JP2016186251A - Electric compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the deformation of a partition wall dividing a space provided in a housing of an electric compressor and accommodating a compression mechanism and an electric motor from a space accommodating a circuit board of an inverter circuit even if an internal pressure increase or the like occurs to the former space.SOLUTION: A boss 11i is provided to protrude from a portion near a center of a partition wall 11c that divides a housing 7 accommodating a compression mechanism and an electric motor rotating a rotor of the compression mechanism from a circuit accommodation section 11b accommodating an inverter circuit 9 driving an electric motor toward the circuit accommodation section 11b, a boss 11j is provided to face the boss 11i and protrude from a cap 11g toward the circuit accommodation section 11b, and tip ends of the two bosses 11i and 11j are abutted on each other. The cap 11g is fixedly fastened to the circuit accommodation section 11b by bolts 13 in the bosses 11i, 11j and a plurality of portions on a peripheral edge of an opening 11f of the circuit accommodation section 11b.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a compressor for a refrigeration cycle that compresses a refrigerant, and more particularly to an electric compressor using an electric motor as a power source.

  The compressor used in the refrigeration cycle sucks low-temperature and low-pressure refrigerant and discharges the refrigerant that has been compressed to high temperature and pressure. Among compressors, there is an electric compressor having an electric motor as a power source of a refrigerant compression mechanism, and the electric compressor is provided with a drive circuit that converts DC power from a power source into AC by an inverter and supplies the AC to the electric motor. .

  The inverter has power switching elements such as IGBTs (Insulated Gate Bipolar Transistors) and MOSFETs (Metal Oxide Semiconductor Field Effect Transistors), and solders the terminals to the circuit board. Has been implemented.

  The circuit board on which the power switching element is mounted is housed in a separate space partitioned by the partition wall from the space for housing the compression mechanism and the electric motor in the housing of the electric compressor, and is erected from the partition wall at the corner. (For example, patent document 1).

JP 2014-58961 A

  In the electric compressor described above, the power switching element of the circuit board generates heat due to a loss (switching loss) at the time of switching. Therefore, it is often performed that the power switching element is brought into contact with the partition wall exposed to the accommodation space of the compression mechanism or the electric motor, and the power switching element is cooled by the refrigerant flowing through the accommodation space of the compression mechanism or the electric motor. .

  Therefore, when the internal pressure rises in the housing space of the compression mechanism or electric motor in the housing and the partition wall is deformed to the circuit board housing space side, the position of the power switching element in contact with the partition wall is the circuit board. The stress concentrates on the soldering portion of the power switching element to the circuit board.

  When such stress concentrates on the soldering part, cracks occur in the soldering part or the solder peels off from the circuit board conductive pattern and floats, etc., so that the connection is made between the power switching element and the circuit board conductive pattern. Defects may occur.

  The present invention has been made in view of the above circumstances, and the object of the present invention is to provide a circuit board for an inverter circuit and this space even when an internal pressure rises in a space for housing a compression mechanism or an electric motor in a housing of an electric compressor. An object of the present invention is to provide an electric compressor capable of suppressing deformation of a partition wall that partitions a housing space.

In order to achieve the above object, an electric compressor of the present invention according to the first aspect of the present invention comprises:
In an electric compressor that drives a refrigerant compression mechanism with an electric motor,
A main body housing containing the compression mechanism and the electric motor;
A circuit housing in which a drive circuit of the electric motor is housed and partitioned from the main body housing by a partition wall;
The power switching element of the drive circuit is mounted by soldering terminals, and the circuit board of the drive circuit fixed to the partition wall by contacting the power switching element to the partition wall;
A cap for closing the opening of the circuit housing;
A column interposed between the partition wall and the cap in the vicinity of the center of the partition wall;
It is characterized by providing.

  According to the present invention, the circuit housing that is partitioned from the main housing of the electric compressor by the partition wall and the cap that closes the opening of the circuit housing are physically coupled directly to the outside of the opening of the circuit housing. In addition to this, the circuit housing and the cap are physically coupled to each other through the support column near the center of the partition wall.

  For this reason, in addition to the strength of the peripheral edge of the partition wall separating the main body housing and the circuit housing being increased due to the physical coupling between the circuit housing and the cap, the physical strength through the support of the circuit housing and the cap is physically increased. Due to the coupling, the strength in the vicinity of the center that is farthest from the peripheral edge of the partition wall and is originally low in strength increases.

  Therefore, the strength of the partition wall that partitions the space for housing the compression mechanism and the electric motor in the housing of the electric compressor and the space for housing the circuit board of the inverter circuit is reinforced so that the compression mechanism and Even if the internal pressure rises in the accommodation space of the electric motor, it is possible to suppress the partition wall from being deformed.

