ELECTRICALLY DRIVED COMPRESSOR

Abstract

Electrically driven compressor (11), comprising a circuit board (21) for controlling an electric motor housed in the compressor (11), characterized in that several capacitors (22) with sockets (24) are surface-mounted on each of the two surfaces of the circuit board (21), and characterized by a housing body (13, 16) formed integrally with the compressor (11) in which the circuit board (21) is received and fixed, a first buffer element (31) inserted between the capacitors (22) mounted on the surface of the circuit board (21) located near the compressor (11) and the housing body (13, 16), and a second buffer element (32) inserted between the capacitors (22) mounted on the surface of the circuit board (21) furthest from the compressor (11) and the housing body (13, 16).

Description

TECHNICAL FIELD

[0001] The present invention relates to an electrically driven compressor. STATE OF THE ART

[0002] In JP 2009 - 114 961 A it is proposed to fix a power board in an inverter receiving section of an electrically driven compressor by means of screws on several fixing seating surfaces.

[0003] DE 11 2012 003 286 T5 discloses a vibration-resistant structure for an electrical circuit of an electric compressor.

[0004] CN 1 04 201 865 A discloses an electronic system and a method for reducing vibration noise in the electronic system.

[0005] CN 2 06 947 183 U discloses an aluminum electrolytic capacitor with an anti-vibration base. SUMMARY OF THE INVENTION OBJECT OF THE INVENTION

[0006] To increase the vibration resistance of a circuit board, it is conceivable to use a thick copper board to ensure flexural rigidity. However, thick copper boards are expensive and lead to increased costs. The object of the present invention is to increase vibration resistance in a cost-effective manner. SOLUTION TO THE TASK

[0007] An electrically driven compressor according to one aspect of the present invention includes a circuit board for driving an electric motor housed in the compressor, with a plurality of capacitors having sockets surface-mounted on both surfaces of the circuit board. The electrically driven compressor includes a casing body formed integrally with the compressor and in which the circuit board is housed and fixed, a first buffer member interposed between the capacitors mounted on the surface of the circuit board close to the compressor and the casing body, and a second buffer member interposed between the capacitors mounted on the surface of the circuit board far from the compressor and the casing body. EFFECTS OF THE INVENTION

[0008] According to the present invention, connection pads for surface mounting multiple capacitors are formed on both surfaces of the board, ensuring flexural rigidity due to the increased section modulus. Compared to using a thick copper board, this allows for increased vibration resistance in a cost-effective manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] They show: Fig. 1 an external view of a compressor; Fig. 2 views of a circuit board; and Fig. 3 a sectional view of a recording state of the board. DESCRIPTION OF THE EMBODIMENTS

[0010] Embodiments of the present invention are described below with reference to the figures. The figures are schematic and may differ from actual embodiments. The following embodiment also illustrates exemplary devices and methods for implementing the technical concept of the present invention, but the configuration is not limited to the details below. Thus, modifications to the technical concept of the present invention can be made in various ways within the technical scope set forth in the claims. EmbodimentConstruction

[0011] Fig. 1 shows an external view of a compressor.

[0012] Compressor 11 (electrically driven compressor) is an electrically driven scroll compressor, used, for example, in a refrigeration circuit of a vehicle air conditioning system. It is installed in a vehicle and, when driven by an electric motor housed therein, draws in refrigerant, compresses it, and discharges it.

[0013] On an axially front side, an inverter housing section 12 (housing body) is integrally formed, which is hermetically sealed by a front cover 13. A connector 14 for a low-voltage circuit and a connector 15 for a high-voltage circuit are provided on the outer wall of the inverter housing section 12.

[0014] Fig. 2 shows views of the circuit board.

[0015] Inside the inverter receiving section 12, a circuit board 21 is housed, on which an inverter for driving an electric motor is formed. The thickness of the circuit board 21 is, for example, approximately 1.6 to 1.8 mm.

[0016] In the figure, (a) shows one surface of the circuit board 21, (b) a side surface of the circuit board 21, and (c) another surface of the circuit board 21. On one surface of the circuit board 21, a plurality of capacitors 22 are surface-mounted. Here, an example in which seven are mounted closely together is shown. On the other surface of the circuit board 21, a plurality of capacitors 22 are surface-mounted. Here, an example in which eleven are mounted closely together is shown. The capacitors 22 form a smoothing / filtering circuit connected in parallel with a power supply line and are, for example, aluminum solid electrolytic capacitors. The capacitors 22 are arranged such that the mounting area on one surface and the mounting area on the other surface overlap each other in plan view.

[0017] Fig. 3 shows a sectional view of a recording state of the board.

