JP3533900B2 - Control device for mechanical supercharger - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle including an internal combustion engine having a mechanical supercharger driven by an engine output shaft through 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 improved acceleration performance and reduced shock.

[0002]

2. Description of the Related Art A conventional device of this type is disclosed in, for example, Japanese Patent Laid-Open No. 7-195963. This is because the mechanical supercharger is bypassed in the upstream and downstream of the engine intake system at the time of kickdown (stepping downshift), which is a shift to the lower speed side with the increase of the throttle opening in the automatic transmission. By increasing the opening degree of the bypass valve of the bypass passage to be connected to suppress supercharging pressure, torque reduction is performed by suppressing supercharging pressure to reduce gearshift shock in response to gearshift shock caused by kickdown. .

[0003]

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

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 conventional problems, the present invention aims to improve drivability by masking the clutch from OFF to ON shock in a mechanical supercharger with a clutch, and at the same time, improves acceleration performance and reduces shock. The purpose is to

[0005]

Therefore, in the invention according to claim 1, an internal combustion engine having a mechanical supercharger driven by an engine output shaft through a clutch in an engine intake system, and an automatic transmission. In a vehicle equipped with, as shown in FIG.
Kickdown detection means for detecting kickdown, which is a shift to the lower gear side due to an increase in throttle opening in the automatic transmission, and a first predetermined time T1 delayed from the detection of kickdown.
And a clutch connecting means for connecting the clutch,
By detecting kickdown, the mechanical turbocharger is bypassed.
Of the bypass passage that connects the upstream and downstream of the engine intake system
After controlling the valve to be almost fully closed, the second
The predetermined time T2 (however, T2 ≧ T1)
Bypass valve control means for controlling the opening degree of the bypass valve to be almost fully opened
And are provided to configure a control device for the mechanical supercharger.

[0006]

[0007]

The invention according to claim 2 is characterized in that the bypass valve control means gradually reduces the opening degree of the bypass valve after the shift down of the kickdown is completed.

[0009]

According to the invention of claim 1, by connecting the clutch of the mechanical supercharger in synchronism with kickdown, torque increase during kickdown and torque decrease due to clutch OFF → ON. It becomes possible to cancel the shift, mask the clutch from OFF to ON shock, and at the same time reduce shift shock.

Further , by controlling the opening degree of the bypass valve of the mechanical supercharger in synchronization with kickdown, finer torque control becomes possible, and in particular, the first predetermined value can be obtained from the detection of kickdown. By delaying the time T1 and connecting the clutch, it is possible to match the OFF → ON of the clutch with the torque peak at the time of shifting, which is more effective.

As for the control of the bypass valve, it is controlled to be substantially fully closed by detection of kickdown, and is controlled to be substantially fully opened after the second predetermined time T2. Type supercharger clutch O
It is possible to perform the advance rotation before N, and to suppress the supercharging pressure immediately after the clutch is turned on by the bypass valve substantially fully opened in the latter half of the kickdown to suppress the torque peak during the gear shift.

According to the second aspect of the present invention, by gradually reducing the opening degree of the bypass valve after the end of the gearshift for kickdown, the torque increase after the end of the gearshift can be smoothed.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. FIG. 2 is a system diagram showing an embodiment. The internal combustion engine 1 includes a roots-type or Rishorum-type mechanical supercharger 3 downstream of an intake system thereof, 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,
It has 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, which is interposed in the bypass passage 7.

The control unit 9 for controlling the engine controls the fuel injection amount and the ignition timing according to the engine operating conditions, controls the ON / OFF of the clutch 6, and controls the opening degree of the bypass valve 8. The automatic transmission 10 is the engine 1
Of the torque converter 11 interposed on the output side of the gear, and a gear transmission mechanism 12 connected via the torque converter 11
And a hydraulic actuator 13 for connecting / disconnecting various speed change elements in the gear speed change mechanism 12.
The hydraulic pressure for the hydraulic actuator 13 is turned on via various electromagnetic valves (shift solenoids) not shown.
・ OFF controlled.

Control unit 1 for automatic transmission control
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 that detects the transmission output shaft rotation speed No.
Here, the control unit 14 for automatic transmission control
The gear shift mechanism 12 is set via the hydraulic actuator 13 by automatically setting the shift speeds of the first speed to the fourth speed according to the transmission output shaft speed (vehicle speed) No and the throttle opening θ.
The shift control is performed to control the gear to that gear.

The automatic transmission control unit 14 is connected to the engine control unit 9 by a communication line, and commands ON / OFF control of the clutch 6 and opening control of the bypass valve 8. Next, the 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 the shift control routine. In step 1 (denoted as S1 in the figure. The same applies hereinafter), the throttle opening θ detected by the various sensors, the engine speed Ne, the transmission output shaft speed No, and the like are read. In step 2, the transmission output shaft speed (vehicle speed) N
The optimum shift stage is determined from o and the throttle opening θ by referring to the shift map.

In step 3, the current shift speed and the optimum shift speed are compared, and it is determined whether or not these are different and the shift operation is necessary. If the current shift speed is different from the optimum shift speed and the gear shift operation is required, the process proceeds to step 4, where an operation signal is output to the shift solenoid required for the gear shift operation this time, and the shift actuator is operated via the hydraulic actuator 13. The gear shift mechanism 12 is controlled to the optimum shift speed.

Then, in step 5, it is determined whether or not the shift operation at this time is a kick down (stepping down shift) which is a shift to the lower speed side with an increase in the throttle opening θ (Δθ ≧ a predetermined value). This portion corresponds to the kickdown detecting means. In the case of kickdown, the routine proceeds to step 6, where the kickdown flag FKD = 1 is set and the timer T for counting the elapsed time from the detection of kickdown is started from 0.

