JP2014043125A - On-vehicle structure of inverter in electric vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an on-vehicle structure which inhibits vibrations of an inverter mounted on an electric vehicle.SOLUTION: An on-vehicle structure of an inverter comprises: two side members 3b which extend in a longitudinal direction at both lateral sides of a front compartment 9; a cross member 4 which is located astride the two side members 3b; an inverter 5 mounted on the cross member 4; and a bracket 6 which fixes the inverter 5 to the cross member 4. The bracket 6 connects with an upper surface of the inverter 5 and connects with the cross member 4 and thus fixes the inverter 5 at the upper and lower sides.

Description

  The present invention relates to an in-vehicle structure of an inverter in an electric vehicle. The electric vehicle in this specification includes a fuel cell vehicle.

  The electric vehicle includes an inverter that converts the DC power of the battery into AC power having a frequency suitable for driving the motor. Usually, the inverter is mounted in the front compartment of the vehicle together with the motor. An inverter is a device that was not found in an engine car and has a relatively large size, so that there is a lot of room for introducing a technology that was not available in a conventional engine car. Several proposals have been made on the in-vehicle structure of the inverter (Patent Documents 1 to 3).

  The technique of patent document 1 fixes an inverter to a vehicle body via two opposing brackets. There is an advantage that the vibration of the vehicle body is not easily transmitted to the inverter because the bracket serves as a cushioning material. Patent Document 2 relates to protection of an inverter at the time of a collision. The technique of Patent Document 2 includes two side members extending in the front-rear direction on both sides in the front compartment, and a cross member spanned between the two side members. The inverter is fixed to the cross member by a bracket. The bracket is connected to the rib provided on the side surface of the inverter and to the cross member. In this technique, even when the side member is deformed so as to be crushed back and forth by an impact at the time of a collision, the inverter moves rearward together with the bracket, and the impact is alleviated. Patent Document 3 also relates to a technique for protecting an inverter in the event of a collision. The inverter is fixed on a table fixed to the side member, and the rear surface of the inverter is fixed by a bracket extending rearward from the front body in front of the inverter beyond the top of the inverter.

JP 2009-120109 A JP 2012-096746 A JP 2009-040336 A

  In any patent document, the inverter is fixed to the side member or the cross member. The side member and the cross member correspond to a so-called vehicle body frame, and are members that secure the structural strength of the vehicle body. If fixed to such a member, the inverter is firmly supported by the vehicle. However, the side member and the cross member vibrate when traveling. Since the inverter has a corresponding weight, the vibrations of the side member and the cross member are transmitted to the inverter, and when the inverter vibrates, the vibration of the entire vehicle body increases and drivability deteriorates. The technique of patent document 1 suppresses the vibration transmitted to the inverter through the bracket without directly contacting the inverter with the vehicle body in order to suppress the vibration of the inverter. However, the fixing strength of the inverter may be insufficient unless it is brought into direct contact with the vehicle body. In the techniques of Patent Documents 2 and 3, the side surface or bottom surface of the inverter is fixed to a frame such as a cross member or a side member. In such a fixing method, it is fixed only below the center of gravity of the inverter, and there is a possibility that the swing of the inverter cannot be sufficiently suppressed. The technology disclosed in the present specification provides an in-vehicle structure that can suppress a swing of an inverter.

  The inverter on-vehicle structure disclosed in this specification includes two side members extending back and forth in both sides of a vehicle interior space (typically in a front compartment), and spans between the two side members. A cross member, an inverter mounted on the cross member, and a bracket for fixing the inverter to the cross member. The bracket is connected to the upper surface of the inverter and to the cross member.

  In the above vehicle-mounted structure, the inverter is firmly supported from the lower surface by a cross member that is one of the frames of the vehicle body, and the upper surface of the inverter is fixed by a bracket. The inverter is firmly supported by the cross member, and the inverter is fixed at the top and bottom thereof, so that the inverter is less likely to shake. Typically, the cross member is fastened to the lower surface of the inverter with a bolt, and the bracket is fastened to the upper surface of the inverter with a bolt.

  More preferably, the bracket may cover the front surface of the inverter. The bracket that covers the front of the inverter functions as a protector in the event of a collision. Damage to the inverter in the event of a collision can be reduced.

  Details and further improvements of the technology disclosed in this specification will be described in the following “DETAILED DESCRIPTION”.

It is a top view of the front compartment which accommodated the inverter. It is sectional drawing along the II-II line of FIG. It is sectional drawing to which the inverter periphery was expanded in FIG.

  An in-vehicle structure 2 according to an embodiment will be described with reference to the drawings. The on-vehicle structure of the embodiment is mounting the inverter 5 on the electric vehicle 10. The inverter 5 is mounted on the front compartment 9 of the electric vehicle 10. FIG. 1 shows a plan view of a front compartment 9 in which the inverter 5 is housed, and FIG. 2 shows a cross-sectional view taken along the line II-II in FIG. In FIG. 2, the internal structure of the inverter 5 is not shown. In the coordinates in the figure, the X axis indicates the front of the vehicle, the Y axis indicates the side of the vehicle, and the Z axis indicates the upper side of the vehicle. The plan view of FIG. 1 corresponds to a view of the front compartment 9 with the hood removed.

  The electric vehicle 10 is a so-called pure EV that includes only a motor for traveling and does not include an engine. Although a motor, a low-voltage battery, and the like are also housed in the front compartment 9, in order to facilitate understanding of the drawings, in FIG. 1 and FIG. 2, illustrations are omitted except for the member that fixes the inverter 5 and the related members. .

