JP5659328B2 - Power converter - Google Patents

Description

  The present invention relates to a cooling technique for a power converter (inverter) that drives a liquid pump.

  A conventional cooling technique for a power converter is shown in FIG. The power converter (inverter) 1 is in close contact with the main body cover 2, the main circuit board 3 mounted in the main body cover, the semiconductor (power module) board 4 mounted on the main circuit board 3, and the back surface of the semiconductor substrate 4. It is comprised from the radiation fin 6 arrange | positioned. An IGBT, DM (diode module), or the like as a semiconductor converts input power into different power, and supplies the converted power to, for example, a pump driving motor.

  Heat due to the loss generated in the semiconductor during power conversion is transferred to the cooling fin 6 and cooled by natural air cooling or forced air cooling by the cooling fan 5 that blows air to the cooling fin 6. Further, in the case of water cooling, the semiconductor is prevented from thermal destruction by cooling it by flowing cold water from a separately provided water cooling device 7 or the like to a flow path (not shown) provided in the base of the cooling fin 6. Yes.

  A method of cooling using a cooling fin or the like as described above is disclosed in Patent Document 1, for example. In Patent Document 1, a cooling fan block for forcibly air cooling the fins of a semiconductor substrate is provided on the back side of the main circuit block.

JP 2000-232288 A

  However, in the case of natural air cooling, a large space is required to secure a sufficient heat dissipation area of the cooling fin.In the case of forced air cooling, the space for installing the cooling fan and the space between the cooling fin and the cooling fan for ventilation are required. It is necessary to secure an appropriate ventilation path between them. In the case of water cooling, a device 7 such as a pump for flowing cold water is required separately from the power converter 1, and furthermore, a structure for flowing cold water is complicated, such as providing a cooling water circulation channel in the cooling fin. It becomes.

  In any case, the current situation is that the cooling device for cooling the heat generation of the semiconductor becomes large. In addition, since the cooling performance of the cooling device is also fixed, an appropriate cooling capacity is required for each type of power converter having a different capacity, and various types of cooling devices are required.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above-described drawbacks of the prior art, and an object thereof is to provide a power conversion device that saves space for cooling and is downsized and has high cooling efficiency.

In order to solve the above-described problems, the present invention includes a semiconductor substrate that converts input power and supplies the semiconductor substrate to the outside, a housing that incorporates the semiconductor substrate, and a heat dissipation unit that is fixed to the housing and dissipates heat from the semiconductor substrate. In the power converter configured to attach the inverter to the pump casing,
The inverter is attached to the pump casing so that the heat radiating part faces the fluid inside the pump, and a fluid introducing part is provided inside the pump to contact the heat radiating part with the fluid inside the pump. A small hole for converting fluid into mist by pressure is provided, and the mist is brought into contact with the heat radiating portion .

  In the power conversion device described above, the fluid introduction unit is configured to be able to vary the cooling performance by adjusting the flow rate of the fluid or the amount of mist.

  Moreover, the power converter device described above is characterized in that the heat radiating portion of the inverter is attached to the casing of the pump so as to face a housing portion of the impeller in the pump.

  Moreover, the power converter device described above is characterized in that the inverter is attached to the casing of the pump via an elastic member.

  According to the present invention, the volume of the cooling fin is reduced, the conventional cooling fan and the water-cooled liquid circulation mechanism are omitted, the space for cooling is reduced, the size is reduced, and the cooling efficiency is increased. Can do.

It is an exploded view of the conventional power converter. It is the schematic of the power converter device of Example 1 of this invention. FIG. 3 is an enlarged view of a part of FIG. 2. It is the schematic of the power converter device of Example 2 of this invention. FIG. 5 is a partially enlarged view of FIG. 4.

  Examples of the power converter according to the present invention will be described with reference to FIGS.

