JP6888502B2 - In-vehicle structure of electrical equipment - Google Patents

Description

The techniques disclosed herein relate to the in-vehicle construction of electrical equipment in the front compartment of an automobile.

In recent years, automobiles have become more electronic, and various electric devices are being installed in the front compartment of the vehicle. In particular, electric vehicles are equipped with many electric devices in a narrow front compartment, including a power converter that converts DC power to AC power that drives a driving motor. Patent Document 1 discloses an automobile in which a power converter is fixed on a transaxle in a front compartment. The upper lid of an electric device such as a power converter is generally fixed to a housing body with bolts (for example, Patent Document 2).

Japanese Unexamined Patent Publication No. 2016-60263 Japanese Unexamined Patent Publication No. 2014-138440

If the electrical device is fixed above the transaxle, another device is also placed in front of the electrical device. In the event of a frontal collision of the vehicle, another component in front may retract and come into contact with electrical equipment. Contact with another device may cause the top lid of the electrical device to come off and expose the parts inside the housing. The housing of the electric device may be divided into an upper case and a lower case. In such a case, the upper case may come off from the lower case when the vehicle collides with the front. Therefore, in the following, an electric device having a housing divided into at least two parts in the vertical direction is targeted.

This specification discloses the in-vehicle structure of electrical equipment in the front compartment of an automobile. The electrical equipment is fixed on the transaxle in the front compartment of the car. As described above, the housing of the electric device is divided into at least two parts in the vertical direction. The four corners of the two parts are fixed to each other with bolts, and both sides in the vehicle width direction and the center in the front-rear direction of the vehicle are fixed to each other with bolts. One of the two parts, bolt includes a bolt hole to be inserted, out of the bolt holes, located on the side of the vehicle center side of the vehicle width direction, and is after the longitudinal direction of the central vehicle bolt The diameter of the bolt hole of the hole is larger than that of the other bolt holes. The two parts are, for example, an upper cover and a case body, an upper case and a lower case, or a case body and a lower cover.

According to the examination, of the bolts that mutually fix the two parts of the housing of the electrical equipment, the two bolts on the side of the housing near the center in the vehicle width direction, the center and the rear in the vehicle front-rear direction. It turned out that the bolt was overloaded than the other bolts. If the load (collision load) when the vehicle collides forward is large, the bolt where the load is concentrated breaks. Then, the other bolts also break in a chain reaction, and the upper part comes off from the lower part. Therefore, in the in-vehicle structure disclosed in the present specification, the diameter of the bolt hole through which the two bolts are passed is made larger than the diameter of the other bolt holes. As a result, the load applied to the two bolts is reduced, the load applied to each bolt fixing the upper portion is leveled, and the bolts are less likely to break. That is, in the event of a collision, the upper portion is less likely to come off from the lower portion. Details of the techniques disclosed herein and further improvements will be described in the "Modes for Carrying Out the Invention" below.

It is a perspective view which shows the device layout in the front compartment of a hybrid vehicle. It is a top view of the front compartment. It is a side view of the power control unit fixed on the transaxle (first embodiment). It is a top view of the power control unit (1st Example). It is sectional drawing along the VV line of FIG. It is a graph which shows the difference by the diameter of a bolt hole of the load applied to a bolt. It is a side view of the power control unit fixed on the transaxle (second embodiment). It is a top view of the power control unit (second embodiment).

(First Example) The vehicle-mounted structure of the first embodiment will be described with reference to the drawings. The vehicle-mounted structure of the first embodiment is applied to a hybrid vehicle provided with an engine and a motor for traveling. FIG. 1 is a perspective view showing a device layout in the front compartment 90 of the hybrid vehicle 100. FIG. 2 is a plan view of the front compartment 90. In the coordinate system in the figure, the positive direction of the F axis indicates the front of the vehicle, and the positive direction of the V axis indicates the upper side of the vehicle. The positive direction of the H axis indicates the left side of the vehicle. In addition, in FIG. 1 and FIG. 2, the device mounted on the front compartment 90 is schematically drawn.

The front compartment 90 houses an engine 95, a transaxle 30, a power control unit 10, a radiator 96, a radiator tank 91, an auxiliary battery 5, and the like. Various other devices are housed in the front compartment 90, but their illustration and description are omitted. The upper cover of the power control unit 10 is fixed to the case body with bolts, but the bolts are not shown in FIG.

