Detailed Description
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In the following description, the direction of gravity is defined based on the positional relationship when the inverter unit 1 is mounted on a vehicle on a horizontal road surface. In the 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 vertical direction), + Z direction is the upper side (the opposite side to the direction of gravity), and-Z direction is the lower side (the direction of gravity). The X-axis direction is a direction perpendicular to the Z-axis direction, and in the present embodiment, indicates a 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 the present embodiment, indicates a direction along the long side of the inverter unit 1.
As shown in fig. 3, the inverter unit 1 is provided on the motor unit 3. The motor unit 3 has an inverter unit 1 and a motor 2. The inverter unit 1 is provided on an upper surface of the motor 2. Therefore, the lower surface of the inverter unit 1 is a motor connecting portion 10A connected to the motor 2. The motor connecting portion 10A is a portion that mechanically connects the inverter unit 1 and the motor 2. As the connection structure of the inverter unit 1 and the motor 2, bolt fastening may be used. Rivet fastening or welding may also be used if it is not necessary to attach or detach the inverter unit 1 and the motor 2. A bracket may be attached to the motor connecting portion 10A, and the inverter unit 1 and the motor 2 may be connected via the bracket.
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.
The motor unit 3 of the present embodiment is mounted on a vehicle having 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. The motor unit 3 may have a reduction gear (not shown) for reducing the rotation speed of the motor 2.
The inverter unit 1 converts a direct current into an alternating current and supplies the alternating current to the motor 2. As shown in fig. 1 to 4, the inverter unit 1 includes an inverter case 10, a control board 20, a power supply unit 30 including an inverter circuit, a capacitor 40, and a plurality of external connection bus bars 50.
The inverter case 10 includes a lower case 11 and a cover member 12 attached to an opening of the lower case 11. The lower case 11 has a bottom wall 11a and a cylindrical side wall 11b extending upward from the peripheral edge of the bottom wall 11 a. The cover member 12 has a top wall 12a and a cylindrical side wall 12b extending downward from the peripheral edge of the top wall 12 a. The lower case 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 face each other.
The lower case 11 has a housing chamber 13 surrounded by a bottom wall 11a and a side wall 11 b. The control board 20, the power supply unit 30, the capacitor 40, and the external connection bus bar 50 are disposed inside the housing chamber 13 when viewed from above.
The housing chamber 13 includes a 1 st housing chamber 13A and a 2 nd housing chamber 13B partitioned in the horizontal direction. That is, the inverter case 10 has the 1 st housing chamber 13A and the 2 nd housing chamber 13B. The 1 st housing chamber 13A and the 2 nd housing chamber 13B are arranged in the longitudinal direction (Y-axis direction) of the inverter case 10. The power supply unit 30 and the external connection bus bar 50 are disposed in the 1 st housing chamber 13A. The control board 20 and the capacitor 40 are disposed in the 2 nd housing chamber 13B.
As shown in fig. 4, the 1 st housing chamber 13A is substantially rectangular in plan view. As shown in fig. 2 and 3, a cooling portion 60 is provided at the bottom of the 1 st housing chamber 13A. That is, the inverter unit 1 has a cooling unit 60. The cooling unit 60 has a coolant flow path 11 d. The refrigerant flow path 11d is a recess that opens on the upper surface side of the bottom wall 11 a. The refrigerant flow path 11d has a substantially rectangular shape in plan view. The refrigerant passage 11d is connected to the pipe connection terminals 14 and 15 on the side surface of the lower case 11 via a tubular passage penetrating the bottom wall 11 a. The pipe connection terminals 14 and 15 are connected to external refrigerant pipes. The power supply portion 30 is fixed to the refrigerant flow path 11 d.
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, the power supply board 31 and the semiconductor module 32 are both flat plates.
The semiconductor module 32 incorporates a three-phase inverter having 6 IGBTs (insulated gate bipolar transistors) in a case. As shown in fig. 3, the semiconductor module 32 has a heat sink 32a, and the heat sink 32a is formed 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 passage 11d from above. The radiator 32a is disposed in the refrigerant flow path 11 d. An annular seal member 33 is disposed around the refrigerant flow path 11 d. The refrigerant flow path 11d is sealed by a sealing member 33 interposed between the upper surface of the bottom wall 11a and the semiconductor module 32.
