JP5183996B2 - Electric compressor - Google Patents

Description

  The present invention relates to an electric compressor that cools a heating element such as a switching element by using a suction refrigerant.

  A conventional electric compressor of this type is disclosed in Patent Document 1. As shown in FIG. 5, the electric compressor 100 includes a housing 101 that houses a compression mechanism section and a motor that drives the compression mechanism section, and a motor control section 102 that is disposed on the outer surface of the housing 101. A base plate 103 is fixed with screws 104 on the outer surface of the housing 101 through which the suction refrigerant passes. A motor control unit 102 is disposed on the base plate 103. The motor control unit 102 includes a power switching element 105 that is a plurality of heating elements. Each power switching element 105 is fixed in close contact with the base plate 103 by screws 106. That is, the power switching element 105 is fixed to the housing 101 via the base plate 103 with the screw 106.

In the above configuration, a motor (not shown) is driven by the motor control unit 102. When the motor is driven, a compression mechanism (not shown) is driven and the refrigerant is compressed. Then, the housing 101 and the base plate 102 are cooled by the suction refrigerant flowing through the housing 101. Heat exchange is performed between the cooled base plate 102 and the power switching element 105, and the power switching element 105 is cooled. As described above, the power switching element 105 can be cooled without providing a dedicated cooling means.
JP 2004-190547 A

  However, in the conventional electric compressor 100, the power switching element 105 is fixed to the base plate 103 with the fastening force of the screw 106. Therefore, when the housing 101 and the base plate 103 fixed to the housing 101 are deformed so as to expand outward due to an internal pressure increase or the like, the power switching element 105 itself is deformed to follow the deformation. When the power switching element 105 itself deforms such as bending, the power switching element 105 is damaged. If the deformation of the power switching element 105 itself becomes large, the power switching element 105 may be damaged.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an electric compressor that can prevent deformation, breakage, etc. of a heating element due to deformation of a housing.

The invention according to claim 1 that achieves the above object includes a housing that accommodates the compression mechanism portion, and a heating element that is disposed on the outer surface of the housing that forms a refrigerant suction path therein and expands outward due to an increase in internal pressure. And a spring-like fixing member that fixes the heat generating element to the outer surface of the housing by a spring force, and the spring-like fixing member biases a central region of the heat generating element.

  A second aspect of the present invention is the electric compressor according to the first aspect, wherein the springy fixing member is formed of a conductive material, and a ground path is formed through the springy fixing member. And

According to the first aspect of the present invention, since the refrigerant sucked into the housing through the refrigerant suction path is at a low temperature, the housing is at a low temperature, and heat exchange is performed with the heat generating element disposed on the outer surface of the housing. Done. The heat generating element can be cooled by this heat exchange. Further, when the outer surface of the housing is deformed so as to expand outward due to an internal pressure increase or the like, the heat generating element changes in a direction away from the outer surface of the housing against the spring force of the spring-like fixing member. The heating element itself does not deform such as bending. Accordingly, it is possible to prevent the heating element from being deformed or damaged due to the deformation of the housing. In addition, when both ends of the heat generating element are urged by the spring-like fixing member, the heat generating element is bent and deformed at the time of deformation in which the portion corresponding to the central region of the heat generating element bulges on the outer surface of the housing. On the other hand, when the central region of the heat generating element is energized, the heat generating element does not bend and deform even when the housing is deformed as described above. Therefore, it is possible to reliably prevent the heating element from being deformed or damaged.

  According to the invention of claim 2, in addition to the effect of the invention of claim 1, it is possible to improve the noise removal performance of the heating elements and the like.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 to 4 show an embodiment of the present invention, FIG. 1 is a front view of an electric compressor, FIG. 2 is a sectional view taken along line AA in FIG. 1, and FIG. 3 is a sectional view taken along line BB in FIG. FIG. 4 is a front view of the electric compressor with the cover and circuit board removed.

  As shown in FIGS. 1 to 4, the electric compressor 1 has a housing 2. The housing 2 includes a cylindrical compressor housing member 3, a front housing member 4 arranged on one side of the compressor housing member 3, and a rear housing arranged on the other side of the compressor housing member 3. It is comprised from the member (not shown).

