JP2013096475A - Control device of vehicle - Google Patents

Abstract

An object of the present invention is to appropriately control a lock-up hydraulic pressure even when abnormal combustion occurs and to keep a fluctuation in acceleration of a vehicle within an allowable range.
A vehicle according to the present invention includes an engine and an automatic transmission on which a lock-up clutch is mounted. The lock-up clutch 56 is controlled by a lock-up hydraulic pressure, and executes engagement and disengagement between the pump impeller 46 and the turbine runner 48 of the automatic transmission 40. When the ECU 80 detects abnormal combustion of the engine 10, the ECU 80 calculates a target lockup oil pressure that can keep the acceleration fluctuation of the vehicle within an allowable range, and matches the lockup oil pressure with the target lockup oil pressure. Thereby, when the abnormal combustion occurs, it is possible to suppress an increase in the rotation of the engine 10 and a change in the acceleration of the vehicle, and it is possible to ensure drivability while reducing the load on the engine 10.
[Selection] Figure 3

Description

  The present invention relates to a vehicle control device used for a vehicle such as an automobile, and more particularly to a vehicle control device in which a lockup clutch is mounted on an automatic transmission.

  As a conventional technique, for example, as disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 2011-112115), a system equipped with an automatic transmission having a frictional engagement element (lock-up clutch) is known. In the prior art, when abnormal combustion occurs, the hydraulic pressure (lockup hydraulic pressure) supplied to the lockup clutch is reduced below the hydraulic pressure required for maintaining the fastening, and the lockup clutch is intentionally slipped.

JP 2011-112115 A Japanese Patent Laid-Open No. 7-25269 JP 2010-151021 A JP 2005-330847 A JP-A-11-059232

  In the above-described conventional technology, the lockup clutch is intentionally slipped when abnormal combustion occurs. However, in this configuration, if the lockup hydraulic pressure is not properly controlled, the engine speed increases excessively, and there is a possibility that the acceleration fluctuation of the vehicle may increase, and the drivability deteriorates.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to appropriately control the lockup hydraulic pressure even when abnormal combustion occurs, and to keep the vehicle acceleration fluctuation within an allowable range. Another object of the present invention is to provide a vehicle control device that can be held in the vehicle.

The first invention is an internal combustion engine that rotates an output shaft by burning fuel in a cylinder;
An input member connected to the output shaft of the internal combustion engine and an output member connected to the drive shaft of the vehicle, and the rotation of the output shaft is transmitted to the drive shaft via these input member and output member. An automatic transmission,
The automatic transmission is interposed between the input member and the output member, and executes the fastening and unfastening of the input member and the output member according to the lockup hydraulic pressure inputted from the outside, and the slip ratio at the time of fastening. A lock-up clutch that can be adjusted,
Abnormal combustion detecting means for detecting abnormal combustion occurring in the cylinder of the internal combustion engine;
A target lockup oil pressure calculating means for calculating a target lockup oil pressure capable of keeping the acceleration fluctuation of the vehicle that occurs when the abnormal combustion occurs within an allowable range;
When abnormal combustion is detected by the abnormal combustion detection means, the abnormal combustion lockup hydraulic pressure control means for making the lockup hydraulic pressure coincide with the target lockup hydraulic pressure;
It is characterized by providing.

The second invention includes an allowable acceleration change amount calculating means for calculating an allowable acceleration change amount which is an upper limit value of acceleration fluctuation allowed during driving of the vehicle based on the speed and acceleration of the vehicle,
The target lockup hydraulic pressure calculating means is configured to calculate the target lockup hydraulic pressure based on at least the allowable acceleration change amount.

  According to a third aspect of the invention, there is provided a combustion correspondence correcting means for correcting the allowable acceleration change amount based on an index representing the abnormal combustion and / or the occurrence frequency of the abnormal combustion.

4th invention, the target acceleration calculation means which calculates the target acceleration of a vehicle based on the speed of a vehicle and the said allowable acceleration variation | change_quantity,
Based on the known vehicle inertia, the gear ratio set by the automatic transmission and the target acceleration, a target torque to be obtained on the output member side of the automatic transmission is calculated, and based on the target torque, the target torque is calculated. A target rotational speed setting means for setting a target rotational speed of the output member,
The target lockup hydraulic pressure calculating means is configured to calculate the target lockup hydraulic pressure based on a difference between a target rotational speed of the output member and an engine rotational speed of the internal combustion engine.

  According to a fifth aspect of the present invention, there is provided an accelerator corresponding correcting means for correcting the allowable acceleration change amount when the accelerator opening of the internal combustion engine is reduced during the operation of the abnormal combustion lockup hydraulic pressure control means.

  6th invention comprises the gear ratio variable means which increases the gear ratio set by the said automatic transmission, when the accelerator opening degree of an internal combustion engine increases at the time of the operation | movement of the said lockup oil pressure control means at the time of abnormal combustion It is said.

