JP5924174B2 - Electric compressor - Google Patents

Description

  The present invention relates to an electric compressor in which a compression unit, an electric motor, and a motor drive circuit are arranged in this order along the axial direction of a rotating shaft.

  This type of electric compressor is disclosed in Patent Document 1, for example. The motor drive circuit includes a flat circuit board and a plurality of types of electrical components mounted on the circuit board. Examples of electrical components include switching elements and capacitors. Here, the capacitor generally includes an electrolytic capacitor, a film capacitor, etc. Among them, since the film capacitor has a smaller internal resistance than the electrolytic capacitor, the influence of the ripple current generated by the switching operation of the switching element is affected. Even if it is received, it does not generate heat easily, and contributes to extending the life of the motor drive circuit.

  Incidentally, a film capacitor is generally composed of a rectangular parallelepiped case that forms an outline of the film capacitor and a dielectric that is accommodated in the case. Such a film capacitor has a rectangular parallelepiped shape when a plurality of film capacitors are mounted side by side on a mounting base made of a metal material that is assembled to the housing of the electric compressor. They are easy to line up and have excellent mountability. Further, a filler is filled between the case of the film capacitor and the mounting base so that the film capacitor does not come off the mounting base due to vibration of the vehicle or the like.

  For example, as shown in FIG. 4, the mounting base 92 to which the film capacitor 91 is mounted has a housing hole 92 a that can house a case 91 a that houses a dielectric (not shown). The accommodation hole 92a is formed to correspond to the shape of the case 91a. A recess 92b is formed at the inner edge of the accommodation hole 92a. In the state where the case 91a is accommodated in the accommodation hole 92a, the case 91a is fixed to the mounting base 92 via the filler 93 by filling the gap 93 between the case 91a and the recess 92b. The Further, when a plurality of film capacitors 91 are accommodated in the accommodation holes 92a, a gap is formed between the cases 91a of the adjacent film capacitors 91, and the gaps are filled with a filler 93, thereby adjoining film capacitors 91. 91 cases 91a are fixed to each other.

JP 2005-201108 A

  However, in the electric compressor, the size of the electric compressor is reduced due to the limitation of the space to be mounted on the vehicle, and accordingly, the space for mounting the motor drive circuit is limited. Therefore, as shown in FIG. 4, in order to secure a space for filling the filler 93, a recess 92b is formed in the mounting base 92, or a gap is formed between cases 91a of adjacent film capacitors 91. In other words, the mounting space for other electrical components and the like around the film capacitor 91 is reduced accordingly. As a result, it is necessary to separately secure a mounting space for other electrical components and the like around the film capacitor 91, which increases the mounting space for the entire motor drive circuit.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide an electric compressor capable of reducing the mounting space of a motor drive circuit.

  In order to achieve the above object, the invention according to claim 1 is a compression unit that is housed in a housing and compresses refrigerant, an electric motor that drives the compression unit, and a motor drive circuit that drives the electric motor. Are arranged in this order along the axial direction of the rotating shaft, the motor drive circuit includes a film capacitor, and the film capacitor is accommodated in a substantially rectangular parallelepiped case and the case. An electric compressor attached to a mounting base attached to the housing, wherein the film capacitor is at least one corner of the case facing the mounting base. Has a chamfered portion, and a gap formed between the mounting base and the chamfered portion is filled with a filler. It is the gist of.

  According to the present invention, the chamfered portion is formed in at least one of the corners facing the mounting base in the case of the film capacitor, and the gap for filling the filler between the mounting base and the chamfered portion is provided. Forming. Therefore, it is not necessary to form a recess in the mounting base or to form a gap between adjacent film capacitor cases in order to secure a space for filling the filler. It is possible to suppress a reduction in the mounting space for the electrical parts. Therefore, in order to secure a space for filling the filler, a recess is formed in the mounting base or a gap is formed between the cases of adjacent film capacitors. It is no longer necessary to secure a separate mounting space for electrical components. As a result, compared with the case where a recess is formed in the mounting base or a gap is formed between adjacent film capacitor cases in order to secure a space for filling the filler, the motor drive circuit The mounting space can be made compact.

