JP2012067658A - Engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an engine in which an inverter is efficiently cooled without complicating intake piping.SOLUTION: The engine includes: the intake piping 2; a supercharger 20 having a compressor impeller 22 and a housing 23; an electric motor 19 driving the supercharger 20; a by-pass piping arranged in parallel to an intake piping part 2A of the intake piping 2 and by-passing the compressor impeller 22; an air flow rate adjusting valve for adjusting the flow rate of the intake air flowing in the by-pass piping; the inverter 40 drive-controlling the electric motor 19; an adjusting valve control unit 41 for controlling the operation of the air flow rate adjusting valve; and a heat radiation block 27 connected to the housing 23 and the inverter 40. Here, the heat from the inverter 40 is conducted to the compressor impeller 22 through the heat radiation block 27 and the housing 23.

Description

  The present invention relates to an engine including an electric supercharger that drives and controls an electric motor using an inverter.

An electric supercharger in which a supercharger that is driven by an electric motor is provided in an intake pipe in order to increase the output of an engine for the purpose of reducing fuel consumption of an automobile.
As an example of this electric supercharger, there is known one in which an outlet portion of a supercharger is connected to a compressor inlet portion of a turbocharger that is driven by the dynamic pressure of engine exhaust gas (Patent Document 1).
This electric supercharger is provided with a supercharger that can be supercharged freely by electric power, thereby improving the acceleration of the engine, lowering the back pressure of the engine, and reducing unburned fuel.

On the other hand, the inverter that controls the driving of the electric supercharger motor needs to be controlled at an ultra-high speed exceeding 100,000 rpm, and in general, the voltage of an automobile is 14V, so that the motor is driven. A large current is required.
During continuous operation in such a high rotation / high current state, the loss of the semiconductor element that switches DC power from the battery and the loss due to wiring resistance increase, the temperature of the inverter rises, and each of the inverters It is conceivable that parts are damaged or deteriorated.

  As measures to prevent such an inverter temperature rise, the intake pipe is connected to a series pipe that reaches the supercharger after passing through the heat generating part of the motor and the inverter, and a first bypass that bypasses the motor and the inverter to reach the supercharger. It is known that it is composed of three pipes, a pipe and a second bypass pipe that bypasses the motor, inverter and supercharger to reach the engine, and can be switched to pass through any of the three pipes ( Patent Document 2).

Special Table 2000-500544 JP 2008-215075 A

However, although the thing of the said patent document 2 can cool an inverter, there existed a problem that intake piping was comprised by three piping and intake piping became complicated.
Further, since the inverter and the electric motor are disposed in the intake pipe, there is a problem that the intake resistance of the engine is large.

  An object of the present invention is to provide an engine capable of efficiently cooling an inverter without complicating the intake piping. .

  An engine according to the present invention includes an intake pipe through which intake air flows, a compressor impeller disposed in the intake pipe, a supercharger having a housing surrounding the compressor impeller, and an electric motor that drives the supercharger. A bypass pipe that is arranged in parallel between the upstream side and the downstream side of the compressor impeller of the intake pipe, bypasses the compressor impeller, and the intake air that is provided in the bypass pipe and flows through the bypass pipe. An air flow rate adjustment valve for adjusting the flow rate, an inverter for driving and controlling the electric motor, an adjustment valve control means for controlling the operation of the air flow rate adjustment valve, and a heat dissipation block connected to the housing and the inverter, Heat from the inverter is conducted to the compressor impeller through the heat dissipation block and the housing It is.

  According to the engine of the present invention, since the turbocharger housing and the inverter that controls the electric motor that drives the supercharger are connected by the heat dissipation block, the heat from the inverter is supercharged via the heat dissipation block and the housing. It is conducted to the compressor impeller of the machine, and the inverter is efficiently cooled with a simple structure and without increasing its size.

1 is an overall configuration diagram of an engine according to Embodiment 1 of the present invention. It is a block diagram which shows the electric supercharger of FIG. It is a flowchart which shows operation | movement of the electric supercharger of FIG.

