JP2014096910A - Power conversion apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power conversion apparatus capable of preventing intrusion of a refrigerant into a switching module and capable of reducing a manufacturing cost.SOLUTION: In a cooling case 82, an annular inside seal 88 disposed on the outside of an aperture 83 so as to surround the aperture 83 and a pair of outside seals 89 respectively disposed on the outside of the inside seal 88 and mutually configured by the same component are arranged line-symmetrically, and the pair of outside seals 89 extend along the inside seal 88 and respectively include outside seal parts 89a forming a first discharge passage E1 between the inside seal 88 and themselves and counter extension parts 89b extend in parallel with each other and form a second discharge passage E2 communicated to the first discharge passage E1 in cooperation with each other.

Description

  The present invention relates to a power conversion device, and more particularly to a power conversion device mounted on an electric vehicle such as an electric vehicle or a hybrid vehicle.

  As a conventional power converter, a cooling liquid is directly brought into contact with a semiconductor module substrate to improve the cooling performance, and the possibility of water exposure to electric parts including the semiconductor module is known as zero ( For example, see Patent Document 1.) In the power conversion device described in Patent Document 1, the first seal is provided outside the opening of the cooling flow path, the groove is provided outside the first seal, and the liquid escape holes communicating from the groove to the outside of the heat sink are discretely provided. The second seal is provided outside the groove.

JP 2001-308246 A

  By the way, although the power converter device of patent document 1 is equipped with the structure which prevents the water | moisture content to an electrical component, it is necessary to provide the hole for liquid escape in a heat sink, and there exists a subject that manufacturing cost increases.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a power conversion device that can prevent a refrigerant from entering a switching module and can reduce manufacturing costs. There is.

In order to achieve the above object, the invention according to claim 1
A heat sink having a switching module (for example, switching modules 40a, 40b, and 40c in an embodiment described later) mounted with a switching element (for example, a switching element 44 in an embodiment described later), and a refrigerant for cooling the switching module. (For example, a heat sink 80 in an embodiment described later), and a power converter (e.g., a power converter 30 in an embodiment described later),
The heat sink has a heat radiating substrate (for example, a heat radiating substrate 81 in an embodiment described later) provided with a switching element on the upper surface and a plurality of heat radiating fins (for example, a heat radiating fin 81a in an embodiment described later) on the lower surface, A cooling case (for example, a cooling case 82 in an embodiment described later) having an opening (for example, an opening 83 in an embodiment described later) in which the plurality of heat dissipating fins are accommodated; Configured
The cooling case is disposed outside the opening, and is disposed outside the inner seal (for example, an inner seal 88 in an embodiment described later) and the outer seal that surrounds the opening. A pair of outer seals constituted by parts (for example, outer seals 89 in the embodiments described later) are provided in line symmetry,
The pair of outer seals extend along the inner seal, and form an outer seal portion (for example, a first exhaust passage E1 in an embodiment described later) between the outer seal and the inner seal ( For example, an outer seal portion 89a in an embodiment described later and a second discharge passage (for example, a second exhaust passage in the embodiment described later) that extend in parallel with each other and communicate with the first discharge passage in cooperation with each other. And an opposing extension part (for example, an opposing extension part 89b in an embodiment described later) that forms E2).

The invention according to claim 2 is the structure of claim 1,
The power conversion device is disposed on an upper surface of a floor panel (for example, a floor panel 20 in an embodiment described later) between a right seat and a left seat of a vehicle,
The second discharge passage is opened to the side in the vehicle width direction of the floor panel between the right seat and the left seat.

The invention according to claim 3 is the configuration of claim 2,
The switching module includes a plurality of switching modules,
The power converter is arranged on an upper surface of the floor panel between the right seat and the left seat in a state where the plurality of switching modules are arranged in the vehicle front-rear direction.

