KR19990038390U - Inverter for electric vehicle - Google Patents

Abstract

The present invention relates to an inverter for an electric vehicle, the purpose of which is to improve the cooling efficiency of the cooling water flow path structure of the cooling plate to which the power switching device is attached.

Inverter 500 for an electric vehicle according to the present invention has an inlet end 544 and the outlet end 545 inside the aluminum plate of the aluminum plate made of a predetermined thickness and the curvature cooling water passage 540 is integrated Since the cooling plate 510 is directly cooled by the cooling water passing through the cooling water passage 540, the cooling performance of the power switching device 520 is improved. In addition, since the curvilinear cooling water channel 540 is formed through the fixed block 530 that is coupled with the square groove 511 and the screw 560, no separate welding work is required and the aluminum corrosion preventing coating work is easily performed to assemble it. The productivity is improved and the overall manufacturing cost is reduced.

Description

Inverter for electric vehicle

The present invention relates to an inverter for an electric vehicle, and more particularly, to a cooling structure of an inverter for an electric vehicle that converts direct current power into alternating current power and supplies electric power to a motor.

In recent years, research is being actively conducted for the practical use of so-called electric vehicles that use electricity, which is pollution-free, as a power source.

In an electric vehicle, a wheel driving motor is started by converting DC power supplied from a large capacity battery into an AC power having a variable frequency. An inverter, for example, an insulation kit, is a means for converting DC power into AC power. Insulated Gate Bipolar Transistors are generally widely used.

This inverter generates a large amount of heat during the switching operation, and since its constituent material is a semiconductor element, there is a possibility of malfunction due to heat. Therefore, the inverter must be continuously cooled during operation, and the overall cooling structure thereof is shown in FIG. 1.

Figure 1 shows a water-cooled cooling cycle for cooling the inverter of the electric vehicle. The cooling cycle of the electric vehicle is, as shown in the drawing, the main cooling target is a wheel driving motor (1) and an inverter (5) for supplying electric power thereto. An inverter 5 including a control unit 3 and a plurality of power switching elements is provided together in a single case 2. At this time, in order to increase the heat dissipation effect, the power switching element is mounted on a cooling plate made of aluminum having good thermal conductivity.

On the other hand, the cooling water pipe 4 connected to the water pump 6 is connected to the radiator 7 after passing around the cooling plate of the case 2 and around the motor 1, and again connected to the radiator 7 by the radiator 7. It is connected with 6) to form a closed circuit. At this time, the radiator 7 is provided with a radiating fan 8 to improve its heat exchange efficiency.

In an electric vehicle equipped with such a cooling cycle, the motor 1 driving the wheel is started by being supplied with AC power by the inverter 5. At this time, considerable heat is generated in the inverter 5, and cooling is required as described above in order to smoothly perform the present function.

Accordingly, the water is cooled by circulating water through the cooling water pipe 4 which forms the flow path by operating the water pump 6 to the cooling plate, the adjacent part of the motor 1, the radiator 7 and the like.

On the other hand, the conventional cooling structure of the inverter for supplying power to the motor by converting the DC power into AC power as shown in FIG.

Inverter 50 is composed of a plurality of power switching elements 52, as shown in this, the copper pipe 54 is bent to the tube forming a flow path on the lower surface of the cooling plate 51 made of aluminum having good thermal conductivity. The power switching element 52 is fixed to the upper surface of the cooling plate 51 by using the screw 53.

Accordingly, the cooling water circulates in the copper pipe 54 by the water pump 6, whereby the cooling plate 51 is cooled by the cooling water, and the power switching element 52 provided on the upper surface of the cooling plate 51 is cooled. do.

However, since the copper pipe 54 forming the flow path for cooling the power switching device 52 of the inverter 50 is disposed to be exposed to the outside on the lower surface of the cooling plate 51, the volume occupied by the power pipe becomes large. Since the switching element 52 is indirectly cooled by the cooling plate cooled by the copper pipe 54, there is a limit in the cooling performance, thereby causing a problem in the function of the inverter. In addition, the attachment means is required to install the copper pipe 54 forming the flow path on the lower surface of the cooling plate 51, which complicates the manufacturing method of the cooling plate 51 and increases the manufacturing cost thereof.

In order to solve this problem, another conventional cooling plate is disclosed, and its structure is as shown in FIG. 3.

In the cooling plate 51a having a predetermined thickness, a cooling water passage is integrally formed therein, and the cooling plate 51a is directly cooled by the cooling water passing through the cooling plate 51a, and the power switching element is installed on the cooling plate 51a. Not shown) is cooled.

