Inverter unit and motor unit

Abstract

The inverter unit comprises: an inverter; and a housing that accommodates the inverter. The housing comprises: a bottom portion that extends along a horizontal plane; and a side wall portion that protrudes upward from the outer edge of the bottom portion. The bottom is provided with: a main recess that opens to the upper side; a first recess and a second recess that are recessed downward from the bottom surface of the main recess; a first flow path that extends along a horizontal plane inside the bottom portion and opens between the first recess and the outer side surface of the housing; and a second flow path that extends along a horizontal plane inside the bottom portion and connects the second recess and the outer side surface of the housing. The opening of the main recess is covered by a portion of the inverter. The openings of the first flow path and the second flow path on the outer side surface of the housing are respectively connected to pipes for the flow of refrigerant. A portion of the second flow path overlaps with the main recess when viewed from the top and bottom directions.

Description

Technical Field

[0001] The present invention relates to an inverter unit and a motor unit. This application is based on Japanese Patent Application No. 2018-084460 filed on April 25, 2018. This application claims the benefit of priority over the aforementioned application. The entire contents of the application are incorporated into this application by reference. Background Art

[0002] In recent years, an inverter unit having an inverter has been developed as a control unit for a motor or a generator of a hybrid vehicle or the like. Since the inverter of the inverter unit includes heat generating components, it is required to appropriately cool them. Japanese Publication No. 2003-199363 describes an inverter unit having a housing provided with a refrigerant flow path for cooling the heat generating components.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2003-199363 Summary of the invention

[0006] Problems to be solved by the invention

[0007] In the conventional inverter unit, there is a problem that the refrigerant flow path is complicated in order to improve the cooling efficiency, and the manufacturing cost of the casing is increased.

[0008] In view of the above circumstances, one object of the present invention is to provide an inverter unit that can be manufactured at low cost and can improve cooling efficiency, and a motor unit having the inverter unit.

[0009] Means for solving problems

[0010] One mode of the inverter unit of the present invention comprises: an inverter; and a housing that accommodates the inverter. The housing comprises: a bottom extending along a horizontal plane; and a side wall portion that protrudes upward from the outer edge of the bottom. The bottom is provided with: a main recess that opens to the upper side; a first recess and a second recess that are recessed downward from the bottom surface of the main recess; a first flow path that extends along a horizontal plane inside the bottom and opens between the first recess and the outer side surface of the housing; and a second flow path that extends along a horizontal plane inside the bottom and connects the second recess and the outer side surface of the housing. The opening of the main recess is covered by a portion of the inverter. The openings of the first flow path and the second flow path on the outer side surface of the housing are respectively connected to pipes for the flow of refrigerant. A portion of the second flow path overlaps with the main recess when viewed from the top and bottom directions.

[0011] One aspect of the motor unit of the present invention includes the inverter unit described above and the motor to which the AC current is supplied from the inverter unit.

[0012] Effects of the Invention

[0013] According to one aspect of the present invention, an inverter unit that can be manufactured at low cost and can improve cooling efficiency, and a motor unit including the inverter unit are provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a top view of a motor unit according to one embodiment.

[0015] Figure 2 The figure is a cross-sectional schematic diagram of an inverter unit according to an embodiment.

[0016] Figure 3 It is a top view of the housing of the inverter unit according to one embodiment. DETAILED DESCRIPTION

[0017] Hereinafter, the inverter unit 1 and the motor unit 3 according to the embodiment of the present invention will be described with reference to the drawings. In the following drawings, in order to facilitate understanding of each structure, the actual structure and the scale, number, etc. in each structure may be different.

[0018] In the following description, the direction of gravity is specified based on the positional relationship when the motor unit 3 is mounted on a vehicle located on a horizontal road surface. In addition, the posture of the motor unit 3 and the inverter unit 1 in this specification is only an example and does not limit the posture of the actual installation of the motor unit 3 and the inverter unit 1.

