Supercharging System

Abstract

To provide a supercharging system enabling highly efficient driving of an engine.SOLUTION: A supercharging system (10) is mounted to a vehicle including: an engine; a driving operation section to which a driving operation is input; and an electric power storage section enabling charge / discharge. The supercharging system (10) includes: an exhaust turbine (13) receiving exhaust gas from the engine to generate electric power; an intake air compressor (14) operated by using electric power; a power converter (15) capable of supplying electric power from the electric power storage section via an electric power passage between the exhaust turbine and the intake air compressor and recovering electric power to the electric power storage section; and a control section (16) controlling the power converter. The control section acquires a target value of compression power of the intake air compressor on the basis of an operation of the driving operation section (6) and an operating state of the engine, and controls the power converter (15) so that electric power corresponding to a difference between the acquired target value of the compression power and electric power generated by the exhaust turbine is supplied or recovered from the electric power storage section.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a supercharging system for supplying compressed air to an engine. [Background technology]

[0002] There have been mechanical turbochargers that use the rotational power of an exhaust turbine to drive an intake compressor and send compressed air from the intake compressor to an engine. Patent Document 1 also proposes a turbocharger that uses the rotational power of an exhaust turbine to generate electricity and drives an intake compressor with the generated electricity. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 09-32569 Summary of the Invention [Problem to be solved by the invention]

[0004] The conventional mechanical supercharger described above has a problem that it is difficult to control the intake volume because the amount of compressed air fed depends on the flow velocity of the exhaust gas. On the other hand, in the supercharger of Patent Document 1, the rotation speed of the intake compressor is controlled by electrical control so that intake air with a supercharging pressure corresponding to the fuel injection volume is supplied in a steady mode in which the throttle opening is constant. However, the control of Patent Document 1 leaves room for improvement in the intake supply control in order to drive the engine with high efficiency in various operating conditions.

[0005] An object of the present invention is to provide a supercharging system capable of driving an engine with high efficiency under various operating conditions. [Means for solving the problem]

[0006] (1) A supercharging system according to one embodiment of the present invention 、 Inside A supercharging system mounted on a vehicle including an engine, which is a combustion engine, a driving operation unit to which a driving operation is input, and a power storage unit capable of charging and discharging, an exhaust turbine that generates electricity by receiving exhaust from the engine; an electric intake compressor for supplying compressed intake air to the engine; a power converter that supplies power from the power storage unit via a power path between the exhaust turbine and the intake compressor and that recovers power to the power storage unit; A control unit that controls the power converter; A measuring device for measuring the intake supercharging pressure; Equipped with The control unit is acquiring a target value of a compression power of the intake compressor based on the operation of the operation unit and an operating state of the engine, and controlling the power converter so that power corresponding to a difference between the acquired target value of the compression power and the generated power of the exhaust turbine is supplied from or recovered from the power storage unit; Furthermore, the control unit First map data indicating a relationship between the operation, the operating state, and a boost pressure of the intake air according to the operation and the operating state; second map data indicating a relationship between the operating state, the boost pressure, and the compression power for generating the boost pressure during the operating state; obtaining a target value of the compression power using the first map data and the second map data; When there is a difference between the intake boost pressure obtained from the first map data and the boost pressure measured by the measuring instrument, the target value of the compression power is corrected in accordance with the difference. ( 2 ) Another embodiment of the supercharging system of the present invention comprises: A supercharging system mounted on a vehicle including an internal combustion engine, a driving operation unit including an accelerator operation unit to which a driving operation is input, and a power storage unit capable of charging and discharging, an exhaust turbine that generates electricity by receiving exhaust from the engine; an electric intake compressor for supplying compressed intake air to the engine; a power converter that supplies power from the power storage unit via a power path between the exhaust turbine and the intake compressor and that recovers power to the power storage unit; A control unit that controls the power converter; Equipped with The control unit is acquiring a target value of a compression power of the intake compressor based on the operation of the operation unit and an operating state of the engine, and controlling the power converter so that power corresponding to a difference between the acquired target value of the compression power and the generated power of the exhaust turbine is supplied from or recovered from the power storage unit; and When the rate of increase in the operation amount of the accelerator operation unit is equal to or greater than a threshold value, the target value of the compression power is corrected to a larger value. Effect of the Invention