It is a partially cutaway front view of a general electric compressor. It is explanatory drawing which shows typically the attachment structure of the circuit accommodating part and cap which are used with the electric compressor which concerns on one Embodiment of this invention, notching the principal part. FIG. 3 is an enlarged cross-sectional view of a main part showing a contact portion between a boss of a circuit housing portion and a boss of a cap in FIG. 2. (A), (b) is a principal part expanded sectional view which shows the structure by the another example of the contact part of the boss | hub of the circuit accommodating part of FIG. 2, and the boss | hub of a cap.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a front sectional view showing an electric compressor having a general configuration to which the present invention is applied.

  An electric compressor 1 shown in FIG. 1 includes a compression mechanism 3 and an electric motor 5, a housing 7 (corresponding to a main body housing in the claims) in which these are housed, and an inverter circuit 9 (a drive circuit for the electric motor 5). And an inverter case 11 that accommodates the drive circuit in the claims.

  The compression mechanism 3 includes a pair of side blocks 3a and 3b, a cylinder block 3c sandwiched between them, and a columnar rotor 3e accommodated in an elliptical cylinder chamber 3d formed inside the cylinder block 3c. doing. A plurality of vanes (not shown) are supported on the peripheral surface of the rotor 3e so as to appear and retract.

  When the rotor 3e is rotated in the cylinder chamber 3d by the electric motor 5, each vane of the rotor 3e appears and disappears following the inner peripheral surface of the cylinder chamber 3d, and the two vanes adjacent to the rotor 3e and the cylinder chamber 3d The volume of the configured space changes. Then, while the space volume increases, low-pressure refrigerant is sucked through a suction port (not shown) formed in the side block 3a, and the sucked refrigerant is compressed as the space volume decreases. The compressed high-pressure refrigerant is discharged from a discharge port (not shown) formed in the side block 3b.

  The housing 7 has a cylindrical shape with one end closed. The housing 7 accommodates the compression mechanism 3, and the accommodated compression mechanism 3 exposes the inside of the housing 7 to the closed discharge chamber 7 a on the closed side where the side block 3 b is exposed and the side block 3 a. It is partitioned off from the suction chamber 7b on the opening side. An electric motor 5 is accommodated in the suction chamber 7 b, and the suction chamber 7 b is sealed by an inverter case 11 attached to the opening 7 c of the housing 7.

  The inverter case 11 is disposed outside the suction chamber 7b (housing 7), which closes the suction chamber 7b by closing the opening 7c of the housing 7 and seals the suction chamber 7b, and accommodates the inverter circuit 9. The circuit accommodating part 11b (equivalent to the circuit housing in a claim) is divided and comprised by the partition wall 11c.

  The circuit accommodating portion 11b has a bottomed cylindrical shape with the partition wall 11c as a bottom portion. A plurality of mounting bosses 11d are erected on the peripheral edge of the partition wall 11c toward the circuit housing portion 11b, and the circuit board 9a of the inverter circuit 9 is screwed and fixed to the tip of each mounting boss 11d.

  On the circuit board 9a, a power switching element 9b such as an IGBT or a MOSFET constituting the inverter circuit 9 is mounted by soldering the terminal 9c, and the casing is designed to improve heat dissipation efficiency. Surface contact is made with a thick contact portion 11e formed on the surface of the partition wall 11c on the circuit accommodating portion 11b side. The circuit housing portion 11b is sealed by a cap 11g attached to the opening 11f.

  In such a general electric compressor 1, when an increase in internal pressure or the like occurs in the housing 7 in which the compression mechanism 3 and the electric motor 5 are accommodated, the partition wall 11c is deformed toward the circuit accommodating portion 11b and contacts the partition wall 11c. The position of the contacted power switching element 9b changes with respect to the circuit board 9a. Then, stress concentrates on the place where the terminal 9c of the power switching element 9b is soldered to the circuit board 9a.

  When such stress concentrates on the soldered portion of the terminal 9c, a crack occurs in the soldered portion, or the solder is peeled off from the conductive pattern (not shown) of the circuit board 9a and floats. There is a possibility that a connection failure may occur between the circuit board 9a and a conductive pattern (not shown).

  Therefore, in the present invention, the structure described below is adopted as a fixing structure between the circuit housing portion 11b of the inverter case 11 and the cap 11g.

  FIG. 2 is an explanatory diagram schematically showing a mounting structure of the circuit housing portion 11b and the cap 11g used in the electric compressor 1 according to the embodiment of the present invention, with the main portion cut away.

  In the electric compressor 1 of the present embodiment shown in FIG. 2, a boss 11i (corresponding to a column wall post in the claims) protruding from the vicinity of the center of the partition wall 11c toward the circuit accommodating portion 11b is opposed to this. A boss 11j (corresponding to a column of a cap in the claims) projecting from the vicinity of the center of the cap 11g toward the circuit accommodating portion 11b is brought into contact. And the cap 11g is fastened and fixed to the circuit accommodating part 11b with the volt | bolt 13 in these boss | hubs 11i and 11j and the several places of the periphery of the opening 11f of the circuit accommodating part 11b.

