JP2014146657A - Guidance system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a guidance system which reduces heat resistance thereby improving heat radiation performance and improves the insulation reliability.SOLUTION: A guidance system 10 includes: a coil 20; a UU type core 30; and a cooler 40. A prepreg 60 contacts with the coil 20 (21, 22). The coil 20 (21, 22), the UU type core 30 (31, 32), and the prepreg 60 are molded by a mold resin 50. A part of the prepreg 60, which does not contact with the coil 20 (21, 22), is exposed from the mold resin 50 and heat radiation grease 70 is disposed between the prepreg 60 and the cooler 40.

Description

  The present invention relates to a guidance device.

  The reactor disclosed in Patent Document 1 includes a coil, a magnetic core that forms a closed magnetic path with an inner core portion inserted into the coil and an outer core portion connected to the inner core portion. A coil molded body having a coil and an inner resin portion that covers the outer periphery of the coil and holds the shape thereof, and an outer resin portion that covers at least a part of the outer periphery of the combined body of the coil molded body and the magnetic core. Yeah. In the outer core portion, one surface that becomes the installation side when the reactor is installed projects beyond the surface that becomes the installation side in the inner core portion, and is exposed from the outer resin portion. Moreover, it can be set as the structure which provided the heat sink on the installation side when installing a coil formation body.

JP 2011-71466 A

  By the way, if the reactor disclosed in Patent Document 1 is fixed to the cooler, the distance between the coil and the cooler increases by the thickness of the heat sink. Moreover, since the thickness of the location which covers a coil in the inner side resin part (PPS etc.) of a coil formation body is 1 mm or more, heat dissipation efficiency is bad. Furthermore, the structure which deletes the heat sink disclosed in patent document 1 and fixes a reactor to a cooler via a heat radiating sheet is also considered. In this case, it is conceivable to press the heat-dissipating sheet with the reactor when fixing the reactor to the cooler in order to bring the heat-dissipating sheet and the reactor into close contact with each other. Decreases and the heat dissipation efficiency deteriorates.

  An object of the present invention is to provide an induction device capable of reducing heat resistance to improve heat dissipation and improving insulation reliability.

  The invention according to claim 1 is an induction device including a coil, a core that forms a closed magnetic circuit with respect to the coil, and a cooler, and a prepreg is in contact with the coil, and the coil And the core and the prepreg are molded with a mold resin, a part of the prepreg that is not in contact with the coil is exposed from the mold resin, and heat radiation grease is disposed between the prepreg and the cooler. This is the gist.

  According to the first aspect of the present invention, the prepreg is in contact with the coil, a part of the prepreg that is not in contact with the coil is exposed from the mold resin, and the heat dissipating grease is disposed between the prepreg and the cooler. Therefore, heat resistance can be reduced and heat dissipation can be improved. Further, the insulation between the coil and the cooler can be secured by using the prepreg, and the insulation reliability can be improved.

  As described in claim 2, in the induction device according to claim 1, when the thickness of the prepreg is 50 to 500 μm, the distance between the coil and the cooler is minimized and heat is reduced. Resistance can be reduced and heat dissipation can be improved.

  As described in claim 3, in the induction device according to claim 1 or 2, the sum of the thermal resistance of the prepreg and the thermal resistance of the heat dissipating grease is less than 0.0002 K · m ^ 2 / W. , Heat dissipation is improved.

  As described in claim 4, the guidance device according to any one of claims 1 to 3 may be used in a vehicle.

  According to the present invention, the heat resistance can be improved by reducing the thermal resistance, and the insulation reliability can be improved.

The perspective view of the guidance device in an embodiment. The longitudinal cross-sectional view of a guidance device. The perspective view which shows a core. The longitudinal cross-sectional view which shows the resin mold assembly. The longitudinal cross-sectional view for demonstrating a manufacturing process. The longitudinal cross-sectional view of the guidance apparatus of another example. The longitudinal cross-sectional view of the guidance apparatus for a comparison.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings.
As shown in FIGS. 1 and 2, the induction device 10 includes a coil 20, a UU type core 30, a cooler 40, a mold resin 50, a prepreg 60, and heat radiation grease 70. It constitutes the reactor of the circuit. The induction device (reactor) 10 is for in-vehicle use and is mounted on a hybrid vehicle. Specifically, a booster circuit is configured by using the induction device (reactor) 10, and the DC voltage of the battery, 200 volts, is boosted to a DC voltage of 600 volts by the booster circuit. The 600 volt voltage generated by the booster circuit is converted into a three-phase alternating current by an inverter and supplied to the traveling motor.

