JP3559882B2 - Vehicle output control device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an output control device for a vehicle that performs cooperative control of an internal combustion engine and a transmission.
[0002]
[Prior art]
Conventionally, in this type of vehicle output control device, a throttle opening signal is transmitted from a control device of an engine to a control device of a transmission, and the control device of the transmission converts a throttle opening signal and a vehicle speed signal. The gear ratio is controlled on the basis of the transmission ratio, and the line pressure is controlled on the basis of the throttle opening signal (see Japanese Patent Application Laid-Open No. 8-326856).
[0003]
[Problems to be solved by the invention]
However, in an internal combustion engine in which the throttle opening is not uniquely determined with respect to the accelerator opening and the engine output torque is not uniquely determined with respect to the throttle opening, there are the following problems.
For example, an intake passage is provided with an electrically controlled throttle valve that is electrically driven without mechanically interlocking with an accelerator, while a fuel injection valve that injects fuel directly into a combustion chamber is provided to inject fuel during an intake stroke. In a direct-injection spark ignition type internal combustion engine capable of switching between homogeneous combustion performed by performing injection and stratified combustion performed by injecting fuel in a compression stroke, a target torque is set based on at least the accelerator opening, and the target torque is obtained. When the throttle opening and the fuel injection amount are controlled in a coordinated manner as described above, for example, as shown in FIG. 6 , when the operation is performed by switching between stratified combustion and homogeneous combustion, the throttle opening is controlled in response to the movement of the accelerator opening by the driver. The degree of movement is not uniquely determined, and the engine output torque cannot be represented by the throttle opening.
[0004]
Therefore, the intention of the driver and the engine output torque are read from the movement of the throttle opening, and the control on the transmission side that performs the shift control and the line pressure control is hindered.
In view of such a conventional problem, the present invention ensures transmission-side control by transmitting a signal in place of a throttle opening signal from an engine control device to a transmission control device. It is an object of the present invention to provide a vehicular output control device capable of performing the following.
[0005]
[Means for Solving the Problems]
Therefore, in the invention according to claim 1, the throttle opening is not uniquely determined with respect to the accelerator opening, and the engine output torque is not uniquely determined with respect to the throttle opening. And a transmission connected to the transmission control device, as shown in FIG. 1A, a means for transmitting an accelerator opening signal to the control device of the transmission to the control device of the engine, as shown in FIG. Means for transmitting an engine output torque signal.
[0006]
Further , as shown in FIG. 1B, the means for transmitting the engine output torque signal includes a means for converting the accelerator opening detected by the accelerator opening detecting means into a driver request torque, and a means independent of the driver request. Means for calculating an engine required torque, means for calculating a target torque based on the driver required torque and the engine required torque, and means for converting the target torque into a value corresponding to the accelerator opening degree, and as an engine output torque signal , And transmits an accelerator opening equivalent value of the target torque.
[0007]
The invention according to claim 2 is characterized in that the means for calculating the engine required torque calculates the engine required torque including at least the cold-time correction torque corresponding to the engine cooling water temperature.
The invention according to claim 3 is characterized in that the means for calculating the engine required torque calculates the engine required torque including at least an accessory load correction torque corresponding to the accessory load.
[0008]
The invention according to claim 4 is characterized in that the means for calculating the target torque calculates the target torque by adding the driver required torque and the engine required torque.
In the invention according to claim 5 , the control device for the transmission includes a shift control unit that controls a speed ratio based on an accelerator opening signal and a vehicle speed signal, and a line pressure that controls a line pressure based on an engine output torque signal. And control means (see FIG. 1A).
[0009]
【The invention's effect】
According to the first aspect of the present invention, instead of the throttle opening signal, the accelerator opening, which is the driver's will, and the engine output torque are transmitted separately from the engine control device to the transmission control device. Thereby, control on the transmission side can be ensured.
[0010]
Further, when transmitting the engine output torque signal, the accelerator opening is converted into a driver request torque, while an engine request torque independent of the driver request is calculated, and a target value corresponding to the engine output torque is calculated based on these. By calculating the torque, the engine output torque can be accurately grasped, and by converting this target torque into an accelerator opening equivalent value and transmitting this as an engine output torque signal, the accelerator opening equivalent is obtained. Since the value has the same unit as the value corresponding to the throttle opening, there is an advantage that conventional control on the transmission side can be used as it is.
[0011]
According to the second aspect of the invention, when calculating the engine required torque, the engine required torque can be accurately calculated by taking into account the correction torque at the time of cooling corresponding to the engine cooling water temperature.