The hybrid vehicle 100 includes two motors 7a and 7b and an engine 95 for traveling. The two motors 7a and 7b are housed in the housing of the transaxle 30. The transaxle 30 is provided with two motors 7a and 7b for traveling, as well as a power distribution mechanism and a differential gear. The transaxle 30 and the engine 95 are connected, and the power distribution mechanism is a gear set that synthesizes / distributes the output torque of the engine 95 and the output torques of the motors 7a and 7b. When a high torque is required, the power distribution mechanism synthesizes the output torque of the engine 95 and the output torques of the motors 7a and 7b and transmits them to the differential gear. Further, the power distribution mechanism divides the output torque of the engine 95 and transmits it to the differential gear and one of the motors 7a depending on the situation. In that case, the hybrid vehicle 100 generates electricity with the motor 7a while traveling with the engine torque. The motor 7a also functions as a starter motor for starting the engine 95.

The engine 95 and the transaxle 30 are connected so as to be adjacent to each other in the vehicle width direction. The engine 95 and the transaxle 30 are suspended by two side members 92 that ensure the structural strength of the vehicle. In FIG. 1, one side member is not visible. The radiator 96 is located in front of the transaxle 30.

The power control unit 10 is fixed to the upper surface of the transaxle 30. The power control unit 10 is a device that boosts the DC power of a main battery (not shown) and converts the boosted DC power into AC power suitable for driving a motor.

The power control unit 10 is supported above the transaxle 30 via a front bracket 93 and a rear bracket 94. A radiator tank 91 is arranged on the rear surface of the radiator 96, and the radiator tank 91 is located in front of the power control unit 10.

FIG. 3 shows a side view of the power control unit 10 fixed to the upper surface 30a of the transaxle 30. The upper surface 30a of the transaxle 30 is inclined downward, and the power control unit 10 fixed on the upper surface 30a is also fixed in the forward downward posture. The XYZ coordinate system of FIG. 3 is a coordinate system for the power control unit 10, the X-axis extends parallel to the bottom surface of the housing 50 of the power control unit 10, and the Z-axis is parallel to the rear surface of the housing 50. The Y-axis extends along the vehicle width direction.

The power control unit 10 is fixed by a front bracket 93 and a rear bracket 94 with a gap SP between the upper surface 30a of the transaxle 30. This is to suppress the vibration transmitted from the transaxle 30 to the power control unit 10. A vibration-proof bush (not shown) is sandwiched between the front bracket 93 and the housing 50 of the power control unit 10. A vibration-proof bush (not shown) is also sandwiched between the rear bracket 94 and the housing 50. A connector 17 of a power cable 27 that sends power to motors 7a and 7b inside the transaxle 30 is connected to the left side surface of the housing 50.

The housing 50 of the power control unit 10 is composed of a case body 11 that is open at the top and bottom, an upper cover 12 that covers the upper opening of the case body 11, and a lower cover 13 that covers the lower opening of the case body 11. .. The upper cover 12 is fixed to the case body 11 with a plurality of bolts 43. As shown in FIG. 2, the upper cover 12 and the case body 11 are located at four corners, two locations on both sides in the vehicle width direction and in the center in the vehicle front-rear direction, and the front side in the vehicle front-rear direction. They are fixed to each other at one location in the center in the vehicle width direction, for a total of seven locations. The same applies to the lower cover 13, but the description of the fixed structure of the lower cover 13 will be omitted.

As shown in FIGS. 2 and 3, the radiator tank 91 is located in front of the power control unit 10. As shown in FIG. 2, the radiator tank 91 is located in front of the power control unit 10 near the center in the vehicle width direction. When the vehicle collides forward, the radiator tank 91 retracts together with the radiator 96. Then, the radiator tank 91 collides with the front portion of the power control unit 10 near the center in the vehicle width direction. As described above, the power control unit 10 is fixed on the transaxle 30 in a forward-down posture. Therefore, the radiator tank 91 makes strong contact with the front joint between the case body 11 and the upper cover 12. In particular, as described with reference to FIG. 2, the radiator tank 91 collides with the front of the power control unit 10 near the center. Therefore, when the radiator tank 91 comes into contact with the radiator tank 91, a high load (shear load) is applied to the bolt 43 located closer to the center in the vehicle width direction among the bolts 43 fixing the case body 11 and the upper cover 12. In particular, a load (shearing force) higher than that of other bolts is applied to the bolts at the center and rear of the upper cover 12 in the vehicle width direction toward the center of the vehicle in the vehicle front-rear direction. When a load is concentrated on a particular bolt, that bolt breaks. When one bolt breaks, the load applied to the remaining bolts increases, so the other bolts break in a chain reaction. Finally, the upper cover 12 comes off from the case body 11, and the high voltage parts inside the case body 11 are exposed.