  As shown in FIG. 3, the UU type core 30 includes a U type core 31 and a U type core 32. As shown in FIG. 2, the coil 20 includes a first coil 21 and a second coil 22.

  As shown in FIG. 4, the UU type core 30 (U type core 31, U type core 32), the coil 20 (21, 22), and the prepreg 60 are integrally molded with the mold resin 50 in an assembled state. Thus, a resin mold assembly Arm is constructed.

  As shown in FIG. 3, the U-shaped core 31 has a rectangular bar shape in cross section, and has a U shape as a whole. The U-shaped core 31 has end faces 31a and 31b. Similarly, the U-shaped core 32 also has a rectangular bar shape in cross section, and has a U shape as a whole. The U-shaped core 32 has end faces 32a and 32b. The end surface 31a of the U-shaped core 31 and the end surface 32a of the U-shaped core 32 are abutted, and the end surface 31b of the U-shaped core 31 and the end surface 32b of the U-shaped core 32 are abutted. In this way, a closed magnetic circuit is formed by the UU type core 30.

  As shown in FIG. 4, a square annular coil 21 is wound around one of the two connecting portions of the U-shaped core 31 and the U-shaped core 32. Similarly, a coil 22 having a square ring shape is wound around the other of the two connecting portions of the U-shaped core 31 and the U-shaped core 32. As described above, the annular coil 20 (21, 22) is wound around at least a part of the UU-type core 30 (U-type core 31, U-type core 32). The coil 20 (21, 22) of the present embodiment is used by winding it by edgewise bending using a rectangular wire having a rectangular cross section as a winding. Further, the coil 20 (21, 22) has a base copper plate surface coated with polyimide amide (enamel).

  The coil 21 and the coil 22 are connected to each other at one end, and as shown in FIG. 1, the other end is provided with a terminal portion 21a and a terminal portion 22a, respectively, and the terminal portion 21a and the terminal portion 22a are It extends in the horizontal direction while being exposed from the mold resin 50. In addition, the terminal part 21a and the terminal part 22a may be extended upward in the state exposed from the mold resin 50. FIG.

  As shown in FIG. 4, the outer peripheral portion of the UU type core 30 (U type core 31, U type core 32) is sealed with a mold resin 50. Moreover, the prepreg 60 is arrange | positioned at the lower surface 23 which is a heat radiating surface in the coil 20 (21, 22). The prepreg 60 is a sheet material in which a glass cloth is impregnated with an epoxy resin. The lower surface 23 of the coil 20 (21, 22) and the upper surface 61 of the prepreg 60 are in contact with each other. The outer periphery of the coil 20 (21, 22) excluding the lower surface 23 that is a heat radiating surface is sealed with a mold resin 50. The outer peripheral portion of the prepreg 60 except the lower surface 62 is sealed with the mold resin 50.

  Thus, the upper surface 61 of the prepreg 60 is in contact with the lower surface 23 of the coil 20 (21, 22), and only the coil 20 (21, 22), the UU core 30 and the prepreg 60 are molded with the molding resin 50. Yes. Further, the lower surface 62 that is a part of the prepreg 60 that is not in contact with the coil 20 (21, 22) is exposed from the mold resin 50.

  As shown in FIG. 2, the cooler 40 is a water-cooled cooler. The cooler 40 is made of aluminum die casting, and the surface is a die-cast surface. The cooler 40 is formed in a box shape, and the coolant flows inside. The upper surface of the cooler 40 is formed horizontally, and this upper surface serves as an arrangement surface for the resin mold assembly Arm. A heat dissipating grease 70 is applied to the upper surface of the cooler 40. The thickness t2 of the heat dissipating grease 70 is 0.1 to 0.2 mm. The heat dissipating grease 70 is for absorbing mechanical tolerances.