  According to the first aspect of the present invention, the lockup clutch is appropriately slipped when the abnormal combustion occurs, and it is possible to avoid the torque fluctuation at the time of abnormal combustion becoming a large acceleration fluctuation and acting on the vehicle. As a result, it is possible to keep the acceleration fluctuation of the vehicle within an allowable range while preventing the rotation of the internal combustion engine from rising excessively, and to ensure drivability. Further, since the large torque generated by the abnormal combustion can be released to the automatic transmission side, it is possible to prevent the components of the internal combustion engine from being damaged by an excessive load and to reduce the load on the internal combustion engine.

  According to the second invention, the allowable acceleration change amount can be calculated based on the speed and acceleration of the vehicle. Then, by reflecting this allowable acceleration change amount on the target lockup hydraulic pressure, the lockup hydraulic pressure can be appropriately controlled so that the acceleration fluctuation of the vehicle falls within the allowable range.

  According to the third aspect of the invention, the combustion countermeasure correcting unit can correct the allowable acceleration change amount based on the index indicating abnormal combustion and / or the occurrence frequency of abnormal combustion. As a result, when the level of abnormal combustion is large, the slip ratio of the lock-up clutch is increased, and it is difficult to transmit large torque fluctuations on the internal combustion engine side to the vehicle side, thereby minimizing deterioration in drivability Can be suppressed. Further, when the level of abnormal combustion is small, it is possible to prevent the slip ratio of the lockup clutch from becoming larger than necessary.

  According to the fourth aspect, the target acceleration of the vehicle can be calculated based on the vehicle speed and the allowable acceleration change amount reflecting the abnormal combustion level. Then, the target torque of the automatic transmission can be calculated based on the vehicle inertia, the gear ratio, and the target acceleration, and the target rotational speed of the output member can be set based on the target torque. Thereby, the target lockup hydraulic pressure calculation means can calculate the target lockup hydraulic pressure based on the difference between the target rotation speed of the output member and the engine rotation speed of the internal combustion engine, and the target lockup hydraulic pressure calculation means according to the abnormal combustion level. The up oil pressure can be set appropriately.

  According to the fifth aspect of the present invention, when the accelerator opening of the internal combustion engine decreases during the operation of the abnormal combustion lockup hydraulic pressure control means, the driver has released the accelerator pedal because the acceleration fluctuation is excessive. The allowable acceleration change amount can be corrected based on this determination. Thereby, the damage of the internal combustion engine due to abnormal combustion can be reduced while appropriately changing the drivability according to the driver's desire and sensitivity.

  According to the sixth aspect of the invention, when the accelerator opening of the internal combustion engine increases during the operation of the abnormal combustion lockup hydraulic pressure control means, it is determined that the driver has accelerated, and the gear of the automatic transmission The ratio can be changed (shifted down) to accelerate. Thereby, the damage of the internal combustion engine due to abnormal combustion can be reduced while appropriately changing the drivability according to the driver's desire and sensitivity.

It is a block diagram for demonstrating the system configuration | structure of Embodiment 1 of this invention. FIG. 6 is a characteristic diagram for calculating an allowable acceleration change amount based on vehicle speed and acceleration. In Embodiment 1 of this invention, it is a flowchart of the control performed by ECU. In Embodiment 2 of this invention, it is a characteristic diagram which shows the correction map of the allowable acceleration variation | change_quantity. It is explanatory drawing which shows the execution area | region of the learning control performed based on the parameter | index showing abnormal combustion and the occurrence frequency of abnormal combustion. In Embodiment 2 of this invention, it is a flowchart of the control performed by ECU. In Embodiment 3 of this invention, it is a characteristic diagram which shows the correction map of the allowable acceleration variation | change_quantity. In Embodiment 3 of this invention, it is a flowchart of the control performed by ECU. In Embodiment 4 of this invention, it is a flowchart of the control performed by ECU. In Embodiment 5 of this invention, it is a flowchart of the control performed by ECU.

Embodiment 1 FIG.
[Configuration of Embodiment 1]
The first embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a configuration diagram for explaining a system configuration according to the first embodiment of the present invention. The system of the present embodiment includes, for example, an engine 10 as a multi-cylinder internal combustion engine and an automatic transmission 40, which are mounted on a vehicle (not shown). A combustion chamber 14 is defined in each cylinder of the engine 10 by a piston 12, and the piston 12 is connected to a crankshaft 16 that is an output shaft of the engine 10 via a connecting rod or the like. Further, the engine 10 includes an intake passage 18 that sucks intake air into the combustion chamber 14 (cylinder) of each cylinder, and an exhaust passage 20 that exhausts exhaust gas from each cylinder.