A power supply board 31 for driving the semiconductor module 32 is disposed on the upper surface of the semiconductor module 32. The power supply substrate 31 and the semiconductor module 32 are electrically connected via a plurality of connection pins 34 extending upward from the semiconductor module 32. In the present embodiment, the semiconductor module 32 is located on the cooling unit 60, and the power supply substrate 31 is located on the semiconductor module 32. According to this configuration, since the semiconductor module 32 that generates heat more easily than the power supply substrate 31 is disposed directly above the cooling unit 60, the entire power supply unit 30 can be cooled efficiently. Further, by disposing the power supply board 31 connected to the control board 20 above the semiconductor module 32, electrical connection between the boards is facilitated.
As shown in fig. 4, the 2 nd housing chamber 13B is substantially rectangular in shape that is elongated in the X axis direction compared to the 1 st housing chamber 13A. A capacitor 40 is fixed to the bottom of the 2 nd housing chamber 13B. The control substrate 20 is fixed to the upper surface of the capacitor 40 via the bracket 25. The circuit components mounted on the lower surface of the control board 20 and the capacitor 40 are insulated by the bracket 25. The bracket 25 may be fixed to the inverter case 10. In addition, the control board 20 may be directly fixed to the upper surface 40b of the capacitor 40, if possible.
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 in the motor unit 3. The control board 20 performs feedback control of the rotation speed of the motor 2 based on the rotation information of the motor 2 output from the encoder.
In the inverter unit 1 of the present embodiment, as shown in fig. 3, the cooling unit 60 and the capacitors 40 are arranged in a direction (Y-axis direction in the present embodiment) along the upper surface of the bottom wall 11a of the lower case 11. Power supply unit 30 is located above cooling unit 60, and lower surface 40a of capacitor 40 is located below lower surface 60a of cooling unit 60.
In the present embodiment, as shown in fig. 2 and 3, the lower surface 60a of the cooling unit 60 is the lower surface of the case protruding portions 61a and 61b protruding downward from the lower surface of the lower case 11. A tubular flow path connecting the refrigerant flow path 11d and the pipe connection terminal 14 is provided inside the case protrusion 61a, and a tubular flow path connecting the refrigerant flow path 11d and the pipe connection terminal 15 is provided inside the case protrusion 61 b. Therefore, the lower surface 60a of the cooling portion 60 is the surface located on the lowermost side among the portions of the lower case 11 that constitute the flow path of the refrigerant.
According to the above configuration, in power supply unit 30, capacitor 40, and cooling unit 60, lower surface 40a of capacitor 40 is located at the lowermost side. Therefore, in the inverter unit 1 of the present embodiment having the motor connecting portion 10A on the lower surface, the capacitor 40 as a heavy object is disposed at a position closest to the motor 2. When the inverter unit 1 swings due to the vibration transmitted from the motor 2, the amplitude increases as the position is farther from the motor 2. By adopting the above configuration, the amplitude ratio of the capacitor 40 disposed in the vicinity of the motor 2 can be made small. The amplitude of the capacitor 40 having the largest weight is reduced, whereby the stress applied to the inverter unit 1 by the vibration can be reduced. Therefore, according to the present embodiment, the inverter unit 1 that is less susceptible to the vibration of the motor 2 is provided.
Further, in the present embodiment, the upper surface 30a of the power supply unit 30 and the upper surface 40b of the capacitor 40 are arranged along the same plane. That is, upper surface 30a of power supply unit 30 is substantially parallel to upper surface 40b of capacitor 40. The parallelism of upper surface 30a and upper surface 40b is within 5 °. The parallel angle is preferably within ± 1 °. In the present embodiment, the upper surface 30a of the power supply unit 30 is the upper surface of the power supply substrate 31. In the case where the semiconductor module 32 is disposed above the power supply substrate 31 in the power supply unit 30, the upper surface 30a of the power supply unit 30 becomes the upper surface of the semiconductor module 32.