Embodiment 1 FIG.
Hereinafter, the engine of Embodiment 1 of this invention is demonstrated based on figures.
1 is an overall configuration diagram showing an engine according to Embodiment 1 of the present invention.
This engine is multi-cylinder, but only one cylinder is shown in FIG.
The engine includes an engine main body 1, an intake pipe 2 provided with a throttle valve 3 therein for leading intake air to the engine main body 1, an exhaust pipe 4 for guiding exhaust gas from the engine main body 1 to an exhaust purification device 5, and an intake pipe. An intercooler 6 attached to the electric cooler 2, an electric supercharger 7 provided in the intake pipe 2 upstream of the intercooler 6, an intake pipe 2 and an exhaust pipe 4 downstream of the electric supercharger 7, And a turbocharger 8 provided between the two.

  The engine body 1 includes a cylinder 10, a piston 11 that moves up and down in the cylinder 10 by the rotation of a crank 16, a spark plug 12 provided at the head of the cylinder 10, and a tip that faces the upper space of the cylinder 10. An injector 13 that injects fuel into the upper space, an intake valve 14 that is provided in the upper part of the cylinder 10 and sucks intake air from the intake pipe 2 into the cylinder 10 by opening the intake port, and an upper part of the cylinder 10. An exhaust valve 15 is provided that exhausts exhaust gas in the cylinder 10 to the exhaust pipe 4 by opening the exhaust port.

As shown in FIG. 2, the electric supercharger 7 includes an electric motor 19, a supercharger 20 provided adjacent to the electric motor 19 for supercharging the air in the intake pipe 22, and a battery 24 through a wiring 26. An inverter 40 that drives and controls the motor by converting supplied power obtained from the connected battery 24 to driving power of the electric motor 19 and an aluminum heat dissipation block 27 bonded to the inverter 40 and the supercharger 20 with a bond. I have.
The supercharger 20 includes a housing 23 in which the heat dissipation block 27 is in surface contact, and a compressor impeller 22 that is attached to the tip of the shaft 21 of the electric motor 19 and rotates in the housing 23 to compress the air in the intake pipe 22. ing.
The turbocharger 8 includes an exhaust turbine 28 provided in the exhaust pipe 4, and a compressor impeller 30 provided in the intake pipe 2 connected to the exhaust turbine 28 via a shaft 29.
The turbocharger 20 and the turbocharger 8 compress the air in the intake pipe 2 and send it into the cylinder 10 by the rotation of the compressor impeller 22 and the compressor impeller 30 to achieve not only high output but also low fuel consumption. .

A bypass pipe 31 that bypasses the compressor impeller 22 is juxtaposed with the intake pipe portion 2 </ b> A that is a portion between the upstream side and the downstream side of the compressor impeller 22 in the intake pipe 2.
The bypass pipe 31 is provided with an air flow rate adjustment valve 32 that adjusts the flow rate of the intake air passing through the bypass pipe 31. As the air flow rate adjusting valve 32, for example, an electrically driven electromagnetic valve is used.

The opening and closing of the air flow rate adjustment valve 32 is adjusted in response to a signal from the adjustment valve control means 41.
The detected temperature from the inverter temperature detecting means (not shown) for detecting the temperature of the semiconductor chip (not shown) constituting the inverter 40 is transmitted to the regulating valve control means 41.
The regulating valve control means 41 is detected by the inverter temperature detection means when the electric supercharger 7 is being driven, that is, the electric motor 19 is being driven, and the intake air is flowing through the bypass pipe 31 together with the intake pipe portion 2A. When the temperature is higher than the proper use temperature of the inverter 40, the air flow rate adjustment valve 32 is controlled to be fully closed.
Further, the regulating valve control means 41 is an output from an engine output detection means (not shown) that detects the output of the engine when the drive of the electric supercharger 7 is stopped, that is, the drive of the electric motor 19 is stopped. When the value is equal to or higher than a predetermined value and the temperature from the inverter temperature detection means is higher than the proper use temperature of the inverter, the air flow rate adjustment valve 32 is controlled to be partially closed.
Further, the regulating valve control means 41 controls the air flow regulating valve 32 to be fully closed for a predetermined time after the supply power to the electric motor 19 is stopped.
This predetermined time is determined based on the temperature detected by the intake air temperature detecting means (not shown) for detecting the temperature of the intake air and the inverter temperature detecting means.
Further, the regulating valve control means 41 performs control so that when the air flow rate regulating valve 32 is opened, it is gradually opened compared to when the air flow regulating valve 32 is closed.
The adjusting valve control means 41 is provided inside the control device 25 fixed to the heat dissipation block 27 and the electric motor 19 together with the inverter 40, but may be provided separately from the inverter 40.

