KR20200056227A - Engine system having supercharger and method for contorlling hybrid vehicle including the same - Google Patents

Abstract

An engine system having an electric supercharger according to the present invention includes: an engine having a plurality of cylinders; an intake manifold communicating with an intake port of each cylinder of the engine; an exhaust manifold communicating with an exhaust port of each cylinder of the engine; an intake pipe connected to the intake manifold; an exhaust pipe connected to the exhaust manifold; an electric supercharger which is mounted on the intake pipe and has a motor and a compressor driven by the motor; and an air valve that is opened and closed to selectively supply supercharged air compressed by the electric supercharger to the exhaust manifold.

Description

ENGINE SYSTEM HAVING SUPERCHARGER AND METHOD FOR CONTORLLING HYBRID VEHICLE INCLUDING THE SAME}

The present invention relates to an engine system having a supercharger and a control method for a hybrid vehicle including the same, and more specifically, driving conditions for driving the engine of the hybrid vehicle according to SOC of a battery, a required torque of a driver, and a position value of an accelerator pedal. It relates to an engine system having a supercharger capable of operating the supercharger in an optimal state and a control method of a hybrid vehicle including the same.

In the process of generating power by driving the engine, sufficient external air must be supplied for combustion to obtain desired output and combustion efficiency. To this end, a turbocharger or a supercharger is used as a device for supercharging combustion air to increase the combustion efficiency of the engine.

Recently, electric superchargers have been widely used to increase power output, regenerative braking, and increase SOC (charge state) of batteries.

The electric supercharger can greatly improve low-speed, high-torque responsiveness and fuel efficiency by driving the compressor by an electric motor, and thus is actively used in various hybrid vehicles such as HEV or PHEV.

The electric supercharger may be used alone or in combination with a turbocharger in the engine system of a hybrid vehicle, whereby the electric supercharger is used as a main supply or an auxiliary supply for supplying supercharged air to each cylinder side of the engine.

On the other hand, in a driving condition in which the hybrid vehicle drives the engine, it needs to be used for various purposes in addition to the supply of supercharged air by the electric supercharger.

The items described in this background section are written to improve the understanding of the background of the invention, and may include matters other than the prior art already known to those of ordinary skill in the field to which this technology belongs.

The present invention has been devised in consideration of the above points, and improves driving performance by injecting supercharged air compressed by an electric supercharger into an exhaust system in a catalytic heating section or a cranking section for starting the engine after starting the engine, and An object of the present invention is to provide an engine system having an electric supercharger capable of effectively reducing exhaust gas and a control method of a hybrid vehicle having the same.

One aspect of the present invention for achieving the above object is an engine system having an electric supercharger,

An engine having a plurality of cylinders;

An intake manifold communicating with an intake port of each cylinder of the engine;

An exhaust manifold communicating with an exhaust port of each cylinder of the engine;

An intake pipe connected to the intake manifold;

An exhaust pipe connected to the exhaust manifold;

An electric supercharger mounted on the intake pipe and having a motor and a compressor driven by the motor; And

It may include; an air valve that is opened and closed to selectively supply the compressed air compressed by the electric supercharger to the exhaust manifold side.

The air valve may be connected with a supercharged air introduction pipe allowing the supercharged air to be introduced from the intake pipe and a supercharged air injection pipe allowing the supercharged air to be injected into the exhaust manifold side.

The supercharged air introduction pipe may be configured to connect the downstream point of the compressor of the electric supercharger and the inlet of the air valve.

The supercharged air injection pipe may be configured to connect the outlet of the air valve and the exhaust manifold.

The supercharged air injection pipe may have a plurality of branch pipes branched to uniformly distribute supercharged air to the runners of the exhaust manifold.