FIG. 4 shows a plan view of the power control unit 10. The lower side of the figure corresponds to the front of the vehicle, and the upper side of the figure corresponds to the rear of the vehicle (see the FHV coordinate system). As described above, the upper cover 12 is fixed to the case body 11 at seven places. For the sake of explanation, reference numerals 4a-4g in FIG. 4 represent fastening points. In FIG. 4, the bolt 43 is shown by a virtual line so that the bolt hole 12a through which the bolt 43 passes can be seen. As described above, in the case of the in-vehicle structure of the embodiment, the bolts on the side of the upper cover 12 near the vehicle center in the vehicle width direction and at the center (fastening point 4f) and rear (fastening point 4g) in the vehicle front-rear direction. A high load is applied to 43. Therefore, in the in-vehicle structure of the embodiment, of the seven bolt holes of the upper cover 12, the side closer to the vehicle center in the vehicle width direction, the center (fastening point 4f) and the rear (fastening point 4g) in the vehicle front-rear direction. The diameter of the bolt hole of the above is made larger than the diameter of the bolt hole of another fastening point (fastening point 4a-4e).

FIG. 5 shows a cross-sectional view taken along the line VV of FIG. FIG. 5 shows a cross section of the fastening portion 4f of FIG. 4, but the cross section of the other fastening portions is the same as that of FIG. 5 except for the diameter of the bolt hole 12a. In FIG. 5, the bolt 43 is drawn with a virtual line to help understanding. Of the seven bolt holes 12a of the upper cover 12, the diameters Da2 of the bolt holes on the side closer to the vehicle center in the vehicle width direction and at the center (fastening point 4f) and rear (fastening point 4g) in the vehicle front-rear direction are set. The diameter of the bolt holes at the other fastening points (fastening points 4a-4e) is made larger than Da1. By changing the diameter of the bolt holes as described above, the concentration of the load on the bolts at the fastening points 4f and 4g is alleviated, and the bolts are less likely to break.

In one example, the diameter Da1 of the bolt hole 12a of the fastening portion 4a-4e is 6 mm with respect to the bolt 43 of the M5, and the diameter Da2 of the bolt hole 12a of the fastening portion 4f and 4g is 7 mm. FIG. 6 shows an example of the effect of changing the diameter of the bolt hole 12a. FIG. 6 is a graph showing the difference in the load applied to the bolt depending on the diameter of the bolt hole. The conditions other than the diameter of the bolt hole are the same. The horizontal axis shows the collision load applied to the power control unit 10 from the front, and the vertical axis shows the load applied to the bolt 43. Graph Ga shows the load applied to the bolt 43 at the fastening portion 4 g (see FIG. 4) when the diameters of the bolt holes are all the same Da1 (= 6 mm). In the graph Gb, when the diameter of the bolt holes of the fastening points 4f and 4g is Da2 (= 7mm) and the diameter of the bolt holes of the other fastening points (4a-4e) is Da1 (6mm), the fastening points 4g ( The load applied to the bolt 43 (see FIG. 4) is shown. Graph Gc shows the shear load capacity of the bolt. In the case of Graph Ga, when the collision load exceeds about 60 [kN], the load applied to the bolt exceeds the shear load capacity. On the other hand, in the case of the graph Gb (when the diameters of the two bolt holes are larger than those of the other fastening points), the load applied to the bolts is less than the shear load even with a collision load of 70 [kN]. In this way, by making the diameters of the bolt holes 12a at the center and rear of the upper cover 12 in the vehicle width direction toward the center of the vehicle in the vehicle front-rear direction larger than the diameters of the other bolt holes 12a, the bolts can be made into bolts. The concentrated load applied can be reduced.

A knock pin is sandwiched between the upper cover 12 and the case body 11. A hole for a knock pin (lower pin hole) is provided around the opening of the case body 11, and a hole (upper pin hole) is also provided at a position facing the lower pin hole of the upper cover 12. The knock pin fits into both the lower pin hole of the case body 11 and the upper pin hole of the upper cover 12, and together with the bolt 43, supports the load in the shear direction of the case body 11 and the upper cover 12. The knock pin is also used for positioning when the upper cover 12 is fixed to the case body 11.

(Second Example) The vehicle-mounted structure of the second embodiment will be described with reference to FIGS. 7 and 8. FIG. 7 is a side view of the power control unit 10a fixed on the transaxle 30. FIG. 8 is a plan view of the power control unit 10a. As in the case of FIG. 4, the F-axis positive direction of the coordinate system in the figure indicates the vehicle front, and the H-axis indicates the vehicle width direction. Of the edges of the housing 50a on both sides in the vehicle width direction, the edges in the negative direction of the H axis are closer to the center of the vehicle.