[0019] In the accompanying drawings, an XYZ coordinate system is appropriately shown as a three-dimensional vertical coordinate system. In the XYZ coordinate system, the Z-axis direction represents the vertical direction (i.e., the up-down direction), the +Z direction is the upper side (the opposite side of the gravity direction), and the -Z direction is the lower side (the gravity direction). In addition, the X-axis direction is a direction perpendicular to the Z-axis direction, indicating the front-to-back direction of the vehicle equipped with the inverter unit 1. The Y-axis direction is a direction perpendicular to both the X-axis direction and the Z-axis direction, indicating the width direction (left-right direction) of the vehicle.

[0020] Hereinafter, an inverter unit 1 according to an exemplary embodiment of the present invention and a motor unit 3 including the inverter unit 1 will be described with reference to the drawings.

[0021] <Motor unit>

[0022] Figure 1 It is a top view of the motor unit 3 .

[0023] The motor unit 3 includes an inverter unit 1 , a motor 2 , a housing 4 , and a reduction gear 5 .

[0024] The motor unit 3 of the present embodiment is mounted on a vehicle using a motor as a power source, such as a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHV), or an electric vehicle (EV), and is used as the power source.

[0025] The housing 4 is provided with a storage space for storing the motor 2 and the reduction gear 5. An inverter unit 1 is fixed to the outer side of the housing 4. The motor 2 is supplied with an alternating current from the inverter unit 1. The motor 2 is controlled by the inverter unit 1. The motor 2 has a rotor that rotates around a motor axis J extending in a horizontal direction and a stator located radially outside the rotor. The coil wire of the stator is connected to the inverter unit 1. The reduction gear 5 is connected to the rotor of the motor 2. The reduction gear 5 reduces the rotation of the motor 2 and outputs it.

[0026] <Inverter unit>

[0027] Figure 2 is a schematic cross-sectional view of the inverter unit 1 .

[0028] The inverter unit 1 includes a housing 10 , a cover 11 , a control board 21 , and an inverter 25 .

[0029] (Control board)

[0030] The control board 21 is connected to the motor 2 to control the motor 2. For example, when the motor unit 3 has an encoder such as a resolver, the control board 21 performs feedback control on the rotation speed of the motor 2 based on the rotation speed of the motor 2 measured by the encoder.

[0031] (Inverter)

[0032] The inverter 25 includes a power supply substrate 22, a capacitor 23, and a switching element 24. The switching element of the present embodiment is an insulated gate bipolar transistor (IGBT). The capacitor 23 and the switching element 24 are connected to the power supply substrate 22, respectively. The inverter 25 is connected to an external power supply device. The external power supply device is, for example, a secondary battery mounted on a vehicle. The inverter 25 converts the DC current supplied from the external power supply device 9 into AC current and supplies it to the motor 2.

[0033] (case)

[0034] The housing 10 is made of, for example, an aluminum alloy and is molded by casting such as die casting.

[0035] The housing 10 is opened upward. The upper opening of the housing 10 is covered by a cover 11. A storage space 13 is provided inside the housing 10. The control substrate 21 and the inverter 25 are stored in the storage space 13. The control substrate 21 and the inverter 25 are fixed to the housing 10 inside the storage space 13.

[0036] The housing 10 has a bottom 15 extending along a horizontal plane and a side wall 16 protruding upward from the outer edge of the bottom 15. The storage space 13 is a space surrounded by the bottom 15, the side wall 16 and the cover 11. The bottom 15 is substantially rectangular when viewed from the top and bottom. The bottom 15 is located at the lower side of the storage space 13. The side wall 16 surrounds the storage space 13 from the horizontal direction. The cover 11 is fixed to the upper end surface of the side wall 16.

[0037] The upper surface 15a of the bottom portion 15 is provided with a seat portion 17 protruding upward. That is, the bottom portion 15 has the seat portion 17. The seat portion 17 has an upper surface 17a. The upper surface 17a of the seat portion 17 is a part of the upper surface 15a of the bottom portion 15.