Thus, the heat dissipating grease 70 is disposed between the lower surface 62 of the prepreg 60 and the upper surface of the cooler 40.
The thickness t1 of the prepreg 60 is 50 to 500 μm. The sum of the thermal resistance of the prepreg 60 and the thermal resistance of the heat dissipating grease 70 is less than 0.0002 K · m ^ 2 / W.

  The mold resin 50 is made of PPS (polyphenylene sulfide) resin and has a plurality of mounting projections (bosses) 51 on the outer surface. Specifically, mounting protrusions (bosses) 51 are provided at the four corners of the square resin mold assembly Arm in plan view. Each mounting projection 51 is formed with a through hole 51a through which a screw 80 passes. A screw hole 40 a is formed at a position corresponding to the through hole 51 a in the cooler 40. A screw 80 is screwed into the screw hole 40 a of the cooler 40 through the through hole 51 a of the protrusion 51 of the mold resin 50. As a result, the resin-molded coils 20 (21, 22), the UU type cores 30 (31, 32), and the prepreg 60 are attached to the cooler 40. Note that a metal plate having a through hole may be used as the mounting protrusion (boss), and a part of the metal plate may be embedded in the mold resin 50.

Next, the operation will be described.
In manufacturing the induction device 10, the coil 20 (21, 22), the U-shaped core 31, the U-shaped core 32, and the prepreg 60 are prepared.

  Then, as shown in FIG. 4, the divided cores 31 and 32 and the coil 20 are temporarily assembled, placed in an injection mold, a semi-cured prepreg 60 is attached to the coil 20, and the resin is poured. The mold resin 50 is integrated. That is, the U-shaped cores 31 and 32 are inserted on the inner peripheral side of the coil 20 (21, 22), the prepreg 60 is set at a predetermined position, and the coil 20, the core 30 and the prepreg 60 are connected to the heat radiating portion in the coil 20. The upper surface 61 which is one surface of the prepreg 60 is in direct contact with the lower surface 23 which is and is molded with the molding resin 50 so that the lower surface 62 which is the other surface is exposed. By this injection molding, the prepreg 60 is cured and bonded to the coil 20. Thus, the resin mold assembly Arm is formed.

On the other hand, as shown in FIG. 5, heat radiation grease 70 is applied to the upper surface of the cooler 40. Then, the resin mold assembly Arm is mounted on the upper surface of the cooler 40 via the heat radiation grease 70.
Thereafter, as shown in FIG. 2, the resin mold assembly Arm is fixed to the cooler 40 by screwing screws 80 into the cooler 40. That is, the coil 20, the core 30, and the prepreg 60 are fixed to the cooler 40 in a state in which the heat radiation grease 70 is interposed between the lower surface 62 that is the other surface of the prepreg 60 exposed from the mold resin 50 and the cooler 40. To do.

As a result, the guidance device (reactor) 10 shown in FIGS. 1 and 2 can be manufactured.
And in the induction device (reactor) 10 manufactured in this way, the coil 20 is energized at the time of boosting, and the coil 20 generates heat with this energization. Heat generated in the coil 20 is released from the lower surface 23 to the cooler 40 through the prepreg 60 and the heat radiation grease 70. At this time, the prepreg 60 is thin and easily transmits heat and has excellent heat dissipation. In addition, although a maximum voltage of about DC 800 volts is applied to the coil 20, insulation is ensured by the prepreg 60.

Next, the guidance device 100 as a comparative example shown in FIG. 7 is compared with the guidance device 10 of the present embodiment.
In the induction device 100 of FIG. 7, the core 101 and the coil 102 are insert injection molded with a resin 103, and this is disposed on the upper surface of the cooler 104 via a heat dissipation sheet 105 made of silicone resin. Further, in this state, the screw 106 passes through the resin 103 that seals the core 101 and the coil 102, and a large force 1000N to 5000N (preferably 3000N) to crush the gel-like heat radiation sheet 105 against the cooler 104. Screw in (add screws) to add. By setting it as this pressurization state, the thermal radiation sheet 105 and the cooler 104 can be stuck. The heat generated in the coil 102 is released from the lower surface to the cooler 104 via the heat dissipation sheet 105.

