KR101878310B1 - Inverter cover of motor driven compressor - Google Patents

Abstract

The present invention relates to an inverter cover of an electric compressor. According to one embodiment of the present invention, by forming a cover plate and a side wall by molding a plate material of a magnesium alloy material, an effect of weight reduction and improvement of electromagnetic wave shielding function An inverter cover of an electric compressor is provided.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an inverter cover for an electric compressor,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric compressor, and more particularly, to an inverter cover for an electric compressor that protects an inverter mounted for controlling the rotational speed of an electric motor and has an electromagnetic wave shielding function.

Recently, hybrid vehicles, electric vehicles, or fuel cell vehicles, which use both fossil fuel and electricity as the driving source, are attracting attention due to the low pollution and low fuel consumption policy due to exhaustion of fossil fuel and environmental pollution. ought.

Here, a hybrid vehicle, an electric vehicle, and a fuel cell vehicle obtain power for propelling the vehicle through an electric motor. Accordingly, unlike conventional mechanical air conditioning systems where mechanical compressors are widely used, the trend is toward using electric compressors.

2. Description of the Related Art Generally, an electric compressor has a function of compressing a refrigerant and includes a cylindrical housing having a suction port through which refrigerant flows and a discharge port through which compressed refrigerant is discharged, an electric motor for converting electric energy into mechanical energy, And an inverter for controlling the rotational speed of the electric motor, wherein the inverter is coupled to the outer surface of the housing and is electrically connected to the outside through a cable.

1 is an exploded perspective view showing a conventional electric compressor disclosed in Korean Patent Laid-Open Publication No. 10-2011-0072324 (Patent Document 1), and FIG. 2 is an assembled cross-sectional view of FIG.

1 and 2, the motor-driven compressor includes a main body 30 having a motor unit 31 and a compression unit 32, an inverter 50 for controlling the motor unit 31, And a cover 70 which is coupled to the main body 30 and shields the inverter 50.

The motor unit 31 provided in the main body 30 includes a rotor 31a and a stator 31b to transmit power to the compression unit 32. [ The fixed scroll 32a and the orbiting scroll 32b are provided in the compression section 32. The orbiting scroll 32b is connected to the rotor 31a and rotates together with the fixed scroll 32a and the fixed scroll 32a, Thereby compressing the refrigerant in the space (33).

At this time, the main body 30 has a substantially cylindrical shape, and a closed space is formed inside the main body 30 by the rear surface, the side surface, and the compression portion 32.

A suction port 34 is formed at one side of the main body 30 and a discharge port 34 is formed at a side of the main body 30 to discharge the compressed refrigerant. Are communicated with each other.

Therefore, the refrigerant introduced through the suction port 34 is delivered to the compression section 32 through the motor section 31, compressed, and then discharged to the outside of the compressor through the discharge port.

The inverter 50 supplies power to the motor unit 31 and controls the operation of the motor unit 31. [ 1 and 2 illustrate an example in which the inverter 50 is coupled in the longitudinal direction of the main body 30 but the present invention is not limited thereto. For example, when the inverter 50 is connected to the main body 30 Or may be coupled to one side of the outer circumferential surface.

The inverter 50 includes a plurality of electrical parts such as a transistor 63, a capacitor 64 and an inductor 65 and a printed circuit board (PCB) 60 on which an electronic device 61 such as a fixed resistor, a diode, And a cover 70 coupled to enclose the inverter 50 prevents foreign matter from entering from the outside.

In recent years, there has been a growing demand for compact and lightweight compressors for improving the fuel efficiency of automobiles. For this purpose, the inverter cover of the conventional motor compressor is made of an aluminum alloy.

However, in the case of hybrid cars, electric vehicles, and fuel cell vehicles to which the electric compressors are applied, there is a lot of electric parts, so the electromagnetic wave shielding function of the inverter cover is required. If the electromagnetic shielding function is not sufficient, electromagnetic interference , It may cause malfunction of the electric compressor or other electric equipment.

Accordingly, there is a demand for development of an inverter cover capable of simultaneously satisfying electromagnetic wave shielding with a compact and lightweight compressor.

Patent Document 1: Korean Patent Laid-Open No. 10-2011-0072324 (June 29, 2011)

SUMMARY OF THE INVENTION The present invention has been devised to solve the problems as described above, and it is an object of the present invention to provide an inverter cover capable of simultaneously satisfying electromagnetic wave shielding while reducing the size and weight of an electric compressor.

According to a preferred embodiment of the present invention, a cover plate on which a circuit board for an inverter is mounted on one side; And a side wall extending to one side along a rim of the cover plate so as to form a receiving space for accommodating the circuit board, wherein the cover plate and the side wall are integrally formed of a magnesium alloy sheet material An inverter cover of an electric compressor is provided.