[0007] According to the present invention, a target value of the compression power (e.g., power consumption) of the intake compressor according to the operation of the operation control unit (e.g., a required torque according to the operation) and the operating state of the engine (e.g., the rotation speed of the engine) is acquired based on the operation of the operation control unit and the operating state of the engine. Then, the power converter is controlled so that the compression power is output from the intake compressor. Therefore, it is possible to supply intake air capable of driving the engine with high efficiency in various operating situations in which the operation of the operation control unit and the operating state of the engine are different. Furthermore, according to the present invention, power is supplied from the power storage unit or recovered to the power storage unit via a power path between the exhaust turbine and the intake compressor, so that power according to the target value of the compression power is supplied to the intake compressor. Therefore, most of the generated power of the exhaust turbine is transmitted to the intake compressor without passing through the power storage unit, improving power efficiency and contributing to highly efficient driving of the engine. [Brief description of the drawings]

[0008] [Figure 1]1 is a block diagram showing a vehicle equipped with a supercharging system according to an embodiment of the present invention. [Diagram 2] 5A and 5B are diagrams showing an example of supercharging pressure map data and compression power map data stored in a control data storage unit. [Diagram 3] 5A and 5B are diagrams showing an example of first correction table data (A) and second correction table data (B) stored in a control data storage unit. [Figure 4] 4 is a flowchart showing a procedure of a supercharging control process executed by a control unit. [Diagram 5] 1A and 1B are diagrams showing a first example (A) and a second example (B) of an exhaust turbine, an intake compressor, a power converter, and power lines between them. [Figure 6] 1A and 1B are diagrams showing a first modified example and a second modified example of an exhaust turbine and an intake compressor. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing a vehicle equipped with a supercharging system according to an embodiment of the present invention. The vehicle 1 in FIG. 1 is an engine vehicle, and is equipped with a supercharging system 10 according to an embodiment of the present invention. The vehicle 1 includes driving wheels 2, an engine 3 which is an internal combustion engine, an auxiliary device 4 (fuel injection device, etc.) for driving the engine 3, a supercharging system 10 which is an auxiliary device of an intake and exhaust system, a driving operation unit 6 operated by a driver, a traveling control unit 20 which receives an operation signal from the driving operation unit 6 and controls the auxiliary device 4 and the supercharging system 10, and a power storage unit 8 which is connected to the supercharging system 10 and performs charging and discharging. The driving operation unit 6 includes an accelerator operation unit, a brake operation unit, and a steering unit.

[0010] The cruise control unit 20 is composed of one ECU (Electronic Control Unit) or multiple ECUs that operate in cooperation with each other. The cruise control unit 20 receives an operation signal (mainly a signal of the accelerator opening degree of the accelerator operation unit) from the driving operation unit 6 and controls the auxiliary equipment 4 and the supercharging system 10 to drive the engine 3 according to the driving operation. More specifically, the cruise control unit 20 calculates a required torque according to the driving operation based on the signal of the accelerator opening degree, and controls the auxiliary equipment 4 and the supercharging system 10 so that the required torque is output from the engine 3. The required torque means an output torque required of the engine 3 based on the driving operation.

[0011] The supercharging system 10 includes an exhaust pipe 11 of the engine 3, an intake pipe 12 of the engine 3, an exhaust turbine 13 provided in the exhaust pipe 11, an intake compressor 14 provided in the intake pipe 12, a power line L1 provided between the exhaust turbine 13 and the intake compressor 14, a power converter 15 that supplies a portion of electric power from a power storage unit 8 or recovers a portion of electric power to the power storage unit 8 via the power line L1 and a branch line L2, a control unit 16 that controls the power converter 15, and a pressure gauge H1 that measures the intake supercharging pressure. The pressure gauge H1 is disposed on the engine 3 side of the throttle valve in the intake pipe 12, and measures the intake pressure at that location.