Another aspect of the present invention is a hybrid vehicle having an electric supercharger connected to the intake manifold side of the engine, and an air valve that opens and closes at least a portion of the supercharged air compressed by the electric supercharger to the exhaust manifold side of the engine. With the control method of,

When the engine is in a required condition, the electric supercharger is operated and the engine is started,

If the air valve corresponds to the open condition, by opening the air valve, at least a portion of the supercharged air compressed by the electric supercharger may be injected into the exhaust manifold side of the engine.

If the current state of the engine is a cranking section for starting the engine, the air valve may be opened.

When the current state of the engine is outside the cranking section, the air valve may be closed.

If the temperature of the catalyst is a catalyst heating section immediately after starting the engine, the air valve can be opened.

If the temperature of the catalyst is outside the catalyst heating section immediately after starting the engine, the air valve may be closed.

According to the present invention, the supercharged air compressed by the electric supercharger can be supplied to the intake manifold side of the engine at normal times, and the electric super in the case of a catalytic heating section or a cranking section for starting the engine after starting the engine By injecting the supercharged air compressed by the charger to the exhaust system side, it is possible to effectively improve driving performance and reduce exhaust gas.

1 is a view illustrating a power train of a hybrid vehicle according to an embodiment of the present invention.
2 is a block diagram showing an engine system having a supercharger according to an embodiment of the present invention.
3 is a block diagram showing an engine system having a supercharger according to another embodiment of the present invention.
4 shows a control method of a hybrid vehicle including an engine system having a supercharger according to an embodiment of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail through exemplary drawings. It should be noted that in adding reference numerals to the components of each drawing, the same components have the same reference numerals as possible even though they are displayed on different drawings. In addition, in describing the embodiments of the present invention, when it is determined that detailed descriptions of related well-known configurations or functions interfere with the understanding of the embodiments of the present invention, detailed descriptions thereof will be omitted.

In describing the components of the embodiments of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are only for distinguishing the component from other components, and the nature, order, or order of the component is not limited by the term. In addition, unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person skilled in the art to which the present invention pertains. Terms such as those defined in a commonly used dictionary should be interpreted as having meanings consistent with meanings in the context of related technologies, and should not be interpreted as ideal or excessively formal meanings unless explicitly defined in the present application. Does not.

Referring to FIG. 1, a hybrid powertrain 1 of a hybrid vehicle according to an embodiment of the present invention includes an engine 2, a motor generator 3, and an automatic transmission 4.

The engine 2 may be a gasoline engine or a diesel engine, and the engine 2 may be controlled by an engine controller 5 (ECU). The operation of the engine 2 can be controlled by the engine controller 5 sending a control command to the throttle valve 18, a fuel injector (not shown), a variable valve timing device (not shown), or the like.

The motor generator 3 may be a synchronous motor generator in which a permanent magnet is embedded in the rotor and a stator coil is wound around the stator, and the motor generator 3 may be controlled by the motor controller 6. The operation of the motor generator 3 can be controlled by the motor controller 6 sending a control command to the motor generator 3.

The clutch 9 can be mounted between the engine 2 and the motor generator 3, and the clutch 9 is separated from the motor generator 3 by the engagement and disengagement. And can be connected.

The automatic transmission 4 may be configured to switch the shift stage according to the driver's intention (vehicle speed, position value of the accelerator pedal, required torque, etc.). The automatic transmission 4 can be controlled by the transmission controller 7 (TCU).

The engine controller 5, the motor controller 6, and the transmission controller 7 can be connected to the hybrid controller 9, and the hybrid controller 8 manages the energy consumption of the entire vehicle and drives the vehicle with the highest efficiency. It can be configured to.

The hybrid controller 8 controls the operation of the engine 2 by the control command of the engine controller 5, the operation control of the motor generator 3 by the control command of the motor controller 6, the engagement of the clutch 9, and The release control, the transmission of the transmission 4 and the like are executed through the control command of the transmission controller 7.

