JP2005098314A - Control device of vehicle with automatic transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device of a vehicle, preventing shifting shock in the course of up-shift for returning an accelerator, improving fuel consumption and preventing deterioration of exhaust gas. <P>SOLUTION: The control device of the vehicle having an automatic transmission with a lock-up mechanism, includes a first shifting co-operation control unit for delaying the operation of a fuel cut control unit and operating a lock-up control unit to control the connecting force of the lock-up mechanism to the connection side in the course of shifting, and making permission decision on the operation of the fuel cut control unit after the end of shifting. The control device of the vehicle further includes a second shifting co-operation control unit for operating the lock-up control unit in the course of shifting to control the connecting force of the lock-up mechanism to the release side when forced fuel cut is performed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a control device for controlling a lockup mechanism according to an operating state of an engine in a vehicle including an automatic transmission with a lockup mechanism.

  Conventionally, as a vehicle control device equipped with this type of automatic transmission, as disclosed in, for example, Japanese Patent Laid-Open No. 57-33253, a lock for fastening and releasing an input shaft and an output shaft of an automatic transmission. In addition to providing an up mechanism, the rotational speed of the input shaft and the output shaft of the automatic transmission is detected, and the torque of the lockup mechanism is controlled so that the difference between the rotational speeds becomes a set value. There is known one that transmits engine power satisfactorily while suppressing transmission of fluctuations.

  Further, during deceleration operation that does not require the output of the engine, a technique for improving fuel efficiency by performing fuel cut control for stopping fuel supply to the engine is generally employed.

  For example, when shifting while returning the throttle, it is possible to improve fuel efficiency by cutting the fuel after shifting if the lock-up clutch is operated during shifting, but if the fuel is cut during shifting, shift shock will occur. It may worsen or generate abnormal noise due to backlash. Therefore, as described in Japanese Patent Publication No. 60-2504, control is generally performed so as to delay entering the fuel cut during the shift.

  Also, Japanese Patent No. 2928314 discloses a vehicle for delaying the engagement of the lock-up clutch after the shift and performing fuel cut control after a predetermined time during the upshift with the throttle valve fully closed to prevent a shock during the shift. A control apparatus is disclosed.

In the case of this control device, since the fastening force of the lock-up clutch is limited during the shift, the engine rotation may be excessively reduced. When the lock-up clutch is engaged after the shift, the engine rotation increases. With a feeling of deceleration, an extra shock may occur.
JP 57-33253 A Japanese Patent Publication No. 60-2504 Japanese Patent No. 2928314

  In order to prevent the shock after the upshift by closing the throttle valve, which is a problem in the vehicle control device disclosed in the above-mentioned patent publication, the shift shock in the state in which the lockup clutch is operated is properly controlled by the shift clutch control. Therefore, it is necessary to keep the lockup clutch engaged even during the shift.

  However, in this case, if the fuel cut is activated during gear shifting, the lock-up clutch damper is engaged, and the lock-up clutch damper is subject to torque fluctuations. It is necessary to avoid it as described in JP-A-60-2504.

  However, delaying the start of fuel cut during a shift may cause problems such as exhaust deterioration. In order to prevent the deterioration of exhaust, it is preferable not to delay the start of fuel cut until after the shift. In this case, the fuel cut starts even during the shift, and the shift shock is worsened or abnormal noise due to backlash is generated.

  Therefore, an object of the present invention is to provide a vehicle control apparatus equipped with an automatic transmission capable of preventing a shift shock during an upshift when the accelerator pedal is off, and improving fuel efficiency and suppressing deterioration of exhaust. Is to provide.

  According to the present invention, there is provided a control device for a vehicle including an automatic transmission with a lockup mechanism, shift determination means for determining a shift time in the automatic transmission, and fuel supply to an engine under a predetermined condition. The fuel cut control means for cutting the lock, the lockup control means for controlling the fastening force of the lockup mechanism, and the operation of the fuel cut control means during the shift determined by the shift determination means, and the lockup control A first shift-time cooperative control means for controlling the fastening force of the lockup mechanism to the fastening side by operating the means, and making a permission determination regarding the operation of the fuel cut control means after the end of the gear shift, and the driving state of the vehicle Based on the fuel cut execution determination means for determining that the operation of the fuel cut control means is executed, and a fuel cut by the fuel cut execution determination means. When the shift is determined by the shift determination means, the lockup control means is actuated during the shift to control the fastening force of the lockup mechanism to the release side. And a control device for a vehicle provided with an automatic transmission.