  A maximum voltage of about DC 800 volts is applied to the coil 102. Here, the coil 102 has a surface coated with polyimideamide (enamel) for insulation, but has a pinhole. Therefore, although the insulating heat radiation sheet 105 is used to insulate from the cooler 104, a large force of 1000N to 5000N (preferably 3000N) is required to crush the gel heat radiation sheet 105 in the manufacturing process. The process load increases. Further, in the state where the thickness of the heat dissipation sheet 105 is crushed 0.9 mm, the insulating safety factor is low. In this way, the insulation is not guaranteed by the heat dissipation sheet 105, but the lower surface of the coil 102 is desired to be covered with a separate highly insulating member. However, since the insulating member has low thermal conductivity, there is a concern that the thermal resistance may deteriorate. .

  On the other hand, in this embodiment shown in FIG. 2, the prepreg 60 as an insulating member is used thinly on the lower surface 23 of the coil 20 (21, 22). That is, the prepreg 60 as the insulating member can be a thermosetting resin B stage sheet, for example, FR-4. And in a manufacturing process, it does not need to increase a process by insert-molding at the time of injection molding.

  Further, the prepreg 60 has high insulation reliability. Moreover, the thickness t1 of the prepreg 60 is 50-500 micrometers, and thermal resistance is reduced by the use by thin wall. Furthermore, the prepreg 60 has a thermal conductivity of about 0.4 to 10 W / m · K. Therefore, it is possible to improve insulation and improve heat dissipation performance by simply adding one insert molding member.

The thermal resistance is calculated as follows.
As shown in FIG. 7, the calculation is performed for the case where the heat radiation sheet 105 is used as the heat radiation material (heat conduction material) between the coil 102 as the heat generation source and the cooler 104.

  It is assumed that the heat dissipation sheet 105 is used with a thermal conductivity λ of 4.5 W / m · K and a thickness t of 0.9 mm. In this case, since the thermal resistance (contact thermal resistance) R is R = t / λ, R = 0.0002 K · m ^ 2 / W.

  On the other hand, the calculation is performed for the case where the prepreg 60 and the heat radiating grease 70 are used as the heat radiating material (heat conducting material) between the coil 20 (21, 22) as the heat source and the cooler 40 as shown in FIG.

The prepreg 60 and the heat dissipating grease 70 are stacked, the prepreg 60 is disposed on the coil 20 side, and the heat dissipating grease 70 is disposed on the cooler 40 side.
In this case, it is assumed that the prepreg 60 has a thermal conductivity λ1 of 3.0 W / m · K and a thickness t1 of 0.12 mm.

In this case, since the thermal resistance (contact thermal resistance) R1 is R1 = t1 / λ1, R1 = 0.00004 K · m ^ 2 / W.
On the other hand, it is assumed that the thermal grease 70 is used with a thermal conductivity λ2 of 3.5 W / m · K and a thickness t2 of 0.2 mm. In this case, since the thermal resistance (contact thermal resistance) R2 is R2 = t2 / λ2, R2≈0.00006 K · m ^ 2 / W.

  Therefore, the total thermal resistance (contact thermal resistance) Rth in the laminate of the prepreg 60 and the heat radiating grease 70 is a serial combination of the heat resistance R1 of the prepreg 60 and the heat resistance R2 of the heat radiating grease 70, that is, Rth = R1 + R2. Therefore, Rth = 0.0001K · m ^ 2 / W.

  Therefore, in the case of the induction device 100 of FIG. 7, that is, compared to the case where the heat radiation sheet 105 is used as the heat radiation material (heat conduction material) between the coil 102 as the heat source and the cooler 104, the present embodiment of FIG. In the case of the induction device 10, that is, when the prepreg 60 and the heat radiation grease 70 are used as the heat radiation material (heat conduction material) between the coil 20 (21, 22) as the heat source and the cooler 40, the thermal resistance is reduced. Can be halved. That is, heat resistance is reduced and heat dissipation is improved.