  The intake passage 18 branches downstream and is connected to the intake port of each cylinder. The intake passage 18 is provided with an electronically controlled throttle valve 22 that adjusts the amount of intake air into the cylinder based on the accelerator opening and the like, and a fuel injection valve 24 that injects fuel into the intake port of each cylinder. ing. Each cylinder has an ignition plug 26 that ignites the air-fuel mixture in the cylinder, an intake valve 28 that opens and closes the intake port with respect to the cylinder, and an exhaust that opens and closes the cylinder with respect to the exhaust port. A valve 30 is provided.

  Next, the automatic transmission 40 connected to the engine 10 will be described. The automatic transmission 40 includes a torque converter 42, a transmission mechanism 50, and a lock-up clutch 56. The torque converter 42 is a known device that transmits power input from the engine 10 to the speed change mechanism 50 using a fluid such as oil. More specifically, the torque converter 42 includes a housing 44 filled with oil, a pump impeller 46 as an input member disposed in the housing 44, and a turbine runner 48 as an output member disposed to face the pump impeller 46. It has.

  The pump impeller 46 is connected to the crankshaft 16 of the engine 10 and rotates integrally with the crankshaft 16. The turbine runner 48 is connected to the input shaft 52 of the speed change mechanism 50 and rotates integrally with the input shaft 52. Here, the speed change mechanism 50 has an input shaft 52 and an output shaft 54, and changes the rotation of the input shaft 52 and transmits it to the output shaft 54. The output shaft 54 of the speed change mechanism 50 (automatic transmission 40) is connected to the drive shaft of the vehicle via a differential gear and a drive shaft (not shown), and transmits power to the drive wheels of the vehicle.

  The lock-up clutch 56 is a known mechanism that is interposed between the pump impeller 46 and the turbine runner 48 of the torque converter 42 and controls the engaged state of both. More specifically, the lock-up clutch 56 is controlled by, for example, an electromagnetic lock-up control valve 58 connected to a hydraulic circuit, and its operating state is the hydraulic pressure (lock-up) supplied to the lock-up control valve 58. According to the hydraulic pressure). In the fastened state, the pump impeller 46 and the turbine runner 48 (the crankshaft 16 and the input shaft 52) rotate integrally with each other. In the disengaged state, the rotation of the pump impeller 46 is transmitted to the turbine runner 48 via oil. In the slip state, the pump impeller 46 and the turbine runner 48 rotate together while slipping, and the degree of slip (slip rate) at this time is adjusted according to the lockup hydraulic pressure.

  Next, a control system of the system according to the present embodiment will be described. The sensor system mounted on the vehicle of the present embodiment includes a crank angle sensor 60, a throttle sensor 62, an accelerator sensor 64, a turbine rotational speed sensor 68, and a gear position sensor 70. Here, the crank angle sensor 60 outputs a signal synchronized with the rotation of the crankshaft 16, the throttle sensor 62 detects the opening (throttle opening) of the throttle valve 22, and the accelerator sensor 64 The operation amount (accelerator opening) of the pedal 66 is detected. The turbine speed sensor 68 detects the turbine speed, which is the speed of the turbine runner 48 of the automatic transmission 40, and the gear position sensor 70 detects the gear position of the speed change mechanism 50.

  The sensor system includes an engine water temperature sensor 72, a transmission oil temperature sensor (TM oil temperature sensor) 74, an in-cylinder pressure sensor 76, a vehicle speed sensor 78, and the like. The engine water temperature sensor 72 detects the temperature of the engine cooling water (engine water temperature), and the TM oil temperature sensor 74 detects the temperature of the lubricating oil (TM oil temperature) of the transmission mechanism 50. The in-cylinder pressure sensor 76 is provided for each cylinder of the engine 10 and detects the in-cylinder pressure of each cylinder. The vehicle speed sensor 78 detects the speed of the vehicle (vehicle speed). In addition to this, the sensor system includes an air flow sensor for detecting the amount of intake air.

  In addition, the system of the present embodiment includes an ECU (Electronic Control Unit) 80 that controls the operating states of the vehicle and the engine. The ECU 80 is configured by an arithmetic processing device having a storage circuit, and each sensor of the sensor system is connected to the input side thereof. Further, on the output side of the ECU 80, actuators such as a throttle valve 22, a fuel injection valve 24, a spark plug 26, and a lock-up control valve 58 are connected. Then, the ECU 80 drives each actuator while detecting operation information of the engine using a sensor system, and executes operation control. Specifically, the engine speed (engine speed) and the crank angle are detected based on the output of the crank angle sensor 60, and the intake air amount is calculated based on the output of the air flow sensor. Further, the engine load (load factor) is calculated based on the intake air amount, the engine speed, and the like. Then, the fuel injection timing and ignition timing are determined based on the crank angle, and when these timings arrive, the fuel injection valve 24 and the spark plug 26 are driven. Thereby, the air-fuel mixture is combusted in the cylinder, and the engine can be operated.

