JP2004197653A - Vehicle control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle control device for effectively reducing the gear shift shock of a vehicle having an automatic transmission and a supercharging means. <P>SOLUTION: The vehicle control device comprises an internal combustion engine 1, the automatic transmission 30 for transmitting the output of the internal combustion engine 1 to driving wheels 31 with automatic gear shift, the supercharging means 11 for supercharging using the exhausting energy of the internal combustion engine 1, and a supercharged pressure changing means 11b for changing supercharged pressure with the supercharging means 11. When the automatic transmission 30 operates gear shift, the supercharged pressure changing means 11b controls the supercharged pressure to controls the output torque of the internal combustion engine 1 so that a level difference in vehicle driving torque generated in the driving wheels 31 is reduced. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a control device for a vehicle having an automatic transmission and a supercharger.
[0002]
[Prior art]
At present, automatic transmissions (automatic transmissions) are very common as vehicle transmissions. As the automatic transmission, one using a fluid coupling is widely used, but an automatic transmission that can be called an automatic clutch in which the clutch operation in a conventional manual transmission is automated has also been put to practical use.
[0003]
[Patent Document 1]
JP-A-7-229432
[Problems to be solved by the invention]
In the automatic transmission, there is a tendency that a step occurs in the driving torque of the vehicle during the shift, giving a sense of incongruity to the driver (a so-called shift shock). For this reason, in the above-mentioned [Patent Document 1] and the like, the amount of intake air is adjusted to reduce shift shock. However, when the internal combustion engine is equipped with a supercharger, if the intake air amount is adjusted to reduce the shift shock, the exhaust air energy changes due to the change in the intake air amount. The amount will change further. That is, when the turbocharger is provided, it has been difficult to stably reduce the shift shock by the intake air amount.
[0005]
Accordingly, an object of the present invention is to provide a vehicle control device capable of effectively reducing a shift shock in a vehicle including an automatic transmission and a supercharging unit.
[0006]
[Means for Solving the Problems]
The vehicle control device according to claim 1, wherein the internal combustion engine, an automatic transmission that automatically changes the output of the internal combustion engine and transmits the output to drive wheels, and a supercharging unit that performs supercharging by using exhaust energy of the internal combustion engine And supercharging pressure changing means for changing the supercharging pressure by the supercharging means. The supercharging pressure changing means controls the supercharging pressure at the time of shifting of the automatic transmission to control the output torque of the internal combustion engine. Thus, the step of the vehicle drive torque generated in the drive wheels is reduced. Here, the supercharging pressure changing means refers to one capable of actively changing the supercharging pressure by the supercharging means.
[0007]
According to a second aspect of the present invention, in the vehicle control device according to the first aspect, the supercharging means is a turbocharger, and the supercharging pressure changing means rotationally drives a rotating shaft of a turbine / compressor of the turbocharger. A supercharger, wherein the supercharging pressure changing means controls the supercharging pressure by controlling the amount of electric power supplied to the electric motor at the time of shifting of the automatic transmission, thereby reducing a step in vehicle driving torque. .
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the control device of the present invention will be described below. FIG. 1 shows a configuration diagram (mainly around an engine) of a vehicle having the control device of the present embodiment.
[0009]
The engine 1 mounted on the vehicle according to the present embodiment is a multi-cylinder engine. Here, only one of the cylinders is shown in FIG. 1 as a sectional view. The engine 1 is of a type in which fuel is injected into the upper surface of a piston 4 in a cylinder 3 by an injector 2. This engine 1 is capable of performing stratified combustion, and is a so-called lean burn engine. By supercharging a larger amount of intake air with a turbocharger, which will be described later, and performing lean burn, it is possible to realize high output in addition to low fuel consumption.
[0010]
The engine 1 compresses air sucked into the cylinder 3 through the intake passage 5 by the piston 4, injects fuel into a hollow formed on the upper surface of the piston 4, and moves a rich mixture to the vicinity of the ignition plug 7. It can be collected and ignited by the spark plug 7 to burn (stratified combustion). If fuel is injected during the intake stroke, normal homogeneous combustion can also be performed. The interior of the cylinder 3 and the intake passage 5 are opened and closed by an intake valve 8. The exhaust gas after combustion is exhausted to the exhaust passage 6. The interior of the cylinder 3 and the exhaust passage 6 are opened and closed by an exhaust valve 9. An air cleaner 10, an air flow meter 27, a turbo unit 11, an intercooler 12, a throttle valve 13, and the like are arranged on the intake passage 5 from the upstream side.