  According to the first aspect of the present invention, the first discharge passage can be formed between the seals by the inner seal and the pair of outer seals. Even if the refrigerant leaks outside the inner seal, Can be discharged through the first and second discharge passages. Therefore, it is possible to prevent the refrigerant from entering the upper surface side of the heat dissipation board from the bolt hole arranged outside the outer seal. Moreover, since it can be comprised by two types of seal components, an inner seal and an outer seal, the manufacturing cost of a power converter device can be reduced.

  According to the second aspect of the present invention, since no high-piezoelectric parts are arranged on the side in the vehicle width direction on the upper surface of the floor panel between the right seat and the left seat where the second discharge passage is opened, the second Even if the refrigerant is discharged from the discharge passage, it is possible to prevent the high-piezoelectric component from getting wet.

  According to the invention of claim 3, the refrigerant passing through the first and second discharge passages is discharged in the vehicle width direction on the upper surface between the right seat and the left seat even when a plurality of switching modules are provided. Can do.

1 is a longitudinal sectional view at the center in the vehicle width direction of an electric vehicle equipped with a power conversion device according to an embodiment of the present invention. It is a principal part perspective view of the electric vehicle shown in FIG. It is a disassembled perspective view of the power converter device arrange | positioned at the upper surface of a center tunnel part. It is a disassembled perspective view of a power converter. It is an electric circuit diagram of a power converter. It is a perspective view which shows a power converter device in the state which removed the terminal block provided in the upper case and the current sensor. It is a principal part enlarged front view which shows a power converter device in the state which removed the terminal block provided in the upper case and the current sensor. It is sectional drawing of the power converter device in the position along the VIII-VIII line of FIG. It is a top view of a cooling case.

  Hereinafter, an electric vehicle equipped with a power conversion device according to an embodiment of the present invention will be described in detail with reference to the drawings. In the drawing, Fr is the front, Rr is the rear, U is the upper, D is the lower, L is the left, and R is the right.

  As shown in FIG. 1, the electric vehicle 10 of the present embodiment is a hybrid vehicle. For example, a power unit having an engine 12 and a first motor 13 and a radiator (not shown) are arranged in a prime mover chamber 11 that is a front portion of the vehicle. A pair of second motors 16 and a battery 17 are disposed in the motor housing chamber 14 and the luggage space 15 that are the rear part of the vehicle. Further, in the passenger compartment 18 which is an intermediate portion in the front-rear direction of the vehicle 10, a floor panel 20 is provided between the right seat (driver seat in the present embodiment) and the left seat (passenger seat in the present embodiment). A tunnel 21 is formed, and a power conversion device 30 is disposed on the upper surface of the center tunnel portion 20a of the floor panel 20. The power converter 30 is disposed in a center console 23 that is also disposed above the center tunnel 21. The first and second motors 13 and 16 are constituted by, for example, three-phase AC motors.

The power conversion device 30 is a device that converts the direct current of the battery 17 into alternating current and supplies the alternating current to the motors 13 and 16 to drive the motors 13 and 16. As shown in FIGS. 2 and 3, the power conversion device 30 includes three switching modules 40 a provided for the respective motors 3 and 16 in a housing 31 constituted by an upper case 32 and a lower case 33. 40b, 40c, a smoothing capacitor 70 arranged side by side in the vehicle width direction with these switching modules 40a, 40b, 40c, and a switching module disposed below each switching module 40a, 40b, 40c and the smoothing capacitor 70 40a, 40b, 40c and a heat sink 80 for cooling the smoothing capacitor 70 are mainly provided.
In the present embodiment, the lower case 33 includes a cooling case 82 for the heat sink 80, which will be described later, a front lower case 35, and a rear lower case 36. The cooling case 82 also serves as the lower case 33. ing. In FIG. 3, some components such as a fastening member are omitted.

