KR100873821B1 - Inverter structure of water cooling type for electric vehicle - Google Patents

Abstract

An inverter structure of a water cooling type for an electric vehicle is provided to implement a compact size and obtain stability by stacking and arranging respective boards installed inside the inverter by the connector directly. An inverter structure of a water cooling type for an electric vehicle includes a heat sink part(101), an under cover(103), a housing(104), a fixing unit(105), a power module(201), a driving board(202), a control board(203), a power board(204), and a top cover(106). The main cooling path with a predetermined depth is formed in the bottom of the heat sink part. An inlet and an outlet of the main cooling path are formed in the heat sink part. The upper side of the under cover is combined with the lower surface of the heat sink part. The bottom of the housing is coupled to the top of the heat sink part. The fixing unit is positioned inside the housing. The fixing unit is protruded from the top of the heat sink part. The power module is positioned in the top of the heat sink part. The power module is fixed in the fixing unit and includes the connector. The driving board, the control board, and the power board are fixed to the fixing unit. The driving board, the control board, the power board has the connector respectively. At least one of the driving board, the control board, and the power board is connected to the power module through the connector. The bottom of the top cover is coupled to the top of the housing.

Description

Water-cooled inverter structure for electric vehicles {INVERTER STRUCTURE OF WATER COOLING TYPE FOR ELECTRIC VEHICLE}

The present invention relates to a water-cooled inverter for an electric vehicle, and more particularly, in order to maximize the cooling performance, each board installed inside the inverter is efficiently disposed and coupled, and the structure of the heat sink and the cooling passage can be easily manufactured. A water-cooled inverter structure for an electric vehicle.

Currently, internal combustion engines, including gasoline engines, which are widely used as engines for automobiles, use heat energy generated by burning fuel in cylinders as power. In such an internal combustion engine, the exhaust gas discharged after combustion contains harmful components such as nitrogen oxides due to combustion and carbon monoxide and hydrocarbons due to incomplete combustion, thereby polluting the atmosphere. Due to the environmental pollution and the depletion of fossil fuels, studies on automobile engines using alternative energy such as solar or electricity are being actively conducted in various countries.

Among the engines for automobiles using such alternative energy, the most practical possibility is an engine for an electric vehicle, which is a method of driving a vehicle using electric energy. The engine for an electric vehicle rotates a motor by electricity supplied from a battery instead of gasoline in a gasoline engine, thereby reducing the rotational force of the motor generated by the reducer, and then transmitting it to the left and right driving wheels through a differential device. It has a structure that enables the driving of the vehicle.

In general, an electric vehicle has a principle of transmitting power to wheels by driving a drive motor constituting a drive system by electricity supplied from a battery corresponding to an energy source. The drive system, which is composed of a drive motor and an inverter controlling the same, is accompanied by high heat during driving due to its structural characteristics and operating characteristics, so that the cooling system is operated as a method for removing such high heat. As shown in FIG. 1, in the system for cooling the drive system, the coolant is circulated in the order of the radiator 11 → cooling pump 12 → inverter 13 → drive motor 14 and again the radiator 11.

In the case of the drive motor 14 constituting the drive system, it is designed to be durable and to withstand heat to some extent. However, the inverter 13, which is composed of many electronic chips, is very sensitive to heat and thus adversely affects the operation or control of the inverter 13 when it is not properly cooled, and the solder to which the elements are bonded melts the circuit. Problem occurs that causes a poor connection of the. The circuit board installed inside the main body of the inverter 13 is generally composed of a power module, a control board, a power board, and a driving board. In particular, most heat generation occurs in a power module including a plurality of power switching elements.

In order to prevent the above problem, as shown in FIG. 2A, the power module 23 is formed on an upper surface of a heat sink 22 formed of an aluminum material having high thermal conductivity, constituting a main body of the inverter 24. ) Is combined to cool the power module 23 by using a copper tube 21 formed with a cooling passage passing through the bottom surface of the heat sink 22. However, the inverter 24 is opposed to the trend toward compactness and light weight in the vehicle since the copper tube 21 is disposed to be exposed to the outside of the heat sink portion 22. In addition, after the copper tube 21 is cooled by cooling water, and the heat sink 22 is cooled by the cooled copper tube 21, the power module 23 is cooled by the cooled heat sink 22. As a result, the cooling performance of the inverter also has its limitations.