The cooling water path is alternately made inside the cooling plate 51a, and its manufacturing process is as follows. First, the first, second, and third drill holes 52a, 52b, and 52c are drilled in parallel to the aluminum cooling plate 51a having a predetermined thickness so as to penetrate laterally the side surface thereof using a gun-drill. . Subsequently, the first connection hole 52d is drilled by using a gun-drill to the side surface of the cooling plate 51a so that one end of the first drill hole 52a adjacent to each other and one end of the second drill hole 52b communicate with each other. The second connecting hole 52e is drilled so that the other end of the second drill hole 52b and one end of the third drill hole 52c communicate with each other. Except for this, the other end of the first drill hole 52a becomes the inlet end 53a of the cooling water passage and the other end of the third drill hole 52c becomes the outlet end 53b so that the coolant is circulated. The opening end of the hole in communication with the rest of the outside is closed using welding means. Reference numeral 54a denotes a weld that closes the opening hole.

Through this welding process, a cooling water passage having one inlet end 53a and an outlet end 53b is provided inside the cooling plate 51a. Afterwards, complete cooling is performed only after coating to prevent aluminum corrosion of the cooling water passage. It becomes the board | substrate 51a.

However, since the cooling plate 51a has to undergo a separate welding process to form a cooling water passage, the processing productivity is lowered, and it is difficult to coat the inner circumferential surface with the cooling water formed with curvature, which requires a lot of manufacturing time and production cost. There is another problem that is rising.

That is, the first and second connection holes 52d and 52e must be drilled again so that the first, second and third drill holes 52a, 52b and 52c are connected, and the inlet end 53a and the outlet end 53b are again formed. All of them have to be blocked by welding, which complicates the manufacturing process. In addition, it is difficult to prevent corrosion of the curvature of the curvature cooling water, and if the coating is not completely completed due to the damage of the coating portion generated during welding, the corrosion phenomenon proceeds and the reliability of the overall inverter is deteriorated.

The present invention is to solve this problem, the main purpose of the present invention has an inlet end and an outlet end inside the aluminum plate made of a predetermined thickness and by forming a curvature cooling water passage integrally, the cooling plate to the cooling water It is to provide an inverter for an electric vehicle that is directly cooled by the cooling water passing through to significantly improve the cooling performance of the power switching device.

And the secondary purpose of the present invention is to close the opening of the square groove formed to connect the end of each drill hole drilled in parallel to form a cooling water path to the cooling plate by screwing the packing rubber plate and the fixing block, the assembly thereof is It is to provide an electric vehicle inverter that is easy and reduces the overall manufacturing cost.

1 schematically illustrates a water-cooled cooling cycle of a general electric vehicle.

2 is an exploded perspective view showing the structure of a conventional power switching device and a cooling plate.

3 is a perspective view showing the structure of another conventional cooling plate.

4 is a perspective view showing the structure of an inverter according to the present invention.

5 is a perspective view of a cooling plate in which a cooling water passage according to the present invention is processed.

6 is an exploded perspective view showing the structure of the cooling water of the cooling plate according to the present invention.

* Description of the symbols for the main parts of the drawings *

500 .. Inverter 510. Cooling plate 511. Square groove

512 .. Step 513. Fixed hole 520. Power switching element

530 .. Fixed block 540. Cooling waterway 544.

545..Exit 550.Packing rubber plate 560.Screw

In order to achieve the above object, the present invention provides an inverter for an electric vehicle having a power switching element provided on an upper surface of a cooling plate having a predetermined thickness and receiving a DC power and converting the same into an AC power.

The cooling plate has at least two drill holes which are bored in a transverse direction so that both ends communicate with the outside, and square grooves and square grooves which are recessed in a rectangular shape at the side portions so as to form a cooling water path by connecting end portions of neighboring drill holes. It is characterized by having a fixed block is inserted into the screw coupled to seal the open portion of the.

Hereinafter, one preferred embodiment according to the present invention will be described in detail with reference to the accompanying drawings.

Figure 4 is a perspective view showing the structure of the inverter, Figures 5 and 6 are perspective views showing the structure of the cooling plate in which the cooling water channel according to the present invention is processed. (The inverter for the electric vehicle according to the present invention is also cooled by the cooling cycle configuration of a general electric vehicle, so refer to FIG. 1 for this.)

Inverter 500 according to the present invention for receiving a DC power is converted into an AC power source, as shown in these, has a predetermined thickness and a plurality of power switching elements 520 in the aluminum plate of the cooling plate 510 The cooling water passage 540 is attached to the water, and the water is circulated to directly cool the power switching device 520 together with the cooling plate 510.

The alternately curved cooling water passage 540 is integrally processed to have one inlet end 544 and an outlet end 545 in the cooling plate, and ends of the cooling water pipes 4 and 1 are respectively provided. By being coupled, the cooling plate 510 is directly cooled, and the power switching device 520 that generates a large amount of heat is configured to be indirectly cooled. The detailed structure thereof is as follows.

First, as shown in FIG. 5, the aluminum cooling plate 510 having a predetermined thickness has an end portion of the first drill hole 541 and an end portion of the second drill hole 542 on one side of the side portion. Square grooves 511 are recessed in a rectangular shape so as to be associated with each other. In addition, a square groove is formed at one side of the opposite side portion to connect the end portion of the second drill hole 542 and the end portion of the third drill hole 543, which will be described later. 512 is configured to seat the fixed block 530 to be described later.

