JPH1182085A - Mechanical supercharger control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the driveability of a mechanical supercharger with a clutch by masking clutch engaging shocks. SOLUTION: Step 5 serves to detect a kickdown or a downshift in an automatic transmission caused by a sudden increase in the throttle opening angle. At a kickdown, Step 7 engages the clutch of a mechanical supercharger after the lapse of the first predetermined time T1 from the kickdown detection point. Subsequently, Step 8 fully closes the bypass valve of the supercharger on the kickdown detection, and then fully opens the valve after the lapse of the second predetermined time T2 longer than the first time T1 from the kickdown detection point.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle provided with an internal combustion engine having a mechanical supercharger (supercharger) driven by an engine output shaft via a clutch in an engine intake system, and an automatic transmission. The present invention relates to a control device for a mechanical supercharger for achieving both acceleration performance improvement and shock reduction.

[0002]

2. Description of the Related Art A conventional apparatus of this kind is disclosed in, for example, Japanese Patent Application Laid-Open No. 7-195963. This is because during a kick-down (step-down shift), which is a shift to a lower gear stage due to an increase in the throttle opening of the automatic transmission, the mechanical turbocharger is bypassed and the upstream and downstream of the engine intake system is bypassed. By suppressing the supercharging pressure by increasing the opening of the bypass valve of the bypass passage to be connected, the transmission shock is reduced by suppressing the supercharging pressure in response to the transmission shock caused by kickdown, thereby reducing the transmission shock. .

[0003]

However, in such a conventional device, although the shift shock can be reduced, a mechanical supercharger with a clutch has a clutch OFF → ON shock, and the shift timing is reduced. There was a problem that the shock was transmitted to the driver when the clutch was changed from OFF to ON before.

[0004] Also, although the shift shock can be reduced,
There is also a problem that the acceleration performance is deteriorated by uniformly suppressing the supercharging pressure. In view of such a conventional problem, the present invention aims to improve drivability by masking the clutch from OFF to ON in a mechanical supercharger with a clutch, and to achieve both improvement in acceleration performance and reduction in shock. The purpose is to plan.

[0005]

According to the first aspect of the present invention, there is provided an internal combustion engine having a mechanical supercharger driven by an engine output shaft via a clutch in an engine intake system, and an automatic transmission. In a vehicle equipped with, as shown in FIG.
Kick-down detecting means for detecting a kick-down, which is a shift to a lower speed side with an increase in the throttle opening in the automatic transmission, and clutch connecting means for connecting the clutch in synchronization with the kick-down. Thus, a control device for the mechanical supercharger is configured.

According to the second aspect of the present invention, the bypass valve further controls the degree of opening of the bypass valve in the bypass passage that connects the upstream and downstream of the engine intake system by bypassing the mechanical supercharger in synchronization with kickdown. A control means is provided. The invention according to claim 3 is characterized in that the clutch connecting means connects the clutch with a delay of a first predetermined time T1 from the detection of kickdown.

[0007] In the invention according to claim 4, the clutch connecting means is provided with a first predetermined time T1 after the kickdown is detected.
The bypass valve control means controls the bypass valve to be almost fully closed by detecting a kick-down, and then controls the bypass valve for substantially the second predetermined time T2 (where T2 ≧ T1) from the detection of the kick-down. ) The opening degree of the bypass valve is controlled to be almost fully opened with a delay.

The invention according to claim 5 is characterized in that the bypass valve control means gradually reduces the opening of the bypass valve after the end of the kick down shift.

[0009]

According to the first aspect of the present invention, the clutch of the mechanical supercharger is connected in synchronization with the kick down, thereby increasing the torque at the time of kick down and reducing the torque by turning the clutch from OFF to ON. , The masking of the clutch from the OFF to the ON shock of the clutch can be achieved, and at the same time, the shift shock can be reduced.

