JP2782711B2 - Control device for turbocharger with rotating electric machine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a control device for a turbocharger with a rotating electric machine in which a motor-generator is mounted on a rotating shaft of a turbocharger. (Prior Art) Various proposals have been made to mount a turbocharger on an exhaust pipe of an engine and directly connect a motor-generator to a rotating shaft of the turbocharger to recover exhaust energy. As a proposal in which an electric-generator is attached to such a turbocharger, there is proposed a turbocharger control of an internal combustion engine in which the electric-generator is operated by a generator or an electric motor is operated in accordance with an engine speed or a load state. Proposals for the apparatus are disclosed, for example, in Japanese Patent Application No. 62-105981 and Japanese Patent Application Laid-Open No. 60-195329. (Problems to be Solved by the Invention) In such a proposed turbocharger with a rotating electric machine, generated electric power is supplied to an electric load or a battery during operation of the generator of the motor-generator, and excess power of the turbocharger is operated during operation of the motor. Although the engine output is improved by assisting the supply operation, when the boost pressure of the turbocharger is increased in accordance with changes in the driving conditions of the vehicle, the fuel flow is also appropriately adjusted according to the increase in the boost pressure. There is no means to increase and control the engine to run with the optimal air / fuel ratio. Therefore, there is a problem that desired acceleration cannot be performed due to lack of driving force of the engine even when the vehicle is under running conditions requiring rapid acceleration. There is also a problem that the exhaust gas is turned into black smoke due to an improper air / fuel ratio. Accordingly, an object of the present invention is to provide a control device for a turbocharger with a rotating electric machine which solves the above-mentioned problem by performing control so that an optimum air / fuel ratio is always obtained according to running conditions of a vehicle. It is in. (Means for Solving the Problems) In order to achieve the object of the present invention as described above, according to the present invention, a rotating electric machine is provided on a rotating shaft of a turbocharger connected to an exhaust pipe of an internal combustion engine. A turbocharger with a rotating electric machine that drives the rotating electric machine to an electric motor when the supercharging pressure is not reached to assist supercharging, and drives the rotating electric machine to generate electricity when the internal combustion engine has an excessive displacement to convert exhaust energy into generated energy. A control unit for calculating an accelerator pedal depression amount of the internal combustion engine, a boost pressure Pc corresponding to the accelerator pedal depression amount detected by the accelerator pedal depression amount detection unit, and a signal from the load sensor 1d. A fuel flow rate calculating means for calculating the fuel flow rate, a calculating means for calculating a boost pressure Pfc corresponding to the fuel flow rate calculated by the fuel flow rate calculating means, and the calculated accelerator Comparing means for comparing the boost pressure Pc corresponding to the dull stepping amount with the boost pressure Pfc corresponding to the fuel flow rate calculated by the fuel flow rate calculating means, and the result of the comparing means being the boost pressure Pc corresponding to the accelerator pedal stepping amount. And a fuel supply amount control means for controlling a fuel supply amount to increase or decrease until the boost pressure Pfc corresponding to the fuel flow rate calculated by the fuel flow rate calculation means coincides with the fuel flow rate calculation means. A control device for a turbocharger is provided. (Operation) In the present invention, the required boost pressure of intake air is calculated in accordance with the amount of depression of the accelerator pedal, and the fuel supply amount for this boost pressure is also calculated to correct the supercharging operation and the fuel flow rate, respectively. Therefore, an appropriate air-fuel ratio is always obtained. Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a configuration block diagram showing one embodiment of the present invention. In FIG. 1, reference numeral 1 denotes an engine which drives a vehicle (not shown) by the combustion energy of air taken in through an intake pipe 1a and fuel supplied through a fuel passage 7a. The exhaust gas after combustion is discharged via 1b. 1c is an accelerator sensor for detecting an accelerator pedal depression amount, and 1d is a fuel injection pump (not shown) of the engine 1.
A load sensor 1e detects a load on the engine based on the rack position, and a rotation sensor 1e detects the number of revolutions of the engine, and transmits a detected signal to an electronic control device described later. Note that a fuel actuator 7 is provided in the fuel passage 7a, and control of the fuel supply amount is performed by an electronic control device described later. Reference numeral 2 denotes a turbocharger connected to the exhaust pipe 1b and the intake pipe 1a, and a turbine 2b driven by exhaust gas.
