Inverter unit, motor unit

Abstract

An inverter unit and a motor unit that can be installed on a motor, wherein the inverter unit comprises: a power supply unit that includes an inverter circuit; an inverter case that accommodates the power supply unit; and an external connection bus bar that is electrically connected to the power supply unit, the inverter case having a lower shell having a bottom wall and a cylindrical side wall extending upward from the periphery of the bottom wall, the power supply unit and the external connection bus bar being connected at a bus bar connection portion that is above the upper end surface of the side wall of the lower shell.

Description

[0001] This application is a divisional application of the invention patent application with application number 201980055016.3, application date August 23, 2019, and invention name “Inverter unit, motor unit”. Technical Field

[0002] The present invention relates to an inverter unit and a motor unit. Background Art

[0003] In the past, an inverter unit having an inverter for controlling a motor and a housing for accommodating the inverter was known. Japanese Publication No. 2003-199363 discloses an electric drive unit (inverter unit) in which components are stacked and fixed in order of size in consideration of compactness, assemblability, manufacturability, and shock resistance.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2003-199363 Summary of the invention

[0007] Problems to be solved by the invention

[0008] The inverter and capacitor of the inverter unit are housed in a cylindrical housing having a bottom wall. In this structure, if a bus bar or wiring is to be connected to a component disposed near the bottom wall of the housing, the connection portion needs to be operated through a narrow gap between the housing and the component, which reduces the efficiency of the assembly operation.

[0009] Means for solving problems

[0010] According to one embodiment of the present invention, an inverter unit is provided, which can be installed on a motor, wherein the inverter unit has: a power supply unit, which includes an inverter circuit; an inverter case, which accommodates the power supply unit; and an external connection bus bar, which is electrically connected to the power supply unit, the inverter case has a lower shell, the lower shell has a bottom wall and a cylindrical side wall extending upward from the periphery of the bottom wall, the power supply unit and the external connection bus bar are connected in a bus bar connection portion that is above the upper end surface of the side wall of the lower shell.

[0011] Effects of the Invention

[0012] According to one aspect of the present invention, there are provided an inverter unit capable of efficiently performing an assembly operation, and a motor unit including the inverter unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1This is a perspective view of the inverter unit according to the present embodiment as viewed from above.

[0014] Figure 2 This is a perspective view of the inverter unit according to the present embodiment as viewed from the bottom.

[0015] Figure 3 It is a partial cross-sectional view of the inverter unit according to the present embodiment.

[0016] Figure 4 It is a plan view showing the internal structure of the inverter unit according to the present embodiment.

[0017] Figure 5 It is a perspective view showing the internal structure of the inverter unit according to the present embodiment.

[0018] Figure 6 It is an exploded perspective view showing the connection structure around the external connection bus bar. DETAILED DESCRIPTION

[0019] Hereinafter, embodiments of the present invention will be described using the drawings.

[0020] In the following description, the gravity direction is specified for description based on the positional relationship when the inverter unit 1 is mounted on a vehicle located on a horizontal road. In addition, in the accompanying drawings, an XYZ coordinate system is appropriately shown as a three-dimensional rectangular coordinate system. In the XYZ coordinate system, the Z-axis direction represents the vertical direction (i.e., the up and 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, and in this embodiment, it represents the direction along the short side of the inverter unit 1. The Y-axis direction is a direction perpendicular to both the X-axis direction and the Z-axis direction, and in this embodiment, it represents the direction along the long side of the inverter unit 1.

[0021] like Figure 3 As shown, the inverter unit 1 is arranged on the motor unit 3. The motor unit 3 has an inverter unit 1 and a motor 2. The inverter unit 1 is arranged on the upper surface of the motor 2. Therefore, the lower surface of the inverter unit 1 is a motor connection part 10A connected to the motor 2. The motor connection part 10A is a part that mechanically connects the inverter unit 1 and the motor 2. Bolt fastening can be used as a connection structure between the inverter unit 1 and the motor 2. If it is not necessary to load and unload the inverter unit 1 and the motor 2, rivet fastening or welding can also be used. A bracket can also be installed on the motor connection part 10A, and the inverter unit 1 and the motor 2 are connected via the above-mentioned bracket.