Next, the electric motor 19 that is driven by the inverter 40 and compensates for the supercharging pressure and the mechanism inertia of the compressor impeller 22 will be described.
The inverter 40 of the electric supercharger 7 drives and controls the electric motor 19 based on command values such as the rotation speed of the crank 16, the position of the throttle valve 3, the intake pressure, the intake air amount.
Here, the position of the throttle valve 3 reflects the driver's accelerator operation. For example, in a vehicle without an electronic stall, the accelerator opening is substituted.
Regarding the suction pressure, for example, a pressure sensor or the like can be provided in the intake pipe 2 downstream of the throttle valve 3 to obtain the suction pressure.
The amount of intake air can be detected, for example, by providing an air flow sensor or the like downstream of the air cleaner 33 in the intake pipe 2.
The inverter 40 converts supply power obtained from the battery 24 through the wiring 26 into drive power for the electric motor 19 to drive the electric motor 19.
At this time, the electric power required for the electric motor 19 is large (for example, in the case of the battery 24 of 14V, it is 200 A or more).
The heat generated by the inverter 40 is transmitted to the compressor impeller 22 through the heat dissipating block 27 in surface contact with the inverter 40 and the housing 23 in surface contact with the heat dissipating block 27, and the heat transmitted to the compressor impeller 22 is transferred into the intake pipe 2. Is taken away by the intake air passing through.

  The heat dissipation block 27 is provided to release heat generated in the inverter 40 by using intake air, and is a block for radiating heat of the inverter 40 generated transiently, for example.

  When the electric motor 19 is not driven, the compressor impeller 22 connected to the electric motor 19 serves as an intake resistance for intake air, but the engine output is equal to or higher than a predetermined value, and the temperature of the inverter 40 is equal to or lower than the predetermined value. In this case, the air flow rate adjustment valve 32 is fully open, and the intake air flows through the bypass pipe 31 that bypasses the compressor impeller 22.

In the engine configured as described above, when the electric supercharger 7 is being driven, the intake air flowing through the intake pipe 2 first flows into the intake pipe section 2A after dust or dust is removed by the air cleaner 33. To do.
The intake air that has flowed into the intake pipe portion 2A passes through the intercooler 6 via the compressor impeller 22 of the supercharger 20 and the compressor impeller 30 of the turbocharger 8. In the intercooler 6, the intake air whose temperature has increased with the pressure increase due to supercharging in the compressor impeller 22 and the compressor impeller 30 is cooled, and the air filling efficiency in the cylinder 10 is improved.
Thereafter, the intake air passes through the throttle valve 3 and is then sucked into the cylinder 10 through the intake valve 14 which is opened.

Further, fuel is injected from the injector 13 into the upper space of the cylinder 10, and the air-fuel mixture in which fuel and air are mixed is compressed by the upward movement of the piston 11.
The compressed air-fuel mixture is ignited and burned by spark discharge of the spark plug 12. The combusted air-fuel mixture is exhausted from the exhaust port of the opened exhaust valve 15 to the exhaust pipe 4 as exhaust gas.
When the exhaust gas passes through the exhaust pipe 4, the exhaust gas is purified by the exhaust gas purification device 5 after driving the exhaust turbine 28 linked to the compressor impeller 30 that supercharges intake air.