  The front housing member 4 includes a front housing body 4A made of aluminum alloy and a front resin housing 4B made of synthetic resin fixed to the outside of the front housing body 4A. In addition, the compressor housing member 3 and the rear housing member (not shown) are integral and made of an aluminum alloy.

  The compression mechanism unit 10 is accommodated in the compressor housing member 3. The compression mechanism unit 10 includes a cylinder block 11 having a substantially elliptical inner peripheral surface, and a front side block 12 and a rear side block 13 disposed on the side surface of the cylinder block 11. A cylinder chamber 14 is formed in these blocks 11, 12 and 13. These blocks 11, 12, 13 are made of an aluminum alloy.

  A rotor 15 is accommodated in the cylinder chamber 14. A rotation shaft 16 passes through the center of the rotor 15, and the rotor 15 and the rotation shaft 16 are fixed. The rotating shaft 16 is rotatably supported by the front side block 12 and the rear side block 13. The rear side block 13 side of the rotating shaft 16 protrudes from the rear side block 13 to the outside.

  A vane 17 is provided at an equally spaced position on the outer periphery of the rotor 15 so as to protrude and retract. Each vane 17 moves while contacting the inner wall of the cylinder chamber 14 by back pressure and its own centrifugal force when the rotor 15 rotates. A plurality of compression chambers are formed in the cylinder chamber 14 between the adjacent vanes 17. Each compression chamber expands its volume in accordance with the rotation of the rotor 15 and repeats a suction process for sucking in the refrigerant, a compression process for reducing the volume, compressing the sucked refrigerant, and discharging it.

  The front side block 12 and the front housing member 4 are formed with a refrigerant suction path 18 including a suction chamber 18a suction port (not shown) and the like. The rear side block 13, the compressor housing member 3, and the rear housing member (not shown) are formed with a refrigerant discharge path (not shown) including a discharge chamber, a discharge port, and the like. In the compression chamber suction process, the refrigerant is sucked into the compression chamber of the cylinder chamber 14 through the refrigerant suction path 18, and in the second half of the compression stroke, the refrigerant compressed in the compression chamber of the cylinder chamber 14 is discharged into the refrigerant discharge path ( It is discharged from (not shown).

  A motor (not shown) is housed inside a rear housing member (not shown). A rotation shaft (not shown) of the motor is connected to the rotation shaft 16 of the compression mechanism unit 10. The motor is driven by the motor control unit 20.

  The motor control unit 20 is provided on the front housing member 4 side as follows. That is, the front housing member 4 is formed with a circuit housing chamber 21 which is the outer surface of the front housing body 4A and is surrounded by the front resin housing 4B. The circuit accommodating chamber 21 accommodates an electronic component such as a switching element 22 that is a heating element and a circuit board 23 on which the electronic component such as the switching element 22 is mounted.

  The switching element 22 is a large element in which a large number of switching element portions are packaged together. Thus, the large switching element 22 is fixed in close contact with the outer surface of the front housing body 4A by the spring force of the springy fixing member 24. The spring fixing member 24 includes a first spring plate 24a having one end fixed to the front resin housing 4B, and a second spring plate 24b having one end fixed to the upper surface of the switching element 22, and the first spring plate 24a. And the other end of both of the second spring plates 24b are fixed by welding or the like. The spring fixing member 24 biases the central region of the switching element 22.

  Further, the first spring plate 24a and the second spring plate 24b of the spring-like fixing member 24 are formed of a conductive material. The ground path of the motor control unit 20 is configured via a spring-like fixing member 24. A description of a specific configuration on the ground side from the spring-like fixing member 24 of the ground path is omitted. The circuit housing chamber 21 is closed by a cover 25.

  In the above configuration, the refrigerant is sucked into the cylinder chamber 14 of the compression mechanism 10 through the refrigerant suction path 18, and the refrigerant compressed in the cylinder chamber 14 of the compression mechanism 10 passes through the refrigerant discharge path (not shown). Discharged. Here, since the refrigerant sucked through the refrigerant suction path 18 is at a low temperature, the front housing body 4A is at a low temperature, and heat exchange is performed with the closely-attached switching element 22. The switching element 22 is cooled by this heat exchange.