  Further, as shown in FIG. 3, a small diameter portion 11m having the same height as the thickness of the circuit board 9a is formed at the tip of the boss 11i of the circuit housing portion 11b. The small diameter portion 11m is inserted into a positioning hole 9d formed in the circuit board 9a in a state where the circuit board 9a is fixed to the mounting boss 11d (see FIG. 2) of the partition wall 11c with screws. By inserting the small diameter portion 11m into the positioning hole 9a, the circuit board 9a is positioned relative to the circuit housing portion 11b in the mounting surface direction of the circuit board 9a.

  Further, the tip surface 11k of the boss 11i of the partition wall 11c and the tip surface 11l of the boss 11j of the cap 11g are in contact with the contact surface 11h of the circuit housing portion 11b and the cap 11g shown in FIG. It is configured. Accordingly, the insertion of the small diameter portion 11m into the positioning hole 9a positions the circuit board 9a with respect to the circuit accommodating portion 11b in the thickness direction of the circuit board 9a.

  In FIG. 3, a portion of the power switching element 9b that is in surface contact with the contact portion 11e of the partition wall 11c is shown in a simplified manner.

  In the electric compressor 1 of the present embodiment configured as described above, the partition walls 11c and the tip surfaces 11k and 11l of the bosses 11i and 11j of the cap 11g are positioned on the contact surface 11h of the circuit housing portion 11b and the cap 11g. Therefore, it becomes easy to manage the dimensions of the bosses 11i and 11j when the partition wall 11c and the cap 11g are manufactured.

  In addition, since the small-diameter portion 11m is formed at the tip of the boss 11i of the partition wall 11c, the circuit board 9a is not attached to the mounting boss 11d of the circuit housing portion 11b before the step of closing the opening 11f with the cap 11g. In the step of fixing with screws, the small diameter portion 11m is inserted into the positioning hole 9d. For this reason, the positioning of the circuit board 9a with respect to the circuit housing portion 11b can be easily performed in a visually visible state, not in a state hidden by the cap 11g.

  According to the electric compressor 1 of the present embodiment, the circuit accommodating portion 11b partitioned from the housing 7 by the partition wall 11c and the cap 11g that closes the opening 11f are physically connected by the bolt 13 outside the opening 11f. Directly coupled. In addition to this, the circuit housing portion 11b and the cap 11g are physically coupled by a bolt 13 via bosses 11i and 11j projecting from the center of the partition wall 11c.

  For this reason, the peripheral edge part of the partition wall 11c which partitions the housing 7 and the circuit accommodating part 11b is reinforced by physical coupling | bonding with the circuit accommodating part 11b and the cap 11g, and intensity | strength increases compared with the other part. In addition, the vicinity of the center of the partition wall 11c is reinforced by physical coupling of the circuit housing portion 11b and the cap 11g via the bosses 11i and 11j, and the strength should be low because it is originally away from the peripheral portion. The strength in the vicinity of the center of the partition wall 11c increases in the same manner as the peripheral edge.

  Therefore, the partition wall 11c that partitions the housing 7 in which the compression mechanism 3 and the electric motor 5 of the electric compressor 1 are housed from the circuit housing portion 11b in which the circuit board 9a of the inverter circuit 9 is housed is near the center, which is originally low in strength. Thus, even if an increase in internal pressure or the like occurs in the housing 7, it is possible to prevent the partition wall 11c from being deformed so as to bulge out toward the circuit housing portion 11b.

  As a result, the power switching element 9b brought into contact with the deformed partition wall 11c moves relative to the circuit board 9a, and is soldered to a soldered portion (not shown) of the terminal 9c with respect to a conductive pattern (not shown) of the circuit board 9a. It is possible to suppress the concentration of stress. Therefore, when stress is concentrated, cracks are generated at the soldering points, or the solder is peeled off from the conductive pattern (not shown) of the circuit board 9a and floats, and the like, so that there is a gap between the power switching element 9b and the circuit board 9a. It is possible to suppress the occurrence of connection failure.

  In this embodiment, the small diameter portion 11m is formed at the tip of the boss 11i of the partition wall 11c. However, as shown in FIG. 4A, the tip of the boss 11i of the partition wall 11c and the tip of the boss 11j of the cap 11g. In addition, the small-diameter portions 11m and 11n may be formed at half the thickness of the circuit board 9a, and the small-diameter portions 11m and 11n may be inserted into the positioning holes 9d of the circuit board 9a from both sides.

  Also, as shown in FIG. 4B, a small diameter portion 11n is formed only at the tip of the boss 11j of the cap 11g with the height of the thickness of the circuit board 9a, and the opening 11f of the circuit housing portion 11b is formed by the cap 11g. It is good also as a structure which inserts the small diameter part 11n in the positioning hole 9d of the circuit board 9a, when closing.