  According to a second aspect of the present invention, in the first aspect of the present invention, a switching element that constitutes the motor drive circuit is attached to the attachment base, and the attachment base and the housing are formed of a metal material. The gist of the present invention is that the mounting base is mounted to the housing so that heat can be transferred.

According to this invention, the heat generated from the film capacitor and the switching element can be radiated to the housing via the mounting base.
According to a third aspect of the present invention, in the first or second aspect of the present invention, the motor drive circuit includes a plurality of the film capacitors, and is assembled to the mounting base and the plurality of film capacitors. The gist of the present invention is to further include a storage case capable of storing the above.

  According to this invention, a plurality of film capacitors can be attached to the mounting base by assembling the housing case to the mounting base in a state where the plurality of film capacitors are housed in the housing case. Therefore, the trouble of attaching the plurality of film capacitors to the attachment base can be saved, and the attachment work of the plurality of film capacitors to the attachment base can be simplified.

  The gist of the invention described in claim 4 is that, in the invention described in claim 3, a chamfered portion is further formed in at least one of the corners of the case facing the housing case.

  According to this invention, a gap for filling the filler can be formed between the housing case and the chamfered portion, and the film capacitor can be connected via the filler by filling the gap with the filler. Can be fixed to the storage case. As a result, vibration resistance in the film capacitor can be improved.

  According to the present invention, the mounting space for the motor drive circuit can be made compact.

(A) is a fragmentary sectional view which shows the electric compressor in embodiment, (b) is sectional drawing which expanded partially the motor drive circuit periphery. (A) is a disassembled perspective view of a film capacitor, (b) is a perspective view of a film capacitor. The perspective view of a some film capacitor, a storage case, and an attachment base. Sectional drawing which shows the state in which the film capacitor in a prior art example is attached with respect to the attachment base.

Hereinafter, an embodiment embodying the present invention will be described with reference to FIGS.
As shown in FIG. 1 (a), the housing H of the electric compressor 10 is made of aluminum (made of a metal material) having a bottomed cylindrical shape to a discharge housing 11 made of aluminum (made of a metal material) having a covered cylindrical shape. The suction housing 12 is joined. A suction port (not shown) is formed on the peripheral wall of the suction housing 12, and the suction port is connected to an external refrigerant circuit (not shown). A discharge port 14 is formed in the discharge housing 11, and the discharge port 14 is connected to an external refrigerant circuit. In the suction housing 12, a compression unit 15 (shown by a broken line in FIG. 1A) for compressing the refrigerant and an electric motor 16 for driving the compression unit 15 are accommodated. In the present embodiment, although not particularly illustrated, the compression unit 15 is composed of a fixed scroll fixed in the suction housing 12 and a movable scroll disposed to face the fixed scroll.

  A stator 17 (stator) is fixed to the inner peripheral surface of the suction housing 12, and the stator 17 has a coil 17 b wound around a tooth (not shown) of a stator core 17 a fixed to the inner peripheral surface of the suction housing 12. It is configured to be turned. A rotation shaft 19 is rotatably supported in the suction housing 12 while being inserted into the stator 17, and a rotor 18 (rotor) is fixed to the rotation shaft 19.

  As shown in FIG. 1B, a cover member 13 made of aluminum (made of a metal material) having a covered cylindrical shape is attached to the bottom wall 12a of the suction housing 12 (on the right side of FIG. 1B). . An accommodation space 13 a is defined by the bottom wall 12 a and the cover member 13. A motor drive circuit 20 for driving the electric motor 16 is accommodated in the accommodation space 13a. Therefore, in this embodiment, the compression part 15, the electric motor 16, and the motor drive circuit 20 are arrange | positioned along with the direction (axial direction) where the axis L of the rotating shaft 19 extends in this order.