[0038] A groove 18 connected in a ring shape is provided on the upper surface 17a of the seat 17. A gasket (water stop member) 19 is accommodated in the groove 18. In addition, a switch element 24 is fixed to the upper surface 17a of the seat 17. The gasket 19 is sandwiched between the seat 17 and the switch element 24.

[0039] A refrigerant flow path 30 is provided at the bottom 15. Pipes 6 are connected to both ends of the refrigerant flow path 30. That is, a pair of pipes 6 are connected to the inverter unit 1. Refrigerant cooled by a radiator (not shown) flows through the pipes 6. The refrigerant flows from the pipes 6 into one end of the refrigerant flow path 30, and cools the inverter 25 while flowing through the refrigerant flow path 30. In addition, the refrigerant flows out from the other end of the refrigerant flow path 30 to the pipes 6, and is transported to the radiator via the pipes 6.

[0040] The bottom 15 is provided with a main recess 35 , a first recess 31 , a second recess 32 , a first flow path 36 , and a second flow path 37 . The main recessed portion 35 , the first recessed portion 31 , the second recessed portion 32 , the first flow path 36 , and the second flow path 37 constitute the refrigerant flow path 30 .

[0041] (Main recess)

[0042] Figure 31 is a top view of the housing 10. The main recess 35 is provided on the upper surface 15a of the bottom 15. More specifically, the main recess 35 is provided on the upper surface 17a of the base 17. The main recess 35 is open to the upper side. When viewed from the top and bottom direction, the main recess 35 is a substantially rectangular shape with one direction in the horizontal plane (in this embodiment, the Y-axis direction) as the length direction. When viewed from the top and bottom direction, the main recess 35 is surrounded by the gasket 19 and the groove 18 into which the gasket 19 is embedded.

[0043] like Figure 2 As shown, the opening of the main recess 35 is covered by the switching element 24. That is, the opening of the main recess 35 is covered by a part of the inverter 25. The bottom surface 35a of the main recess 35 is opposite to the lower surface 24b of the switching element 24 in the up-down direction. The space surrounded by the lower surface 24b of the switching element 24 and the inner wall surface of the main recess 35 constitutes a part of the refrigerant flow path 30. A plurality of heat dissipation pins 24a are provided on the lower surface 24b of the switching element 24. The lower surface 24b of the switching element 24 and the plurality of heat dissipation pins 24a are in contact with the refrigerant flowing in the refrigerant flow path 30.

[0044] According to the present embodiment, a portion of the surface of the inverter 25 (in the present embodiment, the lower surface 24b of the switching element 24 and the surface of the heat sink 24a) constitutes a portion of the inner wall surface of the refrigerant flow path 30. Therefore, the refrigerant flowing in the refrigerant flow path 30 can directly cool the inverter 25. Thus, the cooling efficiency of the refrigerant on the inverter 25 can be improved.

[0045] (1st concave part and 2nd concave part)

[0046] The first recess 31 and the second recess 32 are recessed downward from the bottom surface 35a of the main recess 35. The first recess 31 and the second recess 32 are open upward. The first recess 31 and the second recess 32 are arranged along the Y-axis direction on the bottom surface 35a of the main recess 35. That is, the first recess 31 and the second recess 32 are arranged in the longitudinal direction of the main recess 35. The first recess 31 and the second recess 32 are respectively located at both ends of the main recess 35 in the longitudinal direction.

[0047] The main recess 35, the first recess 31, and the second recess 32 are all opened upward. That is, the opening direction of the main recess 35, the first recess 31, and the second recess 32 is consistent with the opening direction of the housing 10. Therefore, when the housing 10 is molded by casting such as die casting, the main recess 35, the first recess 31, and the second recess 32 can be molded by the shape of the mold. In the formation of the main recess 35, the first recess 31, and the second recess 32 in this embodiment, no subsequent processing such as cutting is required.