[0022] The motor 2 is supplied with an alternating current by the inverter unit 1. The motor 2 is controlled by the inverter unit 1. The inverter unit 1 is connected to a coil wire of a stator of the motor 2.

[0023] The motor unit 3 of this 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 a power source. The motor unit 3 may also include a speed reduction device (not shown) for reducing the rotation of the motor 2.

[0024] The inverter unit 1 converts the DC current into AC current and supplies it to the motor 2. Figures 1 to 4 As shown, the inverter unit 1 includes an inverter case 10 , a control substrate 20 , a power supply unit 30 including an inverter circuit, a capacitor 40 , and a plurality of external connection bus bars 50 .

[0025] The inverter case 10 includes a lower housing 11 and a cover member 12 mounted on an opening of the lower housing 11. The lower housing 11 includes a bottom wall 11a and a cylindrical side wall 11b extending upward from the periphery of the bottom wall 11a. The cover member 12 includes a top wall 12a and a cylindrical side wall 12b extending downward from the periphery of the top wall 12a. The lower housing 11 and the cover member 12 are fastened by bolts in a state where the upper end surface 11c of the side wall 11b and the lower end surface 12c of the side wall 12b are opposed to each other.

[0026] The lower case 11 has a storage chamber 13 surrounded by a bottom wall 11a and side walls 11b. The control board 20, the power supply unit 30, the capacitor 40, and the external connection bus bar 50 are arranged inside the storage chamber 13 as viewed from above.

[0027] The storage chamber 13 includes a first storage chamber 13A and a second storage chamber 13B which are separated in the horizontal direction. That is, the inverter case 10 has the first storage chamber 13A and the second storage chamber 13B. The power supply unit 30 and the external connection bus bar 50 are arranged in the first storage chamber 13A. The control substrate 20 and the capacitor 40 are arranged in the second storage chamber 13B.

[0028] like Figure 4 As shown in FIG. 1 , the first storage chamber 13A is roughly rectangular in plan view. Figure 2 As shown, a cooling unit 60 is provided at the bottom of the first storage chamber 13A. The cooling unit 60 has a refrigerant flow path 11d. The refrigerant flow path 11d is a recessed portion opened on the upper surface side of the bottom wall 11a. The refrigerant flow path 11d is roughly rectangular in a top view. The refrigerant flow path 11d is connected to the pipe connection terminals 14 and 15 on the side of the lower shell 11 via a tubular flow path penetrating the bottom wall 11a. The pipe connection terminals 14 and 15 are connected to external refrigerant pipes. The power supply part 30 is fixed to the refrigerant flow path 11d.

[0029] like Figure 4As shown, the second storage chamber 13B is a substantially rectangular shape that is thinner and longer in the X-axis direction than the first storage chamber 13A. A capacitor 40 is fixed to the bottom of the second storage chamber 13B. The control substrate 20 is fixed to the upper surface of the capacitor 40.

[0030] The control board 20 supplies a drive signal to the motor 2 via the power supply unit 30 to control the motor 2. The control board 20 is electrically connected to an encoder such as a resolver provided on the motor unit 3. The control board 20 performs feedback control of the rotation speed and torque through the rotation speed and current of the motor 2 based on the rotation information of the motor 2 output from the encoder.

[0031] like Figure 1 as well as Figure 4 As shown, the capacitor 40 is connected to the external power supply device 9 via the wiring 9a. The wiring 9a is connected to the capacitor input terminal 41 of the capacitor 40 via the wiring terminal 9b provided at the end of the wiring 9a. The external power supply device 9 is, for example, a secondary battery mounted on a vehicle. The inverter unit 1 converts the direct current supplied from the external power supply device 9 into an alternating current and supplies it to the motor 2 via the external connection bus bar 50.

