JP5664878B2 - Inverter cooling structure - Google Patents

Description

  The present invention relates to a cooling structure for an inverter.

The inverter is configured by housing an inverter module as a switching element in a housing.
An electric vehicle is equipped with an inverter that converts direct current power and alternating current power, converts direct current power stored in a battery into alternating current power, and drives an alternating current motor. Since an inverter used for driving such a motor passes a large current in order to secure a torque required for traveling, considerable heat is generated during the switching operation of the inverter module.

Therefore, in the inverter, a cooling structure is mounted as a countermeasure against heat generation of the inverter module. The cooling structure tends to employ a water cooling type (liquid cooling type) as disclosed in Patent Document 1 in order to ensure stable cooling performance.
Many water-cooled cooling structures contain an inverter module and a cooling chamber adjacent to the inverter inside the housing, and the cooling water (coolant) is introduced into the housing from the outside into the cooling chamber. A structure provided with a flow path on the side and a flow path on the output side that leads out the cooling water in the cooling chamber after cooling by the heat sink to the outside is used.

JP 2009-105174 A

By the way, the cooling structure of the inverter is required to appropriately cool the inverter module with cooling water, or to be able to introduce and discharge cooling water according to the type of electric vehicle.
However, if the cooling water is simply circulated into the cooling chamber through the inlet and outlet channels as described above, the cooling water pumped from the cooling water pump has a strong water flow, There are many water flows that pass directly from the inlet of the inlet-side channel to the outlet of the outlet-side channel, and a water flow that diffuses around the cooling chamber cannot be secured.

The cooling of the inverter module can be appropriately exchanged heat in each part of the inverter module by the water flow diffusing in the cooling chamber, but when the cooling water simply flows from the inlet side flow path to the outlet side flow path as described above. The heat exchange at each part of the inverter module cannot be performed properly.
In order to disperse the cooling water around the cooling chamber, it may be possible to reduce the momentum of the water flow in the cooling chamber by providing an obstacle or the like that inhibits the flow of the cooling water in the cooling chamber. It becomes complicated.

Moreover, the direction of the inlet for introducing cooling water from the outside and the direction of the inlet for extracting cooling water from the cooling chamber are easily affected by the structure that weakens the momentum of the water flow. Accordingly, it is required to newly manufacture specifications with different directions of the inlet of the inlet channel and the outlet of the outlet channel.
Accordingly, an object of the present invention is to secure a liquid flow that diffuses around the cooling chamber with a simple structure, and to maintain the structure that forms the flow to diffuse around the cooling chamber, according to the mounting condition of the inverter. and to provide a cooling structure for inverter that allows changes in electrical output orientation of the cooling water.

According to the first aspect of the present invention, the cooling chamber is formed to have a square and flat concave portion, and the inlet of the inlet channel for allowing the cooling liquid to flow into the cooling chamber, and the cooling liquid from the cooling chamber. an outlet of the outgoing-side flow path to flow out, Rutotomoni provided a point distant from each other in one surface constituting the cooling chamber, which is a direction orthogonal to the extending direction of the inlet channel and the outlet side passage portrait a is opened, the inlet channel and the outlet side flow path while maintaining the spacing between inlet and outlet, with parallel extending bus respectively along the same direction, the guide outlet and the outlet of the outlet side flow path only between, it provided the mouth that opens to the outside branch direction different from the guide outlet.

With this configuration , the coolant flowing into the cooling chamber from the inlet changes in the direction in which it flows while being introduced into the cooling chamber, or moves toward the outlet while the direction of the flow is changed by collision with the wall surface of the recess in the cooling chamber. Therefore, the liquid flow of the coolant flowing between the inlet and the outlet becomes weak. For this reason, a liquid flow that optimally exchanges heat with the inverter module , that is, a liquid flow that diffuses around the cooling chamber is formed in the recess of the cooling chamber. Moreover, depending on the mounting condition of the inverter, the initial electrical outlet, by simply selecting the branched mouth, structure defining liquid flow to adequately cool the inverter module, i.e. the flow to diffuse around the cooling chamber as it is , since change of electrical output orientation of the cooling liquid is performed, likely corresponding to each vehicle model.

  In the second aspect of the invention, the mouth portion is assembled with a nipple member that can be connected to the cooling pipe or a plug member that closes the opening of the mouth portion so that the mouth portion can be easily used.

