JP2884725B2 - Control device for twin turbocharger - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a twin turbocharger control device for arranging two turbochargers for supercharging intake air to an engine and for efficiently collecting exhaust energy.

(Prior Art) In recent years, a turbocharger having a compressor that drives a turbine by exhaust gas energy from an engine and is driven by the turbine torque to pressure-feed the super intake air has been frequently used. In addition, a turbocharger with a rotating electric machine in which a rotating electric machine is attached to a rotating shaft of a turbocharger has been proposed. The rotating electric machine is operated as an electric motor or a generator according to the operating state of the engine to improve engine performance and recover exhaust energy. It is used for

As a control device for this type of turbocharger with a rotating electric machine, a means for electrically driving the rotating electric machine in response to depression of an accelerator pedal of the vehicle to boost the supercharged air, and detecting an abnormality of the turbocharger during electric driving Japanese Patent Application Laid-Open No. H2-223232 discloses a proposal provided with a means for performing the above.

(Problems to be Solved by the Invention) In the turbocharger with the rotating electric machine as described above, the boost pressure can be increased by the electric drive at the time of low rotation and high load of the engine to improve the engine output. There is a problem in that the supplied power increases and the expected improvement in characteristics cannot be obtained at a high power consumption rate.

Also, when recovering exhaust energy as electric power, it is a partial area such as within the operating range of the engine.Furthermore, when a turbocharger with a rotating electric machine is used as a normal turbocharger, friction is large, and There is also a problem of durability during high-speed rotation.

The present invention has been made in view of such a problem, and an object of the present invention is to provide a turbocharger with a rotating electric machine and a normal turbocharger, or a turbocharger with a rotating electric machine, and to operate by arranging two units. An object of the present invention is to provide a twin turbocharger control device which aims to eliminate the disadvantages.

(Means for Solving the Problems) According to the present invention, in order to achieve the above-described object, a turbine provided in one of two divided exhaust passages of an engine and two intake passages merge to form an engine. A compressor provided in one intake passage for taking in air, a first turbocharger in which these turbines and the compressor are connected by a rotating shaft, a turbine provided in the other of the exhaust passage, and a compressor provided in the other of the intake passage; In a second turbocharger in which the turbine and the compressor are connected by a rotating shaft, and a twin turbocharger control device in which a rotating electric machine is provided on a rotating shaft of one of the first and second turbochargers, Open / close valves of the exhaust passages provided in the two exhaust passages for opening and closing them, respectively, and these are provided in the two intake passages. Opening and closing valves of intake passages that open and close respectively, operation detection means for detecting an operation state of the engine, first and second boost pressure sensors for detecting a supercharging pressure of the first and second turbochargers, respectively; A third boost pressure sensor for detecting the supply pressure of the engine, and an output signal from the operation detection means. In a state where the exhaust gas rotationally drives the turbine provided with the rotating electric machine in a low engine load state, the rotating electric machine is controlled. Means for opening the on-off valve of the exhaust passage of the turbocharger provided to cause the rotating electric machine to perform a power generation operation, and, based on an output signal from the operation detecting means, drive the rotating electric machine to the electric motor while the vehicle is accelerating, thereby rotating the compressor. Means for opening the on-off valve to perform a supercharging operation, controlling opening and closing of the first and second boost pressure sensors, the two on-off valves of the exhaust passage, and the two on-off valves of the intake passage. Off valve driving means for holding a supply pressure of the resulting engine from 3 boost pressure sensor to a desired intake pressure, the control device of the twin turbocharger, characterized by comprising is provided.

(Operation) In the present invention, the exhaust passage and the intake passage of the engine are each divided into two parts, and two turbochargers of a large capacity and a small capacity are respectively attached to the divided two paths, and an opening / closing valve is provided in each of these paths. It arranges and controls the opening and closing of each on-off valve based on the magnitude of exhaust energy according to the operating state of the engine, and generates or electrically drives the rotating electric machine arranged in the small-capacity turbocharger, Supercharging is performed by a large-capacity turbocharger, or electric power is generated by a rotating electric machine arranged in the turbocharger.

Example Next, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a first embodiment of a twin turbocharger control device according to the present invention.