  Further, when the engine is in operation, when the pump impeller 46 of the automatic transmission 40 is rotated by the crankshaft 16, this rotation is transmitted to the turbine runner 48 via oil. As a result, the rotation of the crankshaft engine 10 is transmitted to the transmission mechanism 50 via the torque converter 42 and is changed according to the gear position of the transmission mechanism 50. And this rotation is transmitted to a driving wheel via the drive shaft of a vehicle, and makes a vehicle run. At this time, an AT ECU (not shown) mounted on the vehicle executes automatic shift control for changing the gear position of the transmission mechanism 50 in accordance with the driver's gear shift operation, accelerator operation, traveling state of the vehicle, and the like. . Further, the AT ECU locks up the pump impeller 46 and the turbine runner 48 by fastening and releasing the fastening by changing the fastening state of the lockup clutch 56 as necessary, and adjusting the slip ratio of both. Execute control. These controls may be executed by the ECU 80.

[Features of Embodiment 1]
When abnormal combustion occurs in the engine, the peak of the combustion pressure (in-cylinder pressure) increases from that during normal combustion. Therefore, engine components including connecting rods are damaged, and engine acceleration causes vehicle acceleration. There is a risk that fluctuations occur and the drivability deteriorates. On the other hand, when abnormal combustion occurs, it is conceivable to release the lock-up clutch 56 in order to reduce the load on the engine and to ensure operability. However, when the lock-up clutch 56 is simply released, the power transmission from the engine to the automatic transmission changes rapidly, and the drivability tends to deteriorate. For this reason, in the present embodiment, for example, the occurrence of abnormal combustion in the cylinder is detected based on the output of the in-cylinder pressure sensor 76 (such as Pmax which is the maximum value of the in-cylinder pressure). When abnormal combustion is detected, the lockup hydraulic pressure of the automatic transmission 40 is lowered as compared with that during normal combustion, and the lockup clutch 56 is slipped by a necessary minimum. Thereby, it is set as the structure which ensures drivability, while escaping the torque fluctuation by abnormal combustion. Specifically, during abnormal combustion, the target lockup hydraulic pressure that can keep the acceleration fluctuation of the vehicle within an allowable range is calculated, and the lockup hydraulic pressure control during abnormal combustion matches the target lockup hydraulic pressure. Execute. Hereinafter, this control will be described.

(Lock-up hydraulic control during abnormal combustion)
FIG. 2 is a characteristic diagram for calculating an allowable acceleration change amount based on the speed and acceleration of the vehicle. The data map shown in this figure is stored in advance in the ECU 80 as an allowable amount map. The allowable acceleration change amount corresponds to an upper limit value (allowable limit) of acceleration fluctuation that is allowed for ensuring drivability of the vehicle. As shown in FIG. 2, there is a characteristic that the allowable acceleration change amount decreases as the vehicle speed increases and the vehicle acceleration increases. The ECU 80 calculates the speed and acceleration of the vehicle based on the output of the vehicle speed sensor 78, and calculates the allowable acceleration change amount by referring to the allowable amount map based on the calculation result. Then, as shown in the following equation (1), the current acceleration and the allowable acceleration change amount are added to calculate the target acceleration.

Target acceleration = current acceleration + allowable acceleration change amount (1)

  Next, as shown in the following equation (2), the ECU 80 automatically selects the target acceleration, the known vehicle inertia, and the gear ratio (gear position) currently set by the speed change mechanism 50. A target value of the torque (turbine side target torque) to be obtained at the position of the turbine runner 48 of the transmission 40 is calculated.

Turbine-side target torque = target acceleration x vehicle inertia x gear ratio (2)

  Then, by using a torque converter characteristic map (not shown) stored in advance in the ECU 80, the target rotational speed (target turbine) of the turbine runner 48 based on the turbine-side target torque, the engine rotational speed, and the TM oil temperature. Set the number of revolutions. Here, the torque converter characteristic map is a known data map for setting a target turbine speed at which the turbine-side target torque is realized in the current engine speed and oil temperature state. That is, if the torque converter characteristic map is a function F, the target turbine speed is given by the following equation (3).

Target turbine speed =
F (turbine side target torque, engine speed, TM oil temperature) (3)

  In order to realize the target turbine speed obtained in this way, the ECU 80 calculates a target lockup hydraulic pressure based on a known target hydraulic pressure map stored in advance. Here, the target hydraulic pressure map is a data map for calculating a lockup hydraulic pressure that realizes the target turbine rotational speed based on the difference between the target turbine rotational speed and the engine rotational speed. That is, if the target oil pressure map is a function G, the target lockup oil pressure is given by the following equation (4). Then, the ECU 80 performs hydraulic control so that the lockup hydraulic pressure supplied to the lockup control valve 58 matches the target lockup hydraulic pressure.