The thickness of the cover plate and the side wall is preferably 2.5 mm to 3.5 mm.

At least one cable connection hole is formed in the side wall, and a grommet mounting member having a through hole communicating with the cable connection hole is coupled to the inside of the side wall.

At this time, the grommet mounting member is preferably made of a magnesium alloy material.

A first grommet mounting member is coupled along an inner edge of the high voltage cable connection hole, and the low voltage cable connection hole and the low voltage cable connection hole are formed in the high voltage cable connection hole, It is preferred that the second grommet mounting member is coupled along the inner rim of the hole.

In addition, a plurality of fastening bosses for fastening the circuit board may be formed on the inner surface of the cover plate so as to be spaced apart from each other.

According to a preferred embodiment of the present invention, since the inverter cover is formed by press working of the magnesium alloy sheet material, the weight is reduced by 60 to 70% compared with the conventional aluminum material inverter cover having equivalent mechanical properties, Which can contribute to the improvement of automobile fuel efficiency.

In addition, since the inverter cover is made of a magnesium alloy excellent in electromagnetic wave shielding function, it is possible to prevent a malfunction due to electromagnetic wave interference between electrical components.

1 is an exploded perspective view of a conventional electric compressor.
2 is an assembled sectional view of Fig.
3 is a sectional view of an electric compressor according to an embodiment of the present invention;
4 is a perspective view of an inverter cover according to an embodiment of the present invention;
5 is a graph comparing the thickness and mechanical properties of an inverter cover according to an embodiment of the present invention.

Hereinafter, preferred embodiments of an inverter cover of an electric compressor according to an embodiment of the present invention will be described with reference to the accompanying drawings. In this process, the thicknesses of the lines and the sizes of the components shown in the drawings may be exaggerated for clarity and convenience of explanation.

In addition, the terms described below are defined in consideration of the functions of the present invention, which may vary depending on the intention or custom of the user, the operator. Therefore, definitions of these terms should be made based on the contents throughout this specification.

In addition, the following embodiments are not intended to limit the scope of the present invention, but merely as exemplifications of the constituent elements set forth in the claims of the present invention, and are included in technical ideas throughout the specification of the present invention, Embodiments that include components replaceable as equivalents in the elements may be included within the scope of the present invention.

Example

3 is a cross-sectional view of an electric compressor according to an embodiment of the present invention.

3, an electric compressor (hereinafter, referred to as 'compressor') 100 according to an embodiment of the present invention includes a driving unit 200, a compression unit 300, and an inverter unit 400 .

3, the driving unit 200 includes a driving unit housing 210, an intermediate housing unit 220, a driving unit housing 210, and a driving unit housing 210, A stator 230 installed in the housing 220, and a rotor 240 rotating in the stator 230.

In this case, the driving unit housing 210 is a cylindrical portion of the driving unit 200, and the middle unit 220 may be interposed between the driving unit housing 210 and the inverter unit 400, A bearing housing 250 protrudes from the bottom surface of the intermediate housing 220 and a bearing 260 is mounted on the bearing housing 250 to rotatably support the rotary shaft 270 of the rotor 240. Respectively. In addition, a suction port 280 for sucking the refrigerant is formed in the intermediate housing 220 at one side of the circumferential surface.

The stator 230 has a stator core 231 fixedly mounted on the inner circumferential surface of the driving unit housing 210 as a kind of electromagnet by press fitting or the like, And a coil bundle 232 wound on the stator core 231.

The rotor 240 is rotatably driven by being mounted coaxially inside the stator 230 as described above and rotatably inserted into a through hole at the center of the stator core 231 of the stator 230 A rotating shaft 270 disposed along the center axis, and a permanent magnet (not shown) attached to the outer circumferential surface of the rotating shaft 270.

Accordingly, the rotor 240 is rotationally driven by the interaction with the stator 230 according to the driving principle of the motor when the stator 230 is excited, and the rotating shaft 270 is rotated through the bearing 260 210 so as to rotate together with the rotor 240.

The compressing unit 300 compresses the refrigerant by rotating by the rotational driving force generated by the driving unit 200. The compressing unit 300 compresses the refrigerant compressed by the compressing unit 300, The compression unit 300 is coupled to the rear end of the rotary shaft 270 of the driving unit 200 as shown in FIG.

The compression unit 300 includes an orbiting scroll 310 rotatably mounted on an inner rear end of the driving unit housing 210 and a fixed scroll 320 paired with the orbiting scroll 310 to compress the refrigerant The refrigerant flowing into the compression chamber 330 formed between the orbiting scroll 310 and the fixed scroll 320 is compressed by the relative rotation of the orbiting scroll 310 and the fixed scroll 320.

