JP5261139B2 - Inverter-integrated electric compressor - Google Patents

Description

  The present invention relates to an inverter-integrated electric compressor in which a motor drive circuit including an inverter is assembled in a compressor, and in particular, improvement in workability when an electronic component that is vulnerable to thermal stress such as IPM is assembled in a motor drive circuit. The present invention relates to an inverter-integrated electric compressor.

  As a structure of an inverter-integrated electric compressor in which a motor drive circuit including an inverter is assembled in a compressor, the motor drive circuit is covered with an insulating resin coating material, and further, the motor drive circuit, lead wires, and connection terminals There is known a structure in which the two are disposed in a closed space surrounded by metal walls (for example, Patent Document 1). In the motor drive circuit of this compressor, electronic components that are vulnerable to heat, such as an IPM (Intelligent Power Module) having an inverter function, are used.

In addition, there is known a bonded structure in which members constituting an electric circuit are bonded to each other, and a bonded portion having a plurality of bonded portions (for example, Patent Document 2). In such a bonded structure, the bonding strength of the bonded portion is ensured by providing a plurality of bonded portions in the bonded portion.
JP 2008-202564 A JP 2004-185953 A

  In the inverter-integrated electric compressor described in Patent Document 1, a terminal such as a bus bar can be used at an electrical connection location. In such a case, as a method for connecting the terminals, a method using bolt or screw connection or a method using welding is conceivable. However, if there is a restriction on a space where components are mounted, welding must be performed. There is a case.

  However, since the inverter-integrated electric compressor has a larger current flow than a general compressor, if the contact resistance of the joint is relatively high during compressor operation, the heat generated from the joint is transferred to various devices. May cause adverse effects. In addition, when a compressor is used in a vehicle air conditioner and is mounted on a vehicle engine, it is necessary to ensure a bonding strength and a bonding reliability that can withstand a severe high temperature environment such as vibration and an engine room. Is required.

  Accordingly, an object of the present invention is to provide an inverter-integrated electric compressor that is excellent in the bonding strength and bonding reliability of an electrical connection portion, paying attention to the above problems.

In order to solve the above problems, an inverter-integrated electric compressor according to the present invention is for a vehicle air conditioner in which a motor is incorporated and a motor drive circuit including the inverter is provided in a housing space surrounded by a compressor housing . In the inverter-integrated electric compressor composed of a compressor, a bus bar joint portion electrically connected by joining the bus bars is provided in the motor drive circuit, and at least one end of the bus bar at the bus bar joint portion The portion is divided into a plurality of small pieces for joining , at least one of the bus bars is provided on the IPM, and at least one of the bus bars is connected to the substrate of the motor drive circuit .

  In the inverter-integrated electric compressor according to the present invention, at least one end of the bus bar in the bus bar joint portion where the bus bars are electrically connected is divided into a plurality of joining small pieces, thereby providing a plurality of locations. In this case, the bus bars can be joined to each other, so that joining strength and joining reliability are ensured. In addition, since the contact area can be increased, the contact resistance at the joint can be reduced. Furthermore, when a joining method that requires heating, such as welding, is employed, the method of dispersing the welding locations in a plurality of locations as in the present invention is more concentrated than concentrating the total welding area of those welding locations in one location. The energy applied during welding (voltage × current × welding time, etc.) can be kept small, and thermal stress on the electronic component can be reduced. Furthermore, since the welding locations are dispersed and each welding area is subdivided, it is possible to reduce the size of the welding machine and the clamping jig used during welding, so that the productivity of the compressor can be improved.

  In the present invention, a plurality of small pieces for joining may be provided at both ends of the bus bar. Thus, by providing the same small piece for joining at the front-end | tip part of both bus bars, relative positioning of bus bars becomes easy. In addition, in the inverter-integrated electric compressor of the present invention, the bus bars can be joined to each other by TIG welding. In such a case, a plurality of small pieces for joining are provided at the front ends of both bus bars. Then, it becomes easy to accurately fly the arc at the time of TIG welding to each joining piece, and the connection reliability of the welding location is ensured.

Further, the substrate of the motor drive circuit, so often sensitive electronic components to the heat stress is a number connected by at least one bus bar is connected to the substrate of the motor drive circuit, reduce the thermal load Can be achieved effectively. Further, the same applies to the sensitive IPM heat stress, at least one of the busbars by being provided on IPM, it can be effectively achieved to reduce the thermal load. Furthermore, it is preferable that at least one of the bus bars is erected from a substrate of the motor drive circuit. As described above, since the bus bar is erected from the substrate, relative positioning with respect to the bus bar provided on the case member or the like in which the motor drive circuit is accommodated is facilitated.