[0048] (1st flow path)

[0049] like Figure 3 As shown, the first flow path 36 extends along the horizontal plane inside the bottom 15. The first flow path 36 has a first opening 36a and a second opening 36b. The first flow path 36 opens to the outer side surface of the housing 10 at the first opening 36a. In addition, the first flow path 36 opens to the first recess 31 at the second opening 36b. That is, the first flow path 36 opens to the first recess 31 and the outer side surface of the housing 10. The pipe 6 is connected to the first opening 36a.

[0050] The first flow path 36 extends linearly over the entire length. In the present embodiment, the first flow path 36 extends in the Y-axis direction. According to the present embodiment, the first flow path 36 is linear over the entire length, and thus can be easily formed by cutting the bottom portion 15 using a cutting tool such as a drill.

[0051] (2nd flow path)

[0052] The second flow path 37 extends along a horizontal plane inside the bottom 15. The second flow path 37 has a third opening 37a and a fourth opening 37b. The second flow path 37 opens on the outer side surface of the shell 10 at the third opening 37a. In addition, the second flow path 37 opens on the second recess 32 at the fourth opening 37b. That is, the second flow path 37 opens on the second recess 32 and the outer side surface of the shell 10. The piping 6 is connected to the third opening 37a. The third opening 37a faces the same direction as the first opening 36a. In addition, in the present specification, the so-called "two openings face the same direction" includes, in addition to the case where the central axes of the respective openings are strictly parallel to each other, the case where the central axes of the respective openings are inclined to each other within a range of less than ±45°.

[0053] The second flow path 37 has a first straight portion 38 and a second straight portion 39. The first straight portion 38 and the second straight portion 39 are connected to each other. The first straight portion 38 and the second straight portion 39 extend in a straight line. In the present embodiment, the first straight portion 38 extends in the Y-axis direction. In addition, the second straight portion 39 extends obliquely toward the X-axis direction relative to the Y-axis direction. That is, the second straight portion 39 extends obliquely relative to the extension direction of the first straight portion 38. Therefore, the second flow path 37 is a flow path bent at the connection portion between the first straight portion 38 and the second straight portion 39.

[0054] According to the present embodiment, the second flow path 37 is composed of two mutually connected straight portions (the first straight portion 38 and the second straight portion 39). Therefore, the second flow path 37 is formed by machining the first straight portion 38 and the second straight portion 39 on the bottom portion 15 using a cutting tool such as a drill.

[0055] The first straight portion 38 has a first end portion 38a and a second end portion 38b on the opposite side of the first end portion 38a. The first end portion 38a is located directly below the main recess 35. That is, the first end portion 38a is located below the main recess 35 and overlaps with the main recess 35 when viewed from the top and bottom directions. Figure 2 As shown, the second end portion 38b opens on the outer side surface of the shell 10. That is, the first straight portion 38 opens on the outer side surface of the shell 10 at the second end portion 38b. The cap portion 8 is installed on the opening of the second end portion 38b and is closed by the cap portion 8. For example, a spiral thread groove is formed on the inner circumferential surface of the second end portion 38b. In addition, the cap portion 8 is, for example, a bolt, and is fixed to the opening of the second end portion 38b by screwing with the second end portion 38b. By using the bolt, it is possible to prevent the refrigerant from leaking from the opening of the second end portion 38b with a simple structure. Furthermore, a liquid gasket may be applied between the inner circumferential surface of the second end portion 38b and the cap portion 8. When a liquid gasket is applied between the second end portion 38b and the cap portion 8, leakage of the refrigerant can be reliably prevented.

[0056] The second recessed portion 32 is located between the first end portion 38a and the second end portion 38b. Therefore, the first straight portion 38 penetrates the second recessed portion 32. The first straight portion 38 has an area from the first end portion 38a to the second recessed portion 32 and an area from the second recessed portion 32 to the second end portion 38b. That is, a portion of the first straight portion 38 (the area from the second recessed portion 32 to the first end portion 38a) extends linearly from the second recessed portion 32 and reaches the first end portion 38a. In addition, the area from the second recessed portion 32 to the first end portion 38a is an area provided depending on the cutting process for forming the second flow path 37, and becomes a state where the refrigerant is retained inside.