Target lock-up hydraulic pressure =
G (difference between target turbine speed and engine speed) (4)

  The target lockup oil pressure at the time of abnormal combustion calculated in this way is set to a value smaller than the lockup oil pressure at the time of normal combustion. Therefore, according to the abnormal combustion lockup hydraulic control, when the abnormal combustion occurs, the lockup clutch 56 is appropriately slipped to prevent the torque fluctuation during the abnormal combustion from acting on the vehicle as a large acceleration fluctuation. Can do. As a result, it is possible to prevent drivability of the engine from being excessively increased while suppressing the fluctuation in the acceleration of the vehicle to be equal to or less than the allowable acceleration change amount. Further, according to this control, a large torque generated by abnormal combustion can be released to the automatic transmission 40 side, so that the engine parts including the connecting rod are prevented from being damaged by an excessive load, and the engine load Can be reduced.

[Specific Processing for Realizing Embodiment 1]
Next, specific processing for realizing the above-described control will be described with reference to FIG. FIG. 3 is a flowchart of control executed by the ECU in the first embodiment of the present invention. The routine shown in this figure is repeatedly executed while the engine is operating. In the routine shown in FIG. 3, first, in step 100, it is determined whether or not abnormal combustion has occurred based on the output (Pmax or the like) of the in-cylinder pressure sensor 76. If this determination is not established, the control is continued. finish. More specifically, in step 100, it is determined that abnormal combustion has occurred, for example, when Pmax has increased beyond the upper limit during normal combustion.

  If abnormal combustion occurs, in step 102, the current vehicle speed is detected based on the output of the vehicle speed sensor 78, and the acceleration of the vehicle is calculated based on the vehicle speed. Next, in step 104, an allowable acceleration change amount is calculated by referring to an allowable amount map based on the vehicle speed and acceleration. In step 106, the operating states of the engine 10 and the automatic transmission 40 (engine speed, turbine speed, TM oil temperature, gear position, etc.) are acquired. In step 108, based on at least the allowable acceleration change amount, The target lockup hydraulic pressure is calculated by the above equations (1) to (4). In step 110, control is performed so that the lockup hydraulic pressure matches the target lockup hydraulic pressure.

  In the first embodiment, step 100 in FIG. 3 shows a specific example of the abnormal combustion detecting means in claim 1, and step 108 shows a specific example of the target lockup hydraulic pressure calculating means. Step 110 shows a specific example of the abnormal combustion lockup hydraulic pressure control means, and Step 104 shows a specific example of the allowable acceleration change amount calculation means in claim 2. Further, the expression (1) shows a specific example of the target acceleration calculating means, and the expressions (2) and (3) show a specific example of the target rotation speed setting means.

  In the first embodiment, the automatic transmission 40 having a plurality of gear positions has been described as an example. However, the present invention is not limited to this, and the automatic transmission mechanism is provided between a primary pulley and a secondary pulley. The present invention may be applied to CVT in which a belt is wound and continuously variable transmission is performed by the belt.

Embodiment 2. FIG.
Next, a second embodiment of the present invention will be described with reference to FIGS. The present embodiment is characterized in that, in addition to the configuration (FIG. 1) and control substantially the same as those in the first embodiment, correction and learning of the allowable acceleration change amount are executed. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

[Features of Embodiment 2]
FIG. 4 is a characteristic diagram showing a correction map for the allowable acceleration change amount in the second embodiment of the present invention. When the level (intensity) of abnormal combustion is large, it is preferable to increase the amount of decrease in target lockup correspondingly, and to make it difficult for torque fluctuation on the engine side to be transmitted to the vehicle side. For this reason, the correction map shown in FIG. 4 increases the allowable acceleration change amount from the value corresponding to the reference value as the index (Pmax or the like) indicating abnormal combustion becomes larger than the reference value. Further, the correction map is set so that the allowable acceleration change amount is decreased from the value corresponding to the reference value as the index becomes smaller than the reference value. In the present embodiment, similarly to the first embodiment, after calculating the allowable acceleration change amount based on the vehicle speed and acceleration, the allowable acceleration is referred to by referring to the correction map of FIG. 4 based on the index representing abnormal combustion. Correct the amount of change.