According to the third aspect of the present invention, when calculating the engine required torque, the engine required torque can be accurately calculated by considering an auxiliary equipment load correction torque corresponding to the auxiliary equipment load such as an air conditioner. it can.
[0012]
According to the invention of claim 4 , when calculating the target torque, the target torque can be easily calculated only by adding the driver required torque and the engine required torque.
According to the fifth aspect of the present invention, the transmission controls the transmission ratio based on the accelerator opening signal and the vehicle speed signal, while controlling the line pressure based on the engine output torque signal. The transmission control and the line pressure control on the side can be ensured.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described.
FIG. 2 is a system diagram of a direct injection spark ignition type internal combustion engine showing an embodiment. First, this will be described.
Air is sucked into the combustion chamber of each cylinder of the internal combustion engine 1 mounted on the vehicle from the air cleaner 2 by the intake passage 3 under the control of the electronically controlled throttle valve 4.
[0014]
The opening of the electronically controlled throttle valve 4 is controlled by a step motor or the like that operates according to a signal from the control unit 10.
An electromagnetic fuel injection valve (injector) 5 is provided so as to directly inject fuel (gasoline) into the combustion chamber.
The fuel injection valve 5 is energized by a solenoid in response to an injection pulse signal output in the intake stroke or the compression stroke from the control unit 10 in synchronization with the engine rotation, opens the valve, and injects fuel adjusted to a predetermined pressure. It has become. The injected fuel diffuses into the combustion chamber in the case of the intake stroke injection to form a homogeneous mixture, and in the case of the compression stroke injection, forms a layered mixture around the spark plug 6 in a concentrated manner. Based on an ignition signal from the control unit 10, the fuel is ignited by the ignition plug 6 to perform combustion (homogeneous combustion or stratified combustion). The combustion method is classified into homogeneous stoichiometric combustion, homogeneous lean combustion, and stratified lean combustion in combination with air-fuel ratio control.
[0015]
Exhaust gas from the engine 1 is discharged from an exhaust passage 7, and an exhaust purification catalyst 8 is interposed in the exhaust passage 7.
The control unit 10 includes a microcomputer including a CPU, a ROM, a RAM, an A / D converter, an input / output interface, and the like, and receives signals from various sensors.
[0016]
As the various sensors, crank angle sensors 11 and 12 for detecting rotation of a crankshaft or a camshaft of the engine 1 are provided. Assuming that the number of cylinders is n, these crank angle sensors 11 and 12 provide a reference pulse at a predetermined crank angle position (a predetermined crank angle position before the compression top dead center of each cylinder) every 720 ° / n of crank angle. A signal REF is output, and a unit pulse signal POS is output every 1 to 2 °. The engine speed Ne can be calculated from the period of the reference pulse signal REF and the like.
[0017]
In addition, an air flow meter 13 for detecting an intake air flow rate Qa upstream of the throttle valve 4 in the intake passage 3, an accelerator sensor 14 for detecting an accelerator opening (accelerator pedal depression amount) ACC, and an opening TVO of the throttle valve 4 are detected. Throttle sensor 15 (including an idle switch that is turned on when the throttle valve 4 is fully closed), a water temperature sensor 16 that detects the cooling water temperature Tw of the engine 1, and an exhaust passage 7 that responds to the rich / lean exhaust air-fuel ratio. An O ₂ sensor 17 for outputting a signal, an air conditioner switch 18 and the like are provided.
[0018]
Here, the control unit 10 as a control device of the engine performs predetermined arithmetic processing by a built-in microcomputer while inputting signals from the various sensors, and performs a throttle operation by the electronically controlled throttle valve 4. The fuel injection amount and the injection timing by the fuel injection valve 5 and the ignition timing by the spark plug 6 are controlled.
Regarding the throttle control (control of the electronically controlled throttle valve 4), a target throttle opening tTVO is set according to a target torque of the engine which is set from the accelerator opening ACC and the engine speed Ne and obtained. Then, the motor of the electronically controlled throttle valve 4 is driven to control the opening.
[0019]
As for the fuel injection control (control of the fuel injection valve 5), the combustion method is set according to the engine operating conditions, and the fuel injection amount and the injection timing by the fuel injection valve 5 are controlled accordingly.
More specifically, a plurality of maps that determine the combustion method using the engine speed Ne and the basic fuel injection amount Tp as parameters are provided for each condition such as the water temperature Tw and the time after starting. According to the parameters of the actual operation state of the engine, the combustion method is set to one of the homogeneous stoichiometric combustion, the homogeneous lean combustion and the stratified lean combustion.