In FIG. 1, reference numeral 1 denotes an engine, which is provided with two turbochargers 2 and 3, and exhaust gas from an exhaust manifold 11 is branched into exhaust passages 12a and 12b, and a turbine 21 and a turbocharger 3 of the turbocharger 2, respectively.
The exhaust gas after driving is combined and discharged from the muffler 13 into the atmosphere.

Reference numeral 22 denotes a compressor driven by the torque of the turbine 21, and 32 denotes a compressor driven by the torque of the turbine 31, and the respective flow paths 23 and 33 of the compressed air by the compressors 22 and 32 are joined to the intercooler 15. Guided through the intake pipe 16 to the intake manifold 17
It is formed such that air is introduced into the air.

The turbocharger 3 has a rotating electric machine 4 serving as a motor-generator on a rotating shaft thereof, and the capacity of the turbocharger is smaller than that of the turbocharger 2.

5a and 5b are respective opening / closing valves arranged in the exhaust passages 12a and 12b, and the opening / closing control of each passage is performed by valve actuators 51a and 51b.
Reference numerals 5c and 5d denote on-off valves disposed in the flow paths 23 and 33, respectively, and the opening and closing control of the respective flow paths is performed by valve actuators 51c and 51d. Each control command for these valve actuators 51a, 51b, 51c and 51d is issued from a controller described later.

Reference numeral 61 denotes a power converter, which is composed of an AC / DC bidirectional converter having a converter and an inverter, converts DC power from the battery 62 into AC power of a predetermined frequency, and supplies the AC power to the rotating electric machine 4 for electric driving, or The AC power from the rotating electric machine 4 during the power generation operation is converted into DC power of a predetermined voltage,
It charges 62. The control command to the power converter 61 is configured to be issued from the controller 6.

Reference numeral 90 denotes a boost pressure sensor which detects a boost pressure to be pumped to the engine 1, 92 detects a boost pressure due to the operation of the turbocharger 2, and 93 detects a boost pressure due to the operation of the turbocharger 3. .

19 is an engine rotation sensor for detecting the number of revolutions of the engine 1, 71 is an accelerator depression amount sensor for detecting the depression amount of the accelerator pedal 7, and 72 is a vehicle speed sensor for detecting the speed of the vehicle. Each signal line from these sensors serving as driving detection means is connected to the controller 6.

The controller 6 comprises a microcomputer, a central control unit for performing arithmetic processing, arithmetic processing procedures and processing procedures,
It is provided with various memories for storing calculation results and the like, input / output devices, and the like. When signals from the above-described various sensors are input, predetermined processing is performed based on these signals,
It is configured such that a command is issued to the above-described valve actuator or power converter.

FIG. 2 is a chart showing the operating state of the engine and the opening / closing control of various on-off valves in the present embodiment, and FIG. 3 is a processing flow chart showing an example of the operation of the present embodiment.

Next, the operation of this embodiment will be described with reference to FIGS.

In step 1, the signal from the vehicle speed sensor 72 is checked, and if the vehicle speed is 0, it is determined that the vehicle is stopped and idling is in progress, and the process proceeds to step 2, in which only the open / close valve 5b of the four open / close valves is opened and the turbo is opened. The charger 3 is driven by the exhaust gas to cause the rotating electric machine 4 to perform a power generation operation, and the output thereof is sent to the battery 62 via the power converter 61 to be charged.

In step 1, it is determined that the vehicle is running. In step 3, if the vehicle is accelerating, the on-off valves 5a and 5d are opened, and the turbocharger 2 is opened.
Is driven by the exhaust energy, and the turbocharger 3 supercharges the engine 1 by the electric drive of the rotating electric machine 4.
To pump.

In step 4, when the engine is rotating at medium speed and high load, the on-off valve 5b is also opened and the turbocharger 3 in the state of step 3 is opened.
And the supercharging operation is urged by supplying exhaust gas to the rotating electric machine 4 to reduce energization to the rotating electric machine 4.

Then, in step 5, both turbochargers 2 and 3
Are compared, and when the boost pressure of the turbocharger 2 is low, the electric drive of the turbocharger 3 is continued in step 6 and the turbocharger 2
If the boost pressure is high, go to step 7
By opening 5a and 5c, only the turbocharger 2 is operated, and the operation of the turbocharger 3 is stopped.

