JPH0747846A - Motor control unit lower surface cooling structure for electric automobile - Google Patents

Abstract

PURPOSE:To provide a car body structure excellent in space utility in a cabin, ensuring cooling performance, reliability (including waterproof, durability) of a cooling system, etc., by considering optimizing a total unit as the cooling system for an electric automobile. CONSTITUTION:In an electric automobile mounting a motor control unit 10 to arrange batteries 8 concentrated in a box 7 provided under a floor 4 of a car body, the motor control unit 10 is set up in a cabin, to provide a cooling air passage in a lower part of this motor control unit 10 and a discharge air hole of this cooling air passage on the box 7. Discharge air from the discharge air hole is discharged between the floor 4 and the box 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to cooling of semiconductor elements of a motor control unit (Power Drive Unit, hereinafter abbreviated as PDU) mounted on an electric vehicle, and more particularly to a packaging structure for a cooling structure of an electric vehicle.

[0002]

2. Description of the Related Art As a prior art of a cooling structure for an electric vehicle controller, the technology described in Japanese Patent Publication No. 53-45043 is known. The mounting base 11 of the controller is made of steel plate, a window 13 is provided in a part of the mounting base 11, and a cooling piece 14 made of a material having a high thermal conductivity is mounted using the window 13. A semiconductor element having a large current capacity among the components of the controller such as a thyristor is attached to the cooling piece 14, and the other components of the controller are attached to the attachment base 11. Further, Japanese Utility Model Laid-Open No. 48-12966 discloses a cooling device for a semiconductor element used in an electric vehicle, but does not show a state of being mounted on the electric vehicle.

[0003]

However, none of the above-mentioned prior arts discloses a cooling system or a packaging when mounted on an electric vehicle, and the high efficiency of the entire vehicle (for example, space efficiency, It is not always perfect in terms of performance, reliability, etc .. Therefore, the present invention is a PD mounted on an electric vehicle.
Considering the optimization of the electric vehicle as a whole in the cooling structure of U's semiconductor elements, ensuring space utility cooling performance inside the vehicle interior, and providing a body structure with excellent cooling system reliability (including waterproofness and durability) The purpose is to provide.

[0004]

In order to solve the above problems, the present invention has a battery centrally arranged via a box under the floor of an electric vehicle equipped with a PDU, the PDU being installed indoors, and the lower part of this PDU. A cooling air passage was provided in the air conditioner, and an exhaust air hole for the cooling air passage was provided on the battery box.
Also, the exhaust air from the exhaust holes is exhausted between the floor and the box.

[0005]

According to the above means, the PDU is provided in the vehicle compartment, which is advantageous in space utility, especially in the front,
Alternatively, it is highly safe and is not easily damaged even in the event of a collision from the rear. In addition, since the ventilation holes are provided on the battery box installed under the vehicle body, it is hard to be hit directly by water from the water pool on the road surface while traveling, and the waterproof property is good. Further P
Since the cooling air passage for the DU is provided below the PDU,
The semiconductor device can be cooled efficiently.

[0006]

Embodiments of the present invention will now be described with reference to the accompanying drawings. FIG. 1 is a side sectional view of an electric vehicle to which a semiconductor element cooling structure of a PDU of the present invention is applied, FIG. 2 is a plan sectional view of the same, and FIG. In the figure, 1 is an electric vehicle, 2 is a front wheel, 3 is a rear wheel, 4 is a floor, 5
Is a front seat and 6 is a rear seat. Further, a battery box 7 is provided under the floor 4 from the front seat 5 to the rear seat 6, and the battery box 7
A large number of batteries 8 are centrally arranged therein. The battery 8 may be a lead battery using sulfuric acid as an electrolytic solution, a nickel-cadmium battery using an alkaline aqueous solution as an electrolytic solution, a nickel-zinc battery, a nickel-hydrogen battery, or the like, but more efficient in the future. A lithium battery using an organic solvent as an electrolyte is also conceivable. A motor 9 driven by the battery 8 is provided between the rear wheels 3,
The rear wheel 3 is driven by this motor 9. The motor 9 may be a DC motor or an AC motor.

The electric vehicle 1 changes the rotation speed (related to the voltage) and the driving force (proportional to the current) of the motor 9 according to various running such as flatland, slope, high speed, low speed, acceleration, constant speed, forward movement and reverse movement. It is necessary to freely change it. For that purpose, a PDU (motor control unit) 10 is provided between the battery 8 and the motor 9 to convert the DC voltage of the battery 8 into the required voltage and current. As shown in FIGS. 1 and 2, the PDU 10 is arranged above the battery box 7 and below the rear seat 6 which is a dead space in the room (in the present embodiment, the right side under the rear seat). Incidentally, 40 is a cable connecting the motor 8 and the PDU 10.

As shown in FIGS. 1, 4 and 5, the PDU 10 comprises a chopper made of a semiconductor element IGBT11 and a current sensor 12 connected to the IGBT11 by a cable not shown, and these are housed in a casing 13. There is. In order to improve efficiency, the PDU 10 considers the performance of withstand voltage, withstand current, switching speed, and on-resistance as an IGBT 11 as a chopper switching element.
Are using. Power MOS FET, S in the future
The use of semiconductor devices such as I-transistors is also conceivable.