In order to improve the above problem, a conventional structure of another heat sink is disclosed, which is as shown in FIG. 2B. That is, after the plurality of cooling passages 31 intersecting the inside of the heat sink portion 32 are integrally formed, and the heat sink portion 32 is cooled by the cooling water passing through the cooling passage 31, The power module 33 coupled to the upper surface of the heat sink 32 is cooled. Accordingly, the cooling loss due to the contact resistance during the cooling of the heat sink portion 22 by the conventional copper tube 21 can be reduced to increase the cooling performance.

However, in order to manufacture the cooling passages 31 of the heat sink portion of the conventional inverter shown in FIG. 2B, a plurality of cooling passages 31 are horizontally passed through the side surfaces of the heat sink portion 32 using a drilling machine. Except for the two holes 35a of the inlet and the outlet so as to circulate the cooling water, the remaining holes 35b should be welded and closed, and then coating should be performed to prevent corrosion of the aluminum of the cooling passage 31. Therefore, the manufacturing process is complicated to fabricate the cooling flow path 31 of the heat sink 32, and in the case of poor welding or poor coating treatment, leakage or corrosion of the cooling water occurs, and accordingly, reliability of the inverter Lowers.

The present invention has been made to solve the above problems, the boards installed inside the inverter are efficiently arranged and coupled, the structure of the heat sink and the cooling flow path is made simple, thereby compacting the water-cooled inverter structure for electric vehicles And to improve the cooling performance and to improve the cooling performance while reducing the manufacturing process to enable productivity and low-cost manufacturing.

Other objects, specific advantages and novel features of the invention will become more apparent from the following detailed description and preferred embodiments in conjunction with the accompanying drawings.

In order to achieve the above object, the present invention, the main cooling passage having a predetermined depth on the lower surface is formed integrally with the heat sink portion formed with the inlet and outlet of the main cooling passage, the upper surface is coupled with the lower surface of the heat sink portion A lower cover, a housing having a lower surface coupled to an upper surface of the heat sink portion, a fixing portion located inside the housing and coupled in a shape protruding from the upper surface of the heat sink portion, and positioned on an upper surface of the heat sink portion. A power module fixed to the government and having a connector, and fixed to the fixing unit, positioned above the power module, each having a connector, at least one of which is directly coupled to the power module and a connector, and each adjacent Drive board, control board, and power board directly coupled to the connector, and the bottom surface includes a top cover coupled to the upper surface of the housing. Eojinda.

In addition, the heat sink and the housing is characterized in that integrally molded.

In addition, the heat sink, the housing and the fixed portion is characterized in that the molded integrally.

In addition, the sub-cooling flow path connected to the main cooling flow path of the heat sink portion is integrally formed on the outer surface of the housing, the undercover is coupled in contact with the outer surface formed integrally with the main cooling flow path and the sub-cooling flow passage, And an inlet and an outlet of at least one cooling passage selected from the main cooling passage and the subcooling passage.

In addition, one side is in contact with the upper surface of the housing and the other side further comprises a gasket coupled to contact with the lower surface of the top cover.

The present invention realizes compactness and stability of the water-cooled inverter structure for an electric vehicle, because each board installed in the inverter is directly coupled to the connector and stacked.

In addition, by simply integrally molding the main cooling flow path of the heat sink portion and the sub-cooling flow path of the housing, it is possible to improve the cooling performance of the water-cooled inverter structure for electric vehicles, and at the same time reduce the manufacturing process to improve productivity and low cost manufacturing.

Hereinafter, a water-cooled inverter structure for an electric vehicle according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Figure 3 is an exploded perspective view of the water-cooled inverter structure for an electric vehicle according to a preferred embodiment of the present invention, Figure 4 is a perspective view of the combination of the embodiment of Figure 3, Figure 5a is a bottom portion of the heat sink according to an embodiment of the present invention 5B is a bottom perspective view of a heat sink unit according to another embodiment of the present invention.

As shown in the figure, the boards installed in the inverter body, the power module 201 is located on the heat sink 101, the fixed to the fixing part 105, and provided with a connector, and the high It is fixed to the front part 105 and positioned above the power module 201, each having a connector, at least one of which is directly coupled to the power module 201 and a connector, and each of which is directly adjacent to the connector There is a driving board 202, a control board 203 and a power board 24. The control board 203 receives a signal from the outside of the inverter and transmits a control command to the power board 203. When a signal is transmitted from the control board 203 to the power board 204, the signal transmitted to the power board 204 is transmitted to the driving board 202 to implement a switching action of the power module 201. It will drive the inverter.