  In the present embodiment, the smoothing capacitor 70 is divided into three divided capacitors 71. As a result, as shown in FIGS. 3 and 4, each switching module 40 a, 40 b, 40 c and each divided capacitor 71 are mounted on each of the three heat radiating boards 81 constituting the heat sink 80 and unitized. Three power converters 34 are accommodated in the housing 31. Therefore, the three switching modules 40a, 40b, and 40c are arranged side by side in the vehicle front-rear direction, and the three split capacitors 71 are also arranged side by side in the vehicle front-rear direction.

  Each of the switching modules 40a, 40b, and 40c is a module that houses an electric circuit that performs DC / AC conversion. In the switching modules 40a, 40b, and 40c, a semiconductor module 41 including a three-phase inverter circuit 50 (FIG. 5) and a drive board 43 on which an electric circuit that drives the three-phase inverter circuit 50 is mounted are arranged. .

  As shown in FIG. 5, the three-phase inverter circuit 50 includes two switching elements 44 connected in series to each other, and a flywheel diode 45 connected in antiparallel to each of the switching elements 44. Yes. The node N1 on one end side of the two switching elements 44 connected in series is connected to the positive side of the battery 17 and the node N2 on the other end is connected to the negative side, whereby the connection point N3 of the two switching elements 44 is AC output. Terminal for one phase. The three-phase inverter circuit 50 is provided with three sets of two switching elements 44 connected in series to each other in order to obtain an AC output for the three phases required to drive the motors 13 and 16. The connection point N3 constitutes an AC output terminal for three phases. As the switching element 44, an IGBT, a MOSFET, or the like can be used.

  The semiconductor module 41 is configured by combining three packages packaged for each circuit for one phase of AC output on which the two switching elements 44 and the flywheel diode 45 are mounted. As shown in FIG. 4, on one side surface of the semiconductor module 41, positive and negative DC input terminals 47P and 47N corresponding to the nodes N1 and N2 are provided for each circuit for one phase of AC output. An AC input / output terminal 48 corresponding to the connection point N3 is provided on the side surface on the opposite side, and is arranged on the heat sink 80 with the DC input terminals 47P and 47N of each phase facing the same side. The semiconductor module 41 is screwed to the heat dissipation substrate 81 from above (see FIG. 8).

  As shown in FIG. 5, the drive board 43 includes a gate drive circuit 51 and a driver control unit 52 having a high-voltage microcomputer and a power supply circuit that supplies power to each part of the drive board 43. The gate drive circuit 51 is a circuit for switching the switching elements 44 of the three-phase inverter circuit 50. Each drive board 43 is connected to a motor ECU (electronic control unit) 19 mounted on the vehicle side via a control harness 53. The high voltage microcomputer drives the gate drive circuit 51 based on a control signal output from the motor ECU 19, whereby the motors 13 and 16 are driven according to the control on the vehicle side.

  The drive substrate 43 is fixed with screws so as to cover the semiconductor module 41 from above, and is electrically connected to the semiconductor module 41 through a pin-shaped connecting portion 56. Thereby, the drive substrate 43 is positioned.

  An AC input / output terminal 48 located on the opposite side of the smoothing capacitor 70 in the vehicle width direction with respect to the switching modules 40a, 40b, and 40c is connected to one end of a bus bar 58 that is a conductive member by a terminal block 57. . Each bus bar 58 extends upward, and then is bent toward an intermediate portion in the vehicle width direction, and passes through a current sensor 46 described later. The other end of each bus bar 58 is connected to the output conductive members 59a, 59b, 59c above the switching modules 40a, 40b, 40c. The output conductive members 59a, 59b, 59c Extends in the vehicle longitudinal direction. The output conductive member 59a of the switching module 40a extends forward and is connected to the first motor 13 via the front lower case 35, and the output conductive members 59b and 59c of the switching modules 40b and 40c extend rearward. The pair of second motors 16 are connected to each other through the rear lower case 36.

  The current sensor 46 is disposed above the switching modules 40a, 40b, and 40c. The current sensor 46 is connected to the motor ECU 19 via the control harness 53 and is used for feedback control and the like.