The engine system 10 having an electric supercharger according to an embodiment of the present invention can be applied to the hybrid vehicle illustrated in FIG. 1. Meanwhile, FIG. 1 illustrates a TMED hybrid vehicle in which the engine 2 and the motor generator 3 are connected via a clutch 9, but the present invention is not limited thereto, and the FMED hybrid vehicle, power branch hybrid It can be applied to various types of hybrid vehicles such as vehicles.

Referring to Figure 2, the engine system 10 according to an embodiment of the present invention, the engine 5 having a plurality of cylinders, the intake manifold 11 in communication with the intake of each cylinder of the engine 5 Wow, an exhaust manifold 12 communicating with the exhaust port of each combustion chamber of the engine 5, an intake pipe 13 connected to the intake manifold 11, and an exhaust pipe 14 connected to the exhaust manifold 12 , An air valve 40 configured to selectively supply at least a portion of the supercharged air compressed by the electric supercharger 30 and the electric supercharger 30 mounted to the intake pipe 13 to the exhaust manifold 12 side It may include.

The engine 5 may have a plurality of cylinders that generate driving force by combustion of fuel.

An air cleaner 19 may be mounted at an end of the intake pipe 13, and an intake air inlet pipe 13a may be connected to the air cleaner 19.

The electric supercharger 30 is disposed in the middle of the intake pipe 13 to compress the intake air sucked through the air cleaner 19 to supply supercharged air to each cylinder side of the engine 5. The electric supercharger 30 may have a motor 31 operated by electrical energy and a compressor 32 driven by the motor 31. The compressor 32 is disposed on the downstream side of the air cleaner 19 so that the compressor 32 can communicate with the outlet of the air cleaner 19.

The electric supercharger 30 can be controlled by the engine controller 5 and / or the hybrid controller 8.

A bypass pipe 33 may be connected to the outlet of the air cleaner 19, and a bypass valve 17 may be mounted to the bypass pipe 33. When the bypass valve 17 is opened, at least a portion of the intake air sucked through the intake air inlet pipe 13a can bypass the electric supercharger 30 through the bypass pipe 33, and the bypass valve 17 When is closed, intake air sucked through the intake air intake pipe 13a may flow toward the electric supercharger 30.

The intake pipe 13 may be equipped with an intercooler 15 and a throttle valve 18, and the intercooler 15 may be disposed downstream of the compressor 32 of the electric supercharger 30, and the throttle valve ( 18) may be disposed downstream of the intercooler 15.

The exhaust pipe 14 may be equipped with one or more catalysts 16 for purifying exhaust gas.

The air valve 40 injects supercharged air to allow at least a portion of supercharged air to be injected into the supercharged air introduction pipe 41 and the exhaust manifold 12 to allow at least a portion of supercharged air to be introduced from the intake pipe 13. The tube 42 can be connected.

The supercharged air introduction pipe 41 may be configured to connect the air valve 40 and the downstream point of the compressor 32 of the electric supercharger 30, whereby the compressor 32 of the electric supercharger 30 Compressed supercharged air may be introduced to the air valve 40 side.

The supercharged air injection pipe 42 may be configured to connect the air valve 40 and the exhaust manifold 12, whereby the supercharged air is injected into the exhaust manifold 12 side as the air valve 40 is opened. Can be. The supercharged air injection pipe 42 may have a plurality of branch pipes 42a that uniformly distribute supercharged air to the runners of the exhaust manifold 12.

Accordingly, when the air valve 40 is opened, the supercharged air compressed by the compressor 32 of the electric supercharger 30 passes through the supercharged air introduction pipe 41 and the supercharged air injection pipe 42 to exhaust the manifold 12 ) Can be supplied evenly distributed to each runner.

3 is an engine system 10 having an electric supercharger 40 according to another embodiment of the present invention, the compressor 21 mounted on the intake pipe 13 and the turbine 22 mounted on the exhaust pipe 14 It may further include a turbocharger 20 having a.

The compressor 21 of the turbocharger 20 may be located on the downstream side of the compressor 32 of the electric supercharger 30.