According to the present invention, the easy single structure, to weaken the coolant liquid flow flowing between the inlet and the outlet, the liquid flow so as to spread around the cooling chamber can be formed.
Therefore, the inverter module can be heat-exchanged optimally. In addition, simply by selecting the initial outlet and the branched outlet according to the state of installation of the inverter, the structure that forms a flow that diffuses around in the cooling chamber remains as it is, and the required coolant can be easily obtained. guide output can direction changes easily correspond to models to be mounted in the inverter.

  According to the invention of claim 2, the mouth portion can be easily used.

The perspective view which shows the electric vehicle (vehicle) carrying the inverter which concerns on one Embodiment of this invention. The perspective view which shows the cooling structure of the inverter. The perspective view which shows each part of the cooling structure. Sectional drawing which follows the AA line in FIG .

Hereinafter, it will be explained based on an embodiment Figures 1 of the present invention shown in FIG.
FIG. 1 shows, for example, an electric vehicle (vehicle). In FIG. 1, reference numeral 1 denotes a vehicle body, and a traveling motor 3 for traveling driving is provided at the center of a power unit space (not shown) formed at the rear of the vehicle body 1. (AC motor) is installed. A water-cooled inverter 5 for driving the motor (hereinafter simply referred to as the inverter 5) is installed immediately above the traveling motor 3. Incidentally, an in-vehicle charger 7 and a DC-DC converter (not shown) are installed adjacent to the inverter 5 on one side in the vehicle width direction across the inverter 5, and a braking system is installed on the other side in the vehicle width direction. The electric vacuum pump 8 is installed, and each device occupies the power unit space.

  The inverter 5 converts the DC power stored in the battery 9 on which the vehicle body 1 is mounted into AC power and supplies the AC power to the traveling motor 3 as drive power. The inverter 5 is connected to a radiator 13 at the front of the vehicle body, a cooling water pump 15 and the like via a cooling water pipe 11. The inverter 5 is cooled by cooling water (corresponding to the cooling liquid of the present application) by the cooling system constituted by these devices.

Cooling structure of the inverter 5 to be cooled by the cooling water is shown in FIGS. FIG. 2 shows the entire cooling structure, FIG. 3 shows an exploded view, and FIG. 4 shows each part viewed from different directions.
That is, the inverter 5 has a capacitor module and a terminal module (both not shown) accommodated in, for example, a middle stage in a vertically divided rectangular casing 17, and the lowermost part in the casing 17 (the lower side of the capacitor module). ) Accommodates an IGBT module 19 (corresponding to the inverter module of the present application) serving as a switching element. The IGBT module 19 is a module that generates a considerable amount of heat due to a switching operation.

  Therefore, a cooling chamber 23 is accommodated in the housing 17 at a position adjacent to the IGBT module 19 (FIG. 3), and the IGBT module 19 is cooled with the cooling water of the previous cooling system. In this cooling structure, a structure in which a rectangular plate-like heat sink 21 (heat dissipating part) is provided below the IGBT module 19 and a cooling chamber 23 is provided below the heat sink 21 is used.

Specifically, as shown in FIGS. 3 and 4 , the cooling chamber 23 is formed with a rectangular and flat concave portion 25 in a part of the lower wall 17 a of the housing 17, and the opening of the concave portion 25 is formed. A chamber space is formed by a structure in which the heat sink 21 is mounted and fixed (for example, bolted). Thus, a cooling chamber 23 facing the lower surface of the heat sink 21 is formed. Incidentally, a large number of cooling fins 21 a protruding into the cooling chamber 23 are provided on the lower surface of the heat sink 21.

The cooling chamber 23 is combined with a flow path structure for circulating the cooling water while reducing the momentum of the water flow so that an appropriate flow of cooling water is secured in the cooling chamber 23. In this flow path structure, as shown in FIGS. 3 and 4 , positions on one surface constituting the cooling chamber 23 that are separated from each other, here, parallel two-point positions on both ends in the vehicle width direction on the bottom surface of the cooling chamber 23. An inlet 27 and an outlet 29 formed in the upper part of the housing 17 and a flat lower wall 17a forming the lower part of the housing 17 and a lead-in path 33 (corresponding to the inlet-side flow path of the present application) and a lead-out path 35 (corresponding to the present application) The structure which weakens the momentum of the water flow is used.