  As shown in FIG. 8, the current sensor 46 includes a terminal block 60 for connecting the other end of the bus bar 58 and the output conductive members 59 a, 59 b, 59 c, and a guide member for guiding the output conductive member 59. 61 is integrally formed to constitute a sensor unit 62. Also, as shown in FIG. 8, a conductive member guide 63 is attached to the terminal block 60 of the switching module 40c located at the rear, and an output conductive member 59b extending from the intermediate switching module 40b is connected to the conductive member guide 63. Guided and routed. Therefore, the output conductive members 59b and 59c of the adjacent switching modules 40b and 40c are routed side by side above the rear switching module 40c.

  As shown in FIG. 5, the smoothing capacitor 70 is provided in parallel to the battery 17 at the input stage of the three-phase inverter circuit 50, and suppresses voltage fluctuations of the battery 17 when the three-phase inverter circuit 50 is switched. Smoothes up and down etc.

  As shown in FIG. 8, the split capacitor 71 is a state in which a plurality of capacitor cells 73 are protruded from the insertion opening 72 a to the positive and negative terminals 73 </ b> P and 73 </ b> N in a box-shaped case body 72 having an insertion opening 72 a on the side surface. And sealed with a resin material 74.

  As shown in FIG. 6, the split capacitor 71 has the case body 72 disposed so as to extend to the side of the semiconductor module 41 disposed on the heat sink 80 with the insertion opening 72 a facing inward in the vehicle width direction. To do. The split capacitor 71 is fixed to the upper surface of the heat dissipation board 81 with screws by fastening portions 71a and 71a provided on both sides in the front-rear direction.

  Therefore, the positive and negative terminals 73P and 73N of the split capacitor 71 extend in the vehicle width direction toward the switching modules 40a, 40b, and 40c, and the positive electrode of the switching element 44 that extends in the vehicle width direction toward the smoothing capacitor 70. And the negative DC input terminals 47P and 47N.

  Also, as shown in FIGS. 6 and 7, between the adjacent divided capacitors 71, a laminated bus bar 75 that connects the adjacent positive terminals 73 </ b> P and the adjacent negative terminals 73 </ b> N of each divided capacitor 71 is attached. ing. Specifically, the laminated bus bar 75 includes a positive bus bar 76 that connects the positive terminals 73P of the adjacent divided capacitors 71 and a negative bus bar 77 that connects the negative terminals 73N of the adjacent divided capacitors 71 to each other. It is formed by being laminated in an insulated state.

  The connection terminal 76 a of the positive bus bar 76 is fastened together with the positive DC input terminal 47 P of the switching element 44 and the positive terminal 73 P of the split capacitor 71, and the connection terminal 77 a of the negative bus bar 77 is the negative terminal of the switching element 44. It is fastened together with the DC input terminal 47N and the negative terminal 73N of the split capacitor 71.

Here, the switching module and the split capacitor are fixed to the heat dissipation substrate 81 as a power converter, while the laminated bus bar 75 is assembled after the power converter is fixed to the cooling case 82. For this reason, the drive board 43 includes a positive terminal 73P and a negative terminal 73N of the split capacitor 71 and connection terminals 76a and 77a of the positive and negative bus bars 76 and 77 as viewed from above the center tunnel portion 20a. Two notches 43a facing the connecting portion are formed. As a result, the connection terminals 76a and 77a of the positive and negative bus bars 76 and 77 are inserted through the notches 43a, and the positive and negative terminals 73P and 73N of the split capacitor 71 and the positive and negative electrodes of the switching element 44 are obtained. The DC input terminal 47 can be fastened and fixed.
In FIG. 3, the laminated bus bar 78 connects the rear split capacitor 71 and the battery 17.

  The heat sink 80 includes a switching element 44 and a split capacitor 71 on the upper surface, three heat radiation substrates 81 provided with a plurality of heat radiation fins 81a on the lower surface, and three openings 83 for accommodating the plurality of heat radiation fins 81a. And a cooling case 82 in which the refrigerant circulates.