According to the second aspect of the present invention, finer torque control becomes possible by controlling the opening of the bypass valve of the mechanical supercharger in synchronization with kickdown. According to the third aspect of the invention, by connecting the clutch by delaying the first predetermined time T1 from the detection of the kick down,
OFF → ON of the clutch can be adjusted to the torque peak at the time of shifting, which is more effective.

According to the fourth aspect of the present invention, the clutch is connected with a delay of the first predetermined time T1 from the detection of kickdown, and the control of the bypass valve is controlled to be almost fully closed by the detection of kickdown. By controlling the valve to be almost fully opened after the second predetermined time T2, the mechanical turbocharger can be rotated in the run-up state before the clutch is turned on by substantially completely closing the bypass valve at the beginning of kick down, and the bypass at the later stage of kick down can be performed. By substantially fully opening the valve, the supercharging pressure immediately after the clutch is turned on can be suppressed, and the torque peak during shifting can be suppressed.

According to the fifth aspect of the invention, the torque increase after the end of the shift can be made smooth by gradually decreasing the opening of the bypass valve after the end of the kick-down shift.

[0013]

Embodiments of the present invention will be described below. FIG. 2 is a system diagram showing one embodiment. The internal combustion engine 1 is provided with a mechanical system 3 of a Roots type or a Reschorm type downstream of an intake system, here a throttle valve 2.
have. The mechanical supercharger 3 is driven by an engine output shaft 4 via a pulley / belt mechanism 5 and an electric clutch 6. Also, in the intake system,
The engine includes a bypass passage 7 that bypasses the mechanical supercharger 3 and connects the upstream and downstream of the intake system, and a bypass valve 8 of, for example, a duty control type interposed in the bypass passage 7.

The engine control control unit 9 controls the fuel injection amount and the ignition timing in accordance with the engine operating conditions, controls the ON / OFF of the clutch 6 and controls the opening of the bypass valve 8. The automatic transmission 10 includes the engine 1
And a gear transmission mechanism 12 connected via the torque converter 11.
And a hydraulic actuator 13 for connecting and releasing various speed-change elements in the gear transmission mechanism 12.
The operating oil pressure for the hydraulic actuator 13 is turned on via various electromagnetic valves (shift solenoids) not shown.
・ OFF control is performed.

Control unit 1 for controlling automatic transmission
Reference numeral 4 denotes a throttle sensor 15 for detecting the throttle opening θ, and an engine speed sensor 1 for detecting the engine speed Ne.
6. Various signals are input from the transmission output shaft rotation speed sensor 17 for detecting the transmission output shaft rotation speed No.
Here, the automatic transmission control control unit 14
Automatically sets the first to fourth gear stages according to the transmission output shaft rotation speed (vehicle speed) No and the throttle opening degree θ, etc.
Is controlled to the shift speed.

The automatic transmission control unit 14 is connected to the engine control unit 9 via a communication line, and commands ON / OFF control of the clutch 6 and opening degree control of the bypass valve 8. Next, shift control and the like performed by the automatic transmission control unit 14 will be described with reference to the flowchart of FIG.

FIG. 3 is a flowchart of a shift control routine. In step 1 (referred to as S1 in the figure, the same applies hereinafter), the throttle opening θ, the engine speed Ne, the transmission output shaft speed No, and the like detected by the various sensors are read. In step 2, the transmission output shaft rotation speed (vehicle speed) N
The optimum shift speed is determined by referring to the shift map from o and the throttle opening θ.

In step 3, the current gear position and the optimum gear position are compared, and it is determined whether or not the gear positions are different and a shift operation is necessary. If the current gear position is different from the optimum gear position and a shift operation is necessary, the process proceeds to step 4, where an operation signal is output to a shift solenoid required for the current shift operation, and the operation signal is output via the hydraulic actuator 13. Thus, the gear transmission mechanism 12 is controlled to the optimum gear position.

