JP2010232487A - Power converter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide: a warpage prevention structure of an aluminum die-cast molding capable of reducing a manufacturing time and reducing manufacturing cost by preventing warpage after die-casting an aluminum die-cast product to eliminate a warpage correction process; and a power converter using the same. <P>SOLUTION: When die-casting, for instance, a case body of this power converter using aluminum or an aluminum alloy, a warpage prevention reinforcement part such as a rib part or a plate thickness reinforcement part is formed in a warpage occurrence-predicted part after die-casting. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a warp preventing structure for an aluminum die-cast product and a power converter using the same.

  As this type of power conversion device, for example, in an inverter device having an inverter device body incorporating an electronic circuit, a body case surrounding the inverter device body, and a terminal portion provided at one end inside the body case, a body case There is known an inverter device having a structure in which a reactor housing body including a terminal protection cover is detachably attached to one end of the terminal portion side, and a DC reactor electrically connected to the terminal portion is disposed in the reactor housing body. (For example, refer to Patent Document 1).

  In addition, a housing for the motor control device, a heat sink provided with fins in the housing, a cooling fan for cooling the heat sink, a power semiconductor module closely contacting the surface of the heat sink opposite to the fin, and a heat sink in the housing Heat transfer to the surface of a coil in a motor control device including a core disposed on the fin side and a reactor housed in the core and having a coil with a coil end protruding from the longitudinal end of the core. 2. Description of the Related Art A motor control device is known that includes a reactor heat sink brought into contact via a resin and a coil cover disposed beside the longitudinal end of a coil end (see, for example, Patent Document 2).

JP 2007-86101 A JP 2008-86101 A

  However, in the conventional examples described in Patent Documents 1 and 2, an aluminum heat sink is applied in order to obtain the heat dissipation effect of the reactor. Usually, the aluminum heat sink is made of aluminum or an aluminum alloy. It is manufactured by die-casting. At this time, in die casting, since a heat sink is formed by pouring aluminum or an aluminum alloy into a mold at a high pressure in a molten state, warping may occur when the temperature of the aluminum molded product is lowered after molding. However, when a warp occurs, it is necessary to perform a correction process for correcting the warp, and there is an unresolved frame that increases the manufacturing cost and the manufacturing time.

  Therefore, the present invention has been made paying attention to the unsolved problems of the above-described conventional example, and prevents warping after molding of an aluminum die-cast product, omits warping correction processing, and shortens manufacturing time. In addition, an object of the present invention is to provide a warp prevention structure for an aluminum die-cast molded product and a power conversion device using the same, which can reduce the manufacturing cost.

In order to achieve the above object, the warpage prevention structure for an aluminum die cast product according to claim 1 forms a warp prevention reinforcing portion in a predicted warpage occurrence portion after molding when die casting aluminum or an aluminum alloy. It is characterized by that.
According to this configuration, by forming the warpage prevention occurrence portion in the expected warpage occurrence portion after molding, the occurrence of warpage can be prevented, and the warp correction treatment can be omitted, and the aluminum die cast molded product can be formed in a short time. Can be manufactured with high accuracy.

Moreover, the warpage prevention structure of the aluminum die-cast molded product according to claim 2 is the invention according to claim 1, wherein the warpage prevention reinforcing portion is configured by a rib portion that increases the rigidity formed in the warpage occurrence prediction portion. It is characterized by that.
According to this configuration, by forming ribs at the warp occurrence predicted portion to increase the rigidity, it is possible to reliably prevent the warp from occurring when the temperature of the die cast product is lowered after die casting.

The warpage prevention structure of the aluminum die cast product according to claim 3 is characterized in that the warpage prevention reinforcing portion is composed of a plate thickness increasing portion formed at a warpage occurrence prediction portion.
In the invention according to claim 3, since the plate thickness increasing portion is formed in the predicted warpage occurrence portion, it is possible to reliably prevent the warpage from occurring when the temperature of the die cast product is lowered after die casting. .

Further, in the warp preventing structure for an aluminum die cast product according to claim 4, the warp preventing reinforcing portion is constituted by a rib portion and a plate thickness increasing portion for increasing rigidity formed in a warp occurrence predicting portion. It is a feature.
According to this configuration, since the rigidity is reinforced at the rib portion at the warpage occurrence predicted portion and the rigidity is also strengthened at the plate thickness increasing portion, the occurrence of the warpage can be prevented more reliably.

The power conversion device according to claim 5 is applied to a DC reactor storage stand that adds the warp structure of the aluminum die cast product according to any one of claims 1 to 4 to the inverter device. Yes.
According to this configuration, the DC reactor storage stand for storing the DC reactor can be manufactured accurately and in a short time without performing warp correction, and can also serve as a heat sink.