According to the above embodiment, the following effects can be obtained.
(1) As a configuration of the induction device 10, a coil 20 (21, 22), a UU-type core 30 (31, 32) that forms a closed magnetic path with respect to the coil 20 (21, 22), a cooler 40, Is provided. The coil 20 (21, 22) is in contact with the prepreg 60, and the coil 20 (21, 22), the UU cores 30 (31, 32), and the prepreg 60 are molded with the molding resin 50, and the coil 20 (21, 22). A portion of the prepreg 60 that is not in contact with the prepreg is exposed from the mold resin 50, and the heat dissipating grease 70 is disposed between the prepreg 60 and the cooler 40. Accordingly, the heat resistance can be improved by reducing the thermal resistance. Further, the insulation between the coil 20 and the cooler 40 can be secured by using the prepreg 60, and the insulation reliability can be improved.

  (2) Since the thickness of the prepreg 60 is 50 to 500 μm, the distance between the coil 20 and the cooler 40 can be minimized and the heat resistance can be reduced and the heat dissipation can be improved.

(3) Since the sum of the thermal resistance of the prepreg 60 and the thermal resistance of the heat dissipating grease 70 is less than 0.0002 K · m ^ 2 / W, the heat dissipation is improved.
(4) Since it is for in-vehicle use, it is practical.

  (5) The heat radiating sheet 105 is not used, and it may not be pressed with a force of 1000N to 5000N, preferably 3000N. As a result, it is possible to reduce the load in the assembly process.

The embodiment is not limited to the above, and may be embodied as follows, for example.
As shown in FIG. 6 instead of FIG. 2, the prepreg 60 may be attached to the aluminum substrate 90 and may be disposed between the coil 20 (21, 22) and the heat radiating grease 70 by insert molding. That is, a part of the prepreg 60 that is not in contact with the coil 20 may be exposed from the mold resin 50, and the heat radiation grease 70 and the aluminum substrate 90 may be disposed between the prepreg 60 and the cooler 40.

-The cooler may be a water-cooled cooler or an air-cooled cooler.
-Although the reactor was comprised by the coil 20 (21, 22) and the UU type | mold core 30 (31, 32) in the induction device 10, you may comprise a transformer instead.

The induction device may not be an in-vehicle induction device, and may be applied to an induction device used for an industrial inverter other than the in-vehicle use.
Next, the technical idea that can be grasped from the above embodiment and other examples will be described below together with the effects.

(A) A method for manufacturing an induction device including a coil, a core that forms a closed magnetic path with respect to the coil, and a cooler,
A resin molding step of molding the coil, the core, and the prepreg with a mold resin so that one surface of the prepreg is in direct contact with a heat dissipation portion of the coil and the other surface of the prepreg is exposed;
A fixing step of fixing the coil, the core, and the prepreg to the cooler in a state in which heat-release grease is interposed between the other surface of the prepreg exposed from the mold resin and the cooler;
A method for manufacturing a guidance device.

  According to this technical idea, the heat-dissipating sheet 105 is not used, and it is not necessary to press and use the heat-dissipating sheet 105, and the load in the assembly process can be reduced. Moreover, since the prepreg is inexpensive and the heat dissipation sheet 105 can be eliminated, an increase in cost can be suppressed.

  DESCRIPTION OF SYMBOLS 10 ... Guidance device, 20 ... Coil, 30 ... Core, 40 ... Cooler, 50 ... Mold resin, 60 ... Pre-preg, 61 ... Upper surface, 62 ... Lower surface, 70 ... Radiation grease, t1 ... Thickness.

Claims (4)

Coils,
A core that forms a closed magnetic path for the coil;
A cooler,
A guidance device comprising:
A prepreg is in contact with the coil, the coil, the core, and the prepreg are molded with a mold resin, and a part of the prepreg that is not in contact with the coil is exposed from the mold resin, and the prepreg and the cooling An induction device comprising heat dissipating grease placed between the two.   The induction device according to claim 1, wherein the prepreg has a thickness of 50 to 500 μm.   The induction device according to claim 1 or 2, wherein the sum of the thermal resistance of the prepreg and the thermal resistance of the heat-dissipating grease is less than 0.0002 K · m ^ 2 / W.   The guidance device according to any one of claims 1 to 3, wherein the guidance device is for in-vehicle use.