[0032] The power supply unit 30 includes a power supply substrate 31 and a semiconductor module 32 located below the power supply substrate 31. In the present embodiment, both the power supply substrate 31 and the semiconductor module 32 are in the form of a flat plate.

[0033] The semiconductor module 32 has a three-phase inverter having six IGBTs (insulated gate bipolar transistors) built into the housing. Figure 3 As shown, the semiconductor module 32 has a heat sink 32a, which is composed of a plurality of columnar bodies extending downward from the lower surface of the semiconductor module 32. The semiconductor module 32 is fixed to the bottom wall 11a in a state of covering the refrigerant flow path 11d from the upper side. The heat sink 32a is arranged in the refrigerant flow path 11d. An annular sealing member 33 is arranged around the refrigerant flow path 11d. The refrigerant flow path 11d is sealed by the sealing member 33 sandwiched between the upper surface of the bottom wall 11a and the semiconductor module 32.

[0034] A power substrate 31 for driving the semiconductor module 32 is disposed on the upper surface of the semiconductor module 32. The power substrate 31 and the semiconductor module 32 are electrically connected via a plurality of connection pins 34 extending upward from the semiconductor module 32.

[0035] like Figure 4As shown, the semiconductor module 32 has six inverter input terminals 35 on the side opposite to the capacitor 40. The inverter input terminals 35 are connected to six capacitor output terminals (not shown) extending from the capacitor 40. The semiconductor module 32 has three output terminals 36U, 36V, and 36W on the side opposite to the capacitor 40. That is, the power supply unit 30 has output terminals 36U, 36V, and 36W.

[0036] The output terminals 36U, 36V, 36W are connected to the relay bus bars 57U, 57V, 57W, respectively. In the following description, the output terminals 36U, 36V, 36W of the power supply unit 30 are sometimes collectively referred to as output terminals 36. In addition, the relay bus bars 57U, 57V, 57W are sometimes collectively referred to as relay bus bars 57.

[0037] like Figures 4 to 6 As shown, the relay busbar 57 is a strip-shaped metal plate. Two relay busbars 57U and 57W are L-shaped when viewed from the upper side, and the other relay busbar 57U is straight when viewed from the upper side. The relay busbars 57U, 57V, and 57W extend horizontally from the connection portion with the output terminals 36U, 36V, and 36W, and bend upward near the external connection busbar 50. The front end portions of the relay busbars 57U, 57V, and 57W are located above the upper end surface 11c of the lower case 11.

[0038] The relay bus bar 57 is connected to the output terminal 36 at the relay connection portion 70 located on the side of the power supply unit 30. Figure 3 as well as Figure 6 As shown, the relay connection part 70 has a relay part support base 71 that supports the output terminals 36 of the power supply part 30 and the relay bus bar 57 from the bottom, and bolts 72 that connect the output terminals 36U, 36V, 36W of the power supply part 30 and the relay bus bar 57.

[0039] The bolt 72 is a relay fixing member of the relay connection portion 70. The bolt 72 passes through the relay bus bar 57 in the vertical direction and is screwed into the threaded hole of the output terminal 36 of the power supply unit 30. According to this structure, the relay bus bar 57 and the output terminal 36 can be easily and firmly fixed.

[0040] like Figure 5 as well as Figure 6As shown, the relay support platform 71 is a rod-shaped component extending in the X-axis direction along the side of the power supply unit 30. The relay support platform 71 has three terminal support parts 71a arranged at intervals along the length direction (Y-axis direction). That is, the relay support platform 71 has a plurality of terminal support parts 71a arranged in a direction intersecting the up-down direction. A relay partition wall 71b extending in the up-down direction is provided between adjacent terminal support parts 71a. According to this structure, the output terminals 36 can be insulated from each other by the relay partition wall 71b.

[0041] The relay unit support 71 includes a first positioning wall 71 c extending upward from an end portion of the terminal support 71 a on the opposite side to the power supply unit 30 , in the three terminal support portions 71 a .