[0012] The exhaust pipe 11 carries the exhaust gas from the engine 3, and an exhaust turbine 13 is disposed in the exhaust pipe. The exhaust pipe 11 may have a bypass pipe 11a that allows the exhaust gas to flow bypassing the exhaust turbine 13, and a control valve 11b that controls the flow of the exhaust gas to the bypass pipe 11a. The control unit 16 may control the switching of the control valve 11b.

[0013] The intake pipe 12 carries the intake air of the engine 3, and an intake compressor 14 is disposed midway through the intake pipe 12. The intake pipe 12 may have a bypass pipe 12a that allows the intake air to flow bypassing the intake compressor 14, and a control valve 12b that controls the flow of the intake air to the bypass pipe 12a. The control unit 16 may control the switching of the control valve 12b.

[0014] The exhaust turbine 13 has a rotor 13a that rotates upon receiving exhaust gas, and a generator 13b that generates electricity by the rotational motion of the rotor 13a. The exhaust turbine 13 is an axial flow turbine in which the rotation axis of the rotor 13a is arranged along the flow of the exhaust gas. By adopting an axial flow turbine, it is easy to arrange the input side piping and the output side piping of the exhaust turbine 13 on the same axis. In addition, by applying an axial flow configuration that can achieve highly efficient operation when the exhaust flow velocity is high to the exhaust turbine 13, high power recovery efficiency can be achieved when the engine 3 is a high rotation type. The exhaust turbine 13 outputs the generated power to the power line L1.

[0015] The intake compressor 14 is a centrifugal compressor having a rotor 14a that compresses the intake air and an electric motor 14b that rotates and drives the rotor 14a, sucking in the intake air from the axial direction of the rotor 14a and outputting the compressed air radially outward from the rotor 14a. By using a centrifugal compressor, it is easy to adopt an arrangement in which the piping on the input side and the piping on the output side of the intake compressor 14 cross (for example, perpendicularly). The intake compressor 14 is driven by receiving electric power from the power line L1.

[0016] One end of the power line L1 is connected to the generator 13b of the exhaust turbine 13, and the other end is connected to the electric motor 14b of the intake compressor 14. The power line L1 may include a relay or the like between the exhaust turbine 13 and the intake compressor 14 that is always turned on while the turbocharging system 10 is in operation, or may include a rectifier element that prevents current from flowing back toward the generator 13b.

[0017] The power converter 15 is provided on the branch line L2 connected to the power line L1. The power converter 15 is provided between the power line L1 and the power storage unit 8, and recovers power from the power line L1 to the power storage unit 8, and supplies power from the power storage unit 8 to the power line L1. The power converter 15 has a power semiconductor switch, and controls the flow of power by driving the power semiconductor switch.

[0018] The control unit 16 receives information indicating the operation of the driving operation unit 6 (e.g., required torque) and information indicating the operating state of the engine 3 (e.g., the rotation speed of the engine 3) from the driving control unit 20. Furthermore, the control unit 16 receives boost pressure information from a pressure gauge H1. The control unit 16 controls the power converter 15 based on this information. The control unit 16 is composed of one ECU or multiple ECUs that operate in cooperation with each other. The control unit 16 may be configured to be integrated with the driving control unit 20.

[0019] The control unit 16 further has a control data storage unit 17 in which control data for controlling the power converter 15 is stored. The control data storage unit 17 stores supercharging pressure map data MD1, compressed power map data MD2, first correction table data TD1, and second correction table data TD2. The supercharging pressure map data MD1 corresponds to an example of first map data according to the present invention. The compressed power map data MD2 corresponds to an example of second map data according to the present invention.

[0020] Fig. 2 is a diagram showing an example of the boost pressure map data (A) and the power map data (B) of the intake compressor stored in the control data storage unit, and Fig. 3 is a diagram showing an example of the first correction table data (A) and the second correction table data (B) stored in the control data storage unit.

[0021] The supercharging pressure map data MD1 indicates the relationship between the operating state (e.g., rotation speed) of the engine 3, the amount (e.g., required torque) related to the operation of the driving operation unit 6, and the intake supercharging pressure corresponding thereto. The compression power map data MD2 indicates the relationship between the operating state (e.g., rotation speed) of the engine 3, the intake supercharging pressure, and the compression power (e.g., operating power) of the intake compressor 14 required to output the supercharging pressure in the operating state.