Then, in step 7, after the kickdown is detected, the clutch 6 of the mechanical supercharger 3 is controlled to be turned from OFF to ON after the first predetermined time T1. This portion corresponds to the clutch connecting means. Then, in step 8, the bypass valve 8 of the mechanical supercharger 3 is temporarily fully closed, and a second predetermined time T2 is detected from the detection of kickdown.
(However, T2 ≧ T1), the bypass valve 8 of the mechanical supercharger 3 is controlled to be fully opened. This part corresponds to the bypass valve control means.

Then, in step 9, it is judged whether or not there is a rapid acceleration (full-open acceleration) based on the amount of change Δθ of the throttle opening. 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. On the other hand, when the acceleration is not rapid, the engine torque down signal is not output in step 11.

Next, at step 13, the engine speed Ne
Then, the ratio R = No · G / Ne is calculated from the transmission output shaft speed No and the gear ratio G of the optimum gear, and the ratio R
Is below a predetermined value R0 (shift completion). If the ratio R ≦ R0 (end of gear shift), steps 16 to 18 are executed as the processing at the end of kickdown.

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

If it is determined in step 5 that the current shift operation is not kickdown, step 1
Then, the process proceeds to step 5, and it is determined whether or not the kickdown flag FKD = 1. As a result, the kickdown flag FKD = 1
If it is determined that the kickdown control is being performed, steps 16 to 18 are executed as the processing at the end of the kickdown. If the kickdown flag FKD = 0 and it is determined that the kickdown control is not being performed, this routine is ended as it is.

Further, in step 13, the ratio R> R
If it is determined that the gear shifting has not ended, the step 1
Then, the process shifts to 4 to determine whether the timer T is equal to or greater than a predetermined value. As a result, if the timer T ≧ predetermined value, the detection signal of the engine speed sensor 16 or the transmission output shaft sensor 17 may be abnormal. As the processing at the end of kickdown, steps 16 to 18 are executed. If timer T <predetermined value, this routine is finished as it is.

Next, the operation will be described with reference to the time chart of FIG. While the vehicle is running before kickdown, the clutch 6 of the mechanical supercharger 3 is off. At this time, the bypass valve 8 is fully opened to maximize the bypass amount, and the intake resistance of the mechanical supercharger 3 is reduced. It prevents the deterioration of fuel efficiency. Throttle opening θ by stepping on the accelerator pedal
When abruptly increases, the optimum gear shifts to the lower gear, and 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 mechanical supercharger 3 is discharged. The feeder 3 is rotated in the approach run before the clutch is turned on. And
At the time when the first predetermined time T1 has elapsed from the kickdown,
The clutch 6 of the mechanical supercharger 3 is switched from OFF to ON.

FIG. 5 shows the fluctuation of the engine load when the clutch 6 of the Rishorum type mechanical supercharger 3 is changed from OFF to ON (change in applied voltage). The clutch 6 of the mechanical supercharger 3 is shown.
The engine load temporarily peaks due to the change from OFF to ON. Therefore, by connecting the clutch 6 of the mechanical supercharger 3 in synchronism with kick down, torque up during kick down (peak of output shaft torque during gear shift) and torque down due to clutch OFF → ON (engine load) It is possible to cancel the shift shock of the clutch and to mask the clutch from OFF shock to ON shock, and at the same time reduce shift shock.

Then, when the 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.
By suppressing the supercharging pressure immediately after being turned 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 the bypass amount control is not performed and the clutch OFF → ON control is not performed. Is the case where there is bypass amount control and there is no clutch OFF → ON control.
The peak of the transmission output shaft torque is smaller than that of, but still large. Shows the case where the bypass amount control is performed and the clutch OFF → ON control is performed, the peak of the transmission output shaft torque becomes smaller than that in the case.

After the shift down of the kick down, by gradually reducing the opening degree of the bypass valve 8, it is possible to smooth the torque increase after the shift up, and finally to fully close the supercharge. The pressure can be increased and acceleration performance can be improved.

[Brief description of drawings]

FIG. 1 is a functional block diagram showing the 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.

[Figure 4] Time chart for kickdown

FIG. 5 is a diagram showing engine load fluctuations and the like due to clutch OFF → ON.

[Explanation 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 Control unit for engine control 10 automatic transmission 11 Torque converter 12 gear transmission 13 Hydraulic actuator 14 Control unit for automatic transmission control 15 Throttle sensor 16 Engine speed sensor 17 Transmission output shaft speed sensor

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI F02B 39/12 F02B 39/12 F02D 23/00 F02D 23/00 P 41/04 301 41/04 301J (58) Fields investigated (58) Int.Cl. ⁷ , DB name) F02D 29/00-29/06 F02D 41/00-45/00 F02D 23/00 F02B 33/00-39/16 B60K 41/00-41/28

Claims (2)

(57) [Claims] 1. A vehicle including an internal combustion engine having a mechanical supercharger driven by an engine output shaft through a clutch in an engine intake system, and an automatic transmission, the throttle opening of the automatic transmission being increased. Kickdown detecting means for detecting a kickdown which is a shift to the low speed side associated with the above, and a first predetermined time T1 delayed from the detection of the kickdown,
By bypassing the mechanical turbocharger with the clutch connecting means for connecting the clutch and detection of kickdown.
Of the bypass passage that connects the upstream and downstream of the engine intake system
After controlling the valve to be almost fully closed, the second
The predetermined time T2 (however, T2 ≧ T1)
Bypass valve control means for controlling the opening degree of the bypass valve to be almost fully opened
And a control device for a mechanical supercharger. 2. The control device for the mechanical supercharger according to claim 1, wherein the bypass valve control means gradually reduces the opening degree of the bypass valve after the end of the gearshift of the kickdown. .