  When electric power controlled by the motor drive circuit 20 is supplied to the electric motor 16, the rotary shaft 19 and the rotor 18 are rotated at the controlled rotation speed, and the compression unit 15 is driven. By driving the compression unit 15, the refrigerant is sucked into the suction housing 12 from the external refrigerant circuit via the suction port, the refrigerant sucked into the suction housing 12 is compressed by the compression unit 15, and the compressed refrigerant is discharged. Discharge to the external refrigerant circuit via the port 14 is performed.

  The motor drive circuit 20 has a flat circuit board 21. The circuit board 21 is supported on the bottom wall 12a in a state of being separated from the bottom wall 12a by a board support member 12b fixed to the bottom wall 12a. The circuit board 21 is accommodated in the accommodation space 13 a so that the mounting surface of the circuit board 21 is orthogonal to the axial direction of the rotating shaft 19. The circuit board 21 is provided with a drive control circuit (so-called inverter circuit) for the electric motor 16, and a plurality of switching elements 20 a (see FIG. 3) and a plurality of film capacitors 22 are mounted thereon.

  An attachment base 31 made of aluminum (made of metal material) is attached to the bottom wall 12 a of the suction housing 12. The mounting base 31 includes a drive control circuit that constitutes the motor drive circuit 20, a casing 201 (see FIG. 3) in which a plurality of switching elements 20a are accommodated, a plurality of film capacitors 22, and the like. The unit is detachably attached to the bottom wall 12 a of the suction housing 12. The attachment base 31 is attached to the suction housing 12 so that heat can be transferred.

  The mounting base 31 is plate-shaped, and the surface of the suction housing 12 opposite to the bottom wall 12 a forms mounting surfaces 31 a for the plurality of film capacitors 22. In addition, a plurality of boss portions 31b are projected from the surface of the mounting base 31 opposite to the bottom wall 12a of the suction housing 12. Further, a seat portion 31c projects from the surface of the mounting base 31 opposite to the bottom wall 12a of the suction housing 12, and the housing 201 is fixed on the seat portion 31c with an adhesive.

  A housing case 41 made of a resin material is assembled to the mounting base 31. The housing case 41 is formed with a plurality of housing recesses 41 a capable of housing the film capacitor 22. The housing case 41 is formed with a plurality of boss portions 41b into which bolts B1 for assembling to the mounting base 31 can be inserted.

  As shown in FIG. 2A, the film capacitor 22 includes a case 23 having a flat, substantially rectangular parallelepiped shape that forms an outer shape thereof, and a dielectric 24 accommodated in the case 23. The dielectric 24 is formed in a flat shape by winding a metallized film obtained by vapor-depositing metal on a strip-shaped dielectric film and applying pressure from both sides in the radial direction. As the dielectric film, for example, a plastic film such as polyethylene terephthalate (PET) or polypropylene (PP) is used. As the metal deposited on the dielectric film, for example, aluminum, zinc, or a mixture thereof is used. Metal or the like is used. Then, metallized electrodes are formed on both end faces of the metallized film, and leads 24a are welded to the respective metallized electrodes.

  Then, the dielectric 24 is accommodated in a case 23 made of a resin material having an opening on one side, and a resin is injected into the case 23 and cured with a part of the lead 24a protruding from the opening side of the case 23. By doing so, as shown in FIG. 2B, a film capacitor 22 in which a dielectric 24 is accommodated in a case 23 having a flat and substantially rectangular parallelepiped shape is formed.

  Chamfered portions 23a and 23b are formed at both corners of the surface of the case 23 opposite to the surface on which the lead 24a protrudes. Each of the chamfered portions 23a and 23b is formed in a tapered shape and is formed over both corners.

  As shown in FIG. 1B, in the film capacitor 22, one chamfered portion 23 a is disposed on the housing recess 41 a side of the housing case 41, and the other chamfered portion 23 b is disposed on the mounting surface 31 a side of the mounting base 31. It accommodates in the accommodation recessed part 41a so that it may be arrange | positioned. That is, one chamfered portion 23 a is formed at a corner portion of the case 23 facing the housing case 41, and the other chamfered portion 23 b is formed at a corner portion of the case 23 facing the mounting base 31. Is formed.