[0011]
The air cleaner 10 is a filter that removes dust and dirt from the intake air. The air flow meter 27 of the present embodiment is of a hot wire type, and detects an intake air amount as a mass flow rate. The turbo unit 11 performs supercharging using exhaust energy. The turbine-side impeller arranged in the exhaust passage 6 and the compressor-side impeller arranged in the intake passage 5 are connected by one rotating shaft. Hereinafter, this portion will be simply referred to as a turbine / compressor 11a. . Here, the turbocharger functions as a supercharging means.
[0012]
Further, the turbocharger of the present embodiment is a turbocharger with a motor in which a turbomotor (electric motor) 11b is incorporated so that the rotation shaft of the turbine / compressor 11a becomes an output shaft. It is possible to assist the supercharging by driving the turbo motor 11b. The turbo motor 11b can also function as a generator that generates power using exhaust energy, and is sometimes called a motor generator because it has the functions of a motor and a generator. Further, the turbo unit 11 can also function as a normal turbocharger that performs supercharging only with exhaust energy without assisting by the turbo motor 11b.
[0013]
The turbo motor 11b has, as main components, a rotor fixed to the rotating shaft of the turbine / compressor 11a and a stator disposed around the rotor. In addition, since the turbo motor 11b of this embodiment is of a current control type, the current value is variably controlled when the supplied electric energy is variably controlled. Depending on the type of motor, when controlling the amount of supplied power, control may be performed using a voltage value, or control may be performed using the frequency of an AC power supply.
[0014]
On the downstream side of the turbo unit 11 on the intake passage 5, an air-cooled intercooler 12 that lowers the temperature of the intake air whose temperature has increased due to a pressure increase due to supercharging by the turbo unit 11 is arranged. The intercooler 12 lowers the temperature of the intake air to improve the charging efficiency. Downstream of the intercooler 12, a throttle valve 13 for adjusting the amount of intake air is arranged.
[0015]
The throttle valve 13 of the present embodiment is a so-called electronically-controlled throttle valve. The operation amount of an accelerator pedal 14 is detected by an accelerator positioning sensor 15, and the ECU 16 controls the throttle valve 13 based on the detection result and other information amounts. Is determined. The throttle valve 13 is opened and closed by a throttle motor 17 provided in association therewith. In addition to the throttle valve 13, a throttle positioning sensor 18 for detecting the opening degree is also provided.
[0016]
Downstream of the throttle valve 13, a pressure sensor 19 for detecting the pressure (supercharging pressure / intake pressure) in the intake passage 5 is provided. These sensors 15, 18, 19, 27 are connected to the ECU 16 and send the detection results to the ECU 16. The ECU 16 is an electronic control unit including a CPU, a ROM, a RAM, and the like. The above-described injector 2, the ignition plug 7, the turbo motor 11b, and the like are connected to the ECU 16, and these are controlled by signals from the ECU 16.
[0017]
In addition, the ECU 16 is also connected to a hydraulic pressure of a variable valve timing mechanism 20 for controlling the opening / closing timing of the intake valve 8, a controller 21 connected to the turbo motor 11b, a battery 22, and the like. The controller 21 not only controls the driving of the turbo motor 11b, but also has a function as an inverter that converts a DC current of the battery 22 into an AC current and applies the AC current to the turbo motor 11b. In addition, the turbo motor 11b also has a function as a rectifier that performs AC-DC conversion of the electric power regenerated by the turbo motor 11b. The ECU 16 and the controller 21 control the driving and power generation of the turbo motor, and function as supercharging pressure control means.
[0018]
An air-fuel ratio sensor 28 that detects an exhaust air-fuel ratio is disposed on the exhaust passage 6 upstream of the turbo unit 11. The air-fuel ratio sensor 28 of the present embodiment is a so-called linear air-fuel ratio sensor that can linearly detect the exhaust air-fuel ratio of exhaust gas. The air-fuel ratio sensor 28 is connected to the above-described ECU 16, and sends the detection result to the ECU 16. An exhaust purification catalyst 23 for purifying exhaust gas is attached downstream of the turbo unit 11. Then, an EGR (Exhaust Gas Recirculation) passage 24 for recirculating exhaust gas from the exhaust passage 6 (upstream of the air-fuel ratio sensor 28) to the intake passage 5 (surge tank formed downstream of the pressure sensor 19) is provided. It is arranged.
[0019]
An EGR valve 25 for adjusting the amount of exhaust gas recirculation is mounted on the EGR passage 24. The opening control of the EGR valve 25 is also performed by the ECU 16 described above. A crank positioning sensor 26 that detects the rotational position of the crankshaft is attached near the crankshaft of the engine 1. The crank positioning sensor 26 can also detect the engine speed from the position of the crank position.
