JP2007071136A - Supercharging device of engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the deterioration in fuel economy, and to restrain the deterioration in a battery while securing rising responsiveness of supercharging pressure in a supercharging device of an engine having a motor-driven supercharger. <P>SOLUTION: This supercharging device of the engine has a supercharging passage provided with the motor-driven supercharger, a bypass passage connected to the upstream-downstream side of the motor-driven supercharger in the supercharging passage and provided with an intake control valve, and a confluent passage extending to the downstream side from a confluent part of the supercharging passage and the bypass passage and provided with a throttle valve; and is constituted so as to supply electric power to the motor-driven supercharger when an operation state of the engine exists in a predetermined supercharging area and stop supply of the electric power to the supercharger when the operation state exists in a non-supercharging area set on the lower load side than the supercharging area; and adjusts the air volume sucked in the engine by controlling opening of the intake control valve in a state of fully opening the throttle valve when the operation state of the engine exists in the non-supercharging area. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an engine supercharger having an electric supercharger, and belongs to the technical field of an engine intake system.

  Conventionally, superchargers and turbochargers that supercharge intake air as means for increasing engine torque are well known. However, as a result of the supercharging ability being greatly affected by the engine speed, the supercharging pressure is low. There is a drawback of lacking. On the other hand, the electrically driven electric supercharger can control the rotational speed without being affected by the engine rotational speed, and therefore has an advantage that a sufficient supercharging pressure can be generated even in a low rotational speed region.

  And as an intake system provided with this electric supercharger, for example, in Patent Document 1, a supercharging passage in which the electric supercharger is disposed, and an electric supercharger in the supercharging passage above and downstream of the supercharger. Disclosed is an intake system provided with a bypass passage that is connected and provided with an intake control valve, and a merging passage that extends downstream from a merging portion of the supercharging passage and the bypass passage and is provided with a throttle valve. Has been. In this intake system, when the engine operating region is in a predetermined supercharging region on the high load side, the electric supercharger is operated with the intake control valve closed. The intake air amount of the engine is controlled by controlling the opening of the throttle valve as usual.

On the other hand, this type of electric supercharger has a compressor and a motor that drives the compressor, and the number of rotations of the compressor increases or decreases according to the power supplied to the motor, and the resulting supercharging pressure is determined. become. Here, Patent Document 2 discloses an invention relating to control of power supply to an electric supercharger. That is, in the invention described in Patent Document 2, normally, the power supplied to the electric supercharger is large when the pressure difference is large based on the difference between the target supercharging pressure and the actual supercharging pressure at the time of supercharging. The supercharging pressure feedback control is performed so as to increase the supply power, but at the start of supercharging, that is, only when the engine operating state enters the supercharging region, the supercharger is It is controlled to supply the maximum power. As a result, the rotational speed of the electric supercharger is quickly increased, and the responsiveness of the rise of the supercharging pressure when entering the supercharging region is ensured. In the following description, the electric power supplied to the supercharger when the engine operating region enters the supercharging region is referred to as “rush power”.
JP 2004-346910 A JP 2004-169629 A

  By the way, the electric supercharger is usually driven based on the generated power of the alternator driven by the engine. However, in order to ensure responsiveness as when the electric supercharger is started. When a large inrush power is required, the required power cannot be covered by the power supplied from the alternator, and the power is taken out from the battery. At this time, the power taken out from the battery is not small, which may promote the deterioration of the battery, and the power generation time of the alternator increases for charging the battery, resulting in a problem of deterioration in fuel consumption. Moreover, in an operating state where acceleration and deceleration are repeated, the transition from the non-supercharged region to the supercharged region of the operating state is repeated, and power is taken out from the battery at each transition, and the above-described deterioration of the battery In addition, the problem of deterioration in fuel consumption becomes prominent, and the user is forced to replace the battery frequently.

