JP2010174680A - Supercharger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric supercharger having high durability with reduced noise and vibration. <P>SOLUTION: A cushioning material 70 is provided between a first casing 60A housing a compressor 20 and a motor 30 which are connected to an engine via an intake pipe 50 and a second casing 60B housing an inverter device 40, and absorbs relative displacement of the first casing 60A to which vibration of the engine side is transmitted and the second casing 60B to which vibration of the vehicle body side is transmitted. With this, stress concentration at the first casing 60A and the second casing 60B is less likely to occur even when the compressor 20 and the motor 30 (engine side) and the inverter device 40 (vehicle body side) vibrate in different modes. Further, even when electromagnetic vibration of the motor 30 is transmitted to the first casing 60A, the vibration is prevented from being transmitted to the second casing 60B. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electric supercharger applied to an engine of a vehicle such as an automobile.

2. Description of the Related Art Conventionally, superchargers that aim to increase the amount of air in a combustion chamber by increasing the pressure of the supply air sucked into the combustion chamber of an engine such as an automobile and increase the output per cycle have been known for a long time. ing. As one of such turbochargers, a so-called turbocharger that supercharges the engine by introducing exhaust gas discharged from the engine to a turbine and rotating it at high speed and driving a compressor that shares the rotating shaft with the turbine is driven. There is.
However, the operation of such a supercharger requires exhaust of the engine, and quick response cannot be performed at the time of starting or rapid acceleration. Further, when the exhaust pressure increases, the engine is affected, and the combustion of the engine deteriorates and the fuel consumption deteriorates.

  In view of this, an electric supercharger that includes an inverter that converts electric power supplied from a battery and supplies the electric motor to an electric motor, and that drives a compressor by the electric motor to supercharge engine air supply has been proposed (for example, Patent Documents). 1). This inverter is composed of a switching element such as an FET, converts a direct current sent from a battery into an alternating current, and adjusts the voltage and frequency to drive the electric motor.

  In addition, miniaturization of automobile equipment is always required. For this reason, as shown in FIG. 8, an electric supercharger in which a compressor 1, an electric motor 2 that drives the compressor 1, and an inverter 3 that operates the electric motor 2 are integrally housed in a casing 4 has been proposed. . In this electric supercharger, the DC voltage supplied from the battery 5 is converted into an AC voltage by a switching element such as an FET provided in the inverter 3, thereby operating the electric motor 2 and driving the compressor 1. An air inlet is formed in the casing 4. When the compressor 1 is driven, external air is sucked into the casing 4 from the air inlet and is compressed in the compressor 1. The compressed air is sent to the engine 6 of the vehicle via a discharge pipe connected to the compressor 1, thereby supercharging.

  By the way, the electric supercharger for automobile engines is used for the purpose of increasing the engine output and improving the transient response of the engine output. The compressor is rotated at high speed with an electric motor, and compressed air is sent to the engine. Since the rotor and compressor of the electric motor rotating at high speed are directly gearlessly connected, the number of rotations reaches tens of thousands to hundreds of thousands of rpm. On the other hand, the voltage supplied from the battery is relatively low, for example, 12V. As a result, a large current flows through the inverter, and the amount of heat generated in the inverter increases. In addition, since the electric motor also rotates at high speed, the amount of heat generated is large. It is necessary to have a good cooling function in order to suppress the temperature rise due to the loss of heat generated by the electric motor or inverter within the allowable value.

  Therefore, in the configuration as shown in FIG. 8, the motor 2 and the inverter 3 are cooled by the air sucked into the casing 4 by driving the compressor 1 (see, for example, Patent Document 2). ).

  In order to further improve the cooling performance, cooling fins may be formed in the housing of the electric motor 2 provided in the casing 4, or the switching elements of the inverter 3 may be provided on the surface of a plate-shaped heat sink having cooling fins. Conceivable.