In step 5, it is determined whether or not the current shift operation is a kick-down (step-down shift), which is a shift to a lower gear due to an increase in the throttle opening θ (Δθ ≧ predetermined value). This part corresponds to a kick down detection unit. In the case of kick-down, the process proceeds to step 6, in which the kick-down flag FKD is set to 1 and a timer T for measuring an elapsed time from the detection of kick-down is started from 0.

In step 7, control is performed so that the clutch 6 of the mechanical supercharger 3 is changed from OFF to ON after a first predetermined time T1 from the detection of kickdown. This part corresponds to the clutch connecting means. Then, in step 8, the bypass valve 8 of the mechanical supercharger 3 is temporarily fully closed, and the second predetermined time T2
After (however, T2 ≧ T1), control is performed so that the bypass valve 8 of the mechanical supercharger 3 is fully opened. This portion corresponds to bypass valve control means.

Then, in step 9, it is determined whether or not rapid acceleration (full-open acceleration) is performed based on the amount of change Δθ of the throttle opening, and in the case of rapid acceleration, an engine torque down signal is output in step 10 Then, the engine torque is reduced by retarding the ignition timing or the like. On the other hand, if it is not sudden acceleration, in step 11, the engine torque down signal is not output.

Next, at step 13, the engine speed Ne
The ratio R = No · G / Ne is calculated from the transmission output shaft rotation speed No and the gear ratio G of the optimum gear position.
Is determined to be equal to or less than a predetermined value R0 (shift end). If the ratio R ≦ R0 (shift end), steps 16 to 18 are executed as a process at the end of kickdown.

In step 16, the kick down flag F
KD = 0. In step 17, control for gradually decreasing the opening degree of the bypass valve 8 of the mechanical supercharger 3 is started, and finally, the bypass valve 8 is fully closed. This part also corresponds to the bypass valve control means. Then, in step 18, an engine torque down release signal is output, and this routine ends. On the other hand, if it is determined in step 3 that the current gear position and the optimal gear position are the same and it is determined that the gear change operation is unnecessary, the process proceeds to step 12 and the kick down flag FKD = 1
It is determined whether or not. As a result, the kick down flag FK
If D = 1 and it is determined that the kick down control is being performed, the routine proceeds to step 13, where it is determined whether or not the current shift ratio R has become equal to or less than a predetermined value R0 (shift end), and the ratio is determined. If R ≦ R0 (shift end), steps 16 to 18 are executed as processing at the end of kickdown. If it is determined that the kick-down control is not being performed with the kick-down flag FKD = 0, the routine is terminated.

If it is determined in step 5 that the current shift operation is not kick down, step 1 is executed.
Then, it is determined whether or not the kick down flag FKD = 1 is set. As a result, the kick down flag FKD = 1
If it is determined that kick down control is being performed, steps 16 to 18 are executed as a process at the end of kick down. If it is determined that the kick-down control is not being performed with the kick-down flag FKD = 0, the routine is terminated.

Further, in step 13, the ratio R> R
0, if it is determined that the shift is not completed,
The process proceeds to 4 to determine whether the timer T is equal to or greater than a predetermined value. As a result, if the timer T is equal to or greater than the predetermined value, the detection signal of the engine speed sensor 16 or the transmission output shaft sensor 17 may be abnormal. Steps 16 to 18 are executed as processing at the end of kickdown. If the timer T is smaller than the predetermined value, the routine ends.

Next, the operation will be described with reference to the time chart of FIG. During traveling before kickdown, the clutch 6 of the mechanical supercharger 3 is OFF. At this time, the bypass valve 8 is fully opened, the bypass amount is maximized, and the intake resistance by the mechanical supercharger 3 is reduced. It has been eliminated to prevent deterioration of fuel efficiency. Depressing the accelerator pedal, the throttle opening θ
Abruptly increases, the optimal gear shifts to the lower gear, and a kick down (downshift) is performed.