In step 8, the boost pressure to the engine is checked by the boost pressure sensor 90. If the boost pressure is appropriate, the current supercharging operation is continued in step 9; if the boost pressure is high and there is excess, the process proceeds to step 10. Then, the on / off valves 5a, 5b, 5c are opened to allow the turbocharger 2 to perform supercharging, and the on / off valve 5d of the turbocharger 3 is closed to reduce the pneumatic work, thereby causing the rotary electric machine 4 to generate electric power.

Next, at step 11, in this state, the boost pressure sensor 90
Check the boost pressure to the engine, and if the boost pressure is an appropriate value, continue power generation in step 12, but if there is enough boost pressure, proceed to step 13,
The opening degree of the on-off valve 5a is slightly closed, the exhaust flow rate to the turbocharger 3 is increased, and the power generated by the rotating electric machine 4 is increased to recover the exhaust energy.

FIG. 4 is a block diagram showing a configuration of a second embodiment of the present invention. In this embodiment, a rotating electric machine is also arranged in the large-capacity turbocharger 2 in the above-described embodiment. The same parts as those of the embodiment are denoted by the same reference numerals.

In FIG. 4, reference numeral 8 denotes a rotating electric machine arranged on the rotating shaft of the turbocharger 2 for generating electricity when the torque of the turbine 21 is large, and the stator winding of the rotating electric machine 8 is connected to the power converter 63. Wired.

The power converter 63 has two sets of AC / DC bidirectional converters each including a converter and an inverter. One set is used for the rotating electric machine 8, and the other set is used for the rotating electric machine 4. The operation is performed by the power converter 61 in the first embodiment.
It is based on.

FIG. 5 is a processing flowchart showing an example of the operation of the second embodiment.

The second embodiment will be described with reference to the drawing. First, when the engine 1 is idling, only the on-off valve 5b is opened, and exhaust energy is sent to the turbocharger 3 which is easy to drive with a small capacity to generate electric power by the rotating electric machine 4. At this time, since the on-off valve 5d at the outlet of the compressor 32 is closed, the compressor 32
And the turbine torque is efficiently converted to electric energy.

At the time of starting in step 21, the on-off valves 5a and 5d are opened, and electric power is supplied to the rotary electric machine 4 via the power converter 63. For this reason, the small and highly responsive turbocharger 3 is electrically driven so that the exhaust pressure can be prevented from increasing and the supercharging pressure increases, and the turbocharger 2 to which the exhaust gas is supplied has the on-off valve 5c closed. Therefore, the number of revolutions rapidly rises.

In the next step 22, the boost pressures by the turbochargers are compared by the boost pressure sensors 92 and 93, and when the boost pressure sensor 92 is large, the on-off valves 5a, 5
By opening c, supercharging is performed by the turbocharger 2 whose rotation has already been increased, the on-off valve 5d is closed, and power supply to the rotating electric machine 4 is cut off to stop supercharging from the turbocharger 3. If the value of the boost pressure sensor 93 is larger, the process proceeds to step 23, and the supercharging operation of the turbocharger 3 is continued.

In step 25 following the state of supercharging of the turbocharger 2, the boost pressure to the engine 1 is checked by the boost pressure sensor 90, and it is necessary to obtain the boost pressure from the signals from the engine rotation sensor 19 and the depression amount sensor 71 of the accelerator pedal 7. If it is higher than the boost pressure, it is determined that the boost pressure is excessive, and the routine proceeds to step 27, where the on-off valve 5b is also opened to drive the turbine 31 of the turbocharger 3 to operate the rotary electric machine 4 as a generator. At this time, since the on-off valve 5d is closed, the small and easy-to-drive turbocharger 3 efficiently collects exhaust energy as electric power. If it is determined in step 25 that the boost pressure is not excessive, the process proceeds to step 26, where supercharging is performed by the turbocharger 2.