  On the other hand, in a state where the operating state is in the non-supercharging region, predetermined electric power is supplied to the electric supercharger, the rotational speed is increased in advance, and the inrush power when shifting to the supercharging region is suppressed. Although it is conceivable, the operation time of the alternator becomes longer due to the necessity of the predetermined power supply, and the deterioration of fuel consumption becomes a problem.

  Accordingly, an object of the present invention is to prevent deterioration of fuel consumption and suppress deterioration of a battery while ensuring responsiveness of rising of a supercharging pressure in an engine supercharging device having an electric supercharger. .

  In order to solve the above problems, the present invention is configured as follows.

  First, the invention according to claim 1 is provided with a supercharging passage provided with an electric supercharger, and an intake control valve connected to the upstream side of the electric supercharger in the supercharging passage. A bypass passage and a joining passage that extends downstream from a joining portion of the supercharging passage and the bypass passage and is provided with a throttle valve, and the engine operating state is in a predetermined supercharging region. The power supply to the electric supercharger is performed, and the power supply to the supercharger is stopped when the electric supercharger is in a non-supercharge region set at a lower load side than the supercharge region. An engine supercharging device that is inhaled into the engine by controlling the opening of the intake control valve with the throttle valve fully opened when the engine is in the non-supercharging region. It is characterized by adjusting the amount of air.

  In the state where the power supply to the supercharger is stopped in the non-supercharged region, the motor is rotated at a very low speed with a small amount of electric power for the purpose of recognizing the rotational phase of the supercharger motor. Including the state.

  The invention according to claim 2 is the engine supercharging device according to claim 1, wherein when the engine operating state is on a low load side in the non-supercharging region, the intake control valve is fully The amount of air taken into the engine is adjusted by controlling the opening of the throttle valve in the closed state.

  According to a third aspect of the present invention, there is provided a supercharging device for an engine according to the first aspect, further comprising a supercharger rotational speed detecting means for detecting an actual rotational speed of the electric supercharger, and When the state shifts from the non-supercharged region to the supercharged region and power supply to the electric supercharger is started, the actual rotational speed immediately before the start of power supply to the supercharger detected by the detection means The larger the difference from the target rotational speed at the time of feeding, the larger the power supplied to the supercharger.

  First, according to the first aspect of the present invention, when the operating state of the engine is in the non-supercharging region, the intake of the intake control valve is controlled while the throttle valve is fully opened. The amount of air to be adjusted will be adjusted. At this time, since the throttle valve is fully opened, the intake negative pressure generated in the combustion chamber reaches the supercharging passage through the merging passage, and an air flow is generated due to the pressure difference with the upstream side of the supercharging passage. It will be. Then, the supercharger is rotated by the air flow in the supercharging passage.

  Therefore, when the operating state shifts from the non-supercharging region to the supercharging region and the rotation of the supercharger increases when the supercharger rotates in this manner, the rotation increases from the state where the supercharger stops. Since the rotation can be increased in the same manner with a small amount of energy as compared with the case where it is performed, inrush power is suppressed. As a result, an increase in the ratio that can be covered by the generated power of the alternator prevents the power from being taken out of the battery, thereby preventing the battery from deteriorating. At this time, although the inrush power is suppressed, the rotation can be quickly increased, so that the responsiveness at the rise of the supercharging pressure is not deteriorated, and the fuel consumption is deteriorated by suppressing the inrush power. Is prevented.

  By the way, since the throttle valve is disposed in the joining passage extending downstream of the joining portion of the supercharging passage and the bypass passage, the total amount of air flowing in from the supercharging passage and the bypass passage can be controlled. Since the intake control valve is disposed in the bypass passage, the air flowing through the supercharging passage cannot be controlled, and the opening degree of the intake control valve is adjusted with the throttle valve fully opened as described above. When configured to do so, it becomes impossible to control the amount of intake air, and hence the engine load.

