JP7017125B2 - Power control unit - Google Patents

Description

The technology disclosed herein relates to a power control unit mounted 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, in electric vehicles, a power control unit that converts the electric power of a DC power source into an AC power source for driving a traveling motor is added, and many electric devices are mounted in a narrow front compartment (for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2018-1810

A cable connector for power transmission of a DC power source for a traveling motor is connected to the housing of the power control unit. In the event of a vehicle collision, the equipment in the front compartment may move and the connector of the power control unit may interfere with other equipment and damage the connector. Then, there is a possibility that the metal terminals to which a high voltage is applied are short-circuited. The present specification provides a power control unit that is resistant to interference with other devices.

This specification discloses a power control unit mounted on the front compartment of an automobile, which converts the power of a DC power source into AC power for driving a traveling motor. The power control unit includes a power control unit case. The power control unit is arranged on the side surface of the power control unit case, and includes a connection portion for electrically connecting the power control unit and the DC power supply. The power control unit includes a back protective wall covering the back surface, which is a surface opposite to the surface facing the power control unit case of the connection portion, and a cover portion having a side protection wall covering the side surface of the connection portion. A part of the end surface of the side protection wall facing the power control unit case is fixed to the side surface of the power control unit case with a first distance from the side surface of the power control unit case. The power control unit includes a plate-shaped member that covers at least a part of the back protective wall of the cover portion. The power control unit includes a protrusion arranged on the side surface of the power control unit case with a height of a first distance or less. The protruding portion is arranged so as to overlap the portion of the side protective wall of the cover portion that is not fixed to the power control unit case when viewed from the normal direction of the rear protective wall. The cover is stronger than the connection. The plate-shaped member has higher strength than the cover portion.

In the event of a vehicle collision, the equipment in the front compartment may move (or the power control unit itself may move) and other equipment may interfere with the back protective wall of the cover. Even in such a case, the plate-shaped member covering the back surface protective wall can disperse the collision load over the entire back surface protection wall, so that the cover portion can be prevented from being damaged. Then, of the side protective wall of the cover portion, the portion fixed to the side surface of the power control unit case is restricted from being displaced in the direction in which the cover portion approaches the power control unit case by the fixing mechanism. Further, of the side protective wall of the cover portion, the portion not fixed to the power control unit case is displaced in the direction in which the cover portion approaches the power control unit case due to the protruding portion arranged so as to overlap the side protective wall. Is regulated. This makes it possible to suppress the deformation of the cover portion. As a result of the deformation of the cover portion, it is possible to prevent the occurrence of a situation in which a collision load is input to the connection portion and the connection portion is damaged. Details and further improvements to the techniques disclosed herein will be described in the "Modes for Carrying Out the Invention" section below.

It is a perspective view which shows the device layout in the front compartment of a hybrid vehicle. It is a block diagram of a power control unit of a hybrid vehicle and its peripheral equipment. It is a side view which shows the positional relationship between a power control unit and a brake actuator. It is a partial perspective view which showed the connection relationship between the rear surface of a power control unit, and a DC power connector. It is a partial perspective view which showed the arrangement relation of a DC power connector and a cover part. It is a figure which looked at the structure which DC power connector was covered with a cover part from the direction perpendicular to the rear surface of a case. It is the figure which looked at the structure which DC power connector was covered with a cover part from the front direction of a vehicle. It is sectional drawing in the line AA of FIG. It is sectional drawing in BB line of FIG. It is sectional drawing of the comparative example.

The power control unit of the embodiment will be described with reference to the drawings. The power control unit of the embodiment is applied to a hybrid vehicle equipped with an engine and a motor for driving. FIG. 1 is a perspective view showing a device layout in the front compartment 90 of the hybrid vehicle 100. 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. It should be noted that FIG. 1 is a schematic drawing of the device mounted on the front compartment 90.