[0022] The first correction table data TD1 indicates a relationship between a specific operation of the driving operation unit 6 (e.g., a sudden accelerator operation) and the above-mentioned correction value of the compressed power corresponding to the specific operation. A sudden accelerator operation is an accelerator operation in which the increase rate of the accelerator operation amount per predetermined time is equal to or exceeds a preset threshold value, and multiple stages of the specific operation are set according to the above-mentioned increase rate. The second correction table data TD2 indicates a correction value for reducing the error between the target boost pressure and the actual boost pressure. The first correction table data TD1 and the second correction table data TD2 indicate a correction value of the compressed power (operating power).

[0023] <Operation description> Fig. 4 is a flowchart showing the procedure of the supercharging control process executed by the control unit. The control unit 16 repeatedly executes the supercharging control process of Fig. 4 for each predetermined control cycle while the engine 3 is running. When one control cycle is started, the control unit 16 first refers to the supercharging pressure map data MD1 based on information (required torque) related to the operation of the driving operation unit 6 and the operating state (rotation speed) of the engine 3, and obtains a target value of the intake supercharging pressure (hereinafter referred to as "target supercharging pressure") corresponding to the above operation and operating state (step S1).

[0024] Next, the control unit 16 refers to the compression power map data MD2 and acquires the compression power of the intake compressor 14 (e.g., the operating power of the intake compressor 14) required to output the target boost pressure in the operating state of the engine 3 in the current control cycle (step S2). The compression power value acquired in step S2 corresponds to the target value of the compression power to be output from the intake compressor 14 under the control of the control unit 16.

[0025] Next, the control unit 16 determines whether a specific operation (sudden accelerator operation) that requires rapid acceleration has been performed (step S3). If a specific operation has been performed, the driving control unit 20 notifies the control unit 16. Then, if the determination result in step S3 is YES, the control unit 16 determines the correction amount of the compression power (the operating power of the intake compressor 14) according to the amount of the specific operation by referring to the first correction table data TD1, and applies the correction amount to the compression power (step S4).

[0026] Furthermore, the control unit 16 compares the target boost pressure of the nth previous (one or more previous) control cycle with the boost pressure measured by the pressure gauge H1 corresponding to the timing at which intake air is output by the control of the control cycle, and calculates the error in the boost pressure (step S5).Then, the control unit 16 determines whether the error in the boost pressure exceeds a threshold value (e.g., ±5%) (step S6), and if the determination result is YES, determines the correction amount of the compression power (operating power of the intake compressor 14) corresponding to the error by referring to the second correction table data TD2, and applies the correction amount to the compression power (step S7).

[0027] Next, the control unit 16 controls the power converter 15 so that the intake compressor 14 operates with the finally obtained compression power of the intake compressor 14 (step S8). Through this control, the difference between the operating power of the intake compressor 14 and the power generated by the exhaust turbine 13 is supplied from the power storage unit 8 or recovered to the power storage unit 8 via the power converter 15. Through the control of step S8, power corresponding to the compression power is supplied to the intake compressor 14, and the compression power is output from the intake compressor 14. Then, one supercharging control process ends. When the next control cycle begins, the control unit 16 executes the supercharging control process again from step S1.

[0028] <Example of electrical configuration of turbocharging system> Fig. 5 is a diagram showing a first example (A) and a second example (B) specifically illustrating an exhaust turbine, an intake compressor, a power converter, and the power lines between them. Note that Fig. 5 shows an example in which the exhaust turbine 13 is a centrifugal turbine, but the exhaust turbine 13 may be an axial flow type. The intake compressor 14 may also be an axial flow type.

[0029] The first example shown in Fig. 5(A) is an example in which a DC generator that generates DC power is used as the generator 13b of the exhaust turbine 13, and a DC motor that receives and drives the DC power is used as the electric motor 14b of the intake compressor 14. In this configuration, a DC two-wire type power line having an anode line P and a cathode line N can be applied as the power line L1 and the branch line L2. A DC / DC converter that converts the DC voltage of the power storage unit 8 to the DC voltage of the power line L1 can be applied as the power converter 15. Also, a battery (lithium ion secondary battery, lead battery, etc.) or a capacitor (electric double layer capacitor, etc.) can be applied as the power storage unit 8, but a battery is applied in the example of Fig. 5(A).