  That is, in the non-supercharging region controlled in this way, on the low load side where the required amount of air is small, even if the opening of the intake control valve is fully closed, the air required by the air passing through the supercharging passage There is a problem that an excessive amount of air may be sucked into the engine, and the engine load cannot be reduced.

  On the other hand, according to the invention described in claim 2, the intake control valve is exceptionally fully closed on the low load side in the non-supercharging region, that is, in the region where the air amount cannot be reduced by the intake control valve. Since the intake air amount is adjusted by controlling the opening degree of the throttle valve in this state, the intake air amount can be appropriately controlled. Is resolved. Furthermore, since the intake control valve is closed, the electric supercharger can be caused to rotate slightly by the flow of air through the supercharging passage, and the inrush power is suppressed.

  On the other hand, as described above, the inrush power can be reduced by rotating the supercharger. However, if the inrush power is constant, the engine operating state shifts from the non-supercharge region to the supercharge region. When the power supply to the turbocharger is started, if there is a large difference between the actual rotational speed immediately before the start of power supply and the target rotational speed at the time of supercharging, a response delay occurs due to insufficient power, and the rotational speed difference is When it is small, there is a risk that fuel consumption will deteriorate due to excessive supply of electric power.

  On the other hand, according to the invention described in claim 3, the larger the difference between the actual rotational speed immediately before the start of power supply and the target rotational speed at the time of supercharging, the greater the power supplied to the supercharger. When the rotational speed difference is large, the supplied power is increased to improve the responsiveness of the boost pressure rise, and when the rotational speed difference is small, the supplied power is reduced to realize power saving.

  Embodiments of the present invention will be described below.

  FIG. 1 shows an intake system 1 for an engine according to the present embodiment. The intake system 1 has an intake passage 2 through which fresh air is introduced. The intake passage 2 is connected to an air cleaner 10 on the upstream side, and a supercharging passage 20 in which an electric supercharger 11 is disposed; A bypass passage 21 connected to the upstream side and the downstream side of the supercharger 11 in the supercharging passage 20 and provided with the intake control valve 12, and a downstream side where the supercharging passage 20 and the bypass passage 21 merge. The combined passage 22 in which the throttle valve 13 is disposed, the surge tank 23 formed on the downstream side of the combined passage 22, and a plurality of independent intake air that branches from the surge tank 23 to each of the cylinders # 1 to # 4 And passages 24...

  The electric supercharger 11 is configured such that the compressor 11b rotates by supplying electric power to the motor 11a, and air sucked from the upstream side of the supercharger 11 in the supercharging passage 20 is pumped downstream. It has become. In addition, the power consumption at the time of the rated output of this supercharger 11 is 2 kW.

  In addition, an electric supercharger driver 30 that controls the supply current to the motor 11 a of the electric supercharger 11, and a battery 31 and an alternator 32 that supply electric power to the motor 11 a via the driver 30 are provided. The battery 31 is a 14V power source, and is connected to the driver 30 so as to be able to supply power as indicated by an arrow A, and can store the electric power generated by the alternator 32. The alternator 32 is configured to generate a voltage of 14 V by driving the engine. The alternator 32 directly supplies power to the driver 30 as indicated by an arrow B, while supplying power to the battery 31 as indicated by an arrow C. To charge.

  An engine control unit 100 that controls the entire engine and an intake system controller 101 that controls each device of the intake system 1 based on a control signal output from the engine control unit 100 are provided.

  The engine control unit 100 detects the engine load as a signal from an accelerator opening sensor 40 that detects the depression amount of the accelerator pedal 40a, a signal from the engine speed sensor 41 that detects an engine speed, and the battery 31. A signal from a voltage sensor 42 for detecting the charging state of the motor 11 and a motor rotational speed sensor 43 for detecting the rotational speed of the motor 11a of the electric supercharger 11 are input.

  Based on these input signals, the engine control unit 100 outputs various control signals to the throttle actuator 44 that drives the throttle valve 13 to open and close, the intake system controller 101, and the like.