The front compartment 90 houses an engine 95, a transaxle 30, a power control unit 10, an auxiliary battery 5, and a brake actuator 91. Various other devices are housed in the front compartment 90, but their illustration and description are omitted.

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 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 addition, in FIG. 1, one side member is not visible.

The power control unit 10 is fixed to the upper surface of the transaxle 30. The power control unit 10 is supported via a front bracket 93 and a rear bracket 94. 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. A DC power connector 15 is connected to the rear surface of the case 11 of the power control unit 10. The DC power connector 15 is covered with a cover portion 20. A brake actuator 91 is arranged behind the power control unit 10.

FIG. 2 shows a block diagram of the inside of the power control unit 10 and peripheral devices connected to the power control unit 10. The power control unit 10 includes a converter circuit 12, two inverter circuits 13a and 13b, and a control board 14 for controlling the converter circuit 12 and the inverter circuits 13a and 13b.

The power control unit 10 is connected to the main battery 3 via a DC power cable 25. Reference numeral 15 indicates a connector (DC power connector) attached to the tip of the DC power cable 25. The output of the main battery 3 is 100 volts or more, and the motors 7a and 7b are driven by the electric power of the main battery 3. The output power of the main battery 3 is input to the converter circuit 12. The converter circuit 12 boosts the output voltage of the main battery 3 and supplies it to the inverter circuits 13a and 13b. The inverter circuits 13a and 13b convert the boosted DC power into AC power suitable for driving the motor. The outputs of the inverter circuits 13a and 13b are supplied to the motors 7a and 7b via the motor connector 17 and the motor power cable 27, respectively.

The converter circuit 12 and the inverter circuits 13a and 13b are controlled by a control circuit mounted on the control board 14. The control circuit of the control board 14 operates by receiving power supply from the auxiliary battery 5. The control circuit of the control board 14 operates in response to a command from an external host controller 6. The auxiliary battery 5 and the upper controller 6 are connected to the control board 14 of the power control unit 10 via a communication cable and a communication connector 18.

The auxiliary battery 5 supplies power to the control board 14 in the power control unit 10 and other devices operating at 12 volts. Among the devices mounted on the hybrid vehicle 100, the devices operating at 12 volts are collectively referred to as auxiliary machines. The auxiliary battery 5 is mounted in the front compartment 90 (see FIG. 1).

FIG. 3 shows a side view showing the positional relationship between the power control unit 10 and the brake actuator 91. Also in FIG. 3, the F-axis positive direction of the coordinate system represents the front of the vehicle, and the V-axis positive direction represents the upward direction. The positive direction of the H axis points to the left side of the vehicle. Further, the XYZ coordinate system in FIG. 3 is a coordinate system based on the case 11 of the power control unit 10, the X axis extends in a direction parallel to the bottom surface of the case 11, and the Z axis is parallel to the rear surface of the housing. It extends in the direction of. The XYZ coordinate system is drawn to make it easier to understand the perspective view of FIG. 4 which will be referred to later.

As described above, the power control unit 10 is supported on the upper surface 30a of the transaxle 30 via the front bracket 93 and the rear bracket 94. The motor connector 17 is connected to the left side surface of the case 11. A DC power connector 15 is connected to the rear surface of the case 11. The DC power connector 15 is covered with a cover portion 20. The detailed structure of the DC power connector 15 and the cover portion 20 will be described later.

The connection structure of the case 11, the DC power connector 15, and the cover portion 20 in the embodiment will be described with reference to FIGS. 4 and 5. FIG. 4 is a partial perspective view showing the connection relationship between the rear surface 11a of the case 11 and the DC power connector 15. In FIG. 4, the DC power connector 15 is removed and drawn. Further, the cover portion 20 is omitted. A flange 44 extending in the horizontal direction is provided on the rear surface 11a of the case 11. The flange 44 is provided with a through hole 44a. The DC power connector 15 is arranged so that a part of the facing surface 15b is in contact with the facing surface 44b of the flange 44. The broken line rectangle indicated by the reference numeral 15c in the figure indicates the contact range in contact with the facing surface 44b of the flange 44. Reference numeral 43 in the drawing is an opening provided in the case 11, and a metal terminal (not shown) on the housing side is arranged inside the opening 43. Reference numeral 15a in the figure is an opening provided in the DC power connector 15, and a metal terminal (not shown) on the connector side is arranged inside the opening 15a. When the DC power connector 15 is attached to the case 11, the metal terminal on the housing side and the metal terminal on the connector side come into contact with each other to conduct conduction. The DC power connector 15 is made of a resin which is an insulator.