  According to the present invention, the first shift cooperative control means delays the fuel cut during the shift, prevents a shift shock and an abnormal noise during the shift, and operates the lockup clutch to the engagement side during the shift. As a result, it becomes possible to perform fuel cut immediately after shifting, and to improve fuel efficiency.

  However, depending on the driving state of the vehicle, from the viewpoint of exhaust emission on the engine side, control for forcibly performing fuel cut is performed regardless of the shift of the automatic transmission.

  In this case, the shifts may overlap. In this case, according to the present invention, the first shift cooperative control is not performed, priority is given to the reduction of exhaust emissions, and the shift shock releases the lockup clutch. 2nd shift cooperative control which is canceled by operating to the side is performed.

  As a result, it is possible to perform coordinated control at the time of gear shifting that closely corresponds to the driving state of the vehicle, and it is possible to prevent gear shift shock, improve fuel consumption, and suppress deterioration of exhaust.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing a configuration of an automatic transmission mounted on a vehicle according to an embodiment of the present invention and a control device for the automatic transmission, and an automatic transmission 6 is connected to a crankshaft 4 of an internal combustion engine 2.

  The automatic transmission 6 is connected to the crankshaft 4 and includes a torque converter 8 having a pump impeller 8a and a turbine runner 8b, a lockup clutch 10 for connecting the pump impeller 8a and the turbine runner 8b, and an output of the torque converter 8 And a hydraulic control mechanism 14 for controlling the operation of the lockup clutch 10 and the multi-speed transmission gear mechanism 12.

  The hydraulic control mechanism 14 includes an on-off type solenoid valve (hereinafter referred to as “A solenoid valve”) 14 a that switches between engagement and disengagement of the lockup clutch 10, and an A solenoid valve 14 a that is turned on, and the lockup clutch 10 is engaged. A duty control type solenoid valve (hereinafter referred to as “B solenoid valve”) 14b for controlling the engagement pressure when in the combined state, and a speed change actuator 14c for controlling the shift position (gear ratio) of the gear mechanism 12; Yes.

  The A solenoid valve 14a, the B solenoid 14b, and the speed change actuator 14c are connected to an electronic control unit (hereinafter referred to as "ECU") 16 for controlling an automatic transmission. The ECU 16 is connected via the A solenoid valve 14a and the B solenoid valve 14b. The engagement state of the lockup clutch 10 is controlled, and the shift position of the multi-stage transmission gear mechanism 12 is controlled via the transmission actuator 14c.

  The automatic transmission 6 is provided with a shift position sensor 18 for detecting the shift position SRTDG of the multi-stage transmission gear 12, and the detection signal is supplied to the ECU 16.

  The output of the engine 2 is transmitted from the crankshaft 4 through the torque converter 8, the gear mechanism 12, and the differential device 20 to the left and right drive wheels 22 and 24 in order to drive them. A vehicle speed sensor 26 for detecting the vehicle speed VP of the vehicle is provided on the output side of the automatic transmission 6, and the detection signal is supplied to the ECU 16.

  The engine 2 includes a throttle valve opening sensor 32 for detecting an opening θTH of a throttle valve 30 provided in the middle of the intake pipe 28, an engine water temperature sensor 34 for detecting an engine cooling water temperature TW, and an engine speed NE. An engine speed sensor 36 for detection is provided, and detection signals from these sensors are supplied to the ECU 16. The engine speed sensor 36 outputs a TDC signal pulse at a predetermined crank angle position every 180 degree rotation of the crankshaft 4 and supplies the TDC signal pulse to the ECU 16.

  Further, a throttle actuator 38 made of, for example, an electric motor is connected to the throttle valve 30, and this throttle actuator 38 is connected to the ECU 16. The ECU 16 is connected to an accelerator opening sensor 40 that detects the amount of depression of the accelerator pedal of the vehicle (hereinafter referred to as “accelerator opening”) APFZ, and the detection signal is supplied to the ECU 16.

  The ECU 16 controls the throttle valve opening θTH in accordance with the accelerator opening APFZ and the like. That is, in the present embodiment, the accelerator pedal and the throttle valve 30 are not mechanically connected, and the throttle valve opening θTH is controlled according to the accelerator opening AP and other operating conditions.

  The ECU 16 is further connected to a selection lever position sensor 42 for detecting a selection lever position for selecting an operation mode of the automatic transmission 6 and a brake switch 44 for detecting depression of a brake pedal. It is supplied to the ECU 16.