[0030] In the first example configuration, the control unit 16 controls the output voltage of the power converter 15 (the voltage of the power line L1) to a value corresponding to the target compression power of the intake compressor 14, thereby supplying power from the power storage unit 8 or recovering power to the power storage unit 8 as appropriate according to the power generated by the exhaust turbine 13, thereby enabling the intake compressor 14 to be driven with the target compression power (e.g., operating power).

[0031] In detail, in the configuration of the first example, when the rotation speed of the engine 3 is constant, increasing the voltage of the power line L1 increases the rotation speed of the intake compressor 14, and the operating power and compression power of the intake compressor 14 increase. Thus, the intake boost pressure increases. On the other hand, decreasing the voltage of the power line L1 decreases the rotation speed of the intake compressor 14, and the operating power and compression power of the intake compressor 14 decrease. Thus, the intake boost pressure decreases. Here, if the rotation speed of the exhaust turbine 13 is low and the generated power from the exhaust turbine 13 is small, the effect of increasing the voltage of the power line L1 by supplying the generated power is reduced, and the power sent from the power storage unit 8 to the power line L1 increases by controlling the output voltage of the power converter 15 accordingly. On the other hand, if the rotation speed of the exhaust turbine 13 is high and the generated power of the exhaust turbine 13 is large, the effect of increasing the voltage of the power line L1 by supplying the generated power increases, and the power sent from the power storage unit 8 to the power line L1 is reduced accordingly by controlling the output voltage of the power converter 15. Alternatively, when the generated power of the exhaust turbine 13 is large, power is recovered from the power line L1 to the power storage unit 8 by controlling the output voltage of the power converter 15. Due to this effect, the difference between the generated power of the exhaust turbine 13 and the compression power (operating power) of the intake compressor 14 is supplied from or recovered to the power storage unit 8, and the intake compressor 14 can be driven with the target compression power.

[0032] The second example shown in Fig. 5(B) is an example in which a three-phase AC generator is used as the generator 13b of the exhaust turbine 13, and a three-phase AC electric motor is used as the electric motor 14b of the intake compressor 14. In this configuration, a three-phase three-wire power line can be used as the power line L1 and the branch line L2. An inverter capable of converting the DC voltage of the power storage unit 8 into a three-phase AC voltage can be used as the power converter 15. Also, a battery (lithium ion secondary battery, lead battery, etc.) or a capacitor (electric double layer capacitor, etc.) can be used as the power storage unit 8, but a capacitor is used in the example of Fig. 5(B).

[0033] In the second example configuration, the control unit 16 controls the output voltage of the power converter 15 (the three-phase AC voltage output to the power line L1) to an AC voltage corresponding to the target value of the compression power, so that power is supplied from or recovered to the power storage unit 8 as appropriate according to the power generated by the exhaust turbine 13, and the intake compressor 14 can be driven with the target compression power (e.g., operating power).

[0034] In detail, in the configuration of the second example, the power converter 15 outputs an AC voltage that realizes driving of the intake compressor 14 at a predetermined torque and a predetermined rotation speed, so that the intake compressor 14 is driven by compression power (e.g., operating power) corresponding to the predetermined torque and predetermined rotation speed. Thus, a boost pressure according to the compression power is obtained. At this time, the power generated by the exhaust turbine 13 is sent to the power line L1, and the power converter 15 operates by controlling the AC voltage so that the difference between the power generated by the exhaust turbine 13 and the operating power of the intake compressor 14 is supplied from or recovered to the power storage unit 8.