  Here, when the outer surface of the front housing body 4A is deformed so as to expand outward due to an internal pressure increase or the like, the switching element 22 resists the spring force of the spring-like fixing member 24 and the outer surface of the front housing body 4A. Since the transition is made in a further separating direction (direction of arrow D in FIG. 3), the switching element 22 itself is not deformed such as bending. Accordingly, it is possible to prevent the switching element 22 from being deformed or damaged due to the deformation of the front housing body 4A.

  In particular, as in the present embodiment, when the switching element 22 is a large one in which a large number of switching element portions are packaged in one, the conventional fixing structure is greatly affected by the deformation of the front housing body 4A. However, in the present invention, even a large switching element 22 can be prevented from being deformed or damaged.

  In this embodiment, the spring fixing member 24 is formed of a conductive material, and a ground path is configured through the spring fixing member 24. Therefore, the noise removal performance of the switching element 22 and the like can be improved.

  In this embodiment, the spring fixing member 24 biases the central region of the switching element 22. When both ends of the switching element 22 are urged by the spring-like fixing member 24, the switching element 22 is deformed when the outer surface of the front housing body 4A and the portion corresponding to the central region of the switching element 22 bulge out. It will bend and deform. On the other hand, when the central region of the switching element 22 is energized, even when the front housing body 4A is deformed as described above, the switching element 22 does not bend and deform. Therefore, deformation, breakage, etc. of the switching element 22 can be reliably prevented.

  In this embodiment, the spring fixing member 24 includes a first spring plate 24a fixed to the front resin housing 4B and a second spring plate 24b fixed to the switching element 22. However, the spring-like fixing member 24 may be an integrated body that is fixed to one of the front resin housing 4B and the switching element 22, or may be an integrated body that is not fixed to either. In the case of an integrated body fixed to either the front resin housing 4B or the switching element 22, it is fixed to the mating member by welding or the like. In the case of an integrated object that is not fixed to either, it is fixed to both members by welding or the like.

  In this embodiment, the spring fixing member 24 for fixing the switching element 22 is supported by the front resin housing 4B. However, it may be supported by the front housing member 4 side, and is supported by the front housing body 4A. Of course, you can do it. However, when fixing to the front resin housing 4B as in the present embodiment, the first spring plate 24a can be fixed by insert molding at the time of molding the front resin housing 4B. There is no need to do it.

  In this embodiment, the heat generating element is the switching element 22, but it goes without saying that the present invention can be applied to other elements than the switching element 22.

  In this embodiment, the switching element 22 is directly attached to the bottom surface of the front housing body 4A, but grease or a heat dissipation sheet may be interposed between the switching element 22 and the front housing body 4A. With this configuration, even if the switching element 22 follows the deformation of the front housing body 4A and slightly changes in the direction of the arrow D in FIG. 3, an air layer can be formed between the switching element 22 and the front housing body 4A. Therefore, direct heat conduction between the switching element 22 and the front housing body 4A can be maintained. Thereby, the cooling performance of the switching element 22 can be improved.

1 is a front view of an electric compressor according to an embodiment of the present invention. FIG. 2 shows an embodiment of the present invention and is a cross-sectional view taken along line AA of FIG. 1. 1 shows an embodiment of the present invention and is a cross-sectional view taken along line BB in FIG. 1. FIG. 1 is a front view showing an embodiment of the present invention, with an electric compressor cover and a circuit board removed. It is a disassembled perspective view of the electric compressor of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electric compressor 2 Housing 10 Compression mechanism part 22 Switching element (heating element)
24 Spring fixing member

Claims (2)

A housing (2) that houses the compression mechanism (10), and a heating element disposed on the outer surface of the housing (2) that has a refrigerant suction path (18) formed therein and expands outward due to an increase in internal pressure. (22) and a springy fixing member (24) for fixing the heat generating element (22) to the outer surface of the housing (2) by a spring force. The springy fixing member (24) includes the heat generating element (24). 22) The electric compressor (1) characterized by energizing the central region of 22). An electric compressor (1) according to claim 1,
The electric compressor (1), wherein the spring fixing member (24) is made of a conductive material, and an earth path is formed through the spring fixing member (24).

Images