  According to the present invention, since the warpage preventing reinforcing portion is formed in the expected warpage portion of the aluminum die cast molded product formed by die casting of aluminum or aluminum alloy, the temperature drop after forming the aluminum die cast molded product Further, it is possible to prevent the occurrence of warpage, and there is no need to perform a warp correction process, and an effect that an aluminum molded product can be accurately manufactured while reducing the number of manufacturing steps can be obtained.

  In addition, by forming a DC reactor storage stand to be added to the inverter device with an aluminum molded product with a warp prevention reinforcing part, the DC reactor storage stand can be accurately manufactured while reducing the number of manufacturing steps, and the power conversion device The effect that the mass productivity of can be improved is obtained.

It is a circuit diagram which shows the electric constitution of a power converter device. BRIEF DESCRIPTION OF THE DRAWINGS It is an external appearance perspective view which shows 1st Embodiment at the time of applying this invention to a power converter device. FIG. 3 is an exploded perspective view of FIG. 2. It is the perspective view which looked at the DC reactor storage stand from the plane side. It is the perspective view which looked at the DC reactor storage stand from the bottom face side. It is the perspective view which looked at the DC reactor storage stand which shows other embodiment of this invention from the bottom face side. It is the perspective view which looked at the DC reactor storage stand which shows other embodiment of this invention from the bottom face side.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, the electrical configuration of the power converter will be described with reference to FIG.
This power conversion device has a configuration in which a rectifier 1 and an inverter 2 are connected by a DC reactor 3. Here, the rectifier 1 has a configuration in which three series circuits in which six diodes D1 to D6 are connected in series are connected in parallel, the connection point of the diodes D1 and D2, and the connection of the diodes D3 and D4. Commercial three-phase AC input terminals R, S, and T are derived from the point and the connection point of the diodes D5 and D6, respectively.

  Further, in the inverter 2, three switching arms are formed by semiconductor switching elements Tr11 to Tr16 made of IGBT or the like and six reverse connection diodes D11 to D16, and a connection point between the semiconductor switching elements Tr11 and Tr12, a semiconductor AC output terminals U, V, and W are derived from the connection point of the switching elements Tr13 and Tr14 and the connection point of the semiconductor switching elements Tr15 and Tr16, respectively.

And the inverter 2 of the power converter device which has the said structure is built in the inverter apparatus 11 shown in FIG. 2, and the DC reactor 3 is stored in the DC reactor storage stand 20 shown in FIG.
The inverter device 11 has a main body 12 in which semiconductor switching elements Tr11 to Tr16 as heat generating members constituting the inverter 2 described above are housed. The main body 12 has a configuration in which front and rear case halves 12A and 12B are connected, and an air intake hole 13 is formed in both case halves 12A and 12B.

An operation display unit 14 for performing various setting operations and display is formed on the case half body 12A on the front side. The case half 12B on the back side has a fan accommodating portion 15 formed on the uppermost surface over the entire upper surface, and a semiconductor switching element (not shown) serving as a heat generating component is accommodated below the fan accommodating portion 15. Has been.
The DC reactor storage stand 20 for storing the DC reactor 3 is detachably bolted to the back side of the main body 12, that is, the back side of the case half 12B. Here, in the DC reactor 3, as shown in FIG. 3, a coil 17 is wound around an elliptical iron core 16, and connection terminals 18a and 18b led out from the beginning and end of winding of the coil 17 are projected forward. Have a configuration. The DC reactor 3 is attached to a mounting plate 19 having high thermal conductivity such as aluminum.

  As shown in FIGS. 4 and 5, the DC reactor storage stand 20 is manufactured by die-casting aluminum or an aluminum alloy, and has a relatively thick thickness that covers the rectangular frame portion 21 and the bottom surface of the rectangular frame portion 21. A case body 23 having an open front surface with a thin back plate portion 22 is provided. A storage chamber 24 for storing the DC reactor 10 and a component storage portion 26 separated from each other by a partition wall 25 are formed in the rectangular frame portion 23. A mounting plate portion reinforced by ribs 27 is formed on the upper surface side of the rectangular frame portion 21 so as to protrude upward, and a mounting plate portion 29 is formed on the lower surface side so as to protrude downward.

Further, a warp reinforcing portion 31 is formed on the back side of the back plate portion 22. The warp reinforcing portion 31 is formed when the back plate portion 22 having a thin plate thickness is formed by die casting, and the back plate portion 22 having a thin plate thickness is predicted to be warped when the temperature is lowered after molding. It is composed of lattice-like rib portions 32 that increase the rigidity of the warp occurrence prediction portion on the back side.
Then, the DC reactor 3 is fixed in a state in which the connection terminals 18 a and 18 b protrude forward by screwing the mounting plate 19 into the storage chamber 24. In a state where the DC reactor 3 is stored in the storage chamber 24, the front end surface of the storage chamber 24 is closed by the closing plate 33 with the connection terminals 18a and 18b protruding forward.