[0035] In addition, when the generator 13b of the exhaust turbine 13 is a three-phase AC generator and the electric motor 14b of the intake compressor 14 is a three-phase AC electric motor, the following configuration may be applied. That is, the power line L1 and the branch line L2 are of a DC two-wire system, the intake compressor 14 is connected to the power line L1 via a first inverter, the exhaust turbine 13 is connected to the power line L1 via a second inverter, and the branch line L2 is connected to the power storage unit 8. In such a configuration, the control unit 16 controls the first inverter so that the intake compressor 14 is driven with a target compression power (for example, operating power), and controls the second inverter so that highly efficient power recovery is performed according to the rotation speed of the exhaust turbine 13. Even with such a configuration, an operation can be realized in which the difference between the generated power of the exhaust turbine 13 and the compression power (operating power) of the intake compressor 14 is supplied from the power storage unit 8 or recovered to the power storage unit 8 via the first inverter and the second inverter. A rectifying element such as a power diode that prevents power from being sent to the exhaust turbine 13 side may be provided between the first inverter and the second inverter.

[0036] 5(A) and 5(B), the control unit 16 supplies or recovers the excess or shortage of power from or to the power storage unit 8 via the power converter 15 without measuring the power generated by the exhaust turbine 13, and drives the intake compressor 14 with the target compression power. However, the turbocharging system 10 may have a measuring device that measures a quantity related to the amount of power generated by the exhaust turbine 13 (such as the rotational speed of the rotor), and the control unit 16 may recognize the generated power using the value of the measuring device, calculate the excess or shortage of power, and control the power converter 15 so that the excess or shortage of power is supplied or recovered.

[0037] <Modifications of intake compressor and exhaust turbine> 6 is a diagram showing modified example 1 (A) and modified example 2 (B) of the intake compressor and exhaust turbine. The turbocharging system 10 of this embodiment converts kinetic energy recovered by the exhaust turbine 13 into electric power once and sends it to the intake compressor 14. Therefore, compared to a mechanical turbocharger that sends kinetic energy directly from the exhaust turbine to the intake compressor, there is a high degree of freedom in the arrangement of the exhaust turbine 13 and the intake compressor 14. Because of this degree of freedom, the turbocharging system 10 can be applied with configurations such as modified example 1 and modified example 2.

[0038] As shown in FIG. 6(A), variant example 1 is an example in which a centrifugal type is applied to the exhaust turbine 13 and the intake compressor 14, and the rotation axis A1 of the rotor of the exhaust turbine 13 and the rotation axis A2 of the rotor of the intake compressor 14 are arranged so as not to overlap on the same axis.

[0039] As shown in FIG. 6(B), the second modification is an example in which the exhaust pipe 11 and the intake pipe 12 are spaced apart, and the exhaust turbine 13 and the intake compressor 14 are arranged separately.

[0040] The type and arrangement of the exhaust turbine 13 and the intake compressor 14 are not limited to the examples shown in Figures 1, 6(A) and 6(B) and can be modified in various ways. For example, the rotation axis A1 of the rotor of the exhaust turbine 13 and the rotation axis A2 of the rotor of the intake compressor 14 can be positioned coaxially, or the intake compressor 14 can be an axial flow type. Furthermore, the exhaust turbine 13 and the intake compressor 14 can be arranged in any direction in accordance with the exhaust piping 11 and the intake piping 12.

[0041] When an axial flow exhaust turbine or an axial flow intake compressor is applied, highly efficient operation is achieved when the exhaust or intake flow velocity is high, thereby realizing a supercharging system that can be used in high speed engines and achieve high efficiency. When a centrifugal exhaust turbine or a centrifugal intake compressor is applied, highly efficient operation is achieved when the exhaust or intake flow velocity is low, thereby realizing a supercharging system that can be used in low speed engines and achieve high efficiency. In this way, by selecting the type of exhaust turbine and intake compressor, it is possible to improve the efficiency of supercharging in accordance with engines with various characteristics.

[0042] The location of the exhaust turbine 13 and the intake compressor 14 can be flexibly set during the design of the vehicle 1 in accordance with the space available for arranging the components, making it easy to install a supercharging system even when the space available for arrangement is limited.