The orbiting scroll 310 is formed with an orbiting scroll wrap 311 curved in a spiral shape so as to converge toward the center of the orbiting scroll 310. The center of the orbiting scroll wrap 311 is provided with a The rear end of the rotary shaft 270 is engaged and rotated in synchronization with the rotor 240. [

The fixed scroll 320 is fixed to the inner rear end of the drive housing 210 and is fixed to the orbiting scroll wrap 311 of the orbiting scroll 310. The fixed scroll wrap 321, As shown in FIG.

Therefore, when the orbiting scroll 310 rotates, the mutually-aligned orbiting scroll 310 and the fixed scroll 320 are rotated by the interaction of the respective turning and fixed scroll wraps 311 and 321, The refrigerant compressed at a high pressure is discharged through a discharge port 322 formed through the fixed scroll 320 into a high pressure chamber 350 in a cover housing 340 described later .

At this time, the cover housing 340 is coupled to the rear end of the driving housing 210 so that one opening of the cover housing 340 faces the rear of the fixed scroll 320. At one side of the cover housing 340, And a port 360 is formed through the through-hole.

That is, the refrigerant compressed in the compression chamber is discharged to the high-pressure chamber 350 through the discharge port 322, and the high-pressure refrigerant discharged into the high-pressure chamber 350 is supplied to the outside of the compressor 100 through the discharge port 360 .

The inverter unit 400 controls the operation of the driving unit 200. The inverter unit 400 is electrically connected to the stator 230 of the driving unit 200 and rotates the rotor 240 by removing the stator 230. [ And is driven or stopped.

The inverter unit 400 includes an inverter cover 500 coupled to one side of the intermediate housing 220 and an inverter circuit board 600 mounted on the inverter cover 500 and a circuit board And a plurality of electronic components mounted on the substrate 600. [

Here, the inverter cover 500 serves to prevent foreign matter from entering the inverter unit 400 from the outside.

However, in the case of a hybrid vehicle, an electric vehicle, or a fuel cell vehicle, it is necessary to install various electric devices, and there is a fear that a malfunction may occur due to electromagnetic wave interference between electrical devices.

Therefore, the inverter cover of the compressor shields electromagnetic waves generated from various electric components inside the inverter unit or outside the inverter unit, so that the compressor and the other electric components can operate normally without interference with electromagnetic waves, It is necessary to have the function.

To this end, the inverter cover 500 according to an embodiment of the present invention is manufactured by pressing a plate material of a magnesium alloy material excellent in electromagnetic wave shielding function.

At this time, the inverter cover 500 according to an embodiment of the present invention can be manufactured from a thin magnesium alloy sheet having a thickness of 2.5 mm to 3.5 mm, thereby securing the mechanical property equivalent to that of the conventional aluminum-made inverter cover, The weight is reduced by 60% to 70%, which can contribute to the reduction in size and weight of the compressor.

In addition, the inverter cover 500 according to an embodiment of the present invention is made of a magnesium alloy material and has a better electromagnetic wave shielding function than a conventional aluminum material.

Hereinafter, an inverter cover according to an embodiment of the present invention will be described in more detail with reference to FIG.

FIG. 4 is a perspective view of an inverter cover according to an embodiment of the present invention, and FIG. 5 is a graph comparing the thickness and mechanical properties of an inverter cover according to an embodiment of the present invention.

4, the inverter cover 500 according to an embodiment of the present invention is formed in a housing shape in which a receiving space 530 is formed and one side is opened, and a circuit board 600 for an inverter is disposed on one side And a sidewall 520 extending to one side along the rim of the cover plate 510. The cover plate 510 includes a cover plate 510 and a cover 520. The cover plate 510 includes a cover plate 510,

When the inverter cover 500 is coupled to the rear of the intermediate housing 220, the receiving space 530 defined by the rear surface of the intermediate housing 220 and one side of the cover plate 510 and the inner side surface of the side wall 520, The inverter circuit board 600 is accommodated.

At this time, a flange portion 511 having a fastening hole 511a is formed to protrude outward along the rim of the cover plate 510, and fasteners (not shown) such as bolts are inserted through the fastening holes 511a, The intermediate housing 220 and the inverter cover 500 are coupled to each other.

A plurality of fastening bosses 512 spaced apart from each other are protrudingly formed on the inner surface of the cover plate 510 so as to fix the inverter circuit board 600. A fastener such as a bolt The inverter circuit board 600 is fixedly installed at a predetermined distance from the inner surface of the cover plate 510 by being fastened to the respective fastening bosses 512 through the use circuit board 600.