JP 2006-258094 A Japanese Patent Laying-Open No. 2008-215075 (FIG. 6)

However, in the electric supercharger in which the compressor 1, the electric motor 2, and the inverter 3 are integrally incorporated in the casing 4, there are problems as shown below.
First, as described above, since the motor 2 operates at a high rotation speed of several tens of thousands to several tens of thousands rpm, the electromagnetic vibration generated by the interaction of the magnetic flux density in the gap between the stator and the rotor of the motor 2 is reduced. The impact is not negligible. This electromagnetic vibration mechanically vibrates the stator of the electric motor 2, which is transmitted to the casing 4. Since the casing 4 has a relatively thin surface and a large area compared to the electric motor 2 or the like, there is a problem that when the vibration is transmitted, the casing 4 is likely to vibrate and the noise is increased. Moreover, the noise is very high frequency sound.
In order to solve this noise, it is conceivable to increase the thickness of the casing 4 to increase the rigidity. However, this directly leads to an increase in size and weight of the electric supercharger, and is not a preferable problem solution.

  In order to increase the cooling efficiency of the electric motor 2 and the inverter 3, it is better that the heat transfer area of the electric motor 2 and the inverter 3 and the flow velocity of air in the casing 4 are large. For this purpose, it is conceivable to increase the number of cooling fins of the electric motor 2 and the heat sink of the heat sink of the inverter 3 to narrow the interval between the cooling fins. However, as a result, there is a problem that when the air flowing in the casing 4 passes through the cooling fins, the passing sound (wind noise) increases.

  Further, in the electric supercharger, the casing 4, the inverter 3 and the like are fixed to the vehicle body side, while the compressor 1 is connected to the vehicle engine 6 through a discharge pipe. As a result, vibrations in different modes may be input from the inverter 3 side and from the compressor 1 side, and stress is applied to a specific portion of the casing 4 and a connection portion of the compressor 1, the electric motor 2, and the inverter 3. It may concentrate, and it may impair the durability of the electric supercharger.

  The present invention has been made based on such a technical problem, and an object thereof is to provide an electric supercharger that reduces noise and vibration and has high durability.

The present invention based on such an object is an electric supercharger that is mounted on a vehicle and supplies compressed air to the engine of the vehicle, and compresses the air sucked from outside and discharges the compressed air. A supercharger main body, an electric motor that drives the supercharger main body, an inverter device that operates the electric motor by converting a DC voltage supplied from a DC power source mounted on the vehicle into an AC voltage, and supplying the electric motor; And a casing to which a turbocharger body, an electric motor, and an inverter device are integrally housed, and a feed pipe for feeding compressed air discharged from the turbocharger body to the engine is connected. And a casing accommodates a supercharger main body and an electric motor, and a feed pipe is connected, a first casing opened to the inverter device side, a second casing accommodated the inverter device and opened to the electric motor side A connecting member that is provided between the opening of the first casing and the opening of the second casing and connects the first casing and the second casing so as to be relatively displaceable. And
Since the supercharger main body is connected to the engine of the vehicle via a feed pipe, vibration may be transmitted from the engine side. Further, since the supercharger main body and the electric motor are integrally connected via the drive shaft of the electric motor, the supercharger main body and the electric motor are affected by the vibration on the engine side, while the inverter device is fixed on the vehicle body side. . As a result, the first casing containing the supercharger main body and the electric motor and the second casing containing the inverter device may vibrate in different modes. Therefore, the casing is divided into a first casing and a second casing, and a coupling member is interposed between the two casings to suppress vibrations from being transmitted between the first casing and the second casing. be able to.
Further, even when mechanical vibration is generated in the electric motor due to electromagnetic vibration, it is possible to suppress the vibration from being transmitted to the second casing via the first casing.
Such a connecting member is preferably formed from an elastic material such as a rubber-based material.

  In addition, by providing a cylindrical or box-shaped intake duct at the suction port, it is possible to suppress noise generated in the casing from leaking to the outside. In order to reduce noise, a sound absorbing material may be provided on the inner surface of the intake duct, or a sound absorbing material may be provided on the inner surface of the casing.