[0057] The second straight portion 39 has a third end portion 39a and a fourth end portion 39b on the opposite side of the third end portion 39a. The third end portion 39a is connected to the first end portion 38a of the first straight portion 38. Therefore, the third end portion 39a is located directly below the main recess 35. The third opening 37a is provided at the fourth end portion 39b. That is, the fourth end portion 39b opens on the outer side surface of the housing 10. That is, the second straight portion 39 extends from the first end portion 38a to the outer side surface of the housing 10.

[0058] (Summarize)

[0059] Next, the path of the refrigerant flowing in the refrigerant flow path 30 will be described. The refrigerant flows into the refrigerant flow path 30 from the pipe 6 connected to the first opening 36a. The refrigerant flowing into the refrigerant flow path 30 passes through the first flow path 36, flows into the first recess 31 at the second opening 36b, and then reaches the inside of the main recess 35. The refrigerant reaching the main recess 35 cools the switch element 24 while passing through the space surrounded by the inner wall surface of the main recess 35 and the lower surface 24b of the switch element 24. The refrigerant in the main recess 35 flows into the second flow path 37 via the second recess 32. The refrigerant in the second flow path 37 flows from the second recess 32 to the third opening 37a side, and flows out to the pipe 6 connected to the third opening 37a.

[0060] A portion of the second flow path 37 of the present embodiment is located directly below the main recess 35. That is, a portion of the second flow path 37 is located below the main recess 35 and overlaps with the main recess 35 when viewed from the top and bottom. In other words, the refrigerant flow path 30 of the present embodiment is three-dimensionally configured, and a portion thereof crosses when viewed from the top and bottom. By configuring the refrigerant flow path 30 three-dimensionally, the refrigerant flow path 30 can be miniaturized in the horizontal direction compared to a case where the refrigerant flow path is configured in a plane.

[0061] According to the present embodiment, since a portion of the second flow path 37 is located directly below the main recess 35, an area of ​​the bottom 15 sandwiched between the main recess 35 and the second flow path 37 is cooled by the refrigerant passing through the second flow path 37. Therefore, the refrigerant inside the main recess 35 is effectively used for cooling the inverter 25, and the cooling efficiency of the refrigerant inside the main recess 35 for the inverter 25 can be improved.

[0062] According to this embodiment, the inverter 25 directly contacts the refrigerant in the main recess 35, so the inverter 25 can be effectively cooled without providing a complicated flow path. That is, according to this embodiment, the inverter unit 1 can be manufactured at low cost and the cooling efficiency of the inverter 25 can be improved.

[0063] According to the present embodiment, the first opening 36a and the third opening 37a face the same direction. Therefore, according to the present embodiment, the pipes 6 connected to the first opening 36a and the third opening 37a can be routed in the same direction, and can be easily connected to a radiator (not shown).

[0064] In the installation space of the inverter unit 1, sufficient space is required for arranging the piping 6 in the direction in which the piping 6 extends. In the case of a structure in which a pair of piping extends in different directions, other components cannot be arranged around the inverter unit 1 in the direction in which each piping extends. According to this embodiment, by making the first opening 36a and the third opening 37a face the same direction, the pair of piping 6 can be led out in the same direction. As a result, in the installation space around the inverter unit 1, the degree of freedom of the installation location of other components can be increased.

[0065] In the present embodiment, the first opening 36a of the refrigerant flow path 30 is connected to the pipe 6 on the upstream side, and the third opening 37a is connected to the pipe 6 on the downstream side. Therefore, the refrigerant in the refrigerant flow path 30 flows from the first opening 36a to the third opening 37a via the main recess 35. In the refrigerant flow path 30 of the present embodiment, the path from the main recess 35 to the first opening 36a is shorter than the path from the main recess 35 to the third opening 37a. Therefore, by connecting the pipe 6 on the upstream side to the first opening 36a, a lower temperature refrigerant can be supplied to the main recess 35, and the cooling efficiency of the inverter 25 can be improved.