  The intake system controller 101 outputs a control signal to the intake control valve actuator 45 that opens and closes the intake control valve 12, the electric supercharger driver 30, and the like.

  By the way, as shown in FIG. 2, the engine control unit 100 stores a control map in which each operation region is set according to the accelerator opening and the engine speed. In this control map, a non-supercharging region is set on the low load side and the high rotation side, and a supercharging region is set on the high load low rotation side. Further, a first region is set on the low load side in the non-supercharging region, and a second region is set on the high load side.

  In the first region of the non-supercharging region, the engine control unit 100 controls the intake of the intake control valve actuator 45 via the intake system controller 101 and a signal for controlling the opening of the throttle valve 13 to the throttle actuator 44. A signal for fully closing the valve 12 is output. Further, the engine control unit 100 outputs a signal for supplying a minute current to the motor 11 a to the electric supercharger driver 30 via the intake system controller 101. The throttle valve 13 is of an electronic control type, and the throttle opening does not necessarily correspond to the depression amount of the accelerator pedal 40a.

  In the second region of the non-supercharging region, the engine control unit 100 sends a signal to the throttle actuator 44 to fully open the throttle valve 13 and an intake control valve 12 to the intake control valve actuator 45 via the intake system controller 101. A signal for controlling the opening degree of is output. The engine control unit 100 outputs a signal for supplying a minute current to the motor 11a to the electric supercharger driver 30 via the intake system controller 101.

In the supercharging region, the engine control unit 100 sends the intake control valve 12 to the intake control valve actuator 45 via the intake system controller 101 and the signal for controlling the opening of the throttle valve 13 to the throttle actuator 44. Outputs a signal to fully close. In this supercharging region, the engine control unit 100 supplies the supercharger 11 with a supply current represented by the following expression 1 to the electric supercharger driver 30 via the intake system controller 101. Output a signal.
Supply current = Base current + (Target speed-Actual speed) x Gain (Formula 1)

  Here, the base current is a current value required to realize the power supply of 1 kW. Further, the target rotational speed of the supercharger 11 at the time of supercharging is determined according to the accelerator opening and the engine rotational speed. Then, a value obtained by subtracting the actual rotational speed detected by the motor rotational speed sensor 43 from the target rotational speed of the supercharger 11 and a predetermined gain is added to the base current, and this is supplied as a total supply. It is current.

  Next, the operation of the intake system 1 will be described.

  First, when the engine operating state is in the first region of the non-supercharging region, the intake control valve 12 is fully closed from the engine control unit 100 via the signal for controlling the throttle valve 13 and the intake system controller 101. Therefore, the air introduced into the intake passage 2 reaches the merging passage 22 through the supercharging passage 20 and is sucked into the engine in accordance with the opening degree of the throttle valve 13. The opening of the throttle valve 13 controls the intake air amount so that the target torque is obtained with respect to the target torque calculated based on the parameters of the accelerator opening and the engine speed.

  Further, in this region, the supercharger 11 maintains the idling rotation (5000 rpm) in a state where there is no autorotation effect described later by supplying a small current to the electric supercharger 11. By performing idle rotation in this way, the engine control unit 100 can always recognize the rotational phase of the motor 11a, so that the control response of the supercharger 11 when the operating state shifts to the supercharging region. This improves the responsiveness of the boost pressure rise.

  Further, since the intake control valve 12 is fully closed so that air flows through the supercharging passage 20, the supercharger 11 rotates and is increased to a rotational speed higher than the idle speed.

  Further, when the engine operating state is in the second region of the non-supercharging region, a signal for fully opening the throttle valve 13 from the engine control unit 100 and the opening degree of the intake control valve 12 via the intake system controller 101 Since the control signal is output, the air introduced into the intake passage 2 is introduced into the merging passage 22 through both the supercharging passage 20 and the bypass passage 21, and is sucked into the engine. . As with the throttle valve 13 in the first region, the opening degree of the intake control valve 12 is such that the target torque is obtained with respect to the target torque calculated based on the parameters of the accelerator opening degree and the engine speed. The intake air amount is controlled.