[0018] The circuit board 21 is accommodated in the inverter receiving section 12 and fixed by screws. Terminal pads 23 for surface mounting the capacitors 22 are formed on both surfaces of the circuit board 21. Two terminal pads 23 are provided for each capacitor 22. The capacitors 22 have sockets 24, and two terminals formed on the back surface of the sockets 24 are soldered to the corresponding terminal pads 23. Since the capacitors 22 are arranged such that the mounting area on one surface and the mounting area on the other surface overlap each other, the terminal pads 23 on one surface and the terminal pads 23 on the other surface also overlap each other. At the mounting positions of the capacitors 22, the thickness tb of the circuit board 21 is therefore increased by the proportion of the two terminal pads.

[0019] A partition wall 16 is provided between the inverter housing section 12 and the compressor 11, and the side of the partition wall 16 near the compressor 11 forms a partitioned space in which refrigerant flows. A buffer member 31 (first buffer member) is inserted in a compressed state between the capacitors 22 mounted on the surface of the circuit board 21 closest to the compressor 11 and the partition wall 16 (housing body). A buffer member 32 (second buffer member) is inserted in a compressed state between the capacitors 22 mounted on the surface of the circuit board 21 far from the compressor 11 and a front cover 13 (housing body). The buffer members 31, 32 are formed by gel with a high thermal conductivity. A thickness t1 of the buffer member 31 is set to be greater than a thickness t2 of the buffer member 32. The buffer elements 31, 32 also serve as heat dissipation layers.Since the capacitors 22 have a permissible load with which pressure can be exerted on them, the counterforce of the buffer elements 31, 32 is set such that it is below the permissible load of the capacitors 22. Mode of action

[0020] Next, the main operation of one embodiment is described. To increase the vibration resistance of a circuit board, it is conceivable to use a thick copper board to ensure flexural rigidity. However, thick copper boards are expensive and lead to increased costs.

[0021] Instead of using a thick copper circuit board, the capacitors 22 are surface-mounted on both surfaces of the circuit board 21, each having sockets. More specifically, the capacitors 22 are arranged such that the mounting area on one surface and the mounting area on the other surface overlap each other in plan view. As a result, connection surfaces 23 for surface mounting the capacitors 22 are formed on both surfaces of the circuit board 21, whereby bending rigidity can be ensured due to the increased section modulus. Compared to using a thick copper circuit board, an increase in vibration resistance can thus be achieved in a cost-effective manner.

[0022] Usually, as a measure for vibration resistance, in addition to accommodating capacitors, a filter housing formed by casting resin is also provided on the circuit board.

[0023] In the present embodiment, the buffer member 31 is inserted between the capacitors 22, which are mounted on the surface of the circuit board 21 closest to the compressor 11, and the partition wall 16. The buffer member 32 is inserted between the capacitors 22, which are mounted on the surface of the circuit board 21 far from the compressor 11, and the front cover 13. These buffer members 31, 32 ensure the vibration resistance of the capacitors 22. Since only the structure of inserting the buffer members 31, 32 is involved, the filter housing and the resin molding step can be omitted.

[0024] Also, the thickness t1 of the buffer element 31 is greater than the thickness t2 of the buffer element 32. Therefore, dimensional errors and mounting errors in a direction perpendicular to the surface of the circuit board 21 can be absorbed primarily by the buffer element 31. The buffer element 31 is cooled by the coolant while separated by the partition wall 16, and the buffer element 32 is cooled by the outside air temperature while separated by the front cover 13. The thinner the buffer elements, the higher their heat dissipation performance, but the thickness t1 of the buffer element 31 can be increased by the cooling performance increase of the partition wall 16 compared to the front cover 13. Therefore, the heat dissipation performance of the capacitors 22 mounted on the surface of the circuit board 21 close to the compressor 11 and the capacitors 22 mounted on the surface of the circuit board 21 far from the compressor 11 is the same.

[0025] The above description has been made with reference to a limited number of embodiments, but the scope of protection is not limited thereto, and modifications to the embodiments will be apparent to those skilled in the art based on the above disclosure. LIST OF REFERENCE SYMBOLS 11 compressors 12 Inverter mounting section 13 Front cover 14 connectors 15 connectors 16 Partition wall 21 circuit board 22 Capacitor 23 Connection surface 24 bases 31 Buffer element 32 Buffer element

Claims

[1] Electrically driven compressor (11), comprising a circuit board (21) for controlling an electric motor which is housed in the compressor (11), characterized by that on both surfaces of the board (21) several capacitors (22) with sockets (24) are surface-mounted thereon, and characterized by a housing body (13, 16) formed integrally with the compressor (11) and in which the circuit board (21) is received and fixed, a first buffer element (31) interposed between the capacitors (22) mounted on the surface of the circuit board (21) close to the compressor (11) and the housing body (13, 16), and a second buffer element (32) interposed between the capacitors (22) mounted on the surface of the circuit board (21) remote from the compressor (11) and the housing body (13, 16). [2] Electrically driven compressor (11) according to claim 1, characterized bythat the capacitors (22) are arranged such that the mounting area on one surface and the mounting area on the other surface overlap each other in plan view. [3] Electrically driven compressor (11) according to claim 1 or 2, characterized by that the first buffer element (31) is thicker than the second buffer element (32).

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