  The ECU 16 is connected to an engine control electronic control unit (not shown) that controls the amount of fuel supplied to the engine 2 (opening time of the fuel injection valve), ignition timing, and the like, and transmits control parameter information to each other. It is configured as follows.

  The ECU 16 shapes an input signal from the various sensors described above, corrects the voltage level to a predetermined level, and converts an analog signal value into a digital signal value, and a central processing circuit (CPU). Drive signals to the storage circuit composed of ROM and RAM for storing various calculation programs executed by the CPU, shift maps and calculation results described later, the A solenoid valve 14a, the B solenoid valve 14b, and the transmission actuator 14c. And an output circuit.

  The ECU 16 controls the engagement state, the shift position, and the throttle valve opening θTH of the lockup clutch 10 based on detection signals from various sensors. In addition, the process demonstrated with reference to a flowchart below is performed by CPU of ECU16.

  Referring to FIG. 2, there is shown a principle block diagram of a vehicle control apparatus provided with an automatic transmission with a lockup mechanism according to the present invention. The control device includes a shift determination unit 54 that determines a shift time in the automatic transmission 6, a fuel cut control unit 50 that cuts fuel supply to the engine 2 under a predetermined condition, and an engagement of the lockup clutch 10. And lockup control means 52 for controlling the force.

  When the automatic transmission shifts, it is detected based on the shift map, vehicle speed, and throttle opening built in the ECU 16. The predetermined conditions for operating the fuel cut control means are, for example, an accelerator opening of 3% or less and an engine speed of 2000 rpm or more. The lockup control means 52 includes an A solenoid valve 14a and a B solenoid valve 14b.

  The vehicle control device further delays the operation of the fuel cut control means 50 and operates the lockup control means 52 to control the fastening force of the lockup clutch 10 to the fastening side during the shift determined by the shift determination means 54. In addition, the first shift cooperative control means 56 for making a permission determination regarding the operation of the fuel cut control means 50 after the end of the shift is included.

  The fuel cut execution determination means 58 determines that the operation of the fuel cut control means 50 is executed based on the driving state of the vehicle, that is, by predicting exhaust deterioration. For example, when the engine speed exceeds 4000 rpm or the temperature of the exhaust catalyst is equal to or higher than a predetermined temperature, the fuel cut execution determination unit 58 determines that the operation of the fuel cut control unit 50 is executed.

  Further, when the fuel cut is executed by the fuel cut execution determination means 58, the vehicle control device operates the lockup control means 52 during the shift when the shift determination is determined by the shift determination means 54, and locks up. It includes second shift cooperative control means 60 for controlling the engaging force of the clutch 10 to the disengagement side.

  For example, when the engine speed exceeds 4000 rpm, the accelerator pedal is greatly depressed, and when the accelerator pedal is operated to the off side after the engine speed exceeds 4000 rpm, exhaust deterioration is predicted. Fuel cut is executed even during shifting. Further, the lockup control means 52 is operated to control the fastening force of the lockup clutch 10 to the release side.

  Hereinafter, the vehicle control method according to the embodiment of the present invention will be described with reference to the flowchart of FIG. First, in step 10 (S10 is omitted in FIG. 3), it is determined whether or not there is a failure in AT-related parts such as a solenoid and a sensor. If there is no failure, the routine proceeds to step 11 where it is determined whether or not shifting is in progress.

  If the gear is being changed, the routine proceeds to step 12 where it is determined whether or not the forced fuel cut condition is satisfied. The forced fuel cut condition includes a case where the accelerator pedal is operated to the off side after the engine speed exceeds 4000 rpm and a case where the temperature of the exhaust catalyst is equal to or higher than a predetermined temperature.

  When the forced fuel cut condition is satisfied, a flag prohibiting delay of fuel cut during the shift is set, and the process proceeds to step 13 where the control hydraulic pressure of the lockup clutch 10 is turned off during the shift and the lockup clutch 10 is set to the release side. Control.

  Next, the routine proceeds to step 14 where it is determined whether or not the fuel cut condition is satisfied. If it is satisfied, the fuel cut is executed at step 15. The fuel cut establishment condition in step 14 includes parameters such as an accelerator opening of 3% or less and an engine speed of 2000 rpm or more.

  That is, when the engine speed exceeds 4000 rpm, it is a case where the accelerator pedal is greatly depressed. After the engine speed exceeds 4000 rpm, the accelerator pedal is operated to the off side and the shift is shifted when crossing the upshift line of the shift map. Although the fuel cut delay prohibition flag is set, when the fuel cut condition in step 14 is satisfied, the exhaust gas deterioration is predicted and the fuel cut is always performed in step 15 (even during the upshift). Execute.