Next, operation | movement of the electric supercharger 7 is demonstrated based on the flowchart of FIG.
First, the control device 25 of the electric supercharger 7 reads and stores the inverter temperature detected by the inverter temperature detecting means in a memory (not shown) of the microcomputer (step S101).
Next, it is determined whether or not the electric supercharger 7 is being driven (step S102). Whether or not the electric supercharger 7 is driven at this time may be determined from, for example, an electric supercharge request signal from an engine computer (not shown) or the rotational speed of the shaft 21 of the electric motor 19. In addition, any signal that can determine that the electric supercharger 7 is in the driving state, such as an air pressure downstream of the compressor impeller 22, may be used.
When it is determined in step S102 that the electric supercharger 7 is being driven, the air flow rate adjustment valve 32 controls the passage of the bypass pipe 31 so that air does not flow through the bypass pipe 31 (step). S105).
On the other hand, if it is determined in step S102 that the electric supercharger 7 is not being driven, it is next determined whether the engine output is equal to or less than a predetermined value (step S103).
If it is determined in step S103 that the engine output is smaller than the predetermined value, the intake air amount is small, and even if the compressor impeller 22 becomes the intake resistance of the engine, the output does not decrease so much. Controls the bypass pipe 31 so that the intake air does not flow through the bypass pipe 31 (step S105).
The engine output is obtained by referring to a map determined from the rotation speed of the crank 16, the intake air amount, the fuel injection amount, and the like.

  If it is determined in step S103 that the engine output is greater than the predetermined value, the intake air amount is also large, and the compressor impeller 22 of the electric supercharger 7 may become the engine intake resistance and reduce the output.

In this case, the control device 25 determines whether or not the temperature of the inverter 40 is equal to or higher than a predetermined value (step S104).
When the temperature of the inverter 40 is lower than the predetermined value in step S104, the air flow adjusting valve 32 is fully opened and sucked into the bypass pipe 31 in order to prevent the compressor impeller 22 from becoming the intake resistance and the engine output from decreasing. Control is performed so that air flows (step S107).
On the other hand, when the temperature of the inverter 40 is equal to or higher than the proper use temperature, the semiconductor element and the capacitor serving as the heat source of the inverter 40 may be destroyed or the life may be shortened. The valve 32 is rotated by a predetermined amount, and control is performed so that the intake air flows also to the intake pipe portion 2A where the compressor impeller 22 is disposed together with the bypass pipe 31 (step S106).

  If it is determined in step S102 that the electric supercharger 7 is being driven, the air flow rate adjustment valve 32 controls the passage of the bypass pipe 31 so that air does not flow through the bypass pipe 31 (step S105). ).

Note that step S105 in FIG. 3 is an example when it is determined that the electric supercharger 7 is being driven.
While the electric supercharger 7 is being driven, the regulating valve control means 41 can perform optimum supercharging based on the detection result of the engine operating state from the engine operating state detecting means (not shown). Thus, the air flow rate adjustment valve 32 is controlled to rotate by a predetermined amount, and the intake air may flow through the bypass pipe 31 together with the intake pipe portion 2A.
In this case, the regulating valve control means 41 fully closes the air flow rate regulating valve 32 when the temperature detected by the inverter temperature detecting means is higher than the proper use temperature of the inverter 40.

  As described above, according to the engine of the first embodiment, the heat dissipation block 27 is also provided between the housing 23 of the supercharger 20 and the inverter 40, and the heat from the inverter 40 causes the heat dissipation block 27 and the housing 23 to move. Therefore, the inverter 40 is conducted to the compressor impeller 22 exposed to the intake air, so that the inverter 40 is efficiently cooled with a simple structure and without increasing its size.

