Inverter-Integrated Electric Compressor

Abstract

Provided is an inverter-integrated electric compressor whose inverter section is molded using a urethane resin and which is excellent in joining reliability of electrically connected section. An inverter-integrated electric compressor, wherein the compressor incorporates a motor and wherein a motor drive circuit including the inverter is provided in a containing space surrounded by a compressor housing. A crimping section of a terminal of a conducting wire connected to the inverter is molded, together with the inverter, in a resin charged into the containing space. A gap at the crimping section, the gap being open to the outside, is previously covered and sealed by a gap sealant.

Description

TECHNICAL FIELD OF THE INVENTION

The present invention relates to an inverter-integrated electric compressor in which a motor drive circuit including an inverter is assembled, and specifically, relates to an inverter-integrated electric compressor in which the inverter portion is molded by urethane resin, etc.

BACKGROUND ART OF THE INVENTION

As a structure of an inverter-integrated electric compressor in which a motor drive circuit including an inverter is assembled, a structure is known wherein a motor drive circuit is coated by a resin mold material for insulation so as to be buried in the resin mold material (e.g. Patent document 1). A lead wire for inputting high voltage to the inverter portion in such a compressor, for example, is connected to the inverter portion by being connected by a screw to a circuit board for the inverter portion through a connector for high voltage (an HV connector) comprising a solderless terminal.

PRIOR ART DOCUMENTS

Patent Documents

• Patent document 1: JP-A-2002-70743

SUMMARY OF THE INVENTION

Problems to be Solved by the Invention

In an inverter-integrated electric compressor shown in Patent document 1, a space for housing a motor drive circuit is filled with a mold material such as urethane resin, etc. in order to protect parts constituting the inverter portion, etc. from heat and vibration. However, if the mold material flows in a gap around a conducting wire at a crimping section of the HV connector during the filling operation, because the mold material repeats expansion and contraction caused by a temperature variation of the HV connector accompanied with fluctuation of the operation condition of the compressor, there is a fear that a connection reliability of the crimping section of the HV connector may reduce.

Accordingly, an object of the present invention is to provide an inverter-integrated electric compressor in which an inverter portion is molded by urethane resin, etc. and which is excellent in joining reliability of electrically connected section.

Means for Solving the Problems

To achieve the above-described object, an inverter-integrated electric compressor according to the present invention has a built-in motor and is provided with a motor drive circuit including an inverter which is installed in a containing space surrounded by a compressor housing, and is characterized in that a crimping section of a terminal of a conducting wire connected to the inverter is molded, together with the inverter, in a resin charged into the containing space, and a gap open to the outside at the crimping section is previously covered and sealed by a gap sealant.

In the inverter-integrated electric compressor according to the present invention, because the crimping section is molded together with the inverter at a condition where a gap open to the outside at the crimping section of the terminal of the lead wire connected to the inverter is covered and sealed by a gap sealant, the mold material is prevented from flowing in an inner gap of the crimping section and therefore the joining reliability of the crimping section is secured. As the above-described gap sealant, it is preferred to use a material whose degree of an expansion or contraction caused by a temperature variation of an HV connector is small. By using such a material, it becomes possible to secure a sufficient connection reliability of the above-described crimping section.

Further, in order to cover and seal the inside of the above-described open gap efficiently by using the above-described gap sealant, as for the gap sealant, it is preferred to use a material which can exhibit a fluidized state temporarily by heating, etc. and can be solidified by cooling, etc. Concretely, a gap sealant consisting of solder can be preferably used. For example, by making a condition where a solder is fluidized temporarily by a heated soldering iron, and at that condition, by charging the solder into the open gap, and by solidifying the solder by natural or forcible cooling, the covering and sealing of the gap open to the outside at the crimping section can be performed efficiently.

Further, in the present invention, even though the inside of the open gap is covered and sealed, if a cross-sectional portion of a tip of the conducting wire is exposed, there is a fear that a mold material adhering to an irregularity part of the cross-sectional portion of the tip repeats expansion and contraction, whereby a stress may be applied to the tip of the conducting wire and the joining reliability of the crimping section may reduce. Therefore, it is preferred that the cross-sectional portion of the tip of the conducting wire is covered by the gap sealant so that the irregularity part of the cross-sectional portion of the tip of the conducting wire is smothered thereby.