  The gap formed between the one chamfer 23a and the accommodating recess 41a is filled with the filler 50, and the gap formed between the other chamfer 23b and the mounting surface 31a is filled. The material 51 is filled. The fillers 50 and 51 are resin materials in which a filler such as alumina is mixed into a silicone resin. Therefore, for example, the thermal conductivity is higher than that of an insulating resin material such as polyimide resin or epoxy resin.

Next, a procedure for attaching the plurality of film capacitors 22 to the attachment base 31 will be described.
As shown in FIG. 3, first, each film capacitor 22 is housed in each housing recess 41 a of the housing case 41 so that one chamfered portion 23 a is disposed on the housing recess 41 a side. At this time, the filler 50 is applied in advance on the one chamfered portion 23a. Then, the filling material 50 is filled in the gap formed between the housing recess 41 a of the housing case 41 and the one chamfered portion 23 a, and each film capacitor 22 is placed in the housing case 41 via the filler 50. Housed in a fixed state.

  Next, the housing case 41 in which each film capacitor 22 is housed is assembled to the mounting base 31. At this time, the other chamfer 23b is disposed on the mounting surface 31a side of the mounting base 31, and the filler 51 is preliminarily applied on the other chamfer 23b. Then, the bolt B <b> 1 inserted through the boss 41 b of the housing case 41 is screwed into the boss 31 b of the mounting base 31. Then, the opposing surface 23c facing the mounting base 31 in the case 23 of each film capacitor 22 is in contact with the mounting surface 31a of the mounting base 31, and between the mounting surface 31a of the mounting base 31 and the other chamfered portion 23b. The formed gap 51 is filled with the filler 51. Each film capacitor 22 is fixed to the attachment surface 31 a of the attachment base 31 via the filler 51 and attached to the attachment base 31, and each film capacitor 22 and the housing case 41 are assembled to the attachment base 31.

Next, the operation of this embodiment will be described.
By forming the chamfer 23b at the corner of the case 23 of each film capacitor 22 facing the mounting base 31, a gap for filling the filler 51 is formed between the mounting base 31 and the chamfer 23b. doing. Therefore, it is not necessary to form a recess in the mounting base 31 or to form a gap between the cases 23 of the adjacent film capacitors 22 in order to secure a space for filling the filler 51. Around 22, the mounting space for other electrical components is reduced. As a result, in order to secure a space for filling the filler 51, compared to the case where a recess is formed in the mounting base 31 or a gap is formed between cases of adjacent film capacitors 22, The mounting space for the motor drive circuit 20 is compact. And since each film capacitor 22 is being fixed to the attachment surface 31a of the attachment base 31 via the filler 51, even if each film capacitor 22 vibrates by the vibration of a vehicle, etc., each film capacitor 22 is attached to the attachment base 31. It is hard to come off.

In the above embodiment, the following effects can be obtained.
(1) A chamfer 23b is formed at a corner of the case 23 of the film capacitor 22 facing the mounting base 31, and a gap 51 formed between the mounting base 31 and the chamfer 23b is filled with a filler 51. . Therefore, it is not necessary to form a recess in the mounting base 31 or to form a gap between the cases 23 of the adjacent film capacitors 22 in order to secure a space for filling the filler 51. Around 22, it is possible to suppress a reduction in the mounting space for other electrical components and the like. Therefore, in order to secure a space for filling the filler 51, a recess is formed in the mounting base 31, or a gap is formed between the cases 23 of the adjacent film capacitors 22. There is no need to separately secure a mounting space for other electrical components and the like. As a result, in order to secure a space for filling the filler 51, compared to a case where a recess is formed in the mounting base 31 or a gap is formed between cases 23 of adjacent film capacitors 22. The mounting space for the motor drive circuit 20 can be made compact.

  (2) The switching element 20 a is attached to the attachment base 31. Further, the attachment base 31 is attached to the suction housing 12 so that heat can be transferred. Therefore, the heat generated from each film capacitor 22 and each switching element 20 a can be radiated to the suction housing 12 via the mounting base 31.