  Also in this region, as in the first region, a small amount of current is supplied to the electric supercharger 11, and the supercharger 11 maintains idle rotation in a state where there is no autorotation effect. .

  Since the throttle valve 13 is fully opened, the intake negative pressure in the combustion chamber reaches the supercharging passage 20 via the merging passage 22 and is supercharged by the air flow in the supercharging passage 20 generated by the negative pressure. The machine 11 rotates. At this time, since the intake negative pressure is not blocked by the throttle valve 13, a higher rotation effect (e.g., up to 15000 rpm) than the rotation in the first region can be obtained.

  As a result, as shown in FIG. 3, in the non-supercharging region, engine characteristics are obtained in which high torque can be obtained on the high rotation side only by natural intake.

  When the engine operating state is in the supercharging region, the engine control unit 100 outputs a signal for controlling the throttle valve 13 and a signal for fully closing the intake control valve 12 via the intake system controller 101. Therefore, the air introduced into the intake passage 2 cannot pass through the bypass passage 21 and can pass only through the supercharging passage 20. Then, the electric supercharger 11 operates with electric power equal to or higher than the base current supply power (1 kW), and the air introduced into the supercharging passage 20 is pumped to the downstream side of the supercharger 11. Further, the pumped air is introduced into the merging passage 22 and is sucked into the engine according to the opening degree of the throttle valve 13.

  As a result, as shown in FIG. 3, in the supercharging region, a torque greater than that obtained by only natural intake is obtained mainly on the low rotation side.

  Next, control of the intake system 1 will be described based on the flowchart shown in FIG.

  First, in step S1, various signals are read. At this time, the accelerator position detected by the accelerator position sensor 40, the engine speed detected by the engine speed sensor 41, and the rotation speed signal of the motor 11a detected by the motor speed sensor 43 are input. Next, in step S2, a target torque is determined based on the accelerator opening and engine speed parameters. This target torque is obtained by calculation or by a map.

  In step S3, it is determined whether or not the engine operating region is in the supercharging region. When it is in the supercharging region, the process proceeds to step S4, and a predetermined current is supplied to the electric supercharger 11. At this time, the current supplied to the supercharger 11 is obtained by multiplying the difference between the target rotational speed of the supercharger 11 and the actual rotational speed by a predetermined gain as shown in the above-described equation 1, and the base current. It is obtained by adding to.

  Next, in step S5, the intake control valve 12 is controlled to be fully closed, and in step S6, torque control is performed by controlling the opening of the throttle valve 13, thereby realizing the target torque obtained in step S2.

  If it is determined in step S3 that the engine operating state is in the non-supercharged region, the process proceeds to step S7, where a small current is supplied to the electric supercharger 11, and the supercharger 11 is in the idle rotation state.

  In step S8, it is determined whether or not the engine operating state is in the first region. If it is in the first region, the process proceeds to step S9, where the intake control valve 12 is fully closed, and in step S10, the throttle is Torque control is performed by controlling the opening of the valve 13, and the target torque obtained in step S2 is realized. At this time, since the intake control valve 12 is closed, air to be taken into the engine flows through the supercharging passage 20 and rotates the supercharger 11. Next, when the actual rotation speed of the supercharger 11 is increased by this rotation, the process returns to step S1, and when the shift to the supercharging region is determined in step S3, the target rotation speed and the actual rotation speed are determined. Since the difference is small, the value of the supply current in step S4 is small.

  On the other hand, when it is determined in step S8 that the engine operating region is in the second region, the process proceeds to step S11 where torque control is performed by controlling the opening degree of the intake control valve 12, and in step S12 the throttle is controlled. The valve 13 is controlled to be fully opened, and the target torque obtained in step S2 is realized. Then, by the torque control in steps S11 and S12, negative pressure is generated in the merging passage 22 and the supercharging passage 20, whereby the supercharger 11 rotates. Next, when the actual rotation speed of the supercharger 11 is increased by this rotation, the process returns to step S1, and when the shift to the supercharging region is determined in step S3, the target rotation speed and the actual rotation speed are determined. Since the difference is small, the value of the supply current in step S4 is small.