[0042] The relay support 71 has three cylindrical positioning pins 71d extending upward from the upper surface. Two positioning pins 71d extend upward from the upper surface of the relay partition wall 71b. The other positioning pin 71d extends upward from the upper end surface of the first positioning wall 71c located in the center.

[0043] The relay support 71 has second positioning walls 71e extending upward from the ends of the center portions of the upper surfaces of the two relay partition walls 71b. The second positioning walls 71e also function as partition walls for insulating adjacent relay bus bars 57 from each other.

[0044] The intermediate portion support platform 71 has a flange portion 71f at each of the two ends in the longitudinal direction. The flange portion 71f has a through hole that passes through the flange portion 71f in the vertical direction. Figure 3 As shown, the relay support 71 is fastened to the bottom wall 11 a of the lower case 11 by bolts 73 passing through through holes of the flange 71 f.

[0045] The output terminal 36 of the power supply unit 30 and the relay bus bar 57 are fastened to the terminal support portion 71a of the relay unit support stand 71. Figure 6 As shown, the output terminal 36 is arranged on the upper surface of the terminal support portion 71a. The upper surface of the output terminal 36 and the upper surface of the relay portion partition wall 71b are substantially at the same height. Three relay bus bars 57 are arranged on the relay portion support stand 71.

[0046] The L-shaped relay bus bar 57U is arranged on the upper surface of the output terminal 36U and the relay portion partition wall 71b when viewed from above. The positioning pin 71d passes through the through hole of the relay bus bar 57U. The side of the relay bus bar 57U is positioned by the first positioning wall 71c and the second positioning wall 71e. The bolt 72 passes through the bolt insertion hole of the relay bus bar 57U and is screwed into the threaded hole of the output terminal 36U, thereby bolting the relay bus bar 57U and the output terminal 36U.

[0047] The relay bus bar 57V is arranged on the output terminal 36V and the first positioning wall 71c. The positioning pin 71d passes through the through hole of the relay bus bar 57V. The two side surfaces of the relay bus bar 57V facing the X-axis direction are positioned by the second positioning wall 71e. The bolt 72 passes through the bolt insertion hole of the relay bus bar 57V and is screwed into the threaded hole of the output terminal 36V, thereby bolting the relay bus bar 57V and the output terminal 36V.

[0048] The relay bus bar 57W is disposed in a state of being positioned on the output terminal 36W and the relay portion partition wall 71 b similarly to the relay bus bar 57U, and is fastened using bolts 72 .

[0049] In the inverter unit 1 of the present embodiment, by providing the relay support 71, the bolts 72 can be screwed in while supporting the output terminals 36 from below when fastening the output terminals 36 and the relay busbar 57. Thus, when the bolts 72 are screwed in, bending stress applied to the power supply unit 30 can be suppressed.

[0050] In addition, the relay bus bar 57 is positioned by the first positioning wall 71c, the positioning pin 71d, and the second positioning wall 71e of the relay portion support 71. This facilitates the assembly work of the relay connection portion 70.

[0051] Alternatively, a member may be used in which the relay portion support 71 and the relay bus bar 57 are integrated. According to this structure, the workability when the relay bus bar 57 is mounted on the external connection bus bar 50 can be improved.

[0052] The relay bus bars 57U, 57V, and 57W are connected to the external connection bus bars 50U, 50V, and 50W, respectively, at the bus bar connection portion 55. In the following description, the external connection bus bars 50U, 50V, and 50W may be collectively referred to as the external connection bus bar 50.

[0053] like Figures 4 to 6 As shown, the external connection busbar 50 is a strip-shaped metal plate. The external connection busbars 50U, 50V, and 50W are all straight lines extending in the vertical direction. The front ends of the external connection busbars 50U, 50V, and 50W are located above the upper end surface 11c of the lower case 11.

[0054] The external connecting busbar 50 is maintained at Figure 6In the case of the present embodiment, the external connection busbar 50 is insert-molded on the resin busbar holder 52. The busbar holder 52 has a main body 52a that holds three external connection busbars 50, four partition walls 52b that extend upward from the upper surface of the main body 52a, and a flange 52c that extends horizontally from the lower end of the outer peripheral surface of the main body 52a.