The inverter-integrated electric compressor according to the present invention, be mounted in a narrow space many electronic components is used as a sensitive vehicle air-conditioner compressor heat stress. In addition, when the compressor is mounted on a vehicle engine, the joint can have joint strength and joint reliability that can withstand vibrations transmitted from the engine and the severe high temperature environment of the engine room. It is.

  According to the inverter-integrated electric compressor according to the present invention, at least one tip portion is divided into a plurality of joining small pieces at the joining portion between the bus bars, thereby improving the joining strength and joining reliability. be able to. Moreover, since the contact area of a junction part can be earned, the heat_generation | fever when a large current flows into a junction part at the time of a compressor driving | operation is suppressed by reducing contact resistance. Furthermore, since both the front ends of the bus bar are divided into a plurality of joining pieces, the relative positioning of the bus bars is facilitated, and the productivity of the compressor is improved.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows an example of a scroll-type electric compressor for a vehicle air conditioner as a basic configuration of an inverter-integrated electric compressor 1 according to an embodiment of the present invention. In FIG. 1, reference numeral 2 denotes a compression mechanism composed of a fixed scroll 3 and a movable scroll 4. The movable scroll 4 is turned with respect to the fixed scroll 3 in a state in which the rotation is prevented via the ball coupling 5. A motor 7 is incorporated in the compressor housing (center housing) 6, and the main shaft 8 (rotary shaft) is rotationally driven by the built-in motor 7. The rotational motion of the main shaft 8 is converted into the turning motion of the movable scroll 4 via the eccentric pin 9 disposed on one end side of the main shaft 8 and the eccentric bush 10 rotatably engaged with the eccentric pin 9. ing. In this embodiment, a suction port 11 for sucking refrigerant as a fluid to be compressed is provided in the compressor housing (front housing) 12, and the sucked refrigerant is guided to the compression mechanism 2 through the motor 7 arrangement portion. The refrigerant compressed by the compression mechanism 2 is sent to the external circuit through the discharge port 13, the discharge chamber 14, and the discharge port 16 provided in the compressor housing (rear housing) 15.

  The driving circuit 21 for the motor 7 is provided in the compressor housing 12 (front housing), and more specifically, on the outer surface side of the partition wall 22 with the refrigerant suction path side formed in the compressor housing 12. A motor drive circuit 21 is provided. The motor drive circuit 21 supplies power to the motor 7 via a sealed terminal 23 (an output terminal of the motor drive circuit 21) attached through the partition wall 22 and a lead wire 24. The path side and the motor drive circuit 21 installation side are sealed. By providing the motor drive circuit 21 on the outer surface side of the partition wall 22, at least a part of the electrical components including the motor drive circuit 21 can exchange heat with the suction refrigerant via the partition wall 22. The cooling is possible.

  The motor drive circuit 21 includes an IPM (Intelligent Power Module) 25 having an inverter function and a control circuit 26, and an electrical component such as a capacitor 27 is provided separately or integrally therewith. The motor drive circuit 21 is connected to an external power source (not shown) via a connector 28 as an input terminal. The opening side to the outside of the compressor housing 12 on which the electric parts including the motor drive circuit 21 are mounted is covered in a state of being sealed with a lid member 29, and these electric parts are protected by the lid member 29. .

  An example of the configuration as described above is shown in FIG. In FIG. 2, the electric compressor 1 is provided with a motor drive circuit 21, and an output from the motor drive circuit 21 is fed to each motor winding 41 of the built-in motor 7 via a sealing terminal 23 and a lead wire 24. As a result, the motor 7 is rotationally driven, and the compression mechanism 2 performs compression. The motor drive circuit 21 includes a motor drive high voltage circuit 30 and a control low circuit provided with a motor control circuit 44 for controlling each power element 43 (switching element) of the inverter 42 in the motor drive high voltage circuit 30. A voltage circuit 45 is included, and the control low voltage circuit 45 is configured in the control circuit 26. Electric power from an external power supply 46 (for example, a battery) is supplied to the motor driving high voltage circuit 30 through the high voltage connector 47 and supplied to the inverter 42 via the noise filter 37 and the smoothing capacitor 27. Then, the direct current from the power source 46 is converted into a pseudo three-phase alternating current and then supplied to the motor 7. For example, low voltage power is supplied to the motor control circuit 44 via a control signal connector 49 from an air conditioning control device 48 of the vehicle. In FIG. 2, the control signal connector 49 and the high voltage connector 47 are illustrated at positions apart from each other, but actually they are provided in the same connector 28 shown in FIG. 1. A shield plate 31 is fixed to the control circuit 26, and the shield plate 31 is interposed between the motor driving high voltage circuit 30 and the control circuit 26 having the control low voltage circuit 45 as shown in FIG. Thus, the motor driving high voltage circuit 30 is covered as much as possible to suppress the influence of noise from the motor driving high voltage circuit 30 to the control low voltage circuit 45 side.