According to the embodiment of Figure 3, the exhaust pipe 14 may be equipped with two catalysts (16a, 16b), the two catalysts (16a, 16b) WCC (16a, Warm-up Catalytic Converter) and UCC (16b) , Under floor Catalytic Converter).

The rest of the configuration and operation are similar to or the same as the embodiment of Fig. 2, and detailed description thereof will be omitted.

4 shows a control method of a hybrid vehicle including an engine system 10 having a supercharger 30 according to an embodiment of the present invention.

The hybrid controller 8 may be configured to select any one of the EV mode, the HEV mode, and the engine driving mode, and accordingly, the hybrid vehicle drives the EV mode, the engine driving force, and the motor generator driven only by the driving force of the motor generator. It is possible to travel in any one of the HEV mode, which is driven by the driving force of the engine, and the engine driving mode, which is driven only by the driving force of the engine.

The hybrid controller 8 is provided by the coolant temperature, engine oil temperature, SOC (state of charge) of the battery, driver's required torque, accelerator pedal position value measured by the accelerator position sensor (APS), and the vehicle speed sensor. After reading various driving information of the vehicle, such as the measured vehicle speed, it is possible to determine which of the current driving conditions of the hybrid vehicle corresponds to an EV mode, a HEV mode, or an engine driving mode.

The hybrid controller 8 determines whether the coolant temperature is greater than the reference coolant temperature (S1). The reference coolant temperature is a temperature for determining whether the current driving state of the vehicle is a condition in which engine driving is required (ie, HEV mode and engine driving mode). When the coolant temperature is equal to or lower than the reference coolant temperature, engine driving is not required. It may be a driving condition corresponding to the EV mode.

If the coolant temperature is lower than the reference coolant temperature in step S1, it is determined that the engine is not required to be driven, and the hybrid controller 8 turns the engine 2 off (S11).

In step S1, if the coolant temperature is greater than the reference coolant temperature, it may be determined that there is a possibility that the engine is required to be driven, and the hybrid controller 8 determines whether the engine oil temperature is greater than the reference engine oil temperature (S2). . The reference engine oil temperature is a temperature for determining whether the current driving state of the vehicle is a condition in which engine driving is required (ie, HEV mode and engine driving mode). When the engine oil temperature is lower than the reference engine oil temperature, the engine operation It may be a driving condition corresponding to an EV mode that is not required.

If the engine oil temperature is lower than the reference engine oil temperature in step S2, it is determined that the driving of the engine is not required, and the hybrid controller 8 turns the engine 2 off (S11).

In step S2, if the coolant temperature is greater than the reference coolant temperature, it is determined that there is a possibility that the engine is required to be driven. Accordingly, the hybrid controller 8 determines whether the SOC of the battery is greater than the reference SOC (S3). The reference SOC is an SOC for determining whether the current driving state of the vehicle is a condition in which engine driving is required (ie, HEV mode and engine driving mode). When the SOC of the battery is greater than or equal to the reference SOC, engine driving is not required. It may be a driving condition corresponding to.

If the SOC of the battery is greater than or equal to the reference SOC in step S3, it is determined that engine start is not required, and the hybrid controller 8 turns off the engine 2 (S11).

In step S3, if the SOC of the battery is larger than the reference SOC, it is determined that there is a possibility that engine driving is a required condition, and the hybrid controller 8 selects a mode in which the engine can be driven according to the position value of the accelerator pedal and the vehicle speed. Using the map 50, it is determined whether the position value and the vehicle speed of the accelerator pedal satisfy the condition required to drive the engine (S4).

When the position value of the accelerator pedal and the vehicle speed satisfy the condition that engine driving is not required by the mode selection map 50 in step S4, the hybrid controller 8 turns off the engine 2 (S11).