[0055] The external connection busbars 50U, 50V, and 50W are arranged in a row in the short-side direction (X-axis direction) of the lower case 11 with their respective plate surfaces facing the power supply unit 30. The external connection busbars 50U, 50V, and 50W are respectively located between two partition walls 52b. The partition walls 52b insulate the external connection busbars 50 adjacent to each other in the X-axis direction.

[0056] like Figure 2 as well as Figure 3 As shown, the bus bar holder 52 is inserted from the lower surface side of the lower case 11 into the case through hole 11e that passes through the bottom wall 11a of the lower case 11 in the vertical direction. The bus bar holder 52 is positioned in the vertical direction by the upper surface of the flange portion 52c abutting against the lower surface of the lower case 11. The bus bar holder 52 is fastened to the bottom wall 11a of the lower case 11 by bolts passing through the through holes of the flange portion 52c. According to this structure, the external connection bus bar 50 is configured to pass through the bottom wall 11a of the lower case 11 inside and outside.

[0057] When the bus bar holder 52 is fixed to the lower case 11, the upper ends of the external connection bus bars 50U, 50V, and 50W are arranged at substantially the same height as the upper ends of the relay bus bars 57U, 57V, and 57W. The relay bus bar 57U and the external connection bus bar 50U are fastened by bolts 54 extending in the horizontal direction while the plate surfaces overlap each other. The relay bus bar 57V and the external connection bus bar 50V, and the relay bus bar 57W and the external connection bus bar 50W are also fastened by bolts 54 while the plate surfaces overlap each other.

[0058] That is, the relay bus bar 57 and the external connection bus bar 50 are fastened using the bolts 54 extending in a direction intersecting the up-down direction.

[0059] The connection portion between the relay bus bar 57 and the external connection bus bar 50 by the bolts 54 is a bus bar connection portion 55 in the inverter unit 1 .

[0060] In this embodiment, if Figure 3 as well as Figure 5As shown, the bus bar connection portion 55 is located above the upper end surface 11c of the lower case 11. That is, in the state where the cover member 12 is removed, the bus bar connection portion 55 is located outside the storage chamber 13 of the lower case 11. According to this structure, during the connection operation of the relay bus bar 57 and the external connection bus bar 50, the side wall 11b of the lower case 11 does not become an obstacle, and the assembly operation can be carried out efficiently.

[0061] In the present embodiment, the relay bus bar 57 and the external connection bus bar 50 are fastened using bolts 54 extending in a direction intersecting the vertical direction in the bus bar connection portion 55. Since the bus bar connection portion 55 is located above the upper end surface 11c of the lower housing 11, the fastening operation by the bolts 54 extending in the lateral direction relative to the vertical direction can also be easily performed. In addition, since the bolts can be fastened easily in any direction, the components can be efficiently arranged inside the inverter case 10. As a result, the inverter unit 1 can also be miniaturized.

[0062] In the present embodiment, in the bus bar connection portion 55 , the relay bus bar 57 and the external connection bus bar 50 are fastened in a state where their plate surfaces overlap each other, so that the space occupied by the bus bar connection portion 55 can be reduced.

[0063] The inverter unit 1 of the present embodiment includes a relay bus bar 57 that connects the power supply unit 30 and the external connection bus bar 50. By using the relay bus bar 57, the bus bar connection portion 55 can be arranged above the upper end surface 11c of the lower case 11 without changing the position of the output terminal 36 of the power supply unit 30. According to this structure, the screw fixing operation of the relay bus bar 57 to the external connection bus bar 50 becomes easy.

[0064] In the above embodiment, the configuration in which the power supply unit 30 and the external connection bus bar 50 are connected via the relay bus bar 57 has been described, but the present invention is not limited to this configuration.