  Specifically, the inlet 27 and the outlet 29 are formed by forming a pair of circular through holes in the lower wall 7a. The introduction path 33 and the lead-out path 35 are formed on a lower surface of the lower wall 7a, followed by an inlet 27 and an outlet 29 that are opened in the longitudinal direction, and a pair of tunnel-shaped cylindrical portions along the vehicle front-rear direction, here the vehicle front direction. 33a and 35a are formed. The pair of cylindrical portions 33a and 35a are arranged in the horizontal direction, that is, in parallel to the vehicle front direction (same direction) from the inlet / outlet 27.29 that opens in the vertical direction, with the gap between the inlet 27 and the outlet 29 maintained, for example, It extends to the edge of the lower wall 17a. Then, the end of the inlet cylinder part 27a that opens at the end of the lower wall 17a is used as an introduction port 39 for introducing cooling water, and the end of the outlet cylinder part 29a that also opens at the end of the lower wall 17a is used as cooling water. A derivation port 41 for derivation is used. That is, the introduction path 33 and the lead-out path 35 are formed in the housing 17 so as to extend in parallel in the same direction while maintaining a distance between the inlet 27 and the outlet 29.

  With this flow path structure, cooling water with weakened water flow flows in the cooling chamber 23. That is, the cooling water is received in the horizontal direction by the introduction path 33, and the horizontal water flow becomes vertical when passing through the inlet 27, and further, the vertical flow or cooling chamber collides with the lower surface of the heat sink 21 from the inlet 27. By changing to a lateral flow that collides with the wall surface 23, the flow of the cooling water flowing between the inlet 27 and the outlet 29 is weakened. The same applies to the outlet side, and thereby, a water flow is formed in the cooling chamber 23 so as to diffuse around.

The inlet 39 of the inverter 5 and the inlet side cooling pipe 11 are connected via a nipple member 43 (a joint member for connecting a cooling pipe). The lead-out port 41 of the inverter 5 and the cooling pipe 11 on the outlet side are connected via a nipple member 44 (a joint member for connecting a cooling pipe) so that the cooling water passing through the radiator 13 is circulated in the cooling chamber 23. (Fig. 2).
Further to the inverter 5, the non Ah Ru guide outlet 41 in such orientation constraints, allowing the derivation of the coolant structure is assembled. As shown in FIGS . 2 to 4 , a mouth 47 is formed in the middle of the outlet path 35.

Specifically, the mouth portion 47 forms a branch portion 45 that branches from the lead-out path 35 in a cylindrical portion 35a portion between the outlet 29 and the outlet port 41, here in an intermediate portion, and from this branch portion 45, The cylindrical portion 49 is oriented in a different direction from the original outlet 41, here in a direction shifted at a right angle from the point where the outlet 41 is located, that is, in the vehicle width direction side (here, the side where the electric vacuum pump 8 is mounted). ) Along the lower wall 17a . An opening that faces the end of the cylindrical portion 49, here, the end of the lower wall 17 a is used as a second outlet 51. In other words, the branch path 53 that allows the cooling water to be derived from the second outlet 51 is formed. Thus, the lower wall 17a is provided with a mouth portion 47 for letting out the cooling water in a direction different from the initial outlet port 41. Incidentally, the second outlet 51 is assembled with a plug member 57 (shown in FIG. 4) that closes the outlet 51 when not in use, and a nipple member 59 (see FIG. 4) that can be connected to a cooling pipe when in use. Assemble).

The effect | action of the cooling structure of the inverter 5 comprised in this way is demonstrated.
The inverter 5 as shown in FIG. 1, when mounted so as to be sandwiched between the in-vehicle charger 7 and electric vacuum pump 8, the second outlet port 51, by mounting the plug member 57 The outlet 51 is closed.
In this case, the pumping operation of the cooling pump 15, the cooling water toward the inverter 5 from the radiator 13 from the inlet 39 facing in the longitudinal direction of the vehicle body front side as shown in FIG. 3, 4, lateral inlet channel 33 Then, it reaches the inlet 27 and is introduced into the cooling chamber 23 from the vertically oriented inlet 27 approaching one side in the width direction of the cooling chamber 23.

  Here, the flow direction of the cooling water flowing toward the cooling chamber 23 changes in the flow direction while being introduced into the cooling chamber 23, or the cooling water led out from the inlet 27 collides with the lower surface of the heat sink 21. The momentum is weakened because it collides with the wall surface of 23. The cooling water in the cooling chamber 23 is directed in the same direction as the cooling water flowing toward the outlet 29, passing through the vertical outlet 29 and the horizontal outlet path 35, from the outlet 41 to the cooling pipe 11, and flowing through the inlet path 33. Then, it is led out to the cooling pipe 11.