  The body 7 of the electric vehicle 10 is supported by a frame that ensures the structural strength of the entire vehicle, and a part of the frame is visible in the front compartment 9. A part of the frame that can be seen in the front compartment 9 is bridged between the two side members 3a and 3b that extend back and forth on both sides of the front compartment 9 and the two side members 3a and 3b. Cross member 4. Further, the radiator support 8 connects the tips of the two side members 3a and 3b.

  The cross member 4 is a plate-like member, extends substantially in the center of the front compartment 9 in the vehicle lateral direction (Y-axis direction), and both ends thereof are fixed to the side members 3a and 3b, respectively. The cross member 4 is fixed to the side members 3a and 3b by bolts or welding. An inverter 5 is fixed to the upper surface of the cross member 4. A flange 14 having the same plane as the lower surface of the inverter 5 is provided at the lower end of the rear surface of the inverter 5, and the inverter 5 is fastened to the cross member 4 with bolts 15 through the flange 14.

  The inverter 5 is also fixed on the upper surface of the inverter 5 via the bracket 6. The lower end of the bracket 6 is fixed to the cross member 4 with a bolt 13 in front of the inverter 5. The bracket 6 rises from the cross member 4 on the front surface of the inverter 5, covers the entire front surface of the inverter 5, bends along the front upper corner of the inverter 5, and covers the front of the upper surface of the inverter 5. The inverter 5 is fastened to the upper end of the bracket 6 with a bolt 12 in front of the upper surface.

  Since the lower surface of the inverter 5 is supported by the cross member 4 and is fixed on the upper surface via the bracket 6, the inverter 5 is firmly fixed to the vehicle frame (cross member 4) and fixed vertically. It is difficult to vibrate. The fixing structure of the inverter 5 will be described in more detail with reference to FIG.

  FIG. 3 is an enlarged view of the periphery of the inverter 5 in the cross-sectional view of FIG. G in the figure indicates the center of gravity of the inverter 5. As shown in FIG. 3, the inverter 5 has a front lower portion fixed to the cross member 4 by a bolt 13 via a bracket 6, and a rear lower portion fixed to the cross member 4 by a bolt 15 via a flange 14. Further, the upper front portion is fixed with bolts 12 via the bracket 6. Arrows A, B, and C in FIG. 3 are vectors that connect the center of gravity G of the inverter 5 and the three fixed points of the inverter 5. As indicated by these three vectors A, B, and C, the inverter 5 is fixed at three sides of its center of gravity G. Therefore, the inverter 5 has a structure in which the center of gravity G hardly swings with respect to the pitch vibration of the vehicle (vibration around the axis facing the vehicle lateral direction). That is, the above-described in-vehicle structure 2 secures the fixing strength by fixing the inverter 5 to the cross member 4 that is one of the vehicle frames, and also fixes the inverter 5 up and down by the cross member 4 and the bracket 6. It is also difficult for the pitch vibration of the vehicle to shake.

  The bracket 6 covers the front surface of the inverter 5 and further the upper front corner. Therefore, the bracket 6 serves as a protector, and damage to the inverter 5 at the time of collision can be reduced.

  The side members 3a and 3b, the cross member 4, and the bracket 6 are typically made of steel. The casing of the inverter 5 is typically made of aluminum.

  Points to be noted regarding the inverter on-vehicle structure 2 described in the embodiment will be described. Some vehicles have a frame called a radiator support 8 that connects the front ends of the side members 3a and 3b. The radiator support is located in front of the vehicle. Therefore, when the inverter 5 is fixed using the radiator support, the arrangement position of the inverter 5 is restricted in front of the front compartment. In the in-vehicle structure of the embodiment, the inverter 5 is fixed to the cross member 4, so that there is no restriction as in the case of using the radiator support.

  As shown in FIGS. 2 and 3, the inverter 5 is preferably fixed at three points on the front and rear sides and the top surface of the inverter when viewed from the side of the vehicle. More preferably, when viewed from the side of the vehicle, the three fixed positions are such that three vectors connecting the center of gravity G of the inverter and each of the three fixed points form an angle of 120 degrees with each other. It is good to have been established. Such a positional relationship supports the inverter at three points located at an equal angle with the center of gravity G as the center when viewed from the side of the vehicle. it can. In FIG. 3, when the upper end of the bracket 6 is extended backward so that the vector A faces directly above the center of gravity G, three vectors connecting the center of gravity G of the inverter and each of the three fixed points are 120 degrees to each other. Make an angle.

  The on-vehicle structure described above has an advantage that the collision safety can be improved without increasing the number of parts as a secondary effect (when the bracket 6 covers the front surface of the inverter 5). Moreover, since the above-mentioned vehicle-mounted structure can fix an inverter without requiring special additional parts, it is excellent in the ease of assembling the inverter.

  The front compartment 9 in the embodiment corresponds to an example of “in-vehicle space”. However, the in-vehicle structure disclosed in this specification is not limited to the case where the inverter is mounted in the front compartment. The technology disclosed in this specification can also be applied when an inverter is mounted in a rear compartment.

  The technology disclosed in the present specification is particularly effective for an electric vehicle not equipped with an engine having a large size and weight. Here, the electric vehicle includes a vehicle equipped with a fuel cell as a battery.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings can achieve a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

2: In-vehicle structure 3a, 3b: Side member 4: Cross member 5: Inverter 6: Bracket 7: Body 8: Radiator support 9: Front compartment 10: Electric vehicle 12, 13, 15: Bolt 14: Flange G: Inverter center of gravity

Claims (2)

In-vehicle structure of an inverter in an electric vehicle,
Two side members extending back and forth on both sides of the interior space,
A cross member spanned between the two side members;
An inverter mounted on the cross member;
A bracket for fixing the inverter to the cross member;
With
The bracket is connected to the top surface of the inverter and is connected to the cross member.   The in-vehicle structure according to claim 1, wherein the bracket covers a front surface of the inverter.

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