According to the above configuration, in the inverter unit 1 of the present embodiment, the case of the capacitor 40 and the case of the power supply unit 30 are less likely to interfere with each other. Therefore, in the inverter unit 1, the capacitor 40 and the power supply unit 30 can be disposed close to each other in the horizontal direction (Y-axis direction). This can shorten the wiring connecting the capacitor 40 and the power supply unit 30. When the wiring for dc power supply from the power supply to the IGBT as the switching element is long, the inductive reactance of the wiring increases, and therefore, the surge voltage at the time of turn-off increases. In the present embodiment, since the wiring length for dc power supply to the IGBT can be shortened, the surge voltage can be suppressed. If the surge voltage can be suppressed, the switching time of the IGBT can be shortened, and therefore the efficiency of the inverter can be improved. Further, the effect of reducing heat generation can be obtained by improving the efficiency.
As shown in fig. 1 and 4, the capacitor 40 is connected to the external power supply device 9 via a wiring 9 a. The wiring 9a is connected to the capacitor input terminal 41 of the capacitor 40 via a wiring terminal 9b provided at the terminal of the wiring 9 a. The external power supply device 9 is, for example, a secondary battery mounted on a vehicle. The inverter unit 1 converts a direct current supplied from the external power supply device 9 into an alternating current, and supplies the alternating current to the motor 2 via the external connection bus bar 50.
In the present embodiment, the two wires 9a are fixed to the inverter case 10 by the mounting member 9c that supports the wires 9 a. The mounting member 9c is bolted to the outer side surface of the side wall 11b of the lower case 11. The wiring 9a extending from the mounting member 9c toward the distal end extends into the 2 nd accommodating chamber 13B through a through hole 11e provided in the side wall 11B.
In the 2 nd housing chamber 13B, the wiring terminal 9B and the capacitor input terminal 41 are fastened with a bolt 84. That is, the power supply connection portion 80 for connecting the wiring 9a extending from the external power supply device 9 and the capacitor 40 is disposed in the 2 nd housing chamber 13B of the inverter case 10. According to this configuration, since the wiring 9a is drawn into the 2 nd housing chamber 13B, which is a region in which the capacitor 40 is housed, and connected, the capacitor 40 and the external power supply device 9 can be connected with a minimum space without using a bus bar. Therefore, according to the present embodiment, the inverter unit 1 can be downsized.
Fig. 5 is an exploded perspective view showing the power supply connection part 80.
The power supply connection portion 80 has a bolt (1 st fixing member) 84 connecting the capacitor input terminal 41 extending from the capacitor 40 and the wiring terminal 9b located at the terminal end of the wiring 9a, and a 1 st terminal support base 81 supporting the capacitor input terminal 41 and the wiring terminal 9b from below. The 1 st fixing member, which is a bolt 84, fixes the capacitor input terminal 41 and the wiring terminal 9b to the 1 st terminal support base 81.
As shown in fig. 5, the 1 st terminal support 81 is a rod-like member extending in the Y-axis direction along the side surface of the capacitor 40. The 1 st terminal support base 81 has 2 1 st terminal fixing portions 81a arranged at intervals along the longitudinal direction (Y-axis direction). That is, the 1 st terminal support base 81 has a plurality of 1 st terminal fixing portions 81a arranged in a direction intersecting the vertical direction.
The 1 st terminal support 81 has a 1 st partition 81b extending in the vertical direction between adjacent 1 st terminal fixing portions 81 a. With this structure, the 1 st partition wall 81b can insulate the wiring terminals 9b from each other. In the case of the present embodiment, the 1 st partition walls 81b are disposed at three positions including both ends of the 1 st terminal support base 81, and are disposed so as to sandwich the 1 st terminal fixing portions 81a in the horizontal direction. In the present embodiment, the 1 st partition wall 81b also functions as a positioning member for the wiring terminal 9b when connecting the capacitor input terminal 41 and the wiring terminal 9 b.
The 1 st terminal support base 81 has one flange portion 81c at each of both ends in the longitudinal direction. The flange portion 81c has a through hole penetrating the flange portion 81c in the vertical direction. The 1 st terminal support base 81 is fastened to the bottom wall 11a of the lower case 11 by bolts inserted through the through holes of the flange portion 81 c.