  Thereby, the level of abnormal combustion is reflected in the allowable acceleration change amount, and finally reflected in the target lockup hydraulic pressure. More specifically, when the index indicating abnormal combustion is larger than the reference value, the target lockup hydraulic pressure is corrected to be smaller than the value corresponding to the reference value. When the index indicating abnormal combustion is smaller than the reference value, the target lockup hydraulic pressure is corrected to be larger than the value corresponding to the reference value. According to this configuration, when the level of abnormal combustion is large, the slip ratio of the lock-up clutch 56 is increased, and a state in which a large torque fluctuation on the engine side is difficult to be transmitted to the vehicle side can be realized. Thereby, deterioration of drivability can be minimized. Further, when the level of abnormal combustion is small, it is possible to prevent the slip ratio of the lockup clutch 56 from becoming larger than necessary. Therefore, the target lockup hydraulic pressure can be appropriately set according to the abnormal combustion level.

  Further, in the present embodiment, learning control is performed to learn whether the correction amount of the allowable acceleration change amount based on the correction map is excessive or insufficient based on an index (such as Pmax) indicating abnormal combustion and the frequency of occurrence of abnormal combustion. Hereinafter, an example of this learning control will be described. FIG. 5 is an explanatory diagram (learning region map) showing an execution region of learning control executed based on an index representing abnormal combustion and the occurrence frequency of abnormal combustion. In the learning control, the occurrence frequency of abnormal combustion is measured over a certain period, and when the measured occurrence frequency is out of a predetermined allowable range, the deviation is learned and reflected in the correction map. Here, the allowable range of the occurrence frequency is set by an upper limit value H and a lower limit value L calculated based on Pmax, for example, as shown in FIG.

  That is, in the learning control, when the occurrence frequency of abnormal combustion exceeds the upper limit value H or is lower than the lower limit value L, the correction map is corrected. To give a specific example, for example, when the frequency of occurrence of abnormal combustion is greater than the upper limit value H, it is considered that abnormal combustion (engine acceleration fluctuation) is likely to occur and the drivability of the vehicle is likely to deteriorate. In this case, the correction map of the allowable acceleration change amount is updated so that the finally calculated target lockup hydraulic pressure is reduced as compared with the non-learning state, and the acceleration fluctuation is transmitted to the vehicle side. To suppress. Here, the non-learning state is a state where the occurrence frequency of abnormal combustion is not more than the upper limit value H and not less than the lower limit value L. Further, when the occurrence frequency of abnormal combustion is less than the lower limit value L, it is considered that the behavior of the engine is stable and the acceleration fluctuation is unlikely to occur. Therefore, in this case, the correction map for the allowable acceleration change amount is updated so that the finally calculated target lock-up hydraulic pressure increases as compared with the non-learning state, and power transmission from the engine to the vehicle is performed. To ensure efficiency.

  According to the learning control, the allowable acceleration change amount can be corrected according to the combustion state of the engine, and the combustion state can be appropriately reflected in the target lockup hydraulic pressure. That is, even if abnormal combustion occurs, if the frequency of occurrence is small, it is possible to prevent the lockup hydraulic pressure from being reduced more than necessary. Further, when the frequency of occurrence of abnormal combustion is high, the operability can be ensured by reducing the lockup hydraulic pressure more greatly. Accordingly, it is possible to learn temporal changes of the vehicle, the automatic transmission, the engine, etc., and to appropriately reflect the learning result in the lockup control.

[Specific Processing for Realizing Embodiment 2]
Next, specific processing for realizing the above-described control will be described with reference to FIG. FIG. 6 is a flowchart of control executed by the ECU in the second embodiment of the present invention. In the routine shown in this figure, first, in steps 200, 202, and 204, processing similar to that in steps 100 to 104 of the first embodiment (FIG. 3) is executed. Next, in step 206, the allowable acceleration change amount is corrected by referring to the correction map based on Pmax. In steps 208, 210, and 212, the same control as in steps 106 to 110 in the first embodiment is executed.

  Next, in step 214, the value of Pmax in the current combustion cycle is stored together with the past value. In step 216, whether or not the occurrence frequency of abnormal combustion within a certain period is within the learning range, that is, whether or not the occurrence frequency of abnormal combustion exceeds the upper limit value H or less than the lower limit value L. Determine whether. If this determination is established, in step 218, the above-described learning control is executed, and the correction map for the allowable acceleration change amount is updated (learning correction). If the determination in step 216 is not established, the learning control is not executed and the process ends.

  In the second embodiment, in addition to the specific example described in the first embodiment (FIG. 3 and the like), steps 206, 216 and 218 in FIG. Is shown.

Embodiment 3 FIG.
Next, Embodiment 3 of the present invention will be described with reference to FIG. 7 and FIG. This embodiment is characterized by using a correction map different from that in the second embodiment, although the same control as in the second embodiment is executed. In the present embodiment, the same components as those in the first and second embodiments are denoted by the same reference numerals, and the description thereof is omitted.