If the position value and the vehicle speed of the accelerator pedal by the mode selection map 50 in step S4 satisfies the condition that the engine is required to be driven, the hybrid controller 8 generates the operation signal of the electric supercharger 30 and the engine 2 The start signal is transmitted to the engine controller 5 and the motor controller 6, through which the engine 2 is started by a motor generator 3 or a starter motor (not shown) (S5). At this time, the bypass valve 17 is closed, so that the intake air introduced through the intake air intake pipe 13a is compressed by the compressor 32 of the electric supercharger 30 so that the supercharged air is at the inlet side of the throttle valve 18. Pressurized, the supercharged air passes through the intake pipe 13 and flows into the intake manifold 11 side.

The engine controller 5 determines whether the air valve 40 is in an open condition (S6).

According to one embodiment, the open condition of the air valve 40 may be determined by confirming whether the current state of the engine 2 is within a cranking section for restarting after the on / off of the engine 2. For example, if the RPM of the engine 2 measured by the RPM sensor is less than the set full RPM, it is determined that the current state of the engine 2 is within the cranking section (that is, the engine 2 has not been started). It is possible to open the air valve 40 accordingly. If the RPM of the engine 2 measured by the RPM sensor is greater than or equal to the set full RPM, it can be determined that the current state of the engine 2 is out of the cranking section (that is, the engine 2 has been started). Accordingly, the air valve 40 is closed.

According to another embodiment, the open condition of the air valve 40 is determined by determining whether the current state of the engine 2 is within a catalyst heating section for heating the catalyst to reach a catalyst activation temperature after the engine 2 is started. The opening condition of the valve 40 can be determined. For example, if the temperature of the catalysts 16, 16a, 16b measured by the temperature sensors mounted on the catalysts 16, 16a, 16b is less than the set catalyst activation temperature, it is within the catalyst heating section, and thus the air valve 40 To open. If the temperature of the catalysts 16, 16a, 16b measured by the temperature sensors mounted on the catalysts 16, 16a, 16b exceeds the set catalyst activation temperature, it is out of the catalyst heating section, and the air valve 40 Will be closed.

If the air valve 40 in step S6 corresponds to the open condition, the engine controller 5 opens the air valve 40 (S7) to boost air compressed by the compressor 32 of the electric supercharger 30. It is injected into the exhaust manifold 12 side. The condition of the opening of the air valve 40 is that the current state of the engine 2 is a cranking operation section for restarting after the on / off of the engine 2, or the catalysts 16, 16a, 16b immediately after the engine 2 is started. The air valve 40 is opened by determining that it corresponds to a catalyst heating section in which the catalyst activation temperature has not been reached.

If the air valve 40 does not correspond to the opening condition in step S6, the air valve 40 is closed, and it is determined whether the engine torque commanded by the engine controller 5 is greater than the reference engine torque (S8). The reference engine torque is a torque for determining engine torque blending execution.

If the engine torque is greater than the reference engine torque in step S8, engine torque blending is performed (S9). The required torque calculated by the hybrid controller 8 is the sum of the engine torque commanded by the engine controller 5 and the motor torque commanded by the motor controller 6. Engine torque blending can improve the vehicle's low end torque by relatively reducing the motor torque and increasing the engine torque when the required torque is increased.

If the engine torque is less than the reference engine torque in step S8, the air valve 40 is opened (S7) to inject the supercharged air compressed by the compressor 32 of the electric supercharger 30 to the exhaust manifold 12 side. . If the engine torque is below the reference engine torque, the current state of the engine 2 is a cranking operation section for restarting after the engine 2 is turned on or off, or the catalysts 16, 16a, and 16b immediately after the engine 2 is started. The air valve 40 is opened by determining that it corresponds to a catalyst heating section in which the catalyst activation temperature has not been reached.

After step S11, the hybrid controller 8 calculates the driver's required torque according to the position value of the accelerator pedal and the vehicle speed, and determines that the driver's requested torque is less than the reference requested torque (S12). The reference request torque is a reference request torque for determining whether the engine is running.