  As shown in FIG. 8, bolt holes 81b, 82a, and 32a are formed in the heat dissipation board 81, the cooling case 82, and the upper case 32 at corresponding positions, and bolts 84 are passed through these bolt holes 81b, 82a, and 32a. The center panel 20a of the floor panel 20 is fastened together.

  Further, as shown in FIG. 9, the three openings 83 of the cooling case 82 are each formed in a substantially rectangular shape, and are provided side by side in the vehicle front-rear direction corresponding to the three heat dissipation boards 81. . Further, the front opening 83, the middle opening 83, and the rear opening 83 communicate with each other, and the refrigerant flows between these openings 83.

  Further, between the heat radiating substrate 81 and the cooling case 82, they are arranged outside the three openings 83, respectively, and are arranged outside the annular inner seal 88 surrounding the openings 83 and outside the inner seal 88. A pair of outer seals 89 constituted by the same parts are provided symmetrically with each other. The inner seal 88 and the pair of outer seals 89 are disposed in a seal groove 87 formed on the surface of the cooling case 82 facing the heat dissipation substrate 81.

The pair of outer seals 89 extend along the inner seal 88 and extend in parallel with each other and with the outer seal portion 89a forming the first discharge passage E1 between the inner seal 88 and the first seal. And an opposing extension portion 89b that forms a second discharge passage E2 that communicates with the discharge passage E1.
Each of the second discharge passages E2 is opened to the side in the vehicle width direction of the center tunnel portion 20a where no high piezoelectric equipment is disposed.

  Thus, the first discharge passage E1 can be configured between the seals 88 and 89 by the inner seal 88 and the pair of outer seals 89, and even if the refrigerant leaks outside the inner seal 88, The refrigerant can be discharged through the first and second discharge passages E1 and E2. Therefore, it is possible to prevent the refrigerant from entering the upper surface side of the heat dissipation substrate 81 from the bolt hole 81d disposed outside the outer seal 89.

  Further, since the seal groove 87 is formed symmetrically with respect to the line X extending in the vehicle width direction passing through the second discharge passage E2, the pair of outer seals 89 can be made the same part. The seal structure can be constituted by two kinds of seal parts, that is, the inner seal 88 and the outer seal 89.

  The material of the cooling case 82 is made of aluminum and can be formed into a complicated shape by forming it by die casting, but its strength is lower than that of the heat dissipation substrate 81 made of aluminum formed by extrusion. For this reason, the vehicle width direction both side surfaces 81c of the heat radiating substrate 81 are flush with or protrude from the vehicle width direction both side surfaces 82b of the cooling case 82 so that a load is not received only by the cooling case 82 at the time of a vehicle side collision. (In FIG. 8, the same.)

  Further, as shown in FIG. 3, a front lower case 35 and a rear lower case 36 that extend forward and rearward of the cooling case 82 are connected to the cooling case 82 that constitutes the heat sink 80. The front and rear lower cases 35, 36 are fastened and fixed to the center tunnel portion 20 a via the packing 22 while protruding downward from the front opening 20 b and the rear opening 20 c formed in the center tunnel portion 20 a.

  The front and rear lower cases 35, 36 are each provided with a conductive cable 91 extending from the first motor 13 and two conductive wires extending from the second motor 16 at the protruding portions protruding into the center tunnel 21. Each of the cables 92 is connected (see FIG. 1).