[Features of Embodiment 3]
FIG. 7 is a characteristic diagram showing a correction map for the allowable acceleration change amount in the third embodiment of the present invention. As shown in this figure, in the present embodiment, the allowable acceleration change amount is corrected based on the actual number of times of abnormal combustion (for example, the total number of times of occurrence of abnormal combustion up to that point). Specifically, the allowable acceleration change amount is increased as the number of times of abnormal combustion increases. Here, as the number of times of abnormal combustion increases, engine damage tends to increase accordingly. For this reason, in this embodiment, as the engine damage increases, the allowable acceleration change amount is corrected to the increase side to reduce the accumulation of damage. According to the above control, by correcting the allowable acceleration change amount based on the past history of abnormal combustion, it becomes possible to perform lock-up control according to engine damage, extending the engine life while ensuring drivability. be able to.

[Specific Processing for Realizing Embodiment 3]
Next, specific processing for realizing the above-described control will be described with reference to FIG. FIG. 8 is a flowchart of control executed by the ECU in the third embodiment of the present invention. In the routine shown in this figure, in steps 300 to 318, substantially the same processing as in steps 200 to 218 of the second embodiment (FIG. 6) is executed. However, in step 306, the allowable acceleration change amount is corrected by referring to the correction map shown in FIG. 7 based on the actual number of times of abnormal combustion.

Embodiment 4 FIG.
Next, a fourth embodiment of the present invention will be described with reference to FIG. This embodiment is characterized by using a correction map different from that in the second embodiment, although the same control as in the second embodiment is executed. In the present embodiment, the same components as those in the first and second embodiments are denoted by the same reference numerals, and the description thereof is omitted.

[Features of Embodiment 4]
In the present embodiment, torque calculated by a known method based on the in-cylinder pressure is adopted as an index representing abnormal combustion. Therefore, in the present embodiment, a correction map and a learning area map obtained by converting the horizontal axis in FIGS. 4 and 5 of the second embodiment into torque are used. According to this configuration, it is possible to grasp in detail the engine damage that differs depending on the in-cylinder pressure waveform, and to perform lock-up control with higher accuracy.

[Specific processing for realizing Embodiment 4]
Next, specific processing for realizing the above-described control will be described with reference to FIG. FIG. 9 is a flowchart of control executed by the ECU in the fourth embodiment of the present invention. In the routine shown in this figure, in steps 400 to 418, substantially the same processing as in steps 200 to 218 of the second embodiment (FIG. 6) is executed. However, in step 406, the allowable acceleration change amount is corrected by referring to the correction map based on the torque calculated from the in-cylinder pressure. In step 414, the torque value in the current combustion cycle is stored together with the past value. In step 416, it is determined whether or not the occurrence frequency of abnormal combustion (abnormal torque) within a certain period is within the learning range.

Embodiment 5 FIG.
Next, a fifth embodiment of the present invention will be described with reference to FIG. The present embodiment is characterized in that, in addition to the same configuration and control as in the first embodiment, the control is changed according to the accelerator opening. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

[Features of Embodiment 5]
While the lockup hydraulic pressure control during abnormal combustion is being executed, the lockup hydraulic pressure is mainly reduced. In this state, the driver of the vehicle may want to accelerate. Therefore, in the present embodiment, when the accelerator opening increases during execution of the abnormal combustion lockup hydraulic pressure control, it is determined that the driver has accelerated, and the gear ratio of the transmission mechanism 50 is accelerated. Change (shift down) to On the other hand, if the accelerator opening decreases during execution of the abnormal combustion lockup hydraulic pressure control, it is determined that the driver has released the accelerator pedal 66 because the acceleration fluctuation is excessive. Then, the allowable acceleration change amount (for example, the allowable map shown in FIG. 2) is corrected so that the allowable acceleration change amount becomes small. According to the above control, it is possible to reduce engine damage due to abnormal combustion while appropriately changing drivability according to the driver's desire and sensitivity.

[Specific Processing for Realizing Embodiment 5]
Next, specific processing for realizing the above-described control will be described with reference to FIG. FIG. 10 is a flowchart of control executed by the ECU in the fifth embodiment of the present invention. The routine shown in this figure is repeatedly executed while the engine is operating. In the routine shown in FIG. 10, first, in step 500, it is determined whether or not the abnormal combustion lockup hydraulic pressure control is being executed. If the control is not being executed, the routine is ended as it is. Further, when the determination in step 500 is established, in step 502, it is determined whether or not the accelerator opening is increased.

  If the determination in step 502 is established, in step 504, the speed ratio (gear ratio) of the speed change mechanism 50 is changed based on the accelerator opening by referring to a data map or the like stored in advance in the ECU 80. . At this time, basically, the gear ratio is changed to the increase side (= acceleration side, shift down side) as the accelerator opening increases. On the other hand, if the determination in step 502 is not established, it is determined in step 506 whether or not the accelerator opening is decreased. If this determination is established, in step 508, for example, the allowable amount map (FIG. 2) is changed so that the allowable acceleration change amount decreases.