  In the case of forced fuel cut, the temperature state of the exhaust catalyst (catalyzer) provided in the exhaust system of the engine is considered, and when the temperature is higher than a predetermined temperature at which the catalyst may be deteriorated, the normal steps are performed. Forcibly cut under 14 fuel cut conditions.

  It is also possible to set the engine speed depending on the temperature state, and the higher the temperature, the lower the engine speed from 4000 rpm.

  If it is determined in step 11 that the gear shift is not being performed or if the forced fuel cut condition is not satisfied in step 12, the routine proceeds to step 16 where it is determined whether or not the lockup clutch is slipping too much.

  If it is determined that the lockup clutch is slipping too much, the routine proceeds to step 13 where the control hydraulic pressure of the lockup clutch is turned off during shifting and the lockup clutch 10 is controlled to the release side.

  If it is determined in step 16 that the lock-up clutch 10 is not slipping too much, the routine proceeds to step 17 where the target slip ratio during the shift is searched, and the lock-up control oil pressure at which the target slip ratio is obtained is calculated.

  Next, the routine proceeds to step 18 where the control hydraulic pressure of the lockup clutch obtained at step 17 is introduced into the lockup clutch 10 and the lockup clutch 10 is controlled to the engagement side.

  Next, in step 19, it is determined whether or not the shift has been completed. If it is determined that the shift has been completed, the process proceeds to step 14. In step 14, it is determined whether or not the fuel cut condition described above is satisfied. If it is determined that the fuel cut condition is satisfied, the fuel cut is executed in step 15.

  If it is determined in step 19 that the shift has not been completed, or if it is determined in step 14 that the fuel cut condition is not satisfied, the process proceeds to step 20 and the process is terminated without cutting the fuel.

  FIG. 4 shows a time chart of the control apparatus of the present invention at normal times. That is, in a normal accelerator return upshift, the lockup slip signal is turned on during the shift with the upshift signal turned on to operate the lockup clutch 10 and the start of fuel cut is delayed after the shift. Before the upshift signal rises on, the lockup slip signal may be on or off.

  FIG. 5 shows a time chart of the control device of the present invention at the time of forced fuel cut during shifting. This forced fuel cut at the time of shifting is performed from the viewpoint of preventing deterioration of exhaust, and it is determined that the start of fuel cutting cannot be delayed from the engine operating state, and lockup is performed while the shift up signal is on. The slip signal is turned off, the lockup clutch 10 is not operated or the operation of the lockup clutch is reduced, and the fuel cut is executed even during the shift.

  Before the upshift signal rises on in the time chart of FIG. 5, the forced fuel cut signal and the lockup slip signal may be on or off. The fuel cut is executed a predetermined time after the forced fuel cut signal is turned on and the throttle is turned off.

It is a figure which shows the structure of the automatic transmission mounted in the vehicle which concerns on this invention embodiment, and its control apparatus. It is a block diagram which shows the principle structure of this invention control apparatus. It is a processing flowchart of the embodiment of the present invention. It is a time chart of embodiment of the present invention at the normal time. It is a time chart of the embodiment of the present invention at the time of forced fuel cut during shifting.

Explanation of symbols

2 Engine 6 Automatic transmission 8 Torque converter 10 Lock-up clutch 12 Multi-speed gear mechanism 14 Hydraulic control mechanism 16 Electronic control unit (ECU)
26 Vehicle speed sensor 28 Intake pipe 32 Throttle valve opening sensor 36 Engine speed sensor 40 Accelerator opening sensor

Claims (1)

A vehicle control device including an automatic transmission with a lock-up mechanism,
Shift determination means for determining a shift time in the automatic transmission;
Fuel cut control means for cutting fuel supply to the engine under predetermined conditions;
Lockup control means for controlling the fastening force of the lockup mechanism;
During the shift determined by the shift determining means, the operation of the fuel cut control means is delayed and the lockup control means is operated to control the fastening force of the lockup mechanism to the fastening side. First shift-time cooperative control means for performing permission judgment regarding the operation of the cut control means;
Fuel cut execution determination means for determining that the operation of the fuel cut control means is executed based on a driving state of the vehicle;
When it is determined that the fuel cut is executed by the fuel cut execution determination means and the shift is determined by the shift determination means, the lockup control means is operated during the shift to release the fastening force of the lockup mechanism. Second shift cooperative control means for controlling
A vehicle control device including an automatic transmission.

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