And a compressor 2a for sending intake air to the intake pipe 1a, and a rotating electric machine 3 that operates as a motor or a generator is attached to a rotating shaft 2c connecting these. Reference numeral 1f denotes a partition provided in the exhaust pipe 1b, which is attached to an exhaust flow path for driving the turbine 2b and divides the flow path into two, and one of the flow paths is provided with an exhaust valve 1g, When the gas amount is small, the bypass valve 1g by the actuator 1h
Are closed, and the turbine 2b is efficiently driven at a high speed by increasing the flow rate of exhaust gas in the other flow path. Note that 2d is a turbine rotation sensor and the rotation shaft 2c
This is to detect the rotation speed of. The rotating electric machine 3 has a rotor 3a and a stator 3b. When the rotor 3a is rotationally driven by exhaust energy, the
AC power is generated in 3b and transmitted to the battery 5 via the power converter 4 described later. When electric power from the battery 5 via the power converter 4 is supplied to the stator 3b and the rotor 3a is driven, the intake air is compressed by the operation of the compressor 2a, and the engine 1 is supercharged through the intake pipe 1a. It is configured to be. In addition, 1j is a boost pressure sensor which detects a supercharging air pressure due to the operation of the compressor 2a and transmits it to the electronic control unit 6. FIG. 2 shows an example of an AC power conversion circuit in the power converter 4, and includes a rectifying / smoothing circuit 4a, a duty control circuit 4b, and a choke circuit 4c. The AC power from the rotating electric machine 3 during the operation of the generator is rectified and smoothed.
In step 4a, the current is converted into a direct current, and a predetermined control pulse signal from the electronic control unit 6 is applied to the base input of the transistor Tr to control the effective power value with the pulsating current passing through the transistor Tr. Thereafter, the power having a desired voltage is supplied to the load via the choke Ch. The power converter 4 is a converter circuit for converting the DC power from the battery 5 to an AC having a predetermined frequency to drive the rotating electric machine 3 with an electric motor, and exchanging the DC power with AC power whose frequency can be adjusted. The electronic control unit 6 controls the frequency of the inverter circuit.
This is controlled by the command. Therefore, the AC power from the rotating electric machine 3 during the operation of the generator is converted into DC by the rectifying and smoothing circuit, and is controlled by the converter circuit and the duty control circuit to electric power suitable for charging the battery. The DC power from the battery 5 is converted into AC power of a predetermined voltage and frequency by the operation of the converter circuit and the inverter circuit and supplied to the stator 3b to assist the supercharging operation of the turbocharger driven by the exhaust energy. Things. 3c shown in FIG. 1 is an AC voltmeter and a stator of the rotating electric machine 3.
A terminal voltage of 3b is measured, and a terminal voltage of 4d is a DC voltmeter for measuring the DC terminal voltage of the power converter 4. The measured voltage is sent to the electronic control unit 6. The electronic control unit 6 is composed of a microcomputer, and is a central processing unit for inputting an operation state of the engine 1 and a signal from a voltmeter and performing arithmetic processing and counting of the number of times of control, and an operation state of the engine by depressing an accelerator pedal. Various memory devices that store maps related to the required boost pressure and control programs for the operation of the rotating electric machine, input / output devices that receive input from various sensors, and issue control instructions to actuators, power converters, etc. And so on.