  (3) The plurality of film capacitors 22 were housed in the housing case 41 and the housing case 41 was assembled to the mounting base 31. Therefore, the plurality of film capacitors 22 can be attached to the attachment base 31 by assembling the accommodation case 41 to the attachment base 31 in a state where the plurality of film capacitors 22 are accommodated in the accommodation case 41. Therefore, the trouble of attaching the plurality of film capacitors 22 to the attachment base 31 can be saved, and the attachment work of the plurality of film capacitors 22 to the attachment base 31 can be simplified.

  (4) A chamfer 23a is formed at the corner of the case 23 of the film capacitor 22 on the side facing the housing case 41. Therefore, it is possible to form a gap for filling the filler 50 between the housing case 41 and the chamfered portion 23a. By filling the gap 50 with the filler 50, the film capacitor 22 is replaced with the filler 50. It can fix to the storage case 41 via. As a result, vibration resistance in the film capacitor 22 can be improved.

  (5) Each film capacitor 22 is fixed to the mounting surface 31 a of the mounting base 31 via the filler 51. Therefore, the heat generated from each film capacitor 22 can be easily radiated to the mounting base 31 and the suction housing 12 via the filler 51.

  (6) Each film capacitor 22 is attached to the attachment base 31. Therefore, for example, when it is desired to remove each film capacitor 22 from the mounting base 31, each film capacitor can be removed in a space different from the mounting space of the electric compressor 10 by removing the mounting base 31 from the bottom wall 12a of the suction housing 12. The work of removing 22 from the mounting base 31 can be performed, and the workability can be improved.

In addition, you may change the said embodiment as follows.
In the embodiment, the storage case 41 may not be used, and each film capacitor 22 may be attached to the attachment base 31 via the filler 51.

  In the embodiment, chamfered portions may be further formed at both corners of the surface of the case 23 where the lead 24a protrudes. According to this, a gap for filling the fillers 50 and 51 can be further formed, and a space for filling the fillers 50 and 51 can be further secured.

In the embodiment, the chamfered portions 23a and 23b may be formed to be curved in an arc shape, for example.
In the embodiment, the fillers 50 and 51 may be, for example, an insulating resin material such as a polyimide resin or a silicone resin in which a filler such as alumina is not mixed.

In the embodiment, the number of film capacitors 22 is not particularly limited.
In the embodiment, the housing H and the mounting base 31 may be formed of a metal material other than aluminum.

  In the embodiment, the compression unit 15 may be, for example, a piston type or a vane type.

  H: Housing, 10: Electric compressor, 15: Compression section, 16: Electric motor, 19: Rotating shaft, 20 ... Motor drive circuit, 20a ... Switching element, 22 ... Film capacitor, 23 ... Case, 23a, 23b ... Chamfer 24, dielectric, 31 ... mounting base, 41 ... housing case, 50, 51 ... filler.

Claims (4)

A compression unit that is accommodated in the housing and compresses the refrigerant, an electric motor that drives the compression unit, and a motor drive circuit that drives the electric motor are arranged in this order along the axial direction of the rotating shaft. The motor drive circuit includes a film capacitor, and the film capacitor is configured by a substantially rectangular parallelepiped case and a dielectric housed in the case, and the film capacitor is disposed in the housing. An electric compressor attached to an attachment base to be attached,
A chamfered portion is formed in at least one corner of the case facing the mounting base, and a gap formed between the mounting base and the chamfered portion is filled with a filler. An electric compressor characterized by having A switching element constituting the motor drive circuit is attached to the attachment base,
The mounting base and the housing are made of a metal material,
The electric compressor according to claim 1, wherein the attachment base is attached to the housing so as to be capable of transferring heat. The motor drive circuit has a plurality of the film capacitors,
The electric compressor according to claim 1, further comprising a housing case that is assembled to the mounting base and can accommodate the plurality of film capacitors.   The electric compressor according to claim 3, wherein a chamfered portion is further formed in at least one of the corners of the case facing the housing case.