The cold plate 510 is drilled in three rows, that is, the first, second, and third drill holes 541, 542, 543 in parallel so as to penetrate the side portions laterally. At this time, one end of the first drill hole 541 and one end of the second drill hole 542 are connected through the bottom of the square groove 511, and the other end of the second drill hole 542 and the third drill hole. One end of 543 is drilled to engage through the opposing square bottom. In addition, the drill holes 541, 542, 543 are coated to prevent the corrosion of the aluminum. Since the first, second, and third drill holes 541, 542, 543 are all in communication with the outside, the coating can be easily performed.

As shown in FIG. 6, a square fixed block 530 having the same size is coupled with the screw 560 to block the open portion of the square groove 511. To this end, a plurality of through holes 531 through which the screw 560 penetrates are pierced in the edge portion of the fixed block 530, and the through holes 531 are also provided in the stepped portions 512 of the square groove 511. The fixing hole 513 is machined correspondingly. A rectangular flexible packing rubber plate 550 is provided between the step portion 512 and the fixed block 530 to prevent leakage of the coolant through the gap, and the screw 560 through hole 551 is also fixed therein. It is drilled correspondingly with the through hole 531 of the block 530.

Therefore, when the fixing block 530 is seated on the stepped portion 512 of the rectangular groove 511 on which the packing rubber plate 550 is seated, each through hole 531 and 551 and the fixing hole 513 correspond to each other. When the screw 560 is tightened in such a state, the fixing block 530 is firmly fixed to close the opening of the square groove 511, as well as one end of the first drill hole 541 and the second drill hole. One end of 542 is connected through the bottom of the square groove 511. At this time, since the packing rubber plate 550 provided between the stepped portion 512 and the fixed block 530 is compressed, no gap is generated, so that no cooling water leak occurs. Are combined

Accordingly, the first, second, and third drill holes 541, 542, 543 are connected through the bottoms of the rectangular grooves 511 to form one cooling water path 540. The other end of the first drill hole 541 is connected to the cooling water pipe 4 (see FIG. 1) to form an inlet end 544 through which the cooling water flows, and the other end of the third drill hole 543 is a cooling water pipe. By performing the function of the outlet end 545 connected to the cooling water exit, the cooling water passage 540 is completely formed in the cooling plate 510 as shown in FIG.

The electric vehicle inverter 500 configured as described above converts DC power into AC power to supply power to the motor (see FIG. 1), and generates considerable heat during operation, which requires continuous cooling. Is as follows.

First, due to the operation of the water pump 6 (see FIG. 1), the coolant cools it by passing through the coolant passage 540 inside the cooling plate 510, and then the adjacent portion of the motor 1 (see FIG. 1) and It is circulated through the radiator 7 (see Fig. 1).

At this time, since the cooling water passage 540 is integrally formed in the cooling plate 510 in which the power switching device 520 is installed on the upper surface, the cooling water flows in through the inlet end 544 and the outlet end 545. Exit through the cooling plate 510 and the power switching device 520 is cooled. The cooling plate 510 has a cooling water passage 540 integrally formed therein, so that the cooling plate 510 is directly cooled, so that the cooling action of the power switching device 520 is quickly performed, and the inverter 500 of the power switching device 520 Rapid cooling action prevents overheating damage, and smoothly performs this function of converting DC power into AC power, thereby improving overall reliability.

As described in detail above, the inverter for an electric vehicle according to the present invention has an inlet end and an outlet end inside an aluminum plate made of a predetermined thickness, and a curvature cooling water passage is integrally formed, such that the cooling plate is a cooling water. There is an advantage that the cooling performance of the power switching device is significantly improved by being directly cooled by the cooling water passing through. In addition, since the curvilinear cooling water channel is formed through the fixed block that is screwed into the square groove, no separate welding work is required, and the aluminum anti-corrosion coating is easily performed, thereby improving the assembly productivity and reducing the overall manufacturing cost. .

Claims (2)

In the inverter for an electric vehicle having a power switching device 520 is provided on the upper surface of the cooling plate 510 having a predetermined thickness to receive a DC power source and convert it into an AC power source. The cooling plate 510 has at least two drill holes 541, 542, 543 transversely perforated in both directions so that both ends communicate with the outside, and end portions of the adjacent drill holes 541, 542, 543 are connected to form a cooling water passage 540. For the electric vehicle characterized in that it comprises a rectangular groove 511 recessed in a rectangular shape in the side portion, the fixing block 530 is inserted to seal the open portion of the rectangular groove 511 is coupled to the screw 560. inverter. The step portion 512 of claim 1, wherein the edge portion of the square groove 511 is protruded inward and the fixing block 530 is seated. In between the step portion 512 and the fixed block 530, an electric vehicle inverter, characterized in that the flexible rubber plate 530 of the flexible material to prevent leakage of the cooling water is interposed.