In addition, the cover plate 510 and the side wall 520 of the inverter cover 500 are integrally formed of a magnesium alloy plate material by press working or the like, and the thickness thereof is preferably 2.5 mm to 3.5 mm.

5, if the thickness of the inverter cover 500 is less than 2.5 mm, it becomes difficult to secure a thickness for sealing the inverter unit 400 from external moisture or foreign matter, 500 is larger than 3.5 mm, mechanical properties such as elongation, tensile strength TS and yield stress YS deteriorate as compared with conventional aluminum alloy materials.

At least one cable connection hole is formed in the side wall 520 to supply power to the electronic components in the inverter cover 500.

4, a high voltage cable connection hole 521 is formed at one side of the side wall 520 and a low voltage cable connection hole 522 is formed at the other side of the side wall 520 .

At this time, a grommet (not shown) must be coupled to each of the cable connection holes 521 and 522 in order to prevent the cable inserted into the inverter cover 500 from being sealed and damaged.

However, in the case of the inverter cover 500 according to an embodiment of the present invention, the thickness of the side wall 520 is only 2.5 mm to 3.5 mm, and therefore, a sufficient thickness for grommet mounting is not provided.

Accordingly, in the inverter cover 500 according to an embodiment of the present invention, a grommet mounting member having a predetermined thickness is coupled by a fastener (not shown) such as a bolt along the rim of the cable connection hole inside the side wall 520 .

4, a first grommet mounting member 523 having a predetermined thickness and having a first through hole 523a is formed inside the side wall 520 through which the high-voltage cable connection hole 521 is formed, .

A second grommet mounting member 524 having a second through hole 524a and a predetermined thickness is coupled to the inner side of the side wall 520 through which the low voltage cable connection hole 522 penetrates.

At this time, the high voltage cable connection hole 521 and the first through hole 523a communicate with each other, and the low voltage cable connection hole 522 and the second through hole 524a communicate with each other. Accordingly, the high voltage cable (not shown) passes through the high voltage cable connection hole 521 of the side wall 520 and the first through hole 523a of the first grommet mounting member 523 from the outside, And a low voltage cable (not shown) is connected to the inside of the inverter cover 500 through the low voltage cable connection hole 522 and the second through hole 524a in order.

At this time, the first grommet mounting member 523 and the second grommet mounting member 524 are preferably made of a magnesium alloy material to prevent potential erosion.

The shapes of the first and second through holes 523a and 524a and the thicknesses of the first and second grommet mounting members 523 and 524 are determined by the size of the cable and the through holes 523a and 524a Can be appropriately selected in consideration of the shape and size of the grommet.

100: compressor 200:
270: rotation shaft 280: suction port
300: compression section 330: compression chamber
350: High pressure chamber 360: Discharge port
400: Inverter unit 500: Inverter cover
510: cover plate 520: side wall
521: High voltage cable connection hole 522: Low voltage cable connection hole
523: first grommet mounting member 523a: first through hole
524: second grommet mounting member 524a: second through hole
530: accommodation space 600: circuit board

Claims (6)

A cover plate 510 on which the inverter circuit board 600 is mounted; And
And a side wall 520 extending to one side along the rim of the cover plate 510 so that a receiving space 530 for accommodating the circuit board 600 is formed,
The cover plate 510 and the side wall 520 are integrally formed of a magnesium alloy sheet material,
At least one or more cable connection holes 521 and 522 are formed in the side wall 520 and grommet mounting members 523 and 524 having through holes 523a and 524a communicating with the cable connection holes 521 and 522 are formed in the side wall 520). ≪ IMAGE >
A cover plate 510 on which the inverter circuit board 600 is mounted; And
And a side wall 520 extending to one side along the rim of the cover plate 510 so that a receiving space 530 for accommodating the circuit board 600 is formed,
The cover plate 510 and the side wall 520 are integrally formed of a magnesium alloy sheet material,
Wherein a thickness of the cover plate (510) and the side wall (520) is 2.5 mm to 3.5 mm.
delete The method according to claim 1,
Wherein the grommet mounting members (523, 524) are made of a magnesium alloy material.
The method according to claim 1,
A high voltage cable connection hole 521 and a low voltage cable connection hole 522 are formed so as to be opposed to each other on one side and the other side of the side wall 520, And the second grommet mounting member (524) is coupled along the inner edge of the low voltage cable connection hole (522).
The method according to claim 1,
Wherein a plurality of fastening bosses (512) for fastening the circuit board (600) are protruded from the inner surface of the cover plate (510) so as to be spaced apart from each other.

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