  As described above, according to the power conversion device 30 of the present embodiment, the switching modules 40a, 40b, and 40c on which the switching element 44 is mounted, and the refrigerant for cooling the switching modules 40a, 40b, and 40c are included. A heat sink 80. The heat sink 80 includes a heat radiating substrate 81 in which the switching element 44 is installed on the upper surface and a plurality of heat radiating fins 81a on the lower surface, and an opening 83 that accommodates the plurality of heat radiating fins 81a. And a cooling case 82. In the cooling case 82, a pair of annular inner seals 88 disposed outside the opening 83 and surrounding the opening 83, and disposed outside the inner seal 88, respectively, are configured by the same parts. The outer seal 89 is provided in line symmetry, and the pair of outer seals 89 extend along the inner seal 88 to form a first discharge passage E1 between the inner seal 88 and the outer seal 89a. And opposing extension portions 89b that extend in parallel with each other and cooperate to form a second discharge passage E2 that communicates with the first discharge passage E1. Thus, the first discharge passage E1 can be configured between the seals 88 and 89 by the inner seal 88 and the pair of outer seals 89, and even if the refrigerant leaks outside the inner seal 88, The refrigerant can be discharged through the first and second discharge passages E1 and E2. In addition, it is possible to prevent the refrigerant from entering the upper surface side of the heat dissipation substrate 81 from the bolt hole 81d disposed outside the outer seal 89. Moreover, since it can comprise by two types of seal components, the inner seal 88 and the outer seal 89, the manufacturing cost of the power converter device 30 can be reduced.

  Moreover, the power converter device 30 is arrange | positioned at the upper surface of the center tunnel part 20a of a vehicle, and the 2nd discharge passage E2 is open | released by the vehicle width direction side of the center tunnel part 20a. As a result, the high-pressure electrical component is not disposed on the side in the vehicle width direction on the upper surface of the center tunnel portion 20a where the second discharge passage E2 is opened, so that the refrigerant is discharged from the second discharge passage E2. However, it is possible to prevent the high-piezoelectric component from getting wet.

  Moreover, since the power converter 30 is arrange | positioned on the upper surface of the center tunnel part 20a in the state in which several switching modules 40a, 40b, 40c were located in a line with the vehicle front-back direction, it is provided with several switching modules 40a, 40b, 40c. Even in this case, the refrigerant passing through the first and second discharge passages E1 and E2 can be discharged in the vehicle width direction on the upper surface of the center tunnel portion 20a.

  In addition, this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably.

  Further, although the hybrid vehicle has been described as the application vehicle, the present invention is not limited to this, and may be, for example, an electric vehicle using only a motor as a drive source.

10 Hybrid vehicle (electric vehicle)
12 Engine 13 1st motor 16 2nd motor 20 Floor panel 21 Center tunnel 30 Power converter 43 Drive board 44 Switching element 40a, 40b, 40c Switching module 80 Heat sink 81 Heat radiation board 81a Heat radiation fin 82 Cooling case 83 Opening 88 Inner seal 89 Outer seal 89a Outer seal portion 89b Opposing extension portion E1 First discharge passage E2 Second discharge passage

Claims (3)

A power conversion device comprising: a switching module on which a switching element is mounted; and a heat sink having a refrigerant for cooling the switching module,
The heat sink includes a heat radiating substrate having a switching element installed on the upper surface and a plurality of heat radiating fins on the lower surface, a cooling case in which the refrigerant circulates, and an opening for accommodating the heat radiating fins. Configured with
The cooling case includes an annular inner seal that is disposed outside the opening and surrounds the opening, and a pair of outer seals that are disposed outside the inner seal and are configured by the same components. It is provided in line symmetry,
The pair of outer seals extend along the inner seal and extend in parallel with each other and an outer seal portion that forms a first discharge passage between the inner seal and the first discharge. A power conversion device comprising: an opposing extension portion that forms a second discharge passage communicating with the passage. The power converter is disposed on the upper surface of the floor panel between the right seat and the left seat of the vehicle,
The power conversion device according to claim 1, wherein the second discharge passage is opened to a side in a vehicle width direction of the floor panel between the right seat and the left seat. The switching module includes a plurality of switching modules,
3. The electric power according to claim 2, wherein the power conversion device is disposed on an upper surface of the floor panel between the right seat and the left seat in a state where the plurality of switching modules are arranged in the vehicle front-rear direction. Conversion device.

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