[0020]
As a result of the determination of the combustion method, in the case of homogeneous stoichiometric combustion, the fuel injection amount is set to the stoichiometric air-fuel ratio (14.6) and the air-fuel ratio feedback control by the O ₂ sensor 17 is performed, while the injection timing is set to the intake stroke. To perform homogeneous stoichiometric combustion. In the case of the homogeneous lean combustion, the fuel injection amount is set to a value corresponding to the lean air-fuel ratio of the air-fuel ratio of 20 to 30, and the open control is performed, while the injection timing is set to the intake stroke to perform the homogeneous lean combustion. In the case of stratified lean combustion, the fuel injection amount is set to a value corresponding to a lean air-fuel ratio of about 40, and the open control is performed, while the injection timing is set to the compression stroke to perform the stratified lean combustion. .
[0021]
Regarding the ignition control (control of the ignition plug 6), the ignition timing ADV is set and controlled by referring to a map using the engine speed Ne and the basic fuel injection amount Tp as parameters for each combustion method.
The control unit 10 as a control device of the engine executes the signal transmission routine of FIG. 3 on a regular basis for cooperative control between the engine and the transmission, and executes the signal transmission routine of FIG. , Signals for speed change control and line pressure control are transmitted.
[0022]
The signal transmission routine of FIG. 3 will be described.
In S1, the accelerator opening ACC is detected based on a signal from the accelerator sensor 14. This part, together with the accelerator sensor 14, corresponds to accelerator opening degree detecting means.
In S2, a driver request torque T1 corresponding to the accelerator opening is calculated. That is, the detected accelerator opening ACC is converted into a driver request torque T1 corresponding thereto. Specifically, the accelerator opening ACC is regarded as the throttle opening as it is, the throttle opening area at the throttle opening is obtained, and the throttle opening area may be treated as the driver required torque. Using the opening area conversion table, the accelerator opening degree ACC is converted into the driver required torque T1. This part corresponds to the driver required torque conversion means.
[0023]
In S3, an engine request torque T2 irrelevant to the driver request is calculated. Specifically, the correction torque at the time of cooling is set with reference to the table according to the engine cooling water temperature Tw. In addition, an auxiliary load correction torque is set according to ON / OFF of the air conditioner switch 18. Then, the correction torque for the cold state and the correction torque for the auxiliary equipment load are added, and the result is set as the engine required torque T2. This portion corresponds to engine required torque calculation means. It should be noted that the engine required torque may include an idle-up amount, an overheat-response amount, and the like, in addition to the cooling-time correction torque and the auxiliary load correction torque.
[0024]
In S4, the target torque tTRQ = T1 + T2 is calculated by adding the driver required torque T1 and the engine required torque T2. This part corresponds to the target torque calculating means.
In S5, an accelerator opening VACC corresponding to the target torque is calculated. That is, the calculated target torque tTRQ is converted into the corresponding accelerator opening degree VACC. Specifically, the target torque tTRQ is treated as a throttle opening area, the throttle opening at the throttle opening area is determined, and this throttle opening may be regarded as the accelerator opening as it is. The target torque tTRQ is converted into the accelerator opening degree VACC by using the reverse of the use table. This part corresponds to an accelerator opening equivalent value conversion unit.
[0025]
In S6, the accelerator opening ACC detected in S1 is transmitted to the transmission as an accelerator opening signal. This part, together with the part of S1, corresponds to the accelerator opening signal transmitting means.
In S7, the accelerator opening VACC corresponding to the target torque calculated in S5 is transmitted to the transmission as an engine output torque signal. This part corresponds to the engine output torque signal transmitting means together with the parts S1 to S5.
[0026]
FIG. 4 is a system diagram on the transmission side.
A continuously variable transmission (CVT) 23 is connected to the output shaft 21 side of the engine via a clutch 22.
[0027]
The continuously variable transmission 23 includes a primary pulley 25 whose effective diameter on the input shaft 24 side can be continuously changed, a secondary pulley 27 whose output diameter on the output shaft 26 side (the differential side) can be continuously changed, A belt 28 wound between the pulleys 25 and 27, a primary side cylinder 29 that receives a primary pressure (shift pressure) and acts on the primary pulley 25 in a radially increasing direction, and a secondary pulley that receives a line pressure 27 is provided with a secondary side cylinder 30 acting in the radially expanding direction.
[0028]
Here, the line pressure input to the secondary side cylinder 30 is generated by the line pressure control valve 31 having a relief function using the hydraulic pressure of a hydraulic source such as an oil pump as a source pressure.