The casing 13, as shown in FIG.
The front portion 14 for housing the T11 is elevated, and the rear portion 1 for housing the current sensor 12 is provided from the raised front portion 14.
It is gradually low over the lower part of 5. The raised front portion 14 of the casing 13 is arranged in the raised portion of the front portion 16 of the rear seat 6 as shown in FIG. 1, and the lower portion of the rear portion 15 of the casing 13 becomes the lower portion of the rear portion 6 of the rear seat 6. It is arranged.

Since the IGBT 11 emits heat, the cooling fin 18 is provided at the bottom of the casing 13 for cooling as shown in FIG.
Is provided, and the base 19 and the heat dissipation portion 2 are provided on the heat dissipation fin 18.
The IGBT 11 is mounted via 0. Therefore IG
The BT11 becomes taller and is housed in the raised portion of the front portion of the casing 13 described above. And the radiation fin 18
The lower part of the casing 13 having the above is a cooling air passage 21. As shown in FIG. 6, the cooling air passage 21 has a casing 13
The exhaust hole 22 opens on the left side of the
Similarly, a ventilation hole 23 is opened on the right side of the casing 13. Further, as shown in FIG. 3, the air exhaust hole 22 is opened in the center tunnel 24 of the floor 4 on the battery box 7,
Exhaust air from the exhaust hole 22 is under the floor 4 and the battery box 7.
It is exhausted to the outside (outdoor). The air may be exhausted between the floor 4 and the shield instead of the floor 4 and the battery box 7.

A ventilation duct 25 is connected to the upstream side of the ventilation hole 23. The blower duct 25 is vertically connected to the blower hole 23 as shown in FIG. 1 to FIG. 3 and FIG. 6, extends upward and is then bent, and along the side panel inner 26 of the vehicle body at a position higher than the rear seat. Is extended to the rear of the vehicle. The air duct 25 extending rearward of the vehicle body is provided with a cooling fan 28 on the right side of the trunk 27 at the rear portion of the vehicle body. The motor 29 of the cooling fan 28 is the trunk 2
It is provided inside 7.

As shown in FIG. 3, a cooling fan 28 is provided inside the side panel inner 26.
Further, since the motor 29 is provided inside thereof, there is no possibility that rainwater, water splashed from a water pool on the road surface, or the like will be directly applied to the motor 29, and the reliability and durability of the motor 29 are improved. In addition, a cooling fan 28 is provided in the trunk 27 away from the rear seat 6.
Further, since the motor 29 is provided, the influence of noise on the rear seat 6 is small. Further, even if the cooling fan 28 and the motor 29 are provided on the right side portion in the trunk 27, there is little influence on the loading of luggage.

As shown in FIG. 2, an intake duct 30 is connected to the cooling fan 28 on the side opposite to the motor 29. The intake duct 30 is bent and extends downward, and an intake hole 33 is opened in a gap between a right end portion of the rear bumper 31 which is folded back to the front in plan view and the right side of the vehicle body 32.
Since the intake hole 33 is opened in such a place, the intake hole 33
The cooling fan 28 that follows is located at a position higher than the intake hole 33, and there is no concern that the cooling fan 28 will be directly hit by rainwater or water splashed from a pool of water on the road surface, and thus the waterproofness is good. Further, since the cooling fan 28 and the motor 29 are provided so as to face the inside of the side panel inner 26 and the portion of the right end portion of the rear bumper 31 which is folded back to the front in plan view, both from the side of the vehicle body 32 and from the rear. There is sufficient clearance so that even if a light collision occurs from the side or the rear, the cooling fan 28
Also, the motor 29 is not easily damaged.

[0014]

As described above, according to the present invention, considering the overall optimization of the cooling system of the electric vehicle, the P
Since the DU is provided in the passenger compartment, it is advantageous in terms of space utility, and even if a light collision occurs from the side or the rear, the PDU is not easily damaged and the safety is high. Also, because the ventilation holes are provided above the battery box installed under the vehicle body, it is difficult to be hit directly by rainwater or water splashed from the water pool on the road surface during running, good waterproofness, excellent durability There is. Furthermore, since the cooling air passage for the PDU is provided below the PDU, P
The semiconductor element of DU can be cooled efficiently.

[Brief description of drawings]

FIG. 1 is a side sectional view of an electric vehicle to which a semiconductor element cooling structure of a PDU of the present invention is applied.

[Fig. 2] Similarly, a plane sectional view

FIG. 3 is a sectional view of the same as seen from the rear of the vehicle body.

FIG. 4 is a side sectional view of a PDU.

[FIG. 5] Similarly, a plane sectional view

FIG. 6 is a perspective view of a duct.

[Explanation of symbols]

 1: Electric vehicle 4: Floor 7: Battery box 8: Battery 10: PDU 21: Cooling air passage 22: Exhaust vent

Claims (2)

[Claims] 1. In an electric vehicle equipped with a motor control device, wherein batteries are centrally arranged in a box provided under the floor of a vehicle body, the motor control device is installed in a vehicle compartment, and cooling air is provided below the motor control device. A lower surface cooling structure for a motor control device of an electric vehicle, wherein a passage is provided, and an exhaust hole of the cooling air passage is provided on the box. 2. The lower surface cooling structure for a motor control device of an electric vehicle according to claim 1, wherein the exhaust air from the exhaust holes is exhausted between the floor and the box.