According to the present invention, the casing is divided into the first casing and the second casing, and the coupling member is interposed therebetween, whereby vibration is transmitted between the first casing and the second casing. Can be suppressed. Thereby, even if the 1st casing which accommodated the supercharger main body and the electric motor, and the 2nd casing which accommodated the inverter apparatus vibrate in a mutually different mode, the 1st casing and the 2nd casing are respectively Since it can vibrate independently, it is possible to prevent the casing from being adversely affected by stress concentration or the like. As a result, the durability of the supercharger can be increased.
In addition, even when mechanical vibration is generated in the electric motor due to electromagnetic vibration, it is possible to suppress the vibration from being transmitted to the second casing through the first casing, thereby reducing noise and vibration. it can.

  In addition, by providing a cylindrical or box-shaped intake duct at the suction port, or by providing a sound absorbing material on the inner surface of the intake duct or the inner surface of the casing, it is possible to suppress leakage of noise generated in the casing to the outside, The noise of the turbocharger can be suppressed.

It is sectional drawing of the electric supercharger in this Embodiment. It is sectional drawing which shows the example of the shape of a shock absorbing material. It is an expanded sectional view showing a shock absorbing material provided between the first casing and the second casing. It is sectional drawing which shows the example which provided the intake duct in the electric supercharger. It is sectional drawing which shows the modification of the electric supercharger of FIG. It is sectional drawing which shows the example which provided the sound-absorbing material in the casing. FIG. 5 is a cross-sectional view illustrating an example in which an intake duct having a configuration different from that in FIG. 4 is provided at the intake port. It is a figure which shows the basic composition of an electric supercharger.

Hereinafter, the present invention will be described in detail based on embodiments shown in the accompanying drawings.
FIG. 1 is a diagram for explaining a configuration of an electric supercharger 10 according to the present embodiment.
As shown in FIG. 1, the electric supercharger 10 includes a compressor (supercharger main body) 20 that compresses air, an electric motor 30 that drives the compressor 20, and an inverter device 40 that controls the operation of the electric motor 30. Prepare.

  In the compressor 20, a compressor wheel 22 is rotatably provided in a housing 21. The housing 21 is formed with an intake port for taking in air from the outside and a delivery port for sending out the air. When the compressor wheel 22 rotates in the housing 21, the outside air is sucked from the intake port, and the housing 21 and the compressor Air is compressed in a compression chamber formed between the wheel 22 and the compressed air is sent out from the delivery port. An intake pipe (feed pipe) 50 of the engine of the vehicle on which the electric supercharger 10 is mounted is connected to the delivery port of the housing 21, and the air compressed by the compressor 20 passes through the intake pipe 50 to the engine. Into the combustion chamber.

The electric motor 30 includes a stator 32 that is fixed to the housing 21 via a support member (not shown) and the like, and a rotor 33 that is rotatably supported by a bearing 38 inside the stator 32. As shown in FIG. 2, a plurality of cooling fins 34 that extend radially are integrally formed on the outer peripheral side of the stator 32.
The rotor 33 is connected to the compressor wheel 22 of the compressor 20 via the shaft 35, whereby the compressor wheel 22 rotates integrally with the rotor 33.

The inverter device 40 is an electric supercharger based on a command from an inverter main circuit unit 41 on which a switching element such as an FET (not shown) is mounted on a substrate and an electronic control unit of a vehicle on which the electric supercharger 10 is mounted. And an inverter control unit 42 that controls the operation of the machine 10. The inverter main circuit unit 41 and the stator 32 of the electric motor 30 are electrically connected by a coil cable 36.
The inverter main circuit unit 41 is supplied with a DC voltage such as 12 V from a battery of a vehicle on which the electric supercharger 10 is mounted via a cable or a bus bar, and is connected to a FET or the like based on the control of the inverter control unit 42. An AC voltage is applied to the stator 32 of the electric motor 30 by operating the switching element. As a result, the rotor 33 of the electric motor 30 is rotationally driven.
Here, in the inverter control unit 42, the rotational speed of the rotor 33, that is, the rotational speed of the compressor 20 is controlled by controlling the frequency of the AC voltage applied from the inverter main circuit unit 41 to the stator 32 of the electric motor 30. Is done.

The compressor 20 and the electric motor 30 are accommodated in a box-shaped first casing 60A, and the inverter device 40 is accommodated in a box-shaped second casing 60B.
The intake pipe 50 passes through the first casing 60A, and connects the outlet of the compressor 20 and the combustion chamber of the engine. Further, in the second casing 60B, a suction port 80 for introducing air into the inside thereof is formed on the side surface opposite to the first casing 60A.