  FIG. 2 shows a schematic view of a cross section and a side surface of a power conversion device including a power converter (inverter) and a pump. FIG.2 (b) is a side view of a power converter device, and FIG.2 (a) is sectional drawing which follows the AA line of the same side view. The power converter (inverter) 1 of the first embodiment includes a main body cover 2, a main circuit board 3, and a semiconductor substrate 4 on which a semiconductor is mounted, similarly to the power converter shown in FIG. There is no cooling fan 5, and instead of the cooling fins 6 for radiating the heat of the semiconductor, a thin semiconductor fixing base (heat radiation part) 8 is used. The semiconductor fixing base 8 is formed with fin-like protrusions (not shown) for increasing the heat radiation area. The semiconductor fixing base 8 is attached so as to adhere to the semiconductor of the semiconductor substrate 4 and absorb the generated heat, and is fixed to the end of the main body cover 2.

  The inverter 1 converts commercial AC input power into different AC power in the semiconductor substrate 4 and supplies the AC power to a drive motor (not shown) of the external pump 9.

  As shown in FIG. 2, the inverter 1 is attached to a pump casing 9 a in which the impeller 9 b of the pump 9 is housed, and has a configuration integrated with the pump. The inverter 1 is attached to the casing 9a so that the semiconductor fixed base (heat dissipating part) 8 penetrates through the pump casing 9a and enters the fluid (water) flowing inside the pump.

  In FIG.2 (b), the pulley 9e is rotationally driven by the inverter 1 via a drive motor (not shown), and the impeller 9b rotates. By the rotation of the impeller 9b, the water sucked from the suction port 9c is increased in pressure and discharged from the discharge port 9d.

  FIG. 3 is an enlarged view of a portion surrounded by a broken line in FIG. Reference numeral 10 denotes a fluid introduction portion formed on the inner surface of the pump casing 9a so as to cover the semiconductor fixing base 8 and is formed in a box. The fluid introduction unit 10 causes a part of the high-pressure water flow inside the pump to flow in the direction of the solid arrow, and causes a part of the water flow that flows in the semiconductor fixed base 8 to flow in the direction of the broken arrow to contact the semiconductor fixed base 8. . The fluid introduction part 10 includes introduction / exit holes 10a and 10b that allow a part of a high-pressure water flow to flow in and out.

  Reference numeral 13 denotes an L-shaped mounting bracket for fixing the inverter 1 to the pump casing 9a. The mounting bracket 13 is screwed to the pump casing 9a, but an elastic material 13a is inserted between the mounting bracket 13 and the pump casing 9a so that vibrations of the drive motor and the pump are not transmitted to the inverter 1. . A liquid-tight elastic material 8a is inserted between the side wall of the semiconductor fixed base 8 penetrating the pump casing 9a and the through-wall of the pump casing 9a to seal both of them in a liquid-tight manner, and to drive motors. In addition, transmission of pump vibration to the inverter 1 is prevented. As described above, the elastic members 8a and 13a protect the inverter 1 from vibration so that no electrical failure occurs.

  In the above configuration, the power input to the main circuit board 3 is supplied to the semiconductor substrate 4 and converted into different power by the semiconductor substrate 4. During this power conversion, the semiconductor mounted on the semiconductor substrate 4 generates heat, and the heat is transferred to the semiconductor fixing base 8 that is a heat dissipation path of the semiconductor. The heat transmitted to the semiconductor fixed base 8 is cooled by being brought into contact with the water that has become high pressure by the pump 9 (rotation of the impeller 9b) inside the pump 9.

  The fluid introduction part 10 is formed in a box, and a part of the high-pressure water flow inside the pump flows in and out by providing an introduction / outlet hole 10a in a part thereof, so that the water flow inside the pump is not disturbed. In this way, a decrease in pump efficiency is prevented. The water that has flowed into the fluid introduction part 10 inside the pump merges with the water flow flowing in the pump through the introduction / exit hole 10a, while partially contributing to the cooling of the inverter 1.