Next, the operation of the present invention will be described.
First, in order to assemble a power converter, a cooling fan housing, semiconductor switching elements Tr11 to Tr16 and the like serving as heat generating components are mounted on a substrate in a case half 12B of the inverter device 11 and installed.
Further, the DC reactor 3 mounting plate 19 is fixed in the storage chamber 24 of the DC reactor storage stand 20 to store the DC reactor 3, and the connection terminals 18a and 18g are projected forward by the closing plate 33 on the front end face of the DC reactor 3. It closes in a closed state. Then, the connection terminals 18 a and 18 b are inserted into the case half 12 of the inverter device 11, one end is connected to the inverter 2, and the other end is connected to the rectifier 1.

In this state, the main body 12 is configured by combining the case half 12A with the case half 12B.
By assembling the inverter device in this way, the inverter device 12 to which the DC reactor 3 is connected can be easily configured.
At this time, as described above, the DC reactor storage stand 20 for storing the DC reactor 3 has a grid-like rib portion on the back side of the back plate portion 22 where the plate thickness is thin and warpage is predicted during die casting. 32 is formed as a warp preventing reinforcing portion, and the rigidity is enhanced by the rib portion 32. Therefore, when aluminum or an aluminum alloy is melted and press-fitted into a mold at a high pressure, a die cast molded product is obtained. Is extracted from the mold and cooled at room temperature, it is possible to reliably prevent warping. For this reason, the warp correction process conventionally required can be omitted, the number of manufacturing steps can be reduced, the manufacturing time can be shortened, and mass production can be promoted.

  Further, since the DC reactor storage stand 20 is formed of aluminum or an aluminum alloy, the heat conductivity can be increased and a heat sink having a large heat capacity can be obtained. Overheating of the reactor 3 can be suppressed. At this time, since the rib part 32 plays the role of a radiation fin, the heat radiation effect can be further enhanced.

  In addition, in the said embodiment, although the case where the rib part 32 was formed as a curvature prevention reinforcement part was demonstrated, as shown in FIG. 6, a rib part is abbreviate | omitted and replaced with this. Thus, the plate thickness increasing portion 41 having a thick plate thickness may be formed on the back side of the back plate portion 22 of the DC reactor storage pedestal 20 so as to extend to both left and right ends. In this case, the plate thickness increasing portion 41 is not limited to being formed in a belt shape, and may be formed in a cross shape or an X shape.

Furthermore, as shown in FIG. 7, both the rib portion 32 and the plate thickness increasing portion 41 are formed on the back side of the back plate portion 22 of the torque storage gantry 20 that is vacant in direct current, so that the rigidity is further increased and the occurrence of warpage is further increased. You may make it prevent reliably.
Moreover, in the said embodiment, although the case where the inverter apparatus was applied as a power converter device was demonstrated, it is not limited to this, For example, this invention is applied also to other types of power converter devices, such as an uninterruptible power supply device. Can be applied.

  Furthermore, although the case where this invention was applied to the power converter device was demonstrated in the said embodiment, it is not limited to this, It can apply as a curvature prevention structure of other arbitrary apparatuses.

  DESCRIPTION OF SYMBOLS 1 ... Rectifier, 2 ... Inverter, 3 ... DC reactor, 11 ... Inverter apparatus, 12 ... Main body, 12A, 12B ... Half case, 13 ... Air intake hole, 15 ... Cooling fan accommodating part, 20 ... DC reactor storage stand, DESCRIPTION OF SYMBOLS 21 ... Square frame part, 22 ... Back board part, 23 ... Case body, 24 ... Storage chamber, 32 ... Rib part, 41 ... Thickness increase part

Claims (5)

  A warp prevention structure for an aluminum die cast product, wherein a warp prevention reinforcing portion is formed in a predicted warpage occurrence portion when die-casting aluminum or an aluminum alloy.   2. The warpage preventing structure for an aluminum die cast product according to claim 1, wherein the warp preventing reinforcing portion is constituted by a rib portion for increasing rigidity formed in a warp occurrence predicting portion.   2. The warpage prevention structure for an aluminum die cast product according to claim 1, wherein the warpage prevention reinforcing portion is formed of a plate thickness increasing portion formed in a warpage occurrence prediction portion.   2. The warpage preventing structure for an aluminum die cast product according to claim 1, wherein the warp preventing reinforcing portion is composed of a rib portion and a plate thickness increasing portion which are formed in a warp occurrence predicting portion and which increase rigidity. .   5. A power conversion device, wherein the warp structure of the aluminum die-cast molded product according to any one of claims 1 to 4 is applied to a DC reactor storage stand that adds to an inverter device.

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