  In the electric supercharger 10, a DC voltage supplied from a battery (not shown) of an automobile on which the electric supercharger 10 is mounted is converted into an AC voltage by a switching element such as an FET provided in the inverter device 40. Then, the electric motor 30 is operated and the compressor 20 is driven. By driving the compressor 20, external air is sucked into the first casing 60 </ b> A and the second casing 60 </ b> B from the suction port 80 and compressed by the compressor 20. The compressed air is sent to the intake port of the engine of the vehicle via an intake pipe 50 connected to the compressor 20, thereby supercharging.

The end 60x on the side facing the second casing 60B is opened in the first casing 60A, and the end 60y on the side facing the first casing 60A is opened in the second casing 60B. Between the end portion 60x of the first casing 60A and the end portion 60y of the second casing 60B, a cushioning material (connecting member) 70 is provided.
The cushioning material 70 is formed of an elastic material such as a rubber-based material, and houses the first casing 60A that houses the compressor 20 and the electric motor 30 that are connected to the engine via the intake pipe 50, and the inverter device 40. The second casing 60B is interposed between the first casing 60A and the second casing 60B to which vibration on the engine side is transmitted and the second casing 60B to which vibration on the vehicle body side is transmitted. Moreover, even if the electromagnetic vibration of the electric motor 30 is transmitted to the first casing 60A, the vibration is prevented from being transmitted to the second casing 60B.

In particular, from the function of absorbing the relative displacement between the first casing 60A and the second casing 60B, the cushioning material 70 is provided between the end 60x of the first casing 60A and the end 60y of the second casing 60B. For example, as shown in FIG. 3, the cushioning material 70 is formed in a cylindrical shape having a certain length, and the outer peripheral edge of the end portion 60 x of the first casing 60 </ b> A and the second peripheral edge are formed on the inner peripheral surface thereof. Two step portions and grooves 71 and 71 corresponding to the outer peripheral edge portion of the end portion 60y of the casing 60B are formed, and the outer peripheral edge portion of the end portion 60x of the first casing 60A is formed in these step portions and grooves 71 and 71, respectively. And it is preferable to set it as the structure which fits the outer-periphery edge part of the edge part 60y of 2nd casing 60B. Accordingly, even if the first casing 60A and the second casing 60B are relatively displaced in the radial direction or the axial direction, the function can be sufficiently exhibited without the buffer material 70 falling off.
Furthermore, as shown in FIGS. 3A and 3B, the stepped portions and grooves 71 and 71, and the outer peripheral edge portion of the end portion 60x of the first casing 60A and the end portion 60y of the second casing 60B, Concavities and convexities 72 and 73 that fit together may be formed. Thereby, the buffer material 70 becomes further difficult to come off.

  Further, as shown in FIGS. 2A and 2B, the shape of the cushioning material 70 is an outer circular shape, a polygonal shape, or the like corresponding to the cross-sectional shapes of the first casing 60A and the second casing 60B. Can do.

According to such a configuration, the cushioning material is provided between the first casing 60A containing the compressor 20 and the electric motor 30 connected to the engine via the intake pipe 50 and the second casing 60B containing the inverter device 40. 70 is provided, the relative displacement between the first casing 60A to which the engine-side vibration is transmitted and the second casing 60B to which the vehicle-body side vibration is transmitted can be absorbed, whereby the compressor 20 and the electric motor can be absorbed. Even when the 30 side (engine side) and the inverter device 40 side (vehicle body side) vibrate in different modes, stress concentration hardly occurs in the first casing 60A and the second casing 60B, and the integrated electric supercharger 10 durability can be improved.
Moreover, even if the electromagnetic vibration of the electric motor 30 is transmitted to the first casing 60A, the vibration can be prevented from being transmitted to the second casing 60B. Thereby, it can prevent that the 2nd casing 60B vibrates due to electromagnetic vibration and generate | occur | produces noise, and noise and vibration can be reduced.