Further, the inverter 40 is provided with inverter temperature detecting means for detecting the temperature of the inverter 40, and the regulating valve control means 41 is configured so that the electric motor 19 is being driven and the temperature of the inverter 40 from the inverter temperature detecting means is When the temperature is higher than the proper use temperature of 40, the air flow rate adjustment valve 32 is fully closed, so that the intake air flows 100% through the compressor impeller 22.
Therefore, the heat from the inverter 40 that is thermally conducted to the compressor impeller 22 is released to the intake air, and thermal damage to the inverter 40 can be suppressed.

The regulating valve control means 41 controls the air flow regulating valve 32 to be fully closed for a predetermined time after the supply power to the electric motor 19 is stopped, so that the intake air remains after the supply power to the electric motor 19 is stopped. The compressor impeller 22 is distributed 100%.
Therefore, the stored heat of the heat dissipation block 27 is released to the intake air and the heat dissipation block 27 is cooled, so that a temperature difference between the heat dissipation block 27 and the inverter 40 is secured, and the heat from the inverter 40 is transferred to the heat dissipation block 27. Conducted efficiently.

Further, the regulating valve control means 41 performs control so that when the air flow rate regulating valve 32 is opened, it is gradually opened compared to when the air flow regulating valve 32 is closed.
Therefore, when the air flow rate adjustment valve 32 is opened, the supercharged intake air is suddenly opened, and it is possible to prevent the flow of discontinuous intake air with backflow, and the engine can be driven smoothly.
Before the air flow control valve 32 is closed, the inside of the bypass pipe 31 is under atmospheric pressure, and even when the air flow control valve 32 is suddenly closed, the influence on the flow of the intake air is small.

In addition, an engine output detecting means for detecting the output of the engine is provided, and the regulating valve control means 41 is configured such that the output of the engine is not less than a predetermined value and the temperature from the inverter temperature detecting means when the drive of the motor 19 is stopped When the temperature is higher than the proper use temperature of the inverter 40, the flow rate adjustment valve 32 is controlled so as to be partially closed, and the intake air flows in the intake pipe portion 2A and the bypass pipe 31 in parallel. .
Therefore, even when the drive of the electric motor 19 is stopped, when the inverter 40 is higher than the proper use temperature, the compressor impeller 22 becomes the intake resistance and the engine output is slightly reduced. The air is discharged into the intake air through the compressor impeller 22, and the thermal damage of the inverter 40 is suppressed.

In the engine of the first embodiment, the temperature of the inverter 40 is detected by the inverter temperature detecting means. However, the means for knowing the temperature of the inverter 40 is not limited to this.
For example, the electric motor 19 may be provided with driving force detection means for detecting the driving force of the electric motor 19, and the temperature of the inverter 40 may be estimated from the value obtained from the driving force detection means.
In this case, the regulating valve control means 41 controls the air flow regulating valve 32 to be fully closed when the temperature indirectly provided from the driving force detection means is higher than the proper use temperature of the inverter 40. To do.

In addition, the electric motor 19 may be provided with supply power detection means for detecting the supply power to the electric motor 19, and the temperature of the inverter 40 may be estimated from the value obtained from the supply power detection means.
In this case, the regulating valve control means 41 controls the air flow regulating valve 32 to be fully closed when the temperature indirectly obtained from the supplied power detection means is higher than the proper use temperature of the inverter 40. To do.

In addition, an intake air temperature detecting means for detecting the temperature of the intake air is provided, and the adjustment valve control means 41 detects the intake air temperature for a predetermined time for fully closing the air flow rate adjustment valve 32 after stopping the power supplied to the electric motor 19. The temperature may be determined based on the temperature detected by the means and the temperature of the inverter from the inverter temperature detecting means or the supplied power detecting means.
In order to determine the predetermined time for fully closing the air flow rate adjustment valve 32, the time required for cooling the heat dissipation block 27 to the predetermined temperature can be grasped more accurately by taking the temperature of the intake air into consideration. be able to.