FIG. 5 is a partial perspective view showing the arrangement relationship between the DC power connector 15 connected to the rear surface 11a and the cover portion 20. In FIG. 5, the cover portion 20 is removed and drawn. The DC power connector 15 includes a back surface 15d which is a surface opposite to the facing surface 15b. The cover portion 20 includes a back surface protective wall 20a that covers the back surface 15d. A plate-shaped member 21 that covers the back surface protection wall 20a is arranged on the back surface protection wall 20a. The plate-shaped member 21 will be described later. Further, the cover portion 20 includes a side surface protective wall 20b that covers the left side surface of the DC power connector 15, a side surface protection wall 20c that covers the right side surface, and a side surface protection wall 20d that covers the upper side surface. The cover portion 20 is made of aluminum. The aluminum cover portion 20 has higher strength than the resin DC power connector 15. The side surface protection wall 20d includes a flange 20e that projects toward the power control unit 10 side (that is, the positive side of the X-axis) with respect to the side surface protection walls 20b and 20c. The flange 20e has a surface parallel to the side surface protective wall 20d. The flange 20e is provided with a bolt hole 20f. The lower surface of the flange 20e is arranged so as to be in contact with the upper surface of the flange 44 of the case 11, and is fixed by the bolt 41 through the bolt hole 20f and the through hole 44a. In other words, the end surface of the side surface protective wall 20d facing the case 11 is fixed to the rear surface 11a of the case 11.

The rear surface 11a of the case 11 is provided with two protrusions 42 having a flat crown surface. The protrusion 42 is a cylindrical boss integrally formed with the case 11. The protruding portion 42 is provided at a position facing the cover portion 20. The protrusion 42 is arranged at a position where the side surface protective walls 20b and 20c and a part thereof overlap when viewed from a direction perpendicular to the rear surface 11a (that is, a negative direction of the X-axis). In other words, the protrusion 42 is arranged so as to overlap the side protective walls 20b and 20c that are not fixed to the case 11 when viewed from the normal direction of the back protective wall 20a (that is, the negative direction of the X-axis). 6 and 7).

The detailed structure of the DC power connector 15 and the cover portion 20 will be described with reference to FIGS. 6 to 9. FIG. 6 is a view of the structure in which the DC power connector 15 is covered with the cover portion 20 as viewed from a direction perpendicular to the rear surface 11a (that is, a negative direction of the X axis). In FIG. 6, the protrusion 42 is also shown for reference. FIG. 7 is a view of the structure in which the DC power connector 15 is covered with the cover portion 20 as viewed from the vehicle front direction (that is, the positive direction of the X axis). In FIG. 7, for reference, the position of the protrusion 42 is shown by a dotted line. FIG. 8 is a cross-sectional view taken along the line AA of FIG. That is, FIG. 8 is a cross-sectional view of the structure in which the DC power connector 15 is covered with the cover portion 20 as viewed from the lateral direction (that is, the positive direction of the Y axis) of the power control unit 10. FIG. 9 is a cross-sectional view taken along the line BB of FIG. That is, FIG. 9 is a cross-sectional view of the structure in which the DC power connector 15 is covered with the cover portion 20 as viewed from above the power control unit 10 (that is, in the positive direction of the Z axis).