  FIG. 3 is a perspective view showing a state in which electronic parts such as the IPM 25 are connected to the case member 58 that houses the motor drive circuit 21 of the compressor of FIG. The bus bar 60 as an electrical connection terminal provided on the end surface of the case member 58 is electrically connected to the bus bar 70 provided in the IPM 25 by TIG welding. Further, a part attachment hole 59 is formed by partly drilling the case member 58 along the bus bar 80. A coil component (not shown) for noise removal of the motor drive circuit 21 is inserted into the component mounting hole 59, and is electrically connected to the bus bar 90 provided in the coil component by TIG welding. The bus bars 80 and 90 are welded at joining small pieces 81 and 91 each having a tip portion divided into three parts. Other examples of various electronic components inserted into the component mounting holes 59 include the capacitor 27 and the substrate of the motor drive circuit 21.

  FIG. 4 is a partially enlarged perspective view in which the joint portion of the bus bars 60 and 70 in FIG. 3 is enlarged. In order to make the drawing easier to see, the case member 58 and the IPM 25 of FIG. 3 are not shown. The bus bars 60 and 70 are welded at joining small pieces 61 and 71 in which the front ends of the bus bar 60 and the bus bar 70 are respectively divided into two. In this way, the front end of the bus bar is divided into a plurality of small pieces for joining, so that the arc can be surely blown to the welding location during TIG welding, and high joining strength and joining reliability, and Low contact resistance is realized.

  The inverter-integrated electric compressor according to the present invention can be applied to virtually any type of compressor, but is particularly suitable for use as a compressor for a vehicle air conditioner that is mounted in a narrow space and is susceptible to thermal stress. be able to.

It is a schematic longitudinal cross-sectional view which shows the basic composition of the inverter integrated electric compressor which concerns on one embodiment of this invention. It is the block diagram which showed the air-conditioning control mechanism containing the compressor of FIG. It is a perspective view which shows the connection state of the case member which accommodates the motor drive circuit 21 of FIG. 1, and IPM25 grade | etc., Of FIG. It is the elements on larger scale which expanded the junction part of busbars 60 and 70 of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inverter integrated electric compressor 2 Compression mechanism 3 Fixed scroll 4 Movable scroll 5 Ball coupling 6 Compressor housing (center housing)
7 Motor 8 Main shaft 9 Eccentric pin 10 Eccentric bush 11 Suction port 12 Compressor housing (front housing)
13 Discharge hole 14 Discharge chamber 15 Compressor housing (rear housing)
16 Discharge port 21 Motor drive circuit 22 Partition wall 23 Sealed terminal 24 Lead wire 25 IPM
26 Control circuit 27 Capacitor 28 Connector 29 Lid member 30 Motor drive high voltage circuit 31 Shield plate 37 Noise filter 41 Motor winding 42 Inverter 43 Power element 44 Motor control circuit 45 Control low voltage circuit 46 External power supply 47 High voltage connector 48 Air-conditioning control device 49 Control signal connector 58 Case member 59 Component mounting hole 60, 70, 80, 90 Bus bar 61, 71, 81, 91 Small piece for joining

Claims (5)

In an inverter-integrated electric compressor comprising a compressor for a vehicle air conditioner provided in a housing space in which a motor is incorporated and a motor drive circuit including an inverter is surrounded by a compressor housing, a bus bar is provided in the motor drive circuit. A bus bar joint portion electrically connected by joining each other is provided, and at least one tip end portion of the bus bar in the bus bar joint portion is divided into a plurality of joining small pieces , and at least one of the bus bars is an IPM. An inverter-integrated electric compressor, wherein the inverter-integrated electric compressor is provided on at least one of the bus bars and connected to a substrate of a motor drive circuit .   The inverter-integrated electric compressor according to claim 1, wherein a plurality of small pieces for joining are provided at both ends of the bus bar.   The inverter-integrated electric compressor according to claim 1 or 2, wherein at least one of the bus bars is erected from a substrate of the motor drive circuit. The inverter-integrated electric compressor according to any one of claims 1 to 3 , wherein the joining is performed by TIG welding. It is attached to the vehicle engine, an inverter-integrated electric compressor according to claim 1.

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