The capacitor input terminal 41 and the wiring terminal 9b of the capacitor 40 are fastened to the 1 st terminal fixing portion 81a of the 1 st terminal support base 81. The capacitor input terminal 41 is disposed on the upper surface of the 1 st terminal fixing portion 81a, and the wiring terminal 9b is disposed so as to overlap the upper surface of the capacitor input terminal 41. The bolt 84 penetrates the capacitor input terminal 41 and the wiring terminal 9b, and is screwed into the screw hole 81d of the 1 st terminal fixing portion 81 a. With this configuration, the capacitor input terminal 41 and the wiring terminal 9b are fixed to the lower case 11 via the 1 st terminal support base 81. Since the wiring 9a and the capacitor 40 are firmly fixed, it is also difficult to generate a slack of connection due to vibration during use.
As shown in fig. 1, the cover member 12 has: a cover body 12A connected to an upper end of the side wall 11b of the lower case 11 and covering the power supply unit 30 and the capacitor 40 from above; an access port 12B provided in the cover main body 12A and opened above the power supply connection portion 80; and an end mask 12C detachably attached to the access port 12B.
As shown in fig. 4, the end mask 12C is provided at a position covering the power supply connection portion 80 from above. With this configuration, the power supply connection portion 80 can be operated only by detaching the end mask 12C from the mask body 12A. That is, the worker can perform the wiring connection work while covering the cover main body 12A with another member. This can prevent dust from adhering to the control board 20 and the power supply unit 30 during the wiring connection operation.
In the present embodiment, the bolt 84 as the 1 st fixing member extends in the vertical direction and is screwed from the upper side to the lower side. Therefore, the bolt 84 can be operated from above with the port cover 12C or the cover member 12 removed. With this configuration, the wiring 9a and the capacitor 40 can be easily connected. The inverter unit 1 having excellent assembly workability can be provided.
In the inverter unit 1 of the present embodiment, the control board 20 and the power supply board 31 of the power supply unit 30 are formed as separate boards, and the control board 20 is disposed above the capacitor 40. In the present embodiment, as shown in fig. 3, the bottom surface of capacitor 40 is positioned lower than cooling unit 60, so that a space is easily provided above capacitor 40. With this configuration, compared to the configuration in which the control board 20 is disposed on the power supply unit 30, the unevenness of the upper surface of the inverter unit 1 can be reduced. Therefore, by using the inverter unit 1 in which the control board 20 is disposed on the capacitor 40, the entire motor unit 3 can be downsized.
As shown in fig. 4, the semiconductor module 32 has 6 inverter input terminals 35 on a side surface facing the capacitor 40. The inverter input terminal 35 is connected to 6 capacitor output terminals 42 (see fig. 6) extending from the capacitor 40 in a circuit connection portion 90 connecting the power supply portion 30 and the capacitor 40.
Fig. 6 is a sectional view showing the circuit connecting portion 90.
The circuit connecting portion 90 has a 2 nd terminal support base 91 that supports the inverter input terminal 35 extending from the power supply portion 30 and the capacitor output terminal 42 extending from the capacitor 40 from below, and a bolt (2 nd fixing member) 94 that connects the inverter input terminal 35 and the capacitor output terminal 42 and is fixed to the 2 nd terminal support base 91.
Fig. 7 is a perspective view of the 2 nd terminal support base 91.
The 2 nd terminal support base 91 is a rod-shaped member extending in the X-axis direction along the side surface of the capacitor 40. The 2 nd terminal support base 91 has 6 nd terminal fixing portions 91a arranged at intervals along the longitudinal direction (X-axis direction). That is, the 2 nd terminal support base 91 has a plurality of 2 nd terminal fixing portions 91a arranged in a direction intersecting the vertical direction. The 2 nd terminal support base 91 and the 1 st terminal support base 81 may be formed as a single member.
The 2 nd terminal support base 91 has a 2 nd partition 91b extending in the vertical direction between the adjacent 2 nd terminal fixing portions 91 a. According to this structure, the inverter input terminal 35 and the capacitor output terminal 42 can be insulated from each other by the 2 nd partition wall 91 b. In the case of the present embodiment, the 2 nd partition walls 91b are disposed at a plurality of locations including both ends of the 2 nd terminal support base 91, and are disposed so as to sandwich the 2 nd terminal fixing portions 91a in the horizontal direction.