The inverter-integrated electric compressor according to the present invention can be applied to substantially any types of compressors, and in particular, it can be suitably used as a compressor mounted on a vehicle, which is often installed in a narrow space and its motor drive circuit of which is liable to be affected by heat and vibration.

Effect According to the Invention

In the inverter-integrated electric compressor according to the present invention, because the containing space surrounded by the compressor housing is molded, together with the inverter, under a condition where the gap open to the outside at the crimping section of the terminal of the conducting wire connected to the inverter is previously covered and sealed by the gap sealant, the mold material is prevented from flowing into the crimping section of the terminal of the conducting wire connected to the inverter, and therefore it is possible to secure the connection stability and connection reliability of the crimping section.

BRIEF EXPLANATION OF THE DRAWINGS

FIG. 1 is a schematic vertical cross-sectional view showing a basic configuration of an inverter-integrated electric compressor according to an embodiment of the present invention.

FIG. 2 is a diagram of a configuration showing a control mechanism of air conditioning system including the compressor depicted in FIG. 1 from the viewpoint of electric circuit.

FIG. 3 is a perspective view showing a state where a motor drive circuit is installed in a containing space surrounded by a front housing depicted in FIG. 1.

FIG. 4 depicts a crimping section connecting an HV connector and a lead wire depicted in FIG. 3, where (A) is a perspective view showing an uncovered state of the section and (B) is a perspective view showing a covered state of the section.

EMBODIMENTS FOR CARRYING OUT THE INVENTION

Hereinafter, desirable embodiments of the present invention will be explained referring to figures.

FIG. 1 shows an example of a scroll type inverter-integrated electric compressor for automotive air conditioning system as a basic configuration of an inverter-integrated electric compressor 1 according to an embodiment of the present invention. In FIG. 1, symbol 2 shows a compression mechanism comprising a fixed scroll 3 and a movable scroll 4. Movable scroll 4 is moved orbitally relative to fixed scroll 3 at a condition where the rotation is prevented via ball coupling 5. Motor 7 is incorporated into compressor housing 6 (center housing), and main shaft 8 (rotation axis) is driven to be rotated by the built-in motor 7. Rotational movement of main shaft 8 is transformed to an orbital movement of movable scroll 4, through eccentric pin 9 provided at one end of main shaft 8 and eccentric bush 10 which is engaged rotatably with it. In this embodiment, suction port 11 sucking a refrigerant as a fluid to be compressed is provided in compressor housing 12 (front housing), and the sucked refrigerant is led to compression mechanism 2 through a section placed with motor 7, and the refrigerant which has been compressed by compression mechanism 2 is delivered to an external circuit through discharge hole 13, discharge chamber 14, and discharge port 16 which is provided in compressor housing 15 (rear housing).

Motor drive circuit 21 for motor 7 is provided in compressor housing 12 (front housing), and in more detail, motor drive circuit 21 is provided at the outer surface side of partition wall 22 which is formed in compressor housing 12 for separating from the side of the refrigerant suction route. Motor drive circuit 21 supplies electric power to motor 7 via sealed terminal 23 (output terminal of motor drive circuit 21) attached through partition wall 22, and lead wire 24, and the side of refrigerant suction route and the side of a section placing motor drive circuit 21 are sealed from each other at a section placing sealed terminal 23. By providing motor drive circuit 21 at the outer surface side of partition wall 22, at least a part of electric parts including motor drive circuit 21 can exchange heat through partition wall 22 with sucked refrigerant, so as to be cooled by the sucked refrigerant.

Motor drive circuit 21 includes IPM 25 (intelligent Power Module) having an inverter function and control circuit 26, and is provided with electric parts such as capacitor 27, etc. separately therefrom or integrally therewith. This motor drive circuit 21 is connected to an external power supply (not shown) through connector 28 as an input terminal. The side open to the outside of compressor housing 12, in which electric parts including motor drive circuit 21 are mounted, is covered by lid member 29 at a sealed condition, and these electric parts are protected by the lid member 29.