The primary pressure input to the primary cylinder 29 is generated by the shift control valve 32 having a relief function using the line pressure as the original pressure.
[0029]
Accordingly, although the primary pressure is always lower than the line pressure, the pressure receiving area of the primary side cylinder 29 is set to be larger than the pressure receiving area of the secondary side cylinder 30, so that the ratio of the primary pressure to the line pressure (primary pressure / line pressure) is reduced. By performing the control, the gear ratio can be changed steplessly by changing the pulley ratio.
The duty of the line pressure control valve 31 and the shift control valve 32 is controlled by a control unit 33 as a control device of the transmission.
[0030]
For this control, a signal is input to the transmission control unit 33 from a vehicle speed sensor 34 for detecting the vehicle speed VSP and the like, and an accelerator opening signal (ACC) and an accelerator opening signal (ACC) are transmitted from the engine control unit 10 via a communication line. The engine output torque signal (VACC) is input.
Based on these signals, the transmission control unit 33 controls the transmission control valve 32 and the line pressure control valve 31 in accordance with the transmission control routine of FIG. Control.
[0031]
The transmission control routine of FIG. 5 will be described.
In S21, a target gear ratio is calculated based on the accelerator opening ACC and the vehicle speed VSP with reference to a gear shift map.
In S22, the duty ratio of the shift control valve 32 is controlled so as to obtain the target gear ratio, thereby controlling the primary pressure. Steps S21 and S22 correspond to the shift control means.
[0032]
In S23, the target line pressure is calculated by referring to a predetermined table based on the target torque-equivalent accelerator opening VACC as the engine output torque signal.
In S24, the line pressure control valve 31 is duty-controlled so as to obtain the target line pressure to control the line pressure. Steps S23 and S24 correspond to the line pressure control means.
[0033]
In this way, by controlling the gear ratio on the transmission side based on the accelerator opening signal and the vehicle speed signal, and controlling the line pressure based on the engine output torque signal (accelerator opening corresponding to the target torque) , Shift control and line pressure control on the transmission side can be ensured.
[Brief description of the drawings]
FIG. 1 is a functional block diagram showing the configuration of the present invention. FIG. 2 is a system diagram of an internal combustion engine showing an embodiment of the present invention. FIG. 3 is a flowchart of an engine-side signal transmission routine .
FIG. 4 is a system diagram of a transmission side.
FIG. 5 is a flowchart of a transmission control routine.
FIG. 6 is a diagram showing a conventional problem.
DESCRIPTION OF SYMBOLS 1 Internal combustion engine 4 Electric throttle valve 5 Fuel injection valve 6 Spark plug
10 Control unit for engine control
11,12 Crank angle sensor
13 Air flow meter
14 Accelerator sensor
16 Water temperature sensor
18 Air conditioner switch
21 Engine output shaft
22 clutch
23 Continuously variable transmission (CVT)
25 Primary pulley
27 Secondary pulley
29 Primary side cylinder
30 Secondary side cylinder
31 Line pressure control valve
32 Shift control valve
33 Control unit for transmission control
34 Vehicle speed sensor

Claims (5)

For a vehicle including an internal combustion engine in which the throttle opening is not uniquely determined with respect to the accelerator opening and the engine output torque is not uniquely determined with respect to the throttle opening, and a transmission connected to the output side thereof In the output control device,
In the control device of the engine, a means for transmitting an accelerator opening signal and a means for transmitting an engine output torque signal are provided for the control device of the transmission ,
Means for transmitting the engine output torque signal, means for converting the accelerator opening detected by the accelerator opening detecting means into a driver request torque, means for calculating an engine request torque independent of the driver request, A means for calculating a target torque based on the torque and the required engine torque, and a means for converting the target torque into an accelerator opening equivalent value, and transmits an accelerator opening equivalent value of the target torque as an engine output torque signal. An output control device for a vehicle, comprising: 2. The vehicle output control device according to claim 1 , wherein the means for calculating the engine required torque calculates the engine required torque including at least a cooling-time correction torque corresponding to the engine cooling water temperature. 3. The vehicle according to claim 1 , wherein the means for calculating the engine required torque calculates the engine required torque including at least an accessory load correction torque corresponding to the accessory load. Output control device. The vehicle according to any one of claims 1 to 3 , wherein the means for calculating the target torque calculates the target torque by adding the driver required torque and the engine required torque. Output control device. A transmission control device includes a shift control unit that controls a gear ratio based on an accelerator opening signal and a vehicle speed signal, and a line pressure control unit that controls a line pressure based on an engine output torque signal. The vehicle output control device according to any one of claims 1 to 4 , wherein:

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