[0065] For example, the output terminals 36U, 36V, and 36W of the power supply unit 30 may be shaped to extend upward from the semiconductor module 32. According to this structure, the power supply unit 30 and the external connection bus bar 50 can be directly connected in the bus bar connection portion 55 without using the relay bus bar 57. In this case, the power supply unit 30 and the external connection bus bar 50 are fastened by the bolts 54 extending in the horizontal direction in the bus bar connection portion 55 above the upper end surface 11c of the lower case 11, so that the inverter unit 1 can be easily assembled.

[0066] In the above embodiment, the external connection bus bar 50 is configured to penetrate the bottom wall 11a inside and outside, but the external connection bus bar 50 may be configured to penetrate the side wall 11b inside and outside. In this case, the effect of improving workability can also be obtained by arranging the bus bar connection portion 55 above the upper end surface 11c of the lower case 11.

[0067] like Figure 3 As shown, a protective cover 55a covering the fastening portion between the relay bus bar 57 and the external connection bus bar 50 may be provided on the bus bar connection portion 55. The protective cover 55a is a square cylindrical insulating component having a top wall. The protective cover 55a covers the upper side and the side surface of the fastening portion based on the bolt 54. By providing the protective cover 55a, the bus bar connection portion 55 and the cover component 12 can be insulated.

[0068] Description of symbols

[0069] 1: Inverter unit; 2: Motor; 3: Motor unit; 10: Inverter case; 11: Lower shell; 11a: Bottom wall; 11b, 12b: Side walls; 11c: Upper end surface; 30: Power supply unit; 36, 36U, 36V, 36W: Output terminals; 50, 50U, 50V, 50W: External connection bus bar; 52b: Partition wall; 54, 72, 73: Bolts; 55: Bus bar connection part; 57, 57U, 57V, 57W: Relay bus bar; 70: Relay connection part; 71: Relay part support platform; 71a: Terminal support part; 71b: Relay part partition wall.

Claims

1. An inverter unit, which can be mounted on a motor, wherein: The inverter unit has: a power supply unit including an inverter circuit; an inverter box housing the power supply unit; and an external connection bus bar electrically connected to the power supply unit, The inverter housing has a lower shell having a bottom wall and a cylindrical side wall extending upward from the periphery of the bottom wall. The power supply unit and the external connection bus bar are connected at a bus bar connection portion located above an upper end surface of the side wall of the lower case.

2. The inverter unit according to claim 1, wherein: In the bus bar connection portion, the power supply unit and the external connection bus bar are fastened using bolts extending in a direction intersecting the up-down direction.

3. The inverter unit according to claim 1 or 2, wherein: The inverter unit includes a relay bus bar that connects the power supply unit and the external connection bus bar.

4. The inverter unit according to claim 3, wherein: The external connection busbar and the relay busbar are both strip-shaped metal plates. In the bus bar connection portion, the relay bus bar and the external connection bus bar are fastened by bolts in a state where the plate surfaces of the relay bus bar and the external connection bus bar overlap with each other.

5. The inverter unit according to claim 3 or 4, wherein: The inverter unit includes a relay connection portion that connects the output terminal of the power supply portion and the relay bus bar. The relay connection unit has: a relay unit support stand that supports the output terminal of the power supply unit and the relay bus bar from a lower side; and A relay unit fixing member connects the output terminal of the power supply unit and the relay bus bar.

6. The inverter unit according to claim 5, wherein: The relay unit fixing member is a bolt that penetrates the relay bus bar in the up-down direction and is screwed into a threaded hole provided in the output terminal of the power source unit.

7. The inverter unit according to claim 5 or 6, wherein: The inverter unit has a plurality of the relay bus bars, and the power supply unit has a plurality of the output terminals. The relay unit support base has a plurality of terminal support portions to which the output terminals of the power supply unit and the relay busbars are fixed. The plurality of terminal support portions are arranged in a direction intersecting the up-down direction. A relay portion partition wall extending in the up-down direction is provided between the adjacent terminal support portions.

8. A motor unit comprising: The inverter unit according to any one of claims 1 to 7; and The motor is supplied with AC current by the inverter unit.

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