[0020]
An automatic transmission 30 is provided in association with the engine 1, and a driving force (drive torque) output from a crankshaft of the engine 1 is transmitted to drive wheels 31 after being shifted by the automatic transmission 30. You. The vehicle is driven by the driving force (driving torque) transmitted to the driving wheels 31. The automatic transmission 30 of the present embodiment uses a known general fluid coupling. Therefore, a detailed description of the automatic transmission 30 will be omitted. Although not shown, a rotation speed sensor is incorporated in the automatic transmission 30 on each of an input side and an output side thereof. Further, a differential gear or the like may be provided between the automatic transmission 30 and the driving wheels 31.
[0021]
Control for reducing the shift shock in the vehicle described above will be described. FIG. 2 shows a flowchart of this control.
[0022]
First, it is determined whether there is a shift request (step 200). The shift request is generated by the ECU 16. At present, there are vehicles having two modes, a mode in which the vehicle controls shifting and a mode in which automatic shifting is performed in response to a driver's operation. In the former case, the ECU 16 determines whether or not a shift is necessary based on the depression amount of the accelerator pedal 14 detected by the accelerator positioning sensor 15 and the engine speed detected by the crank positioning sensor. Is generated. In the latter case, the ECU 16 generates a shift request when the driver performs a shift operation (button or lever operation). However, in this case, there may be a case where the shift request is not generated by the ECU 16 when the shift should be prohibited (for example, there is a possibility that an over-rev may occur due to the shift).
[0023]
If there is no shift request, the shift itself is not performed, and the control of the flowchart in FIG. 2 ends. On the other hand, if there is a shift request, it is determined whether or not the turbocharger 11b is actually performing the supercharging assist (step 210). In the present embodiment, the shift shock reduction control by the turbo motor 11b is performed only when the supercharging assist is being executed. Therefore, at step 210, it is determined whether or not the turbocharger 11b is performing the supercharging assist.
[0024]
Here, if step 210 is denied, that is, if the supercharging assist by the turbo motor 11b has not been executed, the control of the flowchart in FIG. 2 ends. On the other hand, when step 210 is affirmed, the correction amount of the supplied current amount is determined from the map (step 220). This map is created in advance based on an experiment or the like and is stored in the ROM in the ECU 16. For example, the above-described correction amount is determined based on the gear before shifting, the gear after shifting, the throttle valve opening, and the engine speed. Is determined. After the correction amount is determined in step 220, the shift hydraulic valve in the automatic transmission 30 is controlled based on a command from the ECU 16 to actually perform a shift (step 230).
[0025]
At the same time, the amount of current supplied to the turbo motor 11b is changed to reflect the determined correction amount (Step 240). When the supply current amount is changed, the intake air amount is changed and the output torque of the engine 1 (that is, the input torque to the automatic transmission 30) is changed, so that the shift shock is reduced. In this way, it is not necessary to simultaneously perform contradictory controls such as closing the throttle valve (= reducing the intake air amount) in order to reduce the shift shock during the supercharging assist (= increase the intake air amount). Further, in this case, only the control of the turbo motor 11b is sufficient, and the control is easy.
[0026]
At the time of upshifting, the number of revolutions decreases, but the amount of air does not immediately decrease, so that the output torque of the engine 1 tends to increase due to excessive air. Therefore, here, the amount of current supplied to the turbo motor 11b is reduced to reduce the amount of intake air, and the output torque of the engine 1 is reduced. That is, the correction amount is set on the side that reduces the supply current amount. Thereby, the step of the torque is reduced (including the case where the step is completely eliminated). Conversely, at the time of downshifting, the amount of current supplied to the turbo motor 11b is increased to increase the amount of intake air, thereby increasing the output torque (and the number of revolutions) of the engine 1. That is, the correction amount is set on the side that increases the supply current amount. Thereby, the step of the torque is reduced (including the case where the step is completely eliminated).
[0027]
In the above-described embodiment, the shift shock reduction control using the turbo motor 11b is performed only when the supercharging assist is performed by the turbo motor 11b. However, when supercharging assist is not performed by the turbo motor 11b (when neither supercharging assist nor regenerative power generation is performed, or when regenerative power generation is performed), the turbo motor 11b is controlled to reduce shift shock. You may let it. When neither supercharging assistance nor regenerative power generation is performed, supercharging assistance is started by supplying electric power to the turbo motor 11b to increase the output torque of the engine 1 (input torque to the automatic transmission 30), or to increase the turbocharger power. The vehicle drive torque can be controlled by starting the regenerative power generation by the motor 11b and reducing the output torque of the engine 1 (input torque to the automatic transmission 30).