  The present embodiment is an embodiment in which a decrease in pump efficiency that occurs due to cooling of the inverter 1 is minimized, and the power converter is downsized and the heat dissipation effect is enhanced. As shown in FIG. 4, the power conversion device in which the inverter 1 and the pump 9 are integrated is configured as in the first embodiment.

  FIG. 5B is an enlarged view of a portion surrounded by a broken line in FIG. 11 is a fluid introduction part provided on the inner surface of the pump casing 9a. The fluid introduction part 11 is formed in a box so as to cover the semiconductor fixing base, and is provided with a small hole 11 a for converting water (fluid) that has become high pressure in the pump into mist (mist) 12. The mist 12 generated from the small hole 11 a is sprayed toward the semiconductor fixing base 8. The sprayed mist 12 finally joins the flowing water flow in the pump through the outflow hole 11b.

  The semiconductor fixing base 8 is directly cooled by the sprayed mist 12 and is also cooled by the heat of vaporization of the mist 12 adhering to the surface of the semiconductor fixing base, thereby increasing the cooling efficiency. Further, by making the fluid mist, the mist spreads to every corner of the semiconductor fixing base 8 and the semiconductor fixing base 8 can be uniformly cooled, and the cooling efficiency is increased. Furthermore, since the amount of water used in the fluid introduction part 11 is less than that of liquid water, it is less likely to cause turbulence in the flow inside the pump, so that a reduction in pump efficiency can be minimized.

  In each of the above-described embodiments, even in the case of inverters having different calorific values, the same cooling device (fluid introduction part) can be used.

  That is, in the first embodiment, by changing the size of the inlet / outlet hole 10a of the fluid introduction part 10 shown in FIG. 2, the amount of water into the fluid introduction part 10 is changed, and the cooling capacity of the semiconductor fixing base 8 is increased. Can be changed. In the second embodiment, the amount of mist 12 generated in the fluid introduction part 11 can be changed by changing the number of small holes 11 a in the fluid introduction part 11.

  Therefore, even when inverters with different calorific values are installed, the same cooling structure can be used, and the number of parts of the cooling device can be reduced.

  The present invention is not limited to the above-described embodiments, and includes various modifications. Further, a part of the configuration of a certain embodiment can be replaced with another embodiment, and the configuration of another embodiment can be added to the configuration of a certain embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

  DESCRIPTION OF SYMBOLS 1 ... Power converter (inverter), 2 ... Main body cover, 3 ... Main circuit board, 4 ... Semiconductor substrate (power module), 8 ... Semiconductor fixed base (heat radiation part), 8a ... Elastic member, 9 ... Pump, 9a ... Pump casing, 9b ... Pump impeller, 10, 11 ... Fluid introduction part, 11a ... Sub-hole converted into mist, 12 ... Mist, 13 ... Mounting bracket, 13a ... Elastic member.

Claims (4)

A semiconductor substrate that converts input power and supplies it to the outside, a housing that contains this semiconductor substrate, and an inverter that is fixed to the housing and that dissipates heat from the semiconductor substrate is attached to the pump casing. In the converted power converter,
The inverter is attached to the pump casing so that the heat radiating part faces the fluid inside the pump, and a fluid introducing part is provided inside the pump to contact the heat radiating part with the fluid inside the pump. A power converter comprising a small hole for converting fluid into mist by pressure, and configured to bring the mist into contact with the heat radiating portion . In the power converter device described in Claim 1,
The said fluid introduction part is comprised so that cooling performance can be varied by adjusting the flow volume or amount of mist of the fluid, The power converter device characterized by the above-mentioned . In the power converter device according to claim 1 or 2,
The power converter according to claim 1 , wherein the heat radiating portion of the inverter is attached to a casing of the pump so as to face a housing portion of the impeller in the pump . In the power converter device according to any one of claims 1 to 3,
The inverter is attached to the casing of the pump via an elastic member .

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