By the way, in the above configuration, it is preferable to use a combination of the following configurations.
That is, in the cooling fins 34 provided in the housing of the electric motor 30, the cooling fins of the inverter heat sink built in the inverter device 40, etc., when the interval is reduced in order to enhance the cooling effect, the first casing 60A, In order to suppress the passage sound (wind noise) of the air flowing through the second casing 60B, for example, as shown in FIG. 4, it is preferable to provide a cylindrical intake duct 90 at the suction port 80 of the second casing 60B. Furthermore, a sound absorbing material made of sponge, glass wool, fiber material, foam material, or the like may be provided on the inner peripheral surface of the intake duct 90.
Thereby, wind noise and the like leaking from the suction port 80 to the outside can be effectively suppressed.

  Further, as shown in FIG. 5, a hood 92 that curves or bends downward may be provided on the inlet side of the intake duct 90. Thereby, the noise emitted from the inlet of the intake duct 90 can be suppressed by the hood 92.

  As shown in FIG. 6, it is also effective to provide a sound absorbing material 93 such as sponge, glass wool, punching metal on the inner peripheral surfaces of the first casing 60A and the second casing 60B. Thereby, noise radiated through the first casing 60A and the second casing 60B, noise radiated by resonance of the first casing 60A and the second casing 60B, and the like can be reduced.

In addition, as shown in FIG. 7, instead of the intake duct 90, the intake duct 94 is arranged so as to be orthogonal to the intake direction into the second casing 60B at the intake port 80 and along the side surface 60z of the second casing 60B. It may be formed. Thus, noise emission can be suppressed by setting the intake duct 94 in a direction orthogonal to the intake direction into the second casing 60B at the intake port 80. Further, since the protruding portion can be made smaller than the intake duct 90 shown in FIG. 4, the electric supercharger 10 can be downsized.
Further, it is preferable to provide a sound absorbing material 95 on the side surface 60z of the second casing 60B along which the air intake duct 94 extends. By providing the sound absorbing material 95, the side surface 60z of the second casing 60B serves as a sound insulating wall, and thereby noise emission from the suction port 80 can be reduced.

  It should be noted that the configurations described in the above embodiments can be selected or changed to other configurations as appropriate without departing from the gist of the present invention.

  DESCRIPTION OF SYMBOLS 10 ... Electric supercharger, 20 ... Compressor (supercharger main body), 30 ... Electric motor, 32 ... Stator, 33 ... Rotor, 34 ... Cooling fin, 40 ... Inverter device, 50 ... Intake pipe (feed pipe) , 60A ... first casing, 60B ... second casing, 70 ... cushioning material (connection member), 80 ... suction port, 90, 94 ... intake duct, 93, 95 ... sound absorbing material.

Claims (6)

An electric supercharger that is mounted on a vehicle and supplies compressed air to the engine of the vehicle,
A turbocharger body that compresses air sucked from outside and discharges the compressed air;
An electric motor that drives the supercharger body;
An inverter device for operating the motor by converting a DC voltage supplied from a DC power source mounted on the vehicle into an AC voltage and supplying the AC voltage to the motor;
A casing to which the supercharger main body, the electric motor, and the inverter device are integrally housed, and a feed pipe for supplying the compressed air discharged from the supercharger main body to the engine is connected;
The casing is
A first casing which accommodates the supercharger main body and the electric motor and is connected to the feeding pipe and which is open to the inverter device side;
A second casing that houses the inverter device and is open to the motor;
A connecting member provided between the opening of the first casing and the opening of the second casing, and connecting the first casing and the second casing so as to be capable of relative displacement;
An electric supercharger comprising:   The electric supercharger according to claim 1, wherein the connecting member is made of an elastic material.   The connection member is for preventing electromagnetic vibration generated when the electric motor is operated from being transmitted to the second casing through the first casing. The electric supercharger as described in.   The electric supercharger according to any one of claims 1 to 3, wherein a cylindrical or box-shaped intake duct is provided in the suction port.   The electric supercharger according to claim 4, wherein a sound absorbing material is provided on an inner surface of the intake duct.   The electric supercharger according to any one of claims 1 to 5, wherein a sound absorbing material is provided on an inner surface of the casing.

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