[0028]
If regenerative power generation has already been performed, the output torque of the engine 1 (input torque to the automatic transmission 30) may be increased by reducing the amount of regenerative power generation or shifting from regenerative power generation to supercharging assist. The vehicle drive torque can be controlled by increasing the amount of regenerative power generation and reducing the output torque of the engine 1 (input torque to the automatic transmission 30). Also in this case, the shift shock can be effectively reduced by changing the supercharging pressure (increase / decrease in assist / increase in regenerative power generation).
[0029]
Note that there is a method of reducing the shift shock by controlling the ignition timing, and this can be used together. It should be noted that reducing the shift shock only by the ignition timing is not preferable in terms of fuel efficiency performance and exhaust gas purification performance. When the shift shock is reduced by controlling the turbo motor 11b as in the present invention, the fuel consumption performance and the exhaust gas purification performance are not adversely affected.
[0030]
Note that the present invention is not limited to the embodiment described above. For example, in the above-described embodiment, the supercharging means is a turbocharger, but as a supercharger, there is a supercharger that performs supercharging using the output of the internal combustion engine in addition to the turbocharger. It can be adopted as a supercharging means. It should be noted that a device using the output of the internal combustion engine is often called a supercharger in comparison with a turbocharger (on the other hand, the entire supercharger including the turbocharger is sometimes called a supercharger).
[0031]
Further, in the above-described embodiment, the supercharging pressure changing unit is a turbo motor. However, when the supercharging means is a turbocharger, the supercharging pressure changing means is realized by another mechanism, for example, a variable geometry turbo (for changing the A / R by variably controlling the cross-sectional area of the flow path, Variable nozzle turbo etc.) can also be adopted. Further, the automatic transmission may be other than the one using the fluid coupling as in the above embodiment (such as the above-mentioned automatic clutch type).
[0032]
【The invention's effect】
The vehicle control device according to the present invention increases or decreases the output torque of the internal combustion engine by controlling the supercharging pressure by the supercharging pressure changing means to increase or decrease the intake air amount. (Shift shock) can be stably reduced. Further, since the supercharging pressure is controlled, the control range is wide, and the shift shock can be effectively reduced. Here, the supercharging pressure means is a turbocharger, and the supercharging pressure changing means is an electric motor (turbomotor) provided in association with the turbocharger, so that the supercharging pressure (intake air amount) can be controlled in a wide range. Can be executed with good responsiveness.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing a configuration of a vehicle having an embodiment of a control device according to the present invention (mainly around an internal combustion engine).
FIG. 2 is a flowchart showing control for reducing a shift shock according to an embodiment of the control device of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Engine, 2 ... Injector, 3 ... Cylinder, 4 ... Piston, 5 ... Intake passage, 6 ... Exhaust passage, 7 ... Spark plug, 8 ... Intake valve, 9 ... Exhaust valve, 10 ... Air cleaner, 11 ... Turbo unit, 11a: Turbine, 11b: Turbomotor, 12: Intercooler, 13: Air cleaner, 13: Throttle valve, 14: Accelerator pedal, 15: Accelerator positioning sensor, 16: ECU, 17: Throttle motor, 18: Throttle positioning sensor, 19 ... Pressure sensor, 20: variable valve timing mechanism, 21: controller, 22: battery, 23: exhaust gas purification catalyst, 24: EGR passage, 25: EGR valve, 26: crank positioning sensor, 27: air flow meter, 28: air-fuel ratio sensor , 30 ... automatic transmission, 31 ... Wheel.

Claims (2)

An internal combustion engine, an automatic transmission for automatically shifting the output of the internal combustion engine and transmitting the output to drive wheels, a supercharging unit for performing supercharging by using exhaust energy of the internal combustion engine, and a supercharging by the supercharging unit A control device for a vehicle including a supercharging pressure changing unit that changes a pressure,
The supercharging pressure changing means may control a supercharging pressure at the time of shifting of the automatic transmission to control an output torque of the internal combustion engine to reduce a step of a vehicle driving torque generated in the driving wheels. Characteristic vehicle control device. The supercharging means is a turbocharger, and the supercharging pressure changing means is an electric motor capable of driving a rotating shaft of a turbine / compressor of the turbocharger,
The supercharging pressure changing means controls a supercharging pressure by controlling an amount of electric power supplied to the electric motor during a shift of the automatic transmission, thereby reducing a step in vehicle driving torque. 2. The vehicle control device according to 1.

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