As shown in FIG. 8, the end surface 20dE of the side surface protective wall 20d of the cover portion 20 is fixed at a position of a first distance D1 from the rear surface 11a of the case 11. Further, a protruding portion 42 having a height H1 is arranged on the rear surface 11a of the case 11. The height H1 is a height equal to or less than the first distance D1. As a result, a gap G1 can be formed between the side surface protective wall of the cover portion 20 and the crown surface of the protruding portion 42. Therefore, even when the vehicle vibrates, the contact between the protruding portion 42 and the cover portion 20 can be prevented, so that the generation of abnormal noise can be prevented. The value of the gap G1 may be determined in consideration of the dimensional variation of the protruding portion 42 and the cover portion 20.

As shown in FIGS. 6 and 8, a plate-shaped member 21 that covers at least a part of the back surface protection wall 20a is arranged on the back surface protection wall 20a of the cover portion 20. As shown in FIG. 6, the outermost shape of the plate-shaped member 21 is smaller than the outermost shape of the back surface protective wall 20a. Further, the plate-shaped member 21 is arranged at a position where it does not protrude from the back surface protective wall 20a. The plate-shaped member 21 is a steel plate. The plate-shaped member 21 made of steel plate has higher strength than the back protective wall 20a of the aluminum cover portion 20. The plate-shaped member 21 is joined to the back surface protective wall 20a with double-sided tape. The plate-shaped member 21 can increase the rigidity of the back surface protective wall 20a.

Further, as shown in FIG. 8, the plate thickness T1 of the back surface protective wall 20a is thicker than the plate thickness T2 of the side surface protection wall 20d. This also makes it possible to increase the rigidity of the back surface protective wall 20a.

As shown in FIG. 9, the right end side E1 of the plate-shaped member 21 is located within the range of the plate thickness T3 of the side protective wall 20c of the cover portion 20. Similarly, the left end side E2 of the plate-shaped member 21 is located within the range of the plate thickness T4 of the side surface protective wall 20b of the cover portion 20. As a result, when the collision load F in the direction of the arrow in FIG. 9 is input to the plate-shaped member 21, the collision load F can be dispersed to the case 11 side via the side surface protective walls 20b and 20c. It is possible to suppress damage to the cover portion 20.

As shown in FIGS. 6 and 8, ribs 20g are formed on the upper portion of the back surface protective wall 20a along the upper side and protruding in the negative direction of the X-axis. As a result, a structure is realized in which a tool such as a flat-blade screwdriver cannot be inserted into the adhesive interface between the back surface protective wall 20a and the plate-shaped member 21 from above the cover portion 20 (that is, in the positive direction of the Z axis). Therefore, it is possible to prevent the plate-shaped member 21 from being artificially peeled off. In the state where the power control unit 10 is mounted on the front compartment 90, various devices are arranged around the cover portion 20, so that the side and the lower side of the cover portion 20 (that is, the positive and negative directions of the Y axis and the negative of the Z axis). It is difficult to insert the tool from the direction). Therefore, the rib 20g can exert its function if it is formed at least on the upper part of the back surface protective wall 20a.

(effect)
The effect will be described with reference to the comparative example of FIG. The cross-sectional view of the comparative example of FIG. 10 corresponds to the cross-sectional view of the present embodiment of FIG. The structure of the comparative example does not include the protrusion 42 and the plate-shaped member 21 as compared with the structure of the present embodiment. When the hybrid vehicle 100 collides forward, the brackets 93 and 94 (see FIG. 3) may be deformed or broken, and the power control unit 10 may move rearward (right side of FIG. 3). A DC power connector 15 covered with a cover portion is connected to the rear surface of the power control unit 10, and a brake actuator 91 is arranged behind the DC power connector 15. When the power control unit 10 retracts, the cover portion interferes with the brake actuator 91. As a result, the collision load F in the direction of the arrow in FIG. 10 is input to the cover portion. The upper side surface protective wall 120d of the cover portion 120 is fixed to the flange 44 by a fixing mechanism by bolts 41. Therefore, like the cover portion 120X shown by the dotted line in FIG. 10, the lower portion of the cover portion 120 is deformed so as to approach the power control unit 10 with the interface between the flange 44 and the side surface protective wall 120d as the rotation center P1. Further, the back protective wall 120a is also dented toward the power control unit 10. As a result, the resin portion inside the DC power connector 15 is crushed. The DC power connector 15 is connected to the main battery, and a high voltage of 100 volts or more is applied to the terminals inside the connector. It is not desirable for the connector to be damaged and the internal terminals to be short-circuited or exposed.

