, the load (throttle valve opening TA), and the like. good. In this case, for example, when the vehicle speed VS is higher or the throttle valve opening TA is larger, the increase amount a of CT1 is larger and the decrease amount b is smaller, so that the vehicle speed is high and the load is large. It is possible to make the supercharger easier to operate. In this way, by changing the judgment value CT2 of CT1, the increase amount a, the decrease amount b, and the like according to the operating parameters, it is possible to change the operating characteristics depending on the vehicle type and the usage situation even with the same engine. Become.

[0027]

According to the present invention, as described above, the delay time when the supercharger is started and stopped is determined in consideration of the past history of operating conditions, so that unnecessary supercharging can be avoided. It is possible to prevent the start and stop of the machine, prevent the deterioration of drivability and fuel consumption, and reduce the durability of the clutch.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of the present invention.

FIG. 2 is a diagram showing a configuration of an embodiment of a supercharging control device of the present invention.

FIG. 3 is a flowchart showing an embodiment of the supercharging control operation of the present invention.

FIG. 4 is a diagram showing a supercharger working load region.

FIG. 5 is a diagram showing a bypass control valve opening setting.

FIG. 6 is a diagram illustrating an effect of the supercharging control device of the present invention.

FIG. 7 is a diagram showing another example of setting the determination value CT2. 1 ... Engine 2 ... Intake pipe 3 ... Supercharger 5 ... Electromagnetic crunch 6 ... Bypass passage 7 ... Bypass control valve 8 ... Throttle valve 13 ... Air flow meter 14 ... Throttle sensor 16 ... Bypass opening sensor 20 ... Control circuit

Claims (1)

[Claims] 1. A supercharger mechanically driven from an engine output shaft through a clutch, operation determining means for determining whether or not an engine load condition is in a supercharger operating region, and the operation determining means. In a supercharger control device including a control means for controlling the operation and stop of the supercharger by connecting or releasing the clutch according to the determination result of 1. Comparing means for comparing a period in the supercharger non-operating region, and operation of the control means for releasing the clutch from the clutch connected state as the period in the supercharger operating region is longer based on the comparison result. A delay time setting means for setting a longer delay time and a longer operation delay time of the control means when connecting the clutch from the clutch released state as the period in the supercharger non-operating region is longer is provided. And a supercharging control device.