JP2007309125A - On-vehicle electric circuit unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an on-vehicle electric circuit unit superior in vibration resistance. <P>SOLUTION: This on-vehicle electric circuit unit has a circuit board, an electric element connected to an electric circuit, and a housing 1 composed of an upper case and a lower case and storing the circuit board 6 and the electric elements 4 and 5. At least a part of the upper case 11 is formed of metal, and the electric elements are fixed in a state of abutting on a part formed of metal of the upper case 11. The electric elements do not vibrate by fixing the electric elements to the upper case, and the vibration resistance is improved. By fixing the electric elements to a metallic part of he upper case, even if the electric elements generate heating, its heat is radiated by being transmitted to this metallic part. Such a constitution can improve the vibration resistance and cooling performance of the electric elements. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electric circuit unit mounted on a vehicle.

  In order to cool the vehicle at the time of idling stop, an electric compressor for vehicles provided with a motor for driving the compressor integrally with an air conditioning compressor has been proposed. In this type of vehicle electric compressor, a synchronous motor (brushless DC motor) is usually employed to finely control the motor speed in accordance with the air conditioning load.

  In order to drive this synchronous motor by a vehicle-mounted battery, an inverter circuit that converts DC power into three-phase AC power, a control circuit for switching control of this inverter circuit, and an inverter from a high-frequency current derived by switching of the inverter circuit There is a need for a complex and high-speed inverter unit that requires high-speed switching, including a smoothing capacitor that protects the switching elements of the circuit and large and small wirings that connect them.

  The three-phase AC wiring that connects this inverter circuit section and the electric compressor to which the three-phase PWM control power is fed from this inverter unit contains a large amount of switching noise, so it is preferable to shorten it as much as possible. Inverter-integrated electric compressors have been proposed in which are integrated with electric compressors.

  The electric compressor which fixed the inverter unit is disclosed by patent documents 1-2, for example.

  In Patent Document 1, a circuit cover is joined and fixed to the outside of a compressor housing in which a compression mechanism is housed, and an electric motor is driven in a housing space surrounded by the compressor housing and the circuit cover. An electric compressor that houses a motor drive circuit is disclosed. In this electric compressor, a circuit board on which a drive circuit is mounted is assembled to a lid member of a circuit cover, and the inverter unit is fixed by joining and fixing the lid member to the housing. As described above, in the electric compressor disclosed in Patent Document 1, consideration is given to the assembly of the inverter unit, but consideration is given to vibration isolation of a relatively large electric element such as a coil and a capacitor, and a power supply connector. It wasn't done.

In Patent Document 2, at least six power switching elements constituting each arm of the multiphase inverter circuit and a bus bar assembly integrally molded with resin and connected to the power switching elements are each housed in a metal base plate. An electric compressor is disclosed in which an inverter assembly that is fixed without being interposed is fixed to the electric compressor while the base plate is in close contact with the outer peripheral surface of the electric compressor housing by fastening only the base plate and the outer peripheral surface of the electric compressor housing. . The electric compressor of patent document 2 has assembled the inverter circuit part in the bus-bar module, and there existed a problem that cooling of the electric element which comprises an inverter circuit part became inadequate. Furthermore, gel (grease) is applied between the bus bar for cooling the electric elements. In such a configuration, it is necessary to remove the gel when removing the bus bar module, and workability is improved. Had fallen. Further, there is a problem that the cost increases because the number of parts increases.
JP 2004-251161 A JP 2004-190547 A

  This invention is made | formed in view of the said actual condition, and makes it a subject to provide the vehicle-mounted electric circuit unit excellent in vibration resistance.

  In order to solve the above-mentioned problems, the present inventors have made studies, and as a result, have come to make the present invention.

  An in-vehicle electric circuit unit according to the present invention includes a circuit board provided with an electric circuit, an electric element connected to the electric circuit, an upper case, and a lower case, and the circuit board and the electric element are accommodated therein. A vehicle-mounted electric circuit unit including a housing, wherein at least a part of the upper case is formed of metal, and the electric element is fixed in a state of being in contact with a part of the upper case formed of metal. It is characterized by that.

  Since the electric element is fixed to the upper case, the electric element does not vibrate, and the electric element does not vibrate even when the circuit unit vibrates during traveling of the vehicle, and thereby the electric element is detached from the circuit board. Is suppressed. That is, vibration resistance was improved. Further, since the electric element is fixed to the metal portion of the upper case, even if the electric element generates heat due to energization, the generated heat is transmitted to the metal portion and is radiated from the outer peripheral surface of the upper case. That is, the cooling performance of the electric element that generates heat particularly when energized is improved. By setting it as said structure, the electric circuit unit of this invention also improves vibration resistance and the cooling property of an electric element.

  The in-vehicle electric circuit unit according to claim 2 is the in-vehicle electric circuit unit according to claim 1, wherein the upper case is made of aluminum. Since the upper case is formed of aluminum, the entire upper case can be allowed to cool, and the cooling performance of the electric element is improved.