Therefore, in the technique described in the present specification, as shown in FIG. 8, the rear surface 11a is provided with the protruding portion 42. When the collision load F in the direction of the arrow in FIG. 8 is input, the side surface protective wall 20d is restricted from being displaced in the direction approaching the power control unit 10 by the fixing mechanism by the bolt 41. Further, the end surface 20bE existing in the lower part of the side surface protection wall 20b is in contact with the protrusion 42, so that the displacement in the direction approaching the power control unit 10 is restricted. Further, in the technique described in the present specification, since the plate-shaped member 21 that covers the back surface protective wall 20a is provided, the rigidity of the back surface protection wall 20a is increased and the collision load is distributed to the entire back surface protection wall 20a. Can be made to. It is possible to prevent the back protective wall 20a from being dented. As described above, the deformation of the cover portion 20 can be suppressed, so that the input of the collision load to the DC power connector 15 can be suppressed. It is possible to prevent the occurrence of a situation in which the resin portion inside the DC power connector 15 is damaged in the event of a collision.

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 exemplified 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 exemplified in the present specification or the drawings can achieve a plurality of purposes at the same time, and achieving one of the purposes itself has technical usefulness.

(Modification example)
The shape of the protrusion 42 is not limited to the boss shape, and various shapes can be adopted. For example, it may be a plate-shaped rib. In the embodiment, the case 11 is provided with two protrusions 42 with respect to the DC power connector 15, but the number is not limited to this. The larger the total area of the crown surface of the protruding portion 42, the better.

There may be various methods for joining the plate-shaped member 21 to the back surface protective wall 20a of the cover portion 20. For example, they may be joined by screwing.

The connection structure of the embodiment may be applied to an electric device other than the power control unit 10. Further, the connection structure of the embodiment may be applied to another connector, for example, a motor connector 17. The connection structure disclosed herein can be applied to various connectors, but is particularly suitable for connectors to which a high voltage of 100 volts or more is applied.

10: Power control unit 11: Case 11a: Rear surface 15: DC power connector 20: Cover part 21: Plate-shaped member 25: DC power cable 30: Transaxle 41: Bolt 42: Protruding part 44: Flange 44a: Through hole 90: Front compartment 91: Brake actuator 100: Hybrid vehicle

Claims (1)

It is a power control unit installed in the front compartment of an automobile that converts the power of a DC power supply into AC power for driving a traveling motor.
Power control unit case and
A connection portion which is arranged on the side surface of the power control unit case and electrically connects the power control unit and the DC power supply,
A cover portion having a back surface protective wall covering the back surface of the connection portion facing the surface facing the power control unit case and a side surface protection wall covering the side surface of the connection portion, and the side surface protection. A cover portion of a wall whose end face facing the power control unit case has a first distance from the side surface of the power control unit case and is fixed to the side surface of the power control unit case.
A plate-shaped member that covers at least a part of the back protective wall of the cover portion, and
A protrusion arranged on the side surface of the power control unit case with a height of the first distance or less, and the side surface protection wall of the cover portion when viewed from the normal direction of the back surface protection wall. Of the protruding portion, which is arranged so as to overlap the portion not fixed to the power control unit case,
Equipped with
The cover portion is stronger than the connection portion and has a higher strength.
The plate-shaped member is a power control unit having higher strength than the cover portion.

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