JP4924508B2 - Reactor device - Google Patents

Description

  The present invention relates to a reactor device formed by filling a magnetic powder mixed resin inside and outside a coil.

2. Description of the Related Art Conventionally, a reactor that injects a magnetic powder mixed resin called a coil and a dust core into a reactor case and hardens the dust core in the case is known (for example, see Patent Document 1 below).
JP 2008-42094 A

  In addition to the method of directly molding and hardening the dust core in the case, there is a method of shortening the time required for molding and hardening by accommodating the coil and the dust core in a mold or the like having a smaller heat capacity than the case and curing it. In this case, the molded and cured reactor is put in a case, and a filler is applied between the case and the reactor to bond the reactor and the case.

  A filler is applied to the inner surface of the case that is to be bonded to the reactor, and the filler is allowed to penetrate without any gaps. At this time, if a liquid pool of the filler occurs on the bottom surface of the case, the adhesive portion on the bottom surface becomes thick. And since the adhesion part of case bottom became thick, the position of the reactor accommodated on an adhesion part, the position of the terminal which protrudes from a reactor, etc. also fluctuate | variate, and a dimensional error will be produced.

  On the other hand, if the amount of filler applied is set to the minimum required amount, if the filler on the case inner wall flows downward or if the filler leaks outside through the gap between the case inner wall and the outer wall of the reactor In addition, since the adhesive force cannot be secured, it is desirable that the coating amount be larger than the minimum necessary amount.

  Furthermore, it is possible to discharge the filler accumulated on the bottom of the case from the gap between the inner wall of the case and the outer wall of the reactor by the pressure of the accommodated reactor. If the gap between the inner wall of the case and the outer wall of the reactor is wide enough, it may cause a dimensional error in the horizontal plane direction.

  This invention solves the said subject, and it aims at providing the reactor apparatus which can absorb the dimensional error by the filler which stored the liquid in the bottom face inside a case.

  In the invention of claim 1, a reactor including a coil that generates a magnetic flux when energized, a dust core made of a magnetic powder mixed resin filled inside and outside the coil, a bottom surface, and a surrounding wall that rises from the bottom surface, A reactor that includes a bottom surface and a surrounding wall that surrounds the reactor inside, and a filler filled between the reactor and the case, wherein the reactor is formed with a hole extending in the central axis direction of the coil. The case has a hollow portion, and the case has a middle core portion facing the hollow portion, and an adhesive is filled between the inner circumferential surface of the hollow portion and the outer circumferential surface of the middle core portion. And a filler reservoir part having a larger distance between the inner peripheral surface of the hollow part and the outer peripheral surface of the center part than the adhesive part above the adhesive part.

  According to the present invention, the filler accumulated on the bottom surface of the inner surface of the case receives the pressure of the reactor accommodated in the case, and rises toward the filler reservoir along the center portion. And since the distance of the inner peripheral surface of a hollow part and the outer peripheral surface of a center part is larger than the adhesion part, the filler storage part can store a sufficient quantity of fillers. As a result, it is possible to prevent the filler from accumulating on the bottom surface of the case, and to solve the problem that a dimensional error occurs due to the thickness of the filler accumulated on the bottom surface. In addition, the inductance value of the reactor is hardly affected even if a filler reservoir is provided near the central axis of the coil. Therefore, the vicinity of the central axis of the coil