From the viewpoint of electric circuit, the above-described configuration can be depicted as shown in FIG. 2, for example. In FIG. 2, electric compressor 1 is provided with motor drive circuit 21, and by supplying an output of motor drive circuit 21 to respective motor coils 47 of built-in motor 7 through sealed terminal 23 and lead wire 24, motor 7 is rotationally driven, and compression by compression mechanism 2 is performed. Motor drive circuit 21 has high voltage circuit for driving motor 30, and low voltage circuit for control 45 which is provided with motor control circuit 44 for controlling respective power elements 43 (switching elements) of inverter 42 in high voltage circuit for driving motor 30, and this low voltage circuit for control 45 is configured in control circuit 26 shown in FIG. 1. Power from external power source 46 (for example, a battery) is supplied to high voltage circuit for driving motor 30 through high voltage connector 47 and is supplied to inverter 42 through noise filter 37 and capacitor for smoothing 27, and after the DC from power source 46 is converted to pseudo three-phase AC by inverter 42, the power is supplied to motor 7. Motor control circuit 44 is supplied with low voltage power, for example, from air conditioning control unit for vehicles 48 through connector for control signal 49. Although this connector for control signal 49 and connector for high voltage 47 are depicted in FIG. 2 at positions separate from each other, both of the connectors are actually installed inside the same connector 28 shown in FIG. 1. Shield plate 31 is fixed to control circuit 26 and, as shown in FIG. 2, this shield plate 31 is interposed between high voltage circuit for driving motors 30 and control circuit 26 provided with low voltage circuit for control 45, covering high voltage circuit for driving motor 30 over an area as broad as possible so as to suppress an influence of noise from the side of high voltage circuit for driving motor 30 to the side of low voltage circuit for control 45.

FIG. 3 is a perspective view showing motor drive circuit 21 being located in containing space 60 surrounded by compressor housing 12 (front housing). Case member 58 and IPM 25 are stored in containing space 60. Further, connector for high voltage 47 consisting of a solderless terminal is connected to the tip of lead wire 24 by being crimped. Connector for high voltage 47 is fixed by a screw to case member 58 and is connected electrically between capacitor 27 and noise filter 37 which are mounted on the back surface of case member 58.

FIG. 4 depicts a crimping section joining connector for high voltage 47 to lead wire 24 shown in FIG. 3, where (A) is a perspective view depicting a state where the crimping section is not covered, and (B) is a perspective view depicting a state where the crimping section is covered with solder. In FIG. 4 (A), connector for high voltage 47 is connected to lead wire 24 by being crimped. In crimping section 61, a plurality of conducting wires bundled by a cover of lead wire 24 forms a gap open to the outside 63, and if a mold material consisting of urethane resin, etc. enters into this open gap 63, the connection reliability of crimping section 61 will reduce. Therefore, as shown in FIG. 4 (B), by molding containing space 60 together with inverter 42 by flowing solder 64 as a gap sealant into open gap 63, and charging the mold material into containing space 60 shown in FIG. 3, the mold material can be prevented from flowing into crimping section 61. In particular, as shown in FIG. 4 (B), by covering the cross-sectional portion of the tip of conducting wire 62 with solder 64 completely, it is possible to secure the connection reliability of crimping section 61 sufficiently even when the mold material adheres to this portion.

INDUSTRIAL APPLICATIONS OF THE INVENTION

The inverter-integrated electric compressor according to the present invention can be applied substantially to all types of compressors, and is specifically suitable for a compressor mounted on a vehicle, which is often installed in a narrow space and is provided with a motor drive circuit that is liable to be affected by heat and vibration.

EXPLANATION 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: high voltage circuit for driving motor
• 31: shield plate
• 37: noise filter
• 41: motor coil
• 42: inverter
• 43: power element
• 44: motor control circuit
• 45: low voltage circuit for control
• 46: external power supply
• 47: connector for high voltage (HV connector)
• 48: air conditioning control unit
• 49: connector for control signal
• 58: case member
• 60: containing space
• 61: crimping section
• 62: conducting wire
• 63: open gap
• 64: solder as a gap sealant

Claims

1. An inverter-integrated electric compressor having a built-in motor and provided with a motor drive circuit including an inverter which is installed in a containing space surrounded by a compressor housing, wherein a crimping section of a terminal of a conducting wire connected to said inverter is molded, together with said inverter, in a resin charged into said containing space, and a gap open to the outside at said crimping section is previously covered and sealed by a gap sealant.

2. The inverter-integrated electric compressor according to claim 1, wherein a cross-sectional portion of a tip of said conducting wire is covered by said gap sealant.

3. The inverter-integrated electric compressor according to claim 1, wherein said gap sealant consists of a solder.

4. The inverter-integrated electric compressor according to claim 1, wherein said inverter-integrated electric compressor is a compressor mounted on a vehicle.