  In step S4, the supply current is controlled according to the above-described equation 1, but immediately after the transition from the non-supercharging region to the supercharging region where the difference between the target rotational speed and the actual rotational speed during supercharging is large. , The total supply current increases, the actual rotation speed increases as the actual rotation speed approaches the target rotation speed, so the supply current decreases, and if the actual rotation speed increases to the target rotation speed, the base current is substantially increased. Only supply.

  This will be described with reference to the graphs of FIGS. 5 and 6. As shown in FIG. 5, the target rotational speed at the time of supercharging is set to 60000 rpm. The rotation speed is slightly higher than 5000 rpm, and the rotation speed of about 15000 rpm is maintained in the second region. And when it transfers to a supercharging area | region from each area | region, as shown in FIG. 6, the state at the time of transfer from the 1st, 2nd area | region where an actual rotation speed is high is a state without autorotation (state of idle rotation). The inrush current is made smaller than that at the time of transition from, and the inrush current is made smaller at the time of transition from the second region than at the time of transition from the first region. Then, the rotation speed of the supercharger 11 increases due to the power supply, and the supply current decreases as the rotation speed increases. When the rotation speed is constantly rotating at 60000 rpm, the supply current is The current I ′ is maintained and the power consumption is maintained at 1 kW. Thus, as the difference between the target rotational speed and the actual rotational speed is larger, the inrush current is increased. As a result, as shown in FIG. Can be increased to the target rotational speed.

  As described above, in this embodiment, when the engine operating state is in the non-supercharging region, the throttle valve 13 is fully opened to control the opening degree of the intake control valve 12 to be sucked into the engine. The amount of air to be adjusted is adjusted. At this time, since the throttle valve 13 is fully opened, the intake negative pressure generated in the combustion chamber reaches the supercharging passage 20 via the merging passage 22, and the air is caused by the pressure difference with the upstream side of the supercharging passage 20. The flow of will occur. Then, the supercharger 11 rotates by the air flow in the supercharging passage 20.

  Therefore, when the operating state shifts from the non-supercharging region to the supercharging region while the supercharger 11 rotates in this manner, the supercharger 11 stops when the rotation of the supercharger 11 is increased. Since the rotation can be increased in the same manner with a small energy as compared with the case where the rotation is increased, the inrush power is suppressed. As a result, the proportion of power generated by the alternator 32 can be increased, thereby preventing the power from being taken out from the battery 31 and preventing the battery 31 from deteriorating. At this time, although the inrush power is suppressed, the rotation of the supercharger 11 can be quickly increased, so that the responsiveness at the rise of the supercharging pressure is not lowered, and the inrush power is reduced. Suppression prevents deterioration of fuel consumption.

  In addition, by fully opening the throttle valve 13 in this way, a maximum pressure difference can be generated on the upstream side and the downstream side of the supercharger 11 in the supercharging passage 20, and a higher rotation effect can be obtained. It becomes possible. Further, although the air flow in the supercharging passage 20 decreases as the opening degree of the intake control valve 12 increases, the high load region where the opening degree of the intake control valve 12 is increased is increased by the electric supercharger 11. Since the need for supply is relatively small, the effect of lowering the rotation effect is small.

  By the way, the throttle valve 13 is disposed in the joining passage 22 extending downstream of the joining portion of the supercharging passage 20 and the bypass passage 21, so that the total amount of air flowing from the supercharging passage 20 and the bypass passage 21 is controlled. However, since the intake control valve 12 is disposed in the bypass passage 21, the air flowing through the supercharging passage 20 cannot be controlled, and the throttle valve 13 is fully opened as described above. When the opening of the intake control valve 12 is adjusted, the intake air amount cannot be controlled, and hence the engine load cannot be controlled.

  That is, in the non-supercharging region controlled in this way, on the low load side where the required amount of air is small, the opening of the intake control valve 12 is required by the air passing through the supercharging passage 20 even if it is fully closed. Air exceeding the amount of air may be sucked into the engine, causing a problem that the engine load cannot be reduced.

  On the other hand, in the low load side in the non-supercharging region, that is, in the first region where the intake control valve 12 cannot fully throttle the air amount, the throttle valve 13 is opened with the intake control valve 12 fully opened. Since the intake air amount is adjusted by controlling the degree, the intake air amount is appropriately controlled, and the aforementioned problem of air amount control is solved. Furthermore, since the intake control valve 12 is closed, the electric supercharger 11 can be caused to rotate slightly by the flow of air through the supercharging passage 20 and the inrush power is suppressed.

  On the other hand, the inrush power can be reduced by rotating the supercharger 11 as described above. However, if the inrush power is made constant, the engine operating state changes from the non-supercharge region to the supercharge region. When the power supply to the supercharger 11 is started, if the difference between the actual rotational speed immediately before the start of power supply and the target rotational speed at the time of supercharging is large, a response delay occurs due to insufficient power, When the rotational speed difference is small, there is a risk that fuel consumption will deteriorate due to excessive power supply.

  On the other hand, when the engine operating region shifts from the non-supercharging region to the supercharging region and the power supply to the electric supercharger 12 is started, the power supply The larger the difference between the actual rotational speed just before the start and the target rotational speed at the time of supercharging, the larger the power supplied to the supercharger 11, so when the speed difference is large, the power supplied is increased and the supercharging pressure is increased. In addition to improving the responsiveness of the rise of the power supply, when the rotational speed difference is small, the supplied power is suppressed to save power, and more precise control becomes possible.

  The present invention relates to an engine supercharger having an electric supercharger and is widely suitable for the automobile industry.

1 is an overall view of an intake system according to an embodiment of the present invention. It is a control map which shows the operation area | region of an engine. It is explanatory drawing of the output characteristic of an engine. It is a flowchart which concerns on control of an intake system. It is a graph which shows the actual rotation speed at the time of transfer to a supercharging area | region. It is a graph which shows the power supply of the supercharger at the time of transfer to a supercharging area | region.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Intake system 11 Electric supercharger 12 Intake control valve 13 Throttle valve 20 Supercharging passage 21 Bypass passage 22 Merge passage 43 Motor rotation speed sensor

Claims (3)

A supercharging passage provided with an electric supercharger; a bypass passage connected to an upstream side of the electric supercharger in the supercharging passage and provided with an intake control valve; and the supercharging passage and the bypass A junction passage extending downstream from a junction with the passage and provided with a throttle valve, and supplying electric power to the electric supercharger when the engine is in a predetermined supercharging region. An engine supercharging device configured to stop power supply to the supercharger when in a non-supercharging region set on a lower load side than the supercharging region,
When the engine operating state is in the non-supercharging region, the amount of air taken into the engine is adjusted by controlling the opening of the intake control valve with the throttle valve fully opened. The engine supercharger. The engine supercharging device according to claim 1,
When the engine operating state is on the low load side in the non-supercharging region, the amount of air drawn into the engine is adjusted by controlling the opening of the throttle valve with the intake control valve fully closed A supercharging device for an engine. The engine supercharging device according to claim 1,
Having a supercharger rotation speed detection means for detecting the actual rotation speed of the electric supercharger;
The actual rotation immediately before the start of power supply of the supercharger detected by the detection means when the operating state of the engine shifts from the non-supercharge region to the supercharge region and the power supply to the electric supercharger is started. A supercharging device for an engine, characterized in that the power supplied to the supercharger increases as the difference between the number and the target rotational speed during supercharging increases.

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