Reference numeral 3d denotes a rotor position sensor that detects a magnetic pole position during rotation of the rotor 3a and uses the detected position when controlling the phase of the power supplied to the rotating electric machine 3. FIG. 3 is a processing flowchart showing the operation of one embodiment of the present invention, and the operation will be described with reference to FIG. First, in step 1, the engine speed is checked based on a signal from the rotation sensor 1e. If it is determined that the engine speed is higher than the idle speed (for example, 800 RPM or more), it is checked whether the clutch is disconnected (step 2). An accelerator position is detected (step 3). If the accelerator position is partially depressed (step 4), the engine speed (step 5), the current boost pressure PB2 (step 6), and the accelerator equivalent boost pressure PB1 are detected from the respective sensors (step 7). The difference between the accelerator equivalent boost pressure PB1 and the current boost pressure PB2 is calculated (step 8). When it is determined that the difference between the equivalent boost pressure PB1 and the current boost pressure PB2 is larger than the predetermined value A, it is necessary to assist the motor operation, and the power supplied to the rotating electric machine 3 required for acceleration is reduced. Calculate (Step 10), detect the turbine speed (Step 11), and determine the duty control necessary for increasing the voltage of the supplied power (Step 12). Then, the power converter 4 is operated (step 13), the phase of the supplied power is determined by the rotor position sensor, and the inverter provided in the power converter 4 is operated (step 14), so that the rotating electric machine operated by the motor is operated. Increase speed. Then boost pressure PB
Is detected (step 15), and the fuel actuator 7 is controlled to control the fuel increase corresponding to the boost pressure increase (step 16). Then, the boost pressure PB is compared with the equivalent boost pressure PB1 (step 17). If PB> the equivalent boost pressure PB1, the accelerator position is detected by the accelerator sensor 1c (step 18), and the engine speed is detected (step 18). 19). Here, PB became more than PB1,
Whether the engine torque requires the assistance of the electric motor is determined by the load range stored therein. In step 20, it is checked whether or not the motor needs to be operated. If the motor is operating, the process proceeds to step 45; if not, the process proceeds to step 34.
Will move to If it is determined in step 9 that the difference between the equivalent boost pressure PB1 and the current boost pressure PB2 is smaller than the predetermined value A, the process directly proceeds to step 17 described above. If it is determined in step 1 that the engine speed is equal to or less than 800 RPM, the process proceeds to step 21 in which the actuator 1h and the bypass 1g are operated to increase the speed of the turbocharger by increasing the flow rate of the exhaust gas, thereby operating the exhaust bypass. Perform control. Next, the voltage V generated by the rotating electric machine 3 is measured (step 22), and the magnitude of the voltage is compared with the bypass voltage Vb (step 23). As a result, when V <Vb, the step-up duty of the high-frequency coil is controlled (step 2).
4) After the generated voltage V is raised above the battery voltage Vb, the battery is charged. If the accelerator is fully depressed in step 4, the process proceeds to step 25, where the engine speed is detected by the rotation sensor 1e, and the maximum driving force (maximum boost pressure) of the engine is searched by the CPU (step 26). ), The rotation speed of the turbocharger turbine and the current boost pressure are detected (steps 27 and 28), and compared with the maximum boost pressure (step 29). If the boost pressure is still smaller than the maximum boost pressure, the duty control necessary for increasing the voltage for driving the rotating electric machine is determined. Here, the power converter is activated (step 30), the phase of the supplied power is determined based on the signal from the rotor position sensor 3d, and the inverter is activated (step 31). Next, the boost pressure after the driving of the rotating electric machine is detected (step 32), the amount of fuel is increased in accordance with the increase (step 33), and the routine proceeds to step 17. When it is determined in step 29 that the pressure has become larger than the maximum boost pressure, the process also proceeds to step 17. When it is determined in step 20 that the motor is not being driven, the process proceeds to step 34, where it is determined whether the supercharging operation or the generator operation is performed according to the load zone stored in the storage device (step 35). Turns off the power generation circuit (step 36). When it is determined that the generator is working,
The generated voltage is measured (step 37), and the generated voltage V and the battery voltage Vb are compared in magnitude (step 38). If V> Vb, control the duty of the power converter (step
39), the battery charging circuit is turned on, and the battery is charged (step 40). Then, the state of charge is checked (step 41). If charging is in progress, the process returns to step 2 of the start. If the battery is not being charged, a failure signal is generated to notify the failure (step 42). If not V> Vb, the generated voltage is measured (step 43), duty control is performed by the power converter 4 (step 44), and the routine proceeds to step 40. Next, FIG. 3 (No. 3) is a processing flow chart in which the relationship between the boost pressure and the fuel is always corrected and controlled so that the normal air / fuel ratio is maintained. That is, when it is determined in step 20 that the motor is operating, the process proceeds to step 45 shown in FIG.