In step S12, if the driver's required torque is less than the reference required torque, the hybrid controller 8 selects the EV mode so that the hybrid vehicle is controlled by the motor controller 6 in the EV mode (S13).

In step S12, if the driver's required torque is greater than or equal to the reference required torque, the hybrid controller 8 selects the HEV mode, so that the hybrid vehicle is controlled in the HEV mode through the engine controller 5 and the motor controller 6 (S14).

As described above, the present invention is configured to inject the supercharged air compressed by the electric supercharger 30 by the opening of the air valve 40 toward the exhaust manifold 12, so that it is necessary to use a separate secondary air injection pump. No, it is possible to not only reduce the exhaust gas but also promote the catalyst activation, so that the catalyst precious metal loading can be drastically reduced, so that cost reduction can be realized. In particular, low-speed and high-speed performance can be significantly improved by reducing the back pressure.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and variations without departing from the essential characteristics of the present invention.

Therefore, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, but to explain, and the scope of the technical spirit of the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted by the claims below, and all technical spirits within the equivalent range should be interpreted as being included in the scope of the present invention.

1: Hybrid powertrain 2: Engine
3: Motor generator 4: Automatic transmission
5: Engine controller 6: Motor controller
7: Transmission controller 8: Hybrid controller
9: Clutch 10: Engine system
11: Intake manifold 12: Exhaust manifold
13: intake pipe 14: exhaust pipe
15: intercooler 16, 16a, 16b: catalyst
17: bypass valve 18: throttle valve
19: Air cleaner 20: Turbocharger
21: compressor 22: turbine
30: electric supercharger 31: motor
32: compressor 33: bypass pipe
40: air valve 41: supercharged air introduction pipe
42: supercharged air injection tube

Claims (10)

An engine having a plurality of cylinders;
An intake manifold communicating with an intake port of each cylinder of the engine;
An exhaust manifold communicating with an exhaust port of each cylinder of the engine;
An intake pipe connected to the intake manifold;
An exhaust pipe connected to the exhaust manifold;
An electric supercharger mounted on the intake pipe and having a motor and a compressor driven by the motor; And
And an air valve that is opened and closed to selectively supply supercharged air compressed by the electric supercharger to the exhaust manifold side. The method according to claim 1,
The air valve is an engine system having an electric supercharger to which a supercharged air introduction pipe allowing supercharged air is introduced from the intake pipe and a supercharged air injection pipe allowing supercharged air to be injected into the exhaust manifold side. The method according to claim 2,
The supercharged air introduction pipe is an engine system having an electric supercharger configured to connect the downstream point of the compressor of the electric supercharger to the inlet of the air valve. The method according to claim 2,
The supercharged air injection pipe is an engine system having an electric supercharger configured to connect the outlet of the air valve and the exhaust manifold. The method according to claim 4,
The supercharged air injection pipe is an engine system having an electric supercharger having a plurality of branch pipes branched to uniformly distribute supercharged air to runners of the exhaust manifold. A control method of a hybrid vehicle having an electric supercharger connected to an intake manifold side of an engine, and an air valve that opens and closes at least a portion of supercharged air compressed by the electric supercharger to the exhaust manifold side of the engine,
When the engine is in a required condition, the electric supercharger is operated and the engine is started,
A control method of a hybrid vehicle in which at least a portion of the supercharged air compressed by the electric supercharger is injected into the exhaust manifold side of the engine by opening the air valve when the air valve is in an open condition. The method according to claim 6,
A control method of a hybrid vehicle that opens the air valve when the current state of the engine is a cranking section for starting the engine. The method according to claim 6,
A control method of a hybrid vehicle that closes the air valve when the current state of the engine is outside the cranking section. The method according to claim 6,
A control method of a hybrid vehicle that opens the air valve when the temperature of the catalyst is a catalyst heating section immediately after the engine is started. The method according to claim 6,
A control method of a hybrid vehicle that closes the air valve when the temperature of the catalyst exceeds the catalyst heating section immediately after the engine starts.

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