Step 28 after operating the turbocharger 3 for power generation
The boost pressure to the engine 1 is checked, and when it is determined that the turbocharger is excessive, the rotating electric machine 8 of the turbocharger 2 is also operated as a generator to recover the exhaust energy as electric power, and the supercharging operation of the turbocharger 2 is performed. It is controlled so that a proper boost pressure is obtained by decreasing the pressure.

As described above, the present invention has been described using the above two embodiments, but various modifications are possible within the scope of the gist of the present invention.
They are not excluded from the scope of the present invention.

(Effect of the Invention) As described above, according to the present invention, the exhaust passage and the intake passage of the engine are each divided into two, and the turbochargers having different supercharging capacities are respectively connected to the divided passages. At the same time, an on-off valve is installed in each of these passages, and the on-off control of these on-off valves is performed according to the operating condition of the engine. When the exhaust energy is low, electric power is generated using a rotating electric machine arranged in a small-capacity turbocharger. And supercharging, power recovery is performed efficiently,
Power consumption during supercharging can be reduced. In addition, when the exhaust energy is large, a large-capacity turbocharger is operated or a rotating electric machine arranged in the turbocharger is used for power generation, so that an advantage that power generation is performed over a wide range of the engine operating range can be obtained. Since there is an effect and the turbocharger can be selectively used according to the magnitude of the exhaust energy, it is possible to improve the durability of the turbocharger and the rotating electric machine.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a first embodiment of a twin turbocharger control device according to the present invention. FIG. 2 is a chart showing an engine operating state and control of an on-off valve in the embodiment. FIG. 4 is a processing flowchart showing the operation of the present embodiment, FIG. 4 is a block diagram showing the configuration of a second embodiment of the present invention,
FIG. 5 is a processing flow chart showing the operation of. DESCRIPTION OF SYMBOLS 1 ... Engine, 2 ... Turbocharger, 3 ... Turbocharger, 4 ... Rotary electric machine, 5a, 5b, 5c, 5d ... On-off valve, 6 ... Controller, 8 ... Rotary electric machine, 12a, 12b ... Exhaust passage, 16 ...
Intake pipe, 19 ... engine rotation sensor, 71 ... stepping amount sensor,
72… Vehicle speed sensor.

Claims (4)

(57) [Claims] A turbine provided in one of two divided exhaust passages of an engine and a compressor provided in one of the intake passages into which the two intake passages merge to take in the engine, and a turbine and a compressor provided in one of the intake passages. A first turbocharger connected by a rotating shaft, a turbine provided on the other of the exhaust passage and a compressor provided on the other of the intake passage, a second turbocharger connecting the turbine and the compressor by a rotating shaft, and In a twin turbocharger control device in which a rotating electric machine is provided on a rotating shaft of one of the first and second turbochargers, an opening / closing valve for an exhaust passage provided in two exhaust passages for respectively opening and closing the two exhaust passages; The opening and closing valves of the intake passages, which are provided in the two intake passages and open and close, respectively, and the operating state of the engine are detected. Operation detection means for detecting the supercharging pressure of the first and second turbochargers, and a third boost pressure sensor for detecting the supply pressure of the engine. In a state where the exhaust gas drives the turbine provided with the rotating electric machine in a low engine load state from the output signal from the detection means, the on-off valve of the exhaust passage of the turbocharger provided with the rotating electric machine is opened to generate a power generation action on the rotating electric machine. Means for performing a supercharging operation by driving a rotating electric machine with an electric motor while the vehicle is accelerating based on an output signal from the operation detecting means to rotationally drive a compressor and opening an on-off valve thereof. First and second boost pressure sensors and the exhaust passage 2
Opening / closing valve driving means for controlling the opening / closing of the two opening / closing valves and the two opening / closing valves of the intake passage to maintain the intake pressure of the engine obtained from the third boost pressure sensor at a desired supply pressure. Twin turbocharger control device. 2. The twin turbocharger control device according to claim 1, wherein the capacity of the turbocharger provided with the rotating electric machine is smaller than the capacity of the turbocharger without the rotating electric machine. 3. The twin turbocharger control device according to claim 1, wherein a rotating electric machine is provided in each of the first and second turbochargers. 4. The twin turbocharger control device according to claim 3, wherein the capacity of the other turbocharger is smaller than the capacity of the other turbocharger.