  In this case, the front end of the mounting boss 11d is the same as the front end surface 11k of the boss 11i so that there is no gap between the mounting boss 11d of the partition wall 11c and the circuit board 9a. The contact surface 11h with the cap 11g is positioned on the same plane.

  In the embodiment of FIGS. 2 and 3 and another example of FIG. 4B, the height of the small diameter portion 11m of the boss 11i of the partition wall 11c and the small diameter portion 11n of the boss 11j of the cap 11g is set to the height of the circuit board 9a. Although the thickness is described, the height may be slightly shorter than the thickness of the circuit board 9a. How is the height of the small diameter portions 11m and 11n of the bosses 11i and 11j of the partition wall 11c and the cap 11g in the example of FIG. 4 (a) not a half of the thickness of the circuit board 9a but slightly shorter than that. It may be good.

  If it does so, the bolt 13 at the time of fastening the partition wall 11c and the bosses 11i, 11j of the cap 11g is given a tightening margin, and the circuit board 9a is firmly clamped by the bosses 11i, 11j, so that the circuit board 9a is It can be firmly positioned with respect to the circuit housing portion 11b in the thickness direction.

  In the above embodiment, the case where the present invention is applied to the electric compressor 1 having the vane rotary type compression mechanism 3 that rotates the rotor 3e in the cylinder chamber 3d has been described as an example. However, the present invention includes, for example, an electric motor that rotates a compression mechanism and a rotating body of the compression mechanism, such as a scroll compressor that rotates a movable scroll with respect to a fixed scroll, and compresses gas, and an electric motor drive circuit. The present invention can be widely applied to electric compressors accommodated in adjacent spaces partitioned by a partition plate.

  The present invention can be used in an electric compressor in which a refrigerant compression mechanism is driven by an electric motor.

DESCRIPTION OF SYMBOLS 1 Electric compressor 3 Compression mechanism 3a, 3b Side block 3c Cylinder block 3d Cylinder chamber 3e Rotor 5 Electric motor 7 Housing (main body housing)
7a Discharge chamber 7b Suction chamber 7c Opening 9 Inverter circuit (drive circuit)
9a Circuit board 9b Power switching element 9c Terminal 9d Positioning hole 11 Inverter case 11a Lid 11b Circuit housing (circuit housing)
11c Partition wall 11d Mounting boss 11e Contact portion 11f Circuit accommodating portion opening 11g Cap 11h Contact surface 11i Partition wall boss (wall-side support)
11j Cap boss (cap side boss)
11k Partition wall boss tip 11l Cap boss tip 11m, 11n Small diameter part

Claims (6)

In the electric compressor (1) that drives the refrigerant compression mechanism (3) by the electric motor (5),
A main body housing (7) containing the compression mechanism (3) and the electric motor (5);
A circuit housing (11b) in which a drive circuit (9) of the electric motor (5) is accommodated and partitioned from the main body housing (7) by a partition wall (11c);
The power switching element (9b) of the drive circuit (9) is mounted by soldering the terminal (9c), and the power switching element (9b) is brought into contact with the partition wall (11c) to form the partition. A circuit board (9a) of the drive circuit (9) fixed to the wall (11c);
A cap (11g) for closing the opening (11f) of the circuit housing (11b);
An electric compressor (1) comprising: a column (11i, 11j) interposed between the partition wall (11c) and the cap (11g) near the center of the partition wall (11c).   The column (11i, 11j) includes a wall-side boss (11i) erected on the partition wall (11c) and a cap erected from the cap (11g) opposite the wall-side boss (11i). The side boss (11j) and the front end surface (11k, 11l) of the wall side boss (11i) and the cap side boss (11j) are connected to the circuit housing (11b) and the cap (11g). The electric compressor (1) according to claim 1, wherein the electric compressor (1h) is in contact with each other.   A small diameter portion (11m) is formed at the tip of at least one of the wall side boss (11i) and the cap side boss (11j), and the small diameter portion (11m) is fixed to the partition wall (11c). The electric compressor (1) according to claim 2, wherein the electric compressor (1) is inserted into a positioning hole (9d) of the circuit board (9a).   The electric compressor (1) according to claim 3, wherein the small diameter portion (11m) is formed with a size smaller than a thickness of the circuit board (9a) in the insertion direction with respect to the positioning hole (9d). ).   The electric compressor (1) according to claim 3 or 4, wherein the small diameter portion (11m) is formed at a tip of the wall-side boss (11i).   The said circuit housing (11b) and the said cap (11g) are being fixed by the bolt fastening in the outer side of the said opening (11f), and the said support | pillar (11i, 11j), The electric compressor (1) according to 3, 4 or 5.