At this time, first, the bypass valve 8 of the mechanical supercharger 3 is temporarily fully closed to reduce the bypass amount, so that the intake air is passed through the mechanical supercharger 3 and The feeder 3 is rotated in advance before the clutch is turned on. And
When the first predetermined time T1 has elapsed since the kick down,
The clutch 6 of the mechanical supercharger 3 is switched from OFF to ON.

FIG. 5 shows the change in the engine load with respect to the OFF → ON (change in applied voltage) of the clutch 6 of the rechargeable mechanical supercharger 3.
By turning OFF from ON, the engine load temporarily shows a peak. Therefore, by connecting the clutch 6 of the mechanical supercharger 3 in synchronization with kick down, torque increase during kick down (peak of output shaft torque during shifting) and torque down due to clutch OFF → ON (engine load) Of the clutch), masking of the clutch from OFF to ON shock can be achieved, and at the same time, the shift shock can be reduced.

Then, when a second predetermined time T2 has elapsed from the kick down, the bypass valve 8 of the mechanical supercharger is fully opened to maximize the bypass amount, so that the clutch 6
By suppressing the supercharging pressure immediately after ON, the torque peak at the time of shifting can be further suppressed. Regarding the peak waveform of the transmission output shaft torque in FIG. 4, the peak of the transmission output shaft torque is extremely large when there is no bypass amount control and there is no clutch OFF → ON control. Indicates the case with bypass amount control and no clutch OFF → ON control.
The peak of the transmission output shaft torque is smaller than in the case, but still large. Indicates the case where the bypass amount control is performed and the clutch OFF → ON control is performed, and the peak of the transmission output shaft torque is smaller than in the case of.

After the end of the kick-down shift, the opening of the bypass valve 8 is gradually reduced to smoothly increase the torque after the end of the shift. By increasing the pressure, the acceleration performance can be improved.

[Brief description of the drawings]

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

FIG. 2 is a system diagram showing an embodiment of the present invention.

FIG. 3 is a flowchart of a shift control routine.

Fig. 4 Time chart at kick down

FIG. 5 is a diagram showing an engine load fluctuation due to clutch OFF → ON, etc.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Internal combustion engine 2 Throttle valve 3 Mechanical supercharger 4 Engine output shaft 5 Pulley / belt mechanism 6 Clutch 7 Bypass passage 8 Bypass valve 9 Engine control control unit 10 Automatic transmission 11 Torque converter 12 Gear transmission mechanism 13 Hydraulic actuator 14 Control unit for automatic transmission control 15 Throttle sensor 16 Engine speed sensor 17 Transmission output shaft speed sensor

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI F02D 41/04 301 F02D 41/04 301J

Claims (5)

[Claims] 1. A vehicle equipped with an internal combustion engine having a mechanical supercharger driven by an engine output shaft via a clutch in an engine intake system and an automatic transmission, the throttle opening of the automatic transmission being increased. A mechanical supercharger, comprising: kick-down detecting means for detecting kick-down, which is a shift to a lower gear side, and clutch connecting means for connecting the clutch in synchronization with kick-down. Control device. 2. A bypass valve control means for controlling an opening degree of a bypass valve of a bypass passage which connects an upstream and a downstream of an engine intake system by bypassing a mechanical supercharger in synchronization with kick down. The control device for a mechanical supercharger according to claim 1, wherein 3. The mechanical supercharger according to claim 1, wherein said clutch connecting means connects said clutch with a delay of a first predetermined time T1 from the detection of kickdown. Control device. 4. The clutch connecting means connects the clutch with a delay of a first predetermined time T1 from the detection of kick down, and the bypass valve control means substantially completely closes the bypass valve upon detection of kick down. 3. The machine according to claim 2, wherein, after the control is performed, the opening degree of the bypass valve is controlled to be substantially fully opened by delaying a second predetermined time T2 (where T2 ≧ T1) from the detection of kickdown. Control device for turbocharger. 5. The control device for a mechanical supercharger according to claim 4, wherein said bypass valve control means gradually reduces the opening of the bypass valve after the end of the kick-down shift. .