[0043] As described above, the supercharging system 10 of this embodiment includes the exhaust turbine 13 that receives exhaust gas from the engine 3 and generates electric power, the intake compressor 14 that operates with electric power, and the power converter 15 that can supply electric power from the power storage unit 8 or recover electric power to the power storage unit 8 via the power path (power line L1) between the exhaust turbine 13 and the intake compressor 14. The control unit 16 determines a target value of the required compression power (e.g., operating power) of the intake compressor 14 based on the operation of the driving operation unit 6 and the operating state of the engine 3, and controls the power converter 15 so that electric power corresponding to the difference between the determined target value of the compression power and the generated electric power of the exhaust turbine 13 is supplied from or recovered from the power storage unit 8. By such control, it is possible to send intake air to the engine 3 at a supercharging pressure according to various operating conditions, for example, from when various output torques of different sizes are required when the rotation speed of the engine 3 is low to when various output torques of different sizes are required when the rotation speed of the engine 3 is high. Therefore, it is possible to realize highly efficient driving of the engine 3 in various operating conditions. Furthermore, since the power converter 15 supplies power to the power line L1 between the exhaust turbine 13 and the intake compressor 14 or recovers power from the power line L1, most of the power generated by the exhaust turbine 13 is transmitted to the intake compressor 14 without passing through the power storage unit 8. This improves power efficiency and contributes to highly efficient driving of the engine 3.

[0044] Furthermore, according to the supercharging system 10 of this embodiment, the control unit 16 has supercharging pressure map data MD1 indicating the relationship between the operating state of the engine 3 (e.g., rotation speed), the amount indicating the operation of the driving operation unit 6 (e.g., required torque), and the intake supercharging pressure corresponding thereto. Furthermore, the control unit 16 has compression power map data MD2 indicating the relationship between the operating state of the engine 3 (e.g., rotation speed), the supercharging pressure, and the compression power (e.g., operating power) of the intake compressor 14 for generating the supercharging pressure during the operating state. Then, the control unit 16 uses the supercharging pressure map data MD1 and the compression power map data MD2 to obtain the target compression power (e.g., operating power) of the intake compressor 14. Therefore, the control unit 16 can appropriately obtain the supercharging pressure corresponding to the operating state of the engine 3 and the operation of the driving operation unit 6 with a small load.

[0045] Furthermore, the supercharging system 10 of this embodiment includes a pressure gauge H1 that measures the intake supercharging pressure, and the control unit 16 corrects the target value of the compression power obtained using the compression power map data MD2 when there is a difference between the target supercharging pressure obtained using the supercharging pressure map data MD1 and the measurement value of the pressure gauge H1. This correction process can further improve the accuracy of the intake supercharging pressure actually supplied from the intake compressor 14. Furthermore, since the control unit 16 once obtains the target supercharging pressure using the supercharging pressure map data MD1, the process of determining the difference between the actual supercharging pressure and the target supercharging pressure becomes easy.

[0046] Furthermore, according to the supercharging system 10 of this embodiment, when a specific operation (sudden accelerator operation) is performed via the driving operation unit 6, the control unit 16 corrects the target value of the compression power (e.g., operating power) of the intake compressor 14 according to the time rate of change of the accelerator operation amount. When a specific operation is performed on the driving operation unit 6, temporarily correcting the intake supercharging pressure may improve the driving efficiency of the engine 3. Therefore, the above-mentioned correction process makes it possible to control the supercharging pressure according to the specific operation of the driving operation unit 6, and the driving efficiency of the engine 3 can be further improved.

[0047] Furthermore, according to the supercharging system 10 of this embodiment, as shown in Fig. 5(A), a configuration can be applied in which the exhaust turbine 13 has a DC generator, the intake compressor 14 has a DC motor, and the power converter 15 is a DC / DC converter. With such a configuration, most of the electric power generated by the exhaust turbine 13 can be sent to the intake compressor 14 without going through the power storage unit 8, and only the excess or deficiency of electric power can be supplied or recovered through the power converter 15. Therefore, the exhaust energy of the engine 3 can be used with high efficiency as the energy for generating the supercharging pressure, which contributes to highly efficient driving of the engine 3.