[0066] <Modification of the Second Flow Path>

[0067] A second flow path 137 of a modified example that can be adopted in the inverter unit 1 of the present embodiment will be described. The second flow path 137 of the present modified example is Figure 3 denoted by an imaginary line (two-dot chain line) in FIG. 2. The second flow path 137 of this modification is different from the second flow path 37 of the above-described embodiment in that it is linear over the entire length.

[0068] The second flow path 137 of this modification extends linearly from the second recess 32 to the outer side of the shell 10. The second flow path 137 extends obliquely toward the X-axis direction relative to the Y-axis direction. The second flow path 137 opens at the second recess 32 and the outer side of the shell 10. The pipe 6 is connected to the opening of the outer side of the shell 10 of the second flow path 137. According to this modification, since the second flow path 137 is linear over the entire length, it can be formed by processing a linear hole. Therefore, according to this modification, compared with the second flow path 37 of the above-mentioned embodiment, the processing steps of the refrigerant flow path 30 can be simplified, and the manufacturing cost can be reduced.

[0069] The above describes the embodiments of the present invention and its variations, but each structure and its combination in the embodiments is only an example, and addition, omission, substitution and other changes of the structure can be made without departing from the scope of the present invention. In addition, the present invention is not limited to the embodiments.

[0070] For example, in the above embodiment, the pipe 6 on the upstream side is connected to the first opening 36a of the refrigerant flow path 30, and the pipe 6 on the downstream side is connected to the third opening 37a. However, the pipe 6 on the downstream side may be connected to the first opening 36a of the refrigerant flow path 30, and the pipe 6 on the upstream side may be connected to the third opening 37a.

[0071] For example, the inverter unit 1 of the above-described embodiment may be reversed upside down and mounted on the motor unit 3 .

[0072] Description of symbols

[0073] 1: inverter unit; 2: motor; 3: motor unit; 6: piping; 8: cap; 10: housing; 15: bottom; 16: side wall; 25: inverter; 31: first recess; 32: second recess; 35: main recess; 35a: bottom surface; 36: first flow path; 37, 137: second flow path; 38: first straight portion; 38a: first end portion; 38b: second end portion; 39: second straight portion.

Claims

1. An inverter unit, comprising: Inverter; and a housing for housing the inverter, The housing has: a bottom portion, which extends along a horizontal plane; as well as a side wall portion protruding upward from the outer edge of the bottom portion, At the bottom are: A main recess that opens toward the upper side; a first recess and a second recess, which are recessed downward from the bottom surface of the main recess; a first flow path extending along a horizontal plane inside the bottom and opening at the first recess and an outer side surface of the housing, respectively; as well as a second flow path extending along a horizontal plane inside the bottom portion and opening at the second recess and at an outer side surface of the housing, respectively; The opening of the main recess is covered by a portion of the inverter, The first flow path and the second flow path are respectively connected to pipes through which refrigerant flows at openings on the outer side surface of the shell. A portion of the second flow path overlaps with the main recess when viewed from the top and bottom direction.

2. The inverter unit according to claim 1, wherein: An opening of the first flow path with respect to the outer side surface of the housing and an opening of the second flow path with respect to the outer side surface of the housing face the same direction as each other.

3. The inverter unit according to claim 1 or 2, wherein: The first flow path extends linearly over its entire length. The second flow path has: a first straight portion extending linearly from the second recess and reaching a first end portion located directly below the main recess; and a second straight portion extending straightly from the first end portion to the outer side surface of the housing, The second straight portion extends obliquely with respect to a direction in which the first straight portion extends.

4. The inverter unit according to claim 3, wherein: The first straight portion passes through the second recess and opens at the outer side surface of the housing at a second end portion opposite to the first end portion. The opening of the second end portion is closed by a cap portion.

5. The inverter unit according to claim 1 or 2, wherein: The first flow path and the second flow path each extend linearly over the entire length.

6. A motor unit comprising: The inverter unit according to any one of claims 1 to 5; and The motor is supplied with AC current by the inverter unit.

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