  By the action of weakening the momentum of the cooling water flow on the outlet side and the action of weakening the momentum of the cooling water on the inlet side, the flow from the inlet 27 to the outlet 29 flows while diffusing to the surroundings, and reaches each part in the cooling chamber 23. Cooling water is distributed. Thus, the cooling water in the cooling chamber 23 becomes a flow suitable for heat exchange with each part of the heat sink 21 and each part of the cooling fin group, and efficiently cools the IGBT module 19 of the inverter 5.

Since the cooling of the inverter 5 is established when the cooling water flows in the same direction in both the introduction path 33 and the outlet path 35, the on-vehicle charger 7 and the electric vacuum are provided on both sides of the inverter 5 as shown in FIG. It is easy to demonstrate under the situation where the pump 8 is installed.
Here, the vehicle type of the electric vehicle on which the inverter 5 is mounted is changed. For example, the electric vacuum pump 8 is mounted not at the side of the inverter 5 but at another point, and the one-dot chain line in FIG. As shown, it is assumed that the cooling water is derived from the space on the side of the inverter 5 where the electric vacuum pump 8 is disposed.

  At this time, the second outlet 51 is selected. That is, a plug member (not shown) is attached to the initial outlet 41 that faces the front side of the vehicle to close the outlet 41, and a nipple member 59 is attached to the second outlet 51 that faces sideways. The outlet cooling pipe 11 is connected to the outlet 51 through the nipple member 59. That is, the cooling water in the cooling chamber 23 is led out from a lateral direction different from the initial leading direction.

Thereby, the IGBT module 19 can be cooled with the structure that weakens the momentum of the water flow for cooling the IGBT module 19 appropriately.
In this way, the inverter 5 is provided with the inlet 27 and the outlet 29 on the same surface of the cooling chamber 23, and the introduction path 33, along the same direction from the inlet 27 and the outlet 29, while maintaining a gap between the inlet 27 and the outlet 29. The IGBT module 19 can be optimally cooled (heat exchange) with a simple structure in which the lead-out path 35 extends in parallel.

In addition, the structure that forms a flow that diffuses around the inside of the cooling chamber 23 is simply selected by selecting the second outlet 51 in the middle of the outlet path 35 according to the mounting condition of the inverter 5. easily can guide out direction of the change of the cooling water required. For this reason, it is not necessary to manufacture the inverter 5 again. In particular, the opening 47 is easy to use because the plug member 57 for closing and the nipple member 59 for connecting pipes are assembled.

Of course, the second outlet 51, in order to utilize the heat of the cooling water which has finished the cooling separately may be connected to the piping member.
Note that the present invention is not limited to the above-described embodiment, and various modifications may be made without departing from the spirit of the present invention. For example, in one embodiment, is used a mouth 47 which branches laterally facing, not limited thereto, but may if orientation different from the orientation of the original electrical outlet 41.

5 Inverter 17 Housing 19 IGBT module (Inverter module)
21,21a Heat sink, cooling fin (heat dissipation part)
23 Cooling chamber 27 Inlet 29 Outlet 33 Inlet path (inlet channel)
35 Lead-out path (exit-side flow path)
39 Inlet port 41 Outlet port 47 Port portion 51 Second outlet port

Claims (2)

An inverter module inside the housing, and a cooling chamber disposed adjacent to the inverter module,
An inlet for introducing the coolant from the outside of the housing at one end, an inlet-side flow path having an inlet for introducing the coolant into the cooling chamber at the other end, and an outlet for leading the coolant to the outside of the housing at one end In the cooling structure of the inverter formed in the casing, an outlet-side flow path having an outlet for allowing the coolant to flow out of the cooling chamber at the other end
The cooling chamber is formed with a square and flat recess.
Vertical wherein the inlet and the outlet, which is a direction orthogonal to the arranged at a point remote from each other of one surface constituting the cooling chamber Rutotomoni, the extending direction of the entering-side flow path and the exit-side flow path Open in the direction,
The entering-side flow path and the exit-side flow path while maintaining the distance between the inlet and the outlet, extends parallel along the same direction, respectively, a front Symbol outlet before Symbol exit-side flow path cooling structure of the inverter, characterized in that only between the outlet mouth which is open to the outside branches to different directions are provided before and Symbol outlet.   The cooling structure for an inverter according to claim 1, wherein the mouth portion is assembled with a nipple member connectable to the cooling pipe or a plug member for closing the opening of the mouth portion.

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