  The in-vehicle electric circuit unit according to claim 3 is the in-vehicle electric circuit unit according to claim 1, wherein the electric element is at least one selected from a coil and a capacitor. These electric elements are relatively large in size and can be erected from a circuit board. And the effect of Claim 1 can be exhibited especially by fixing these elements to an upper case.

  According to a fourth aspect of the present invention, in the in-vehicle electric circuit unit according to the first aspect, the circuit board is fixed to the upper case. With this configuration, the electric element and the circuit board are fixed inside the housing, and vibration resistance is improved.

  The in-vehicle electric circuit unit according to claim 5 is the in-vehicle electric circuit unit according to claim 1, wherein the electric element is connected to the electric circuit through the connection member. With such a configuration, it becomes possible to easily connect the electric element fixed to the upper case to the electric circuit. At this time, the connecting member constitutes a part of the electric circuit.

  The on-vehicle electric circuit unit according to claim 6 is the on-vehicle electric circuit unit according to claim 1, wherein the lower case is formed integrally with the housing of the compressor. In the compressor, the refrigerant flows inside the housing, and the heat generated by the electric element can be cooled using the low temperature of the refrigerant. An example of the circuit unit assembled in the compressor is an inverter circuit of the compressor.

  Hereinafter, the present invention will be described using specific examples. The following examples are specific examples of the present invention, and the present invention is not limited to these examples.

  As an embodiment of the present invention, an inverter unit that is integrally formed with an electric compressor mounted on a vehicle and controls the electric compressor was manufactured.

(Example)
The inverter unit of this embodiment has a housing 1, a power input terminal 2, a bus bar 3, a coil 4, a capacitor 5, an inverter control board 6, and an insulating seal member 7. The configuration of the inverter unit of this example is shown in FIGS. 1 and 2 are diagrams each showing a configuration of the inverter unit of the present embodiment, and appropriately shown cross sections.

  The housing 1 includes a lower case 10 formed integrally with a housing (compressor housing) of an electric compressor, and an upper case 11 assembled to the lower case 10. The housing 1 defines a space in which the power input terminal 2, the bus bar 3, the coil 4, the capacitor 5, the inverter control board 6 and the insulating seal member 7 are housed. If the lower case 10 and the upper case 11 have a shape that can partition a space in which members such as the inverter control board 6 are housed when both are assembled, the shape of the space and the outer peripheral shape are limited. It is not a thing. The lower case 10 and the upper case 11 constituting the housing 1 were manufactured by die casting of an aluminum alloy.

  The lower case 10 and the upper case 11 were assembled with the insulating seal member 7 interposed therebetween. By interposing the insulating seal member 7, it was possible to ensure electrical insulation and sealability (water permeability resistance, etc.) between the lower case 10 and the upper case 11.

  The power input terminal 2 is a member to which a lead wire from an external power source (vehicle battery) is connected, and power for driving the electric compressor is input from the external power source. The power input terminal 2 is a member fixed to the upper case 11 while penetrating the upper surface of the upper case 11.

  The bus bar 3 is a plate-like member fixed by welding in a state where it is connected to the inner end of the housing 1 of the power input terminal 2. The bus bar 3 is a member that connects the power input terminal 2 to the coil 4, the capacitor 5, and the inverter control board 6, and allows a current (voltage) input to the power input terminal 2 to flow through these members. The bus bar 3 can be formed of a conventionally known material as long as it has good conductivity and thermal conductivity.

  The coil 4 and the capacitor 5 are members fixed to the upper case 11 while being electrically connected to the bus bar 3. In this embodiment, the coil 4 and the capacitor 5 are welded and fixed to the bus bar 3 respectively. The coil 4 and the capacitor 5 were fixed to the upper case 11 by pressing the outer circumferences of the coil 4 and the capacitor 5 against the inner wall surface of the upper case 11 with fixing members 40 and 50, respectively. The fixing members 40 and 50 were fixed to the upper case 11 with screws.

  The inverter control board 6 is an electric circuit board fixed to the upper case 11, and is a board having an electric circuit for controlling the driving of the electric compressor. On the inverter control board 6, electric elements (not shown) other than the coil 4 and the capacitor 5 constituting a part of the electric circuit are assembled.

  The inverter control board 6 is electrically connected to the bus bar 3 by connection terminals 60 assembled to the board 6. By this electrical connection, a current (voltage) input via the power input terminal 2 flows through the circuit of the substrate 6 to control the electric compressor. Further, the inverter control board 6 is electrically connected to the electric compressor through a connection terminal (not shown) assembled to the board 6. Via this electrical connection, electric power for driving can be supplied to the electric compressor, and driving of the electric compressor is controlled by controlling this electric power.

  In the inverter unit of this embodiment, the power input terminal 2, the bus bar 3, the coil 4, the capacitor 5, and the inverter control board 6 are assembled (fixed) in this order to the upper case 11, and then the insulating seal member 7 is disposed. Thus, the upper case 11 was manufactured by being assembled (fixed) to the lower case 10.

  That is, the inverter unit of the present embodiment can be easily manufactured because the inverter control board 6 and the like for controlling the electric compressor are assembled to the lower case 10 in a state of being assembled to the upper case 11.