On the other hand, the inverter main body, the heat sink 101 is formed integrally with the main cooling flow path (102a) having a predetermined depth on the lower surface, the inlet and outlet of the main cooling flow path (102a), and the upper surface is the heat sink An undercover 103 coupled with a bottom surface of the portion 101, a housing 104 coupled with an upper surface of the heat sink portion 101, a housing 104 coupled with an upper surface of the heat sink portion 101, and positioned inside the housing 104 and The fixing part 105 coupled to the shape protruding from the upper surface of the 101 and the top cover 106 is coupled to the upper surface of the housing 104.

The power module 201 is located on an upper surface of the heat sink 101, is fixed to the fixing part 105, and has a connector. The power module 201 is composed of a power switching device, and the switching action of the power switching device is the main cause of increasing the heat generation amount of the inverter. Therefore, the power module 201 is brought into contact with the upper surface of the heat sink 101 to be sufficiently cooled.

The driving board 202, the control board 203, and the power board 204 are fixed to the fixing part 103 and positioned above the power module 201, each having a connector. As described above, the power module 201 is directly coupled to the connector, and at the same time, the power module 201 is directly coupled to the connector. For example, the driving board 202 is stacked and disposed above the power module 201, and the driving board 202 is fixed to the fixing part 103 and the connector of the power module 201 and the connector of the driving board 202. Is combined directly. In addition, a control board 203 and a power board 204 are stacked and disposed above the driving board 202 so that the connector of the driving board 202 and the connector of the control board 203 are coupled to each other. The connector of 202 or the control board 203 and the connector of the power board 204 are directly coupled. The connector is a connection portion for operation and control of each board, and conventionally connects the connector of each board with a wire. However, in order to miniaturize and lighten the inside of the vehicle, the direct connector of each board is adopted. In addition, by stacking the boards above the power module 201, the compactness of the inverter may be achieved.

The heat sink 101 has a main cooling passage 102a integrally formed at a lower surface thereof, and an inlet and an outlet of the main cooling passage 102a are formed. Since the power module 201 is in contact with the upper surface of the heat sink 101 and the main cooling passage 102a is to be formed on the lower surface of the heat sink 101, the shape of the main cooling passage 102a is a power installed in the inverter body. It depends on the position of the module 201, and also depends on the number or position of the power switching elements constituting the power module 201. In addition, the shape of the cooling fin is an important design variable in forming the main cooling passage 102a, and the cooling fin is a portion protruding thinly from the main cooling passage 102a and is formed to increase the heat exchange area. In particular, according to the heat generation amount of the power module 201, the pitch of the fin is narrowed to the portion having a large amount of heat generation, and the pitch of the fin is widened to the portion where the heat generation amount is small.

The lower surface of the housing 104 is coupled to the upper surface of the heat sink 101. In general, a hole in the heat sink 101 is bolted to the housing 104. In this case, a cooling loss between the heat sink 101 and the housing 104 cannot be avoided. In order to prevent this, it is preferable to mold the heat sink 101 and the housing 104 integrally. In addition, the sub-cooling passage 102b connected to the main cooling passage 102a of the heat sink 101 may be formed integrally with the outer surface of the housing 104. As a result, only the power module 201 coupled to the heat sink 101 is removed from the cooling method, thereby cooling each of the components inside the inverter. Therefore, not only cooling of the power module 201 but also cooling of other components can be achieved, thereby improving cooling efficiency inside the inverter body.

The fixing part 105 is located inside the housing 104 and is coupled in a shape protruding from an upper surface of the heat sink 101. The fixing part 105 fixes each board installed in the inverter body. The fixing portion 105 is preferably molded integrally with the heat sink 101 and the housing 104. As a result, the fixing unit 105 may be cooled together to further improve cooling efficiency inside the inverter body.

When integrally forming the heat sink 101, the housing 104, and the fixing portion 105 having the main cooling passage 102a and the sub cooling passage 102b, pressure is applied to the molten metal unlike ordinary sand casting methods. The casting method or the precision casting method to obtain a high precision casting by making a precision mold is used. In particular, it is preferable to use a die-casting method which has many advantages such as high speed mass production, dimensional accuracy, surface smoothness, weight reduction of castings, and cutting processing. By integral molding as described above, by cooling the inside of the inverter body without being limited to the cooling of the power module 201, it is possible to maximize the operating efficiency of each circuit board installed in the inverter. In addition, by molding the main cooling passage 102a, the subcooling passage 102b, the heat sink 101, the housing 104, and the fixing portion 105 at one time, the manufacturing process can be reduced and productivity can be improved. Can be.