A boost pressure Pc corresponding to the accelerator pedal position detected in step 18 is calculated. On the other hand, the fuel flow rate is measured by the load sensor 1d (step 46), and the fuel equivalent boost pressure Pfc based on the fuel flow rate is calculated (step 47). Next, the magnitudes of Pc and Pfc are compared (step 48), and Pc> Pfc
If so, the fuel needs to be increased, and the flow rate is corrected by controlling the fuel actuator 7 in the increasing direction (step 49). In step 50, a correction equivalent boost pressure (Fadj1 + ΔP) that should increase due to this correction is calculated. Next, in step 51, the magnitudes of Pc and Fadj1 are compared, and if Pc <Fadj1, the correction is completed, and the routine goes to step 55. In addition,
If Pc ≧ Fadj1 in step 51, steps 48 to 50 are repeated until Pc <Fadj1. On the other hand, if Pc <Pfc in step 48, the process proceeds to step 52, in which the fuel actuator 7 is driven in the decreasing direction to correct the flow rate (step 53), and the reduction-equivalent boost pressure (Fadj2-ΔP) is calculated. I do. Then, the magnitudes of Pc and Fadj2 are compared (step 54). If Pc <Fadj2, the correction is completed, and the routine goes to step 55. Here, Pc ≧
If it is Fadj2, steps 52 and up until Pc <Fadj2
54 is repeated. As described above, the ratio of air and fuel supplied to the engine is corrected so that the normal air-fuel ratio is always maintained. Next, the process proceeds to step 55, in which the rotating electric machine is driven by a motor to calculate the driving power for assisting the supercharging operation, the turbine speed is detected (step 56), and the duty required for the voltage increase is determined (step 57). ), Operate the inverter to adjust the phase and voltage of the supplied power (step 58). Next, the boost pressure is detected (step 59), the amount of fuel is increased according to the increase (step 60), and the control flow returns to step 2. Although the present invention has been described with the above embodiments, various modifications are possible within the scope of the gist of the present invention, and these are not excluded from the scope of the present invention. (Effects of the Invention) According to the present invention, a boost pressure of intake air required by an internal combustion engine is obtained in accordance with an amount of depression of an accelerator pedal, and an appropriate fuel supply amount is calculated in accordance with the boost pressure. Since the supercharging operation of the intake air and the fuel flow rate are corrected, the air-fuel ratio according to the operating state is always obtained, and the required engine output is obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of a control device for a turbocharger with a rotating electric machine according to the present invention, and FIG. 2 shows an example of a power converter used in the embodiment of the present invention. FIG. 3 is a circuit diagram showing the operation of the embodiment of the present invention. 1 ... Engine, 1c ... Accelerator sensor, 1d ... Load sensor, 1e ... Rotation sensor, 1j ... Boost pressure sensor, 2
... turbocharger, 3 ... rotating electric machine, 4 ... electric power converter, 5 ... battery, 6 ... electronic control unit, 7 ... fuel actuator.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI F02D 43/00 301 F02D 43/00 301R

Claims (1)

(57) [Claims] A rotating electric machine is installed on the rotating shaft of the turbocharger connected to the exhaust pipe of the internal combustion engine, and the rotating electric machine is driven by an electric motor in a state where the required supercharging pressure is not reached to assist supercharging. A control device for a turbocharger with a rotating electric machine that drives a rotating electric machine to generate electric energy by driving a rotating electric machine, comprising: an accelerator pedal depression amount detection unit of the internal combustion engine; and an accelerator pedal detected by the accelerator pedal depression amount detection unit. Calculating means for calculating the boost pressure Pc corresponding to the stepping amount; fuel flow calculating means for calculating the fuel flow rate based on a signal from the load sensor 1d; and calculating the boost pressure Pfc corresponding to the fuel flow rate calculated by the fuel flow rate calculating means. A boost pressure Pc corresponding to the calculated accelerator pedal depression amount and a boost pressure corresponding to the fuel flow rate calculated by the fuel flow rate calculating means. Comparing means for comparing the boost pressure Pfc with the boost pressure Pfc corresponding to the accelerator pedal depression amount and the boost pressure Pfc corresponding to the fuel flow rate calculated by the fuel flow rate calculating means. A control device for a turbocharger with a rotating electric machine, comprising: a fuel supply amount control means for controlling a fuel supply amount to increase and decrease.