  The inverter unit of the present embodiment operates in the same manner as the inverter unit used in a conventionally known electric compressor except that the coil 4 and the capacitor 5 are fixed to the housing.

  In the inverter unit of the present embodiment, the large-sized coil 4 and the capacitor 5 which are electric elements standing on the substrate 6 are fixed to the upper case 11, so that even if the electric compressor vibrates, The coil 4 and the capacitor 5 no longer vibrate. That is, in a state where the coil 4 and the capacitor 5 are not fixed, there is a possibility that the stress is repeatedly concentrated on the joint portion with the substrate 6 when the coil 4 and the capacitor 5 vibrate. Since 5 was fixed to the upper case 11, this breakage was not caused and the vibration resistance of the unit was improved.

  In the inverter unit of this embodiment, the bus bar 3 is assembled to the power input terminal 2, the coil 4 and the capacitor 5 by a strong fixing method of welding, so that the mechanical strength is improved and the vibration resistance is improved. is doing.

  Further, in the inverter unit of this embodiment, the coil 4 and the capacitor 5 which are electric elements that generate heat when energized and driven are fixed in a state of being in contact (pressure contact) with the upper case 11, so that these elements generate heat. Even if this occurs, the generated heat is transmitted to the upper case 11 and diffused into the housing 1. Thereby, the coil 4 and the capacitor | condenser 5 are cooled, and the damage to the element by heat is suppressed. Further, since the entire upper case 11 is made of aluminum, even if elements other than the coil 4 and the capacitor 5 generate heat, the entire housing 1 is allowed to cool, thereby improving the cooling performance of the substrate 6.

  In addition, in the electric compressor, the refrigerant flows inside the compressor housing, and the compressor housing is kept at a relatively low temperature due to the low temperature of the refrigerant. Since the lower case 10 is integrally formed with the compressor housing, the lower case 10 is also kept at a low temperature. The heat conducted from the upper case 11 to the lower case 10 is cooled by this low temperature. That is, the inverter unit of the present embodiment has a configuration excellent in the cooling performance of the electric element.

(Deformation example)
This modification example is a modification example of the inverter unit of the above-described embodiment, and its configuration is shown in FIG.

  The inverter unit of this modification is the same as that of the above embodiment except that the power input terminal 2, the communication terminal 8, and the bus bar 3 are integrally formed and assembled to the upper case 11 in a state of constituting one unit. It is an inverter unit of composition.

  In the inverter unit of this modification, the bus bar 3 unit is assembled to the upper case 11, and then the coil 4 and the capacitor 5 are fixed to the upper case 11 and then welded to the bus bar 3. Then, the inverter control board 6 is assembled. The upper case 11 was manufactured by assembling (fixing) the upper case 11 to the lower case 10 with the insulating seal member 7 disposed.

  The inverter unit of this modification has a compressor power input terminal 90 of an electric compressor protruding from the lower case 10 and an output terminal 95 connected to the power terminal 90 assembled to the inverter control board 6. When the upper case 11 and the lower case 10 are assembled, the power supply terminal 90 and the output terminal 95 are connected. By connecting both the terminals 90 and 95, the circuit of the inverter control board 6 can drive the electric compressor.

  In the inverter unit of this modification, when a member such as the power input terminal 2 is assembled to the upper case 11, the member can be assembled in one direction from the opening on the lower case 10 side. That is, the workability of assembly at the time of manufacture is high. For this reason, the inverter unit of the present modification is an inverter unit with excellent assemblability.

  Other configurations are the same as those of the inverter unit of the above embodiment, and the same effects as those of the embodiment are exhibited.

It is the figure which showed the structure of the inverter unit of an Example. It is the figure which showed the structure of the inverter unit of an Example. It is the figure which showed the structure of the inverter unit of the modification example.

Explanation of symbols

1: Housing 10: Lower case 11: Upper case 2: Power input terminal 3: Bus bar 4: Coil 5: Capacitor 6: Inverter control board 7: Insulation seal member 8: Communication terminal 90: Compressor power input terminal 95: Output terminal

Claims (6)

A circuit board with an electrical circuit;
An electrical element connected to the electrical circuit;
A housing comprising an upper case and a lower case, in which the circuit board and the electrical element are housed,
In-vehicle electric circuit unit having
An in-vehicle electric circuit unit characterized in that at least a part of the upper case is formed of metal and the electric element is fixed in a state of being in contact with a part of the upper case formed of metal.   The in-vehicle electric circuit unit according to claim 1, wherein the upper case is made of aluminum.   The in-vehicle electric circuit unit according to claim 1, wherein the electric element is at least one selected from a coil and a capacitor.   The in-vehicle electric circuit unit according to claim 1, wherein the circuit board is fixed to the upper case.   The in-vehicle electric circuit unit according to claim 1, wherein the electric element is connected to the electric circuit via a connecting member.   The in-vehicle electric circuit unit according to claim 1, wherein the lower case is formed integrally with a housing of a compressor.

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