The under cover 103 has an upper surface coupled to a lower surface of the heat sink 101. In general, a hole is drilled in the undercover 103 and bolted to the heat sink 101. In this case, a rubber packing or a gasket is installed between the undercover 103 and the heat sink 101. By preventing the leakage of the cooling water flowing in the main cooling passage (102a). In particular, when the sub-cooling passage 102b is integrally molded together, the under cover 103 has an upper surface in contact with an outer surface of which the main cooling passage 102a and the sub-cooling passage 102b are integrally formed. Are combined to form an inlet and an outlet of at least one selected from the main cooling passage 102a or the subcooling passage 102b. Therefore, leakage of the cooling water flowing through the part cooling flow path 102b formed in the housing 104 can be prevented together. In addition, the inlet and the outlet of the cooling water formed in the undercover 103 are formed to match the inlet and outlet of any one or more selected from the main cooling passage 102a or the subcooling passage 102b to facilitate circulation of the cooling water. Do it.

The top cover 106 has a bottom surface coupled to the top surface of the housing 104. In general, a hole in the top cover 106 is bolted to the housing 104. The lower surface of the top cover 106 and the upper surface of the housing 104 are preferably precisely processed so that the inside of the inverter can be completely sealed. In addition, it is more preferable to install the gasket 107 is coupled to one surface is in contact with the upper surface of the housing 104 and the other surface is in contact with the lower surface of the top cover 106. The gasket is a packing which prevents gas or water from leaking out when metal or other materials come into contact with each other. However, the gasket 107 is in close contact with the top cover 106 and the housing 104 to block the inside of the inverter from the outside. This is to maximize the cooling efficiency.

1 is a schematic diagram of a water-cooled cooling cycle of a typical electric vehicle,

2A and 2B are perspective views of a water-cooled inverter structure for a conventional electric vehicle,

3 is an exploded perspective view of a water-cooled inverter structure for an electric vehicle according to a preferred embodiment of the present invention,

4 is a perspective view of the combination of the embodiment of FIG.

Figure 5a is a bottom perspective view of the heat sink portion according to an embodiment of the present invention,

5B is a bottom perspective view of a heat sink unit according to another embodiment of the present invention.

Description of the main symbols in the drawings

101: heat sink 102a: main cooling flow path

102b: sub-cooling flow path 103: undercover

104 housing 105 fixing part

106: top cover 107: gasket

201: power module 202: drive board

203: control board 204: power board

Claims (5)

A heat sink having an integrally formed main cooling passage having a predetermined depth on a lower surface thereof, and having an inlet and an outlet of the main cooling passage; An under cover having an upper surface coupled to a lower surface of the heat sink portion; A housing having a bottom surface coupled to the top surface of the heat sink portion; A fixing part located inside the housing and coupled to the shape protruding from an upper surface of the heat sink part; A power module positioned on an upper surface of the heat sink and fixed to the fixing part and having a connector; A driving board, a control board, which is fixed to the fixing unit and positioned above the power module, each of which has a connector, at least one of which is directly coupled to the power module and a connector, and each of which is adjacently coupled directly to the connector; Power board, A water cooling inverter structure for an electric vehicle, the lower surface comprising a top cover coupled to the upper surface of the housing. The method of claim 1, The water-cooled inverter structure for an electric vehicle, characterized in that the heat sink and the housing are integrally molded. The method of claim 2, The sub-cooling passage connected to the main cooling passage is integrally formed on the outer surface of the housing, The undercover is electrically coupled with the main cooling passage and the sub-cooling passage in contact with each other, the inlet and outlet of at least one cooling passage selected from the main cooling passage or the sub-cooling passage. Automotive water-cooled inverter structure. The method according to any one of claims 1 to 3, The water-cooled inverter structure for an electric vehicle, characterized in that the heat sink, the housing and the fixed portion integrally molded. The method according to any one of claims 1 to 3, A water-cooled inverter structure for an electric vehicle further comprises a gasket, one side of which is in contact with the top of the housing and the other side is in contact with the bottom of the top cover.

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