The 2 nd terminal support base 91 has one flange portion 91c at each of both end portions in the longitudinal direction (X-axis direction). The flange 91c has a through hole penetrating the flange 91c in the vertical direction. The flange 91c has a positioning pin 91e protruding downward from the front end of the flange 91 c. The positioning pin 91e is inserted into a positioning hole opened in the upper surface of the bottom wall 11a, and the 2 nd terminal support base 91 is positioned on the bottom wall 11 a. The 2 nd terminal support base 91 is fastened to the bottom wall 11a of the lower case 11 by bolts inserted through the through holes of the flange 91 c.
The capacitor output terminal 42 and the inverter input terminal 35 are fastened to the 2 nd terminal fixing portion 91a of the 2 nd terminal support base 91. As shown in fig. 6, the inverter input terminal 35 is disposed on the upper surface of the 2 nd terminal fixing portion 91a, and the capacitor output terminal 42 is disposed on the upper surface of the inverter input terminal 35 in a superimposed manner. The bolt 94 penetrates the capacitor output terminal 42 and the inverter input terminal 35, and is screwed into the screw hole 91d of the 2 nd terminal fixing portion 91 a. According to this configuration, the capacitor output terminal 42 and the inverter input terminal 35 are fixed to the lower case 11 via the 2 nd terminal support base 91. Since the power supply unit 30 and the capacitor 40 are firmly fixed, it is also difficult to generate connection slack due to vibration during use.
The 2 nd terminal support base 91 has a columnar portion 91f extending in the vertical direction on the back surface side of each 2 nd terminal fixing portion 91 a. The lower end surface of the columnar portion 91f abuts the upper surface of the bottom wall 11 a. When the bolt 94 is screwed into the screw hole 91d, the columnar portion 91f supports the 2 nd terminal fixing portion 91a from below. By providing the columnar portion 91f, the lower portion of the 2 nd terminal support base 91 can be thinned, and the weight of the 2 nd terminal support base 91 can be reduced without impairing the strength.
The semiconductor module 32 has 3 output terminals 36 on the side opposite to the capacitor 40. That is, the power supply unit 30 has a plurality of output terminals 36. The 3 output terminals 36 are connected to different relay bus bars 57. The 3 relay bus bars 57 extend in the horizontal direction from the connection position with the output terminal 36 of the power supply section 30.
The 3 relay bus bars 57 are connected to different external connection bus bars 50, respectively. As shown in fig. 2 and 3, the 3 external connection bus bars 50 are linear metal plates extending in the vertical direction. The external connection bus bar 50 is connected to the relay bus bar 57 at an upper end portion. In the case of the present embodiment, the external connection bus bar 50 and the relay bus bar 57 are fastened using the bolt 54. A protective cover 55a is covered on the connection portion of the external connection bus bar 50 and the relay bus bar 57.
The external connection bus bar 50 extends downward from the connection position with the relay bus bar 57, penetrates the bottom wall 11a of the lower case 11, and extends outward of the lower case 11. The external connection bus bar 50 protruding from the lower case 11 is electrically connected to the stator of the motor 2.
Description of the reference symbols
1: an inverter unit; 2: a motor; 3: a motor unit; 9: an external power supply device; 9 a: wiring; 9 b: a wiring terminal; 10: an inverter case; 10A: a motor connecting portion; 11 a: a bottom wall; 11b, 12 b: a side wall; 12: a cover member; 12A: a cover main body; 12B: an access port; 12C: end mask; 13A: a 1 st housing chamber; 13B: a 2 nd accommodating chamber; 20: a control substrate; 30: a power supply unit; 30a, 40 b: an upper surface; 31: a power supply substrate; 32: a semiconductor module; 35: an inverter input terminal; 36: an output terminal; 40: a capacitor; 40a, 60 a: a lower surface; 41: a capacitor input terminal; 42: a capacitor output terminal; 60: a cooling section; 80: a power supply connection part; 84: a bolt (1 st fixing member); 81: 1 st terminal support table; 81 a: 1 st terminal fixing part; 81 b: a 1 st partition wall; 90: a circuit connection portion; 91: a 2 nd terminal support table; 91 a: a 2 nd terminal fixing portion; 91 b: a 2 nd partition wall; 94: bolt (2 nd fixing member).