The power control unit 10a is fixed on the transaxle 30 in the front compartment of the hybrid vehicle as in the case of the first embodiment. The housing 50a of the power control unit 10a is divided into an upper cover 12, an upper case 51, a lower case 52, and a lower cover 13 in the vertical direction. The upper case 51 and the lower case 52 are fixed to each other in the vertical direction by a plurality of bolts 143. A flange 51a is provided at a joint with the lower case 52 of the upper case 51, and a flange 52a is also provided at a joint with the upper case 51 of the lower case 52. In FIG. 8, the flange 52a is located below the flange 51a. The upper case 51 and the lower case 52 are combined so that the flanges 51a and 52a face each other, and are fastened to each other by bolts 143 penetrating the flanges 51a and 52a. In other words, the upper case 51 and the lower case 52 are the four corners of the flanges 51a and 52a (fastening points 104a, 104c, 104e, 104g) and both sides in the vehicle width direction and are centered in the vehicle front-rear direction (fastening points 104b, 104f). ) Are fixed to each other with bolts 143. The flange 51a is provided with a bolt hole 51b through which the bolt 143 is inserted, and the bolt 143 is fixed to the flange 52a of the lower case 52. In FIG. 8, the bolt 143 is represented by a virtual line so that the bolt hole 51b can be seen. The diameters of the bolt holes 51b on the side of the housing 50a near the center of the vehicle in the vehicle width direction and at the center (fastening point 104f) and rear (fastening point 104g) in the vehicle front-rear direction are larger than the diameters of the other bolt holes 51b. Is also getting bigger.

Even in the in-vehicle structure of the second embodiment, the bolt holes 51b at the locations where the load at the time of collision is large (the fastening portion 104f at the center in the vehicle front-rear direction and the fastening portion 104g on the rear side on the side closer to the vehicle center in the vehicle width direction). By making the diameter of the bolt hole 51b larger than the diameter of the other bolt holes 51b, the load bearing capacity at the time of collision is enhanced. Therefore, it is possible to prevent the upper case 51 and the lower case 52 from being separated at the time of a collision.

The upper case 51 and the lower case 52 of the power control unit 10a have openings in the upper part and the lower part, respectively, and the upper opening of the upper case 51 is closed by the upper cover 12 and the lower opening of the lower case 52. Is closed by the lower cover 13. The upper cover 12 is fastened to the upper case 51 with bolts 43, and the lower cover 13 is fastened to the lower case 52 with bolts.

The points to be noted regarding the technique described in the examples will be described. The power control unit 10 corresponds to an example of an electric device. The upper cover 12 and the case body 11 of the first embodiment correspond to an example of "at least two parts" constituting the housing 50. The upper case 51 and the lower case 52 of the second embodiment correspond to another example of "at least two parts" constituting the housing 50a. The in-vehicle structure disclosed herein may be applied to other electrical devices of the power control unit. The device that interferes with the power control unit 10 (electric device) is not limited to the radiator tank. The techniques disclosed herein can also be applied to electrical equipment with a housing without an upper cover.

Although specific examples of the present invention have been described in detail above, these are merely examples and do not limit the scope of claims. The techniques described in the claims include various modifications and modifications of the specific examples illustrated above. The technical elements described herein or in the drawings exhibit their 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 techniques illustrated in the present specification or drawings can achieve a plurality of purposes at the same time, and achieving one of the purposes itself has technical usefulness.

4a-4g: Fastening point 5: Auxiliary battery 7a, 7b: Motor 10, 10a: Power control unit 11: Case body 12: Upper cover 12a, 51b: Bolt hole 13: Lower cover 17: Connector 27: Power cable 30: Transformer Axle 30a: Top 43, 143: Bolt 50, 50a: Housing 51: Upper case 51a, 52a: Flange 52: Lower case 90: Front compartment 91: Radiator tank 92: Side member 93: Front bracket 94: Rear bracket 95: Engine 96: Radiator 100: Hybrid vehicle

Claims (1)

It is an in-vehicle structure of electrical equipment
The electrical equipment is secured on the transaxle in the front compartment of the vehicle.
The housing of the electric device is divided into at least two parts in the vertical direction.
The two said parts are bolted to each other at the four corners and on both sides in the vehicle width direction and in the center in the vehicle front-rear direction.
One of the two said parts is provided with a bolt hole into which the bolt is inserted, among the bolt holes, located on the side of the vehicle center side of the vehicle width direction, and, after the longitudinal direction of the central vehicle The bolt hole in is an in-vehicle structure in which the diameter of the bolt hole is larger than the diameter of the other bolt holes.

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