  In the fifth embodiment, steps 502 and 504 in FIG. 10 show a specific example of the gear ratio variable means in claim 6, and steps 506 and 508 show a specific example of the accelerator correspondence correcting means. Further, in the fifth embodiment, the configuration in the case where the gear ratio variable means and the accelerator correspondence correction means are combined is illustrated, but the present invention is not limited to this, and among the gear ratio variable means and the accelerator correspondence correction means, Only one of the means may be used. Further, in the fifth embodiment, it is assumed that the abnormal combustion lockup hydraulic pressure control described in the first embodiment is being executed. However, the present invention is not limited to this, and any of the first to fourth embodiments described above. The control of the fifth embodiment may be executed while the abnormal combustion lockup hydraulic control system is being executed.

  In the first to fifth embodiments, the automatic transmission 40 including the lock-up clutch 56 has been described as an example. However, the present invention is not limited to a normal automatic transmission (AT) but also to a CVT. Can be applied. In the normal AT, when the accumulation of engine damage becomes large and it is necessary to increase the allowable acceleration change amount, the accelerator opening is not referred to as in the fifth embodiment, and the accelerator opening is not referred to. Is preferably combined with the control of Embodiments 1 and 5 as F / F control (feed forward control).

10 Engine (Internal combustion engine)
12 Piston 14 Combustion chamber 16 Crankshaft (output shaft)
18 Intake passage 20 Exhaust passage 22 Throttle valve 24 Fuel injection valve 26 Spark plug 28 Intake valve 30 Exhaust valve 40 Automatic transmission 42 Torque converter 44 Housing 46 Pump impeller (input member)
48 Turbine runner (output member)
50 transmission mechanism 52 input shaft 54 output shaft 56 lockup clutch 58 lockup control valve 60 crank angle sensor 62 throttle sensor 64 accelerator sensor 66 accelerator pedal 68 turbine rotational speed sensor 70 gear position sensor 72 engine water temperature sensor 74 transmission oil temperature sensor 76 In-cylinder pressure sensor 78 Vehicle speed sensor 80 ECU

Claims (6)

An internal combustion engine that rotates an output shaft by burning fuel in a cylinder;
An input member connected to the output shaft of the internal combustion engine and an output member connected to the drive shaft of the vehicle, and the rotation of the output shaft is transmitted to the drive shaft via these input member and output member. An automatic transmission,
The automatic transmission is interposed between the input member and the output member, and executes the fastening and unfastening of the input member and the output member according to the lockup hydraulic pressure inputted from the outside, and the slip ratio at the time of fastening. A lock-up clutch that can be adjusted,
Abnormal combustion detecting means for detecting abnormal combustion occurring in the cylinder of the internal combustion engine;
A target lockup oil pressure calculating means for calculating a target lockup oil pressure capable of keeping the acceleration fluctuation of the vehicle that occurs when the abnormal combustion occurs within an allowable range;
When abnormal combustion is detected by the abnormal combustion detection means, the abnormal combustion lockup hydraulic pressure control means for making the lockup hydraulic pressure coincide with the target lockup hydraulic pressure;
A vehicle control apparatus comprising: An allowable acceleration change amount calculating means for calculating an allowable acceleration change amount which is an upper limit value of acceleration fluctuation allowed when driving the vehicle based on the speed and acceleration of the vehicle;
2. The vehicle control device according to claim 1, wherein the target lockup hydraulic pressure calculation unit calculates the target lockup hydraulic pressure based on at least the allowable acceleration change amount. 3.   The vehicle control device according to claim 2, further comprising a combustion correspondence correcting unit that corrects the allowable acceleration change amount based on an index representing the abnormal combustion and / or an occurrence frequency of the abnormal combustion. A target acceleration calculating means for calculating a target acceleration of the vehicle based on a vehicle speed and the allowable acceleration change amount;
Based on the known vehicle inertia, the gear ratio set by the automatic transmission and the target acceleration, a target torque to be obtained on the output member side of the automatic transmission is calculated, and based on the target torque, the target torque is calculated. A target rotational speed setting means for setting a target rotational speed of the output member,
4. The vehicle according to claim 2, wherein the target lockup hydraulic pressure calculation unit calculates the target lockup hydraulic pressure based on a difference between a target rotational speed of the output member and an engine rotational speed of the internal combustion engine. Control device.   The accelerator corresponding correction means for correcting the allowable acceleration change amount when the accelerator opening of the internal combustion engine is reduced during the operation of the abnormal combustion lockup hydraulic pressure control means. The vehicle control device according to Item.   6. A gear ratio variable means for increasing a gear ratio set by the automatic transmission when the accelerator opening of the internal combustion engine is increased during operation of the abnormal combustion lockup hydraulic pressure control means. The vehicle control device according to claim 1.

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