[0048] The above describes the embodiments of the present invention. However, the present invention is not limited to the above embodiments. For example, in the above embodiments, an example was shown in which the rotation speed of the engine 3 was applied as a parameter indicating the operating state of the engine according to the present invention. However, the operating state of the engine may be represented by other parameters such as the fuel injection amount, ignition timing, and load. In addition, in the above embodiments, an example was shown in which the required torque was applied as an amount indicating the operation of the driving operation unit according to the present invention. However, as an amount indicating the operation of the driving operation unit, other amounts such as the required power (required value of the engine output power) or the operation amount of the accelerator operation unit may be applied. Furthermore, in the above embodiments, an example was shown in which the target value of the operating power of the intake compressor 14 was applied as the target value of the compression power according to the present invention. However, for example, when the compression power is determined by the input voltage input to the electric motor of the intake compressor 14, the specific values ​​can be changed in various ways, such as the target value of the input voltage can be applied as the target value of the compression power. Other details shown in the embodiments can be changed as appropriate within the scope of the invention. [Explanation of symbols]

[0049] 1 vehicle 2 Drive wheels 3 Engine 4 Auxiliary Equipment 6 Driving operation section 10. Supercharging System 11 Exhaust piping 12 Intake piping 13 Exhaust Turbine 13a Rotating body 13b Generator 14 Intake compressor 14a Rotating body 14b Electric motor A1, A2 rotation axis 15 Power Converter 16 Control section 17 Control data storage unit H1 Pressure Gauge L1 power line L2 branch line MD1 Boost pressure map data MD2 Compression Power Map Data TD1 First correction table data TD2 Second correction table data

Claims

1. A supercharging system mounted on a vehicle including an internal combustion engine, a driving operation unit to which a driving operation is input, and a power storage unit capable of charging and discharging, an exhaust turbine that generates electricity by receiving exhaust from the engine; an electric intake compressor for supplying compressed intake air to the engine; a power converter that supplies electric power from the power storage unit via a power path between the exhaust turbine and the intake compressor and that recovers electric power to the power storage unit; A control unit that controls the power converter; A measuring device for measuring the intake supercharging pressure; Equipped with The control unit is acquiring a target value of a compression power of the intake compressor based on the operation of the operation unit and an operating state of the engine, and controlling the power converter so that power corresponding to a difference between the acquired target value of the compression power and the generated power of the exhaust turbine is supplied from or recovered from the power storage unit; Furthermore, the control unit First map data indicating a relationship between the operation, the operating state, and a boost pressure of the intake air according to the operation and the operating state; second map data indicating a relationship between the operating state, the boost pressure, and the compression power for generating the boost pressure during the operating state; obtaining a target value of the compression power by using the first map data and the second map data; a target value of compression power is corrected in accordance with a difference between the intake boost pressure obtained from the first map data and the boost pressure measured by the measuring instrument.

2. A supercharging system mounted on a vehicle including an internal combustion engine, a driving operation unit including an accelerator operation unit to which a driving operation is input, and a power storage unit capable of charging and discharging, an exhaust turbine that generates electricity by receiving exhaust from the engine; an electric intake compressor for supplying compressed intake air to the engine; a power converter that supplies electric power from the power storage unit via a power path between the exhaust turbine and the intake compressor and that recovers electric power to the power storage unit; A control unit that controls the power converter; Equipped with The control unit is acquiring a target value of a compression power of the intake compressor based on the operation of the operation unit and an operating state of the engine, and controlling the power converter so that power corresponding to a difference between the acquired target value of the compression power and the generated power of the exhaust turbine is supplied from or recovered from the power storage unit; and A supercharging system comprising: a compressor that corrects the target value of the compression power to a larger value when an increase rate of an operation amount of the accelerator operation unit is equal to or greater than a threshold value.

3. The control unit is First map data indicating a relationship between the operation, the operating state, and a boost pressure of the intake air according to the operation and the operating state; second map data indicating a relationship between the operating state, the boost pressure, and the compression power for generating the boost pressure during the operating state; 3. The supercharging system according to claim 2, wherein the control unit acquires the target value of the compression power by using the first map data and the second map data.

4. 4. The turbocharging system according to claim 1, wherein the exhaust turbine has a DC generator, the intake compressor has a DC motor that outputs compression power, and the power converter is a DC / DC converter.

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