Further, the engine according to the present invention can be applied not only to a direct engine that injects fuel into the cylinder 10 but also to a port injection engine that injects fuel into the intake pipe 2 after the throttle valve 3. It is.
Further, the heat dissipation block 27 is not limited to the arrangement shown in FIG. 2 and may be connected to the inverter 40 and the housing 23.
The heat dissipation block may be integrated with the inverter or the housing from the beginning.

  1 Engine, 2 Intake piping, 2A Intake piping, 3 Throttle valve, 4 Exhaust piping, 5 Exhaust purification device, 6 Intercooler, 7 Electric supercharger, 8 Turbocharger, 10 Cylinder, 11 Piston, 12 Spark plug, 13 Injector, 14 Suction valve, 15 Exhaust valve, 16 Crank, 19 Electric motor, 20 Supercharger, 21 Shaft, 22 Compressor impeller, 23 Housing, 24 Battery, 25 Control device, 26 Wiring, 27 Heat radiation block, 28 Exhaust turbine, 29 Shaft, 30 Compressor impeller, 31 Bypass piping, 32 Air flow adjustment valve, 33 Air cleaner, 40 Inverter, 41 Adjustment valve control means.

Claims (8)

An intake pipe through which intake air flows;
A compressor impeller disposed in the intake pipe, and a supercharger having a housing surrounding the compressor impeller;
An electric motor that drives the supercharger;
A bypass pipe bypassing the compressor impeller, arranged in parallel in the intake pipe section between the upstream side and the downstream side of the compressor impeller of the intake pipe;
An air flow rate adjustment valve that adjusts the flow rate of the intake air that is provided in the bypass pipe and flows through the bypass pipe;
An inverter for driving and controlling the electric motor;
Adjusting valve control means for controlling the operation of the air flow rate adjusting valve;
A heat dissipation block connected to the housing and the inverter;
An engine characterized in that heat from the inverter is conducted to the compressor impeller through the heat dissipation block and the housing. The electric motor is provided with driving force detection means for detecting the driving force of the electric motor,
The temperature of the inverter is estimated from the value obtained from the driving force detection means,
The control valve control means controls the air flow rate control valve to be fully closed when the temperature from the driving force detection means is higher than a proper use temperature of the inverter. The engine according to 1. The inverter is provided with inverter temperature detection means for detecting the temperature of the inverter,
The regulating valve control means is configured to fully close the air flow regulating valve when the electric motor is being driven and the temperature from the inverter temperature detecting means is higher than the proper use temperature of the inverter. The engine according to claim 1, wherein the engine is controlled. The electric motor is provided with supply power detection means for detecting electric power supplied to the electric motor,
The temperature of the inverter is estimated from the value obtained from the supply power detection means,
The control valve control means controls the air flow rate control valve to be fully closed when the temperature from the supply power detection means is higher than a proper use temperature of the inverter. The engine according to 1.   The said adjustment valve control means controls the said air flow rate adjustment valve to fully close for a predetermined time after stopping the electric power supplied to the said motor, and cools the said thermal radiation block, It is characterized by the above-mentioned. The engine according to any one of the above. The regulating valve control means controls the air flow regulating valve to be fully closed for a predetermined time after stopping the power supplied to the electric motor, and cools the heat dissipation block,
And an intake air temperature detecting means for detecting the temperature of the intake air,
4. The predetermined time is determined based on a temperature detected by the intake air temperature detecting means and a temperature of the inverter from the inverter temperature detecting means or the supplied power detecting means. Or the engine of 4.   The engine according to any one of claims 1 to 6, wherein the adjustment valve control means controls the air flow rate adjustment valve so that the air flow rate adjustment valve is gradually opened as compared to when the air flow rate adjustment valve is closed. . Engine output detecting means for detecting the output of the engine;
In the case where the electric motor is stopped, the output of the engine is equal to or higher than a predetermined value, and the temperature from the inverter temperature detecting means is higher than the proper use temperature of the inverter. 4. The engine according to claim 3, wherein the flow rate adjustment valve is controlled so as to be partially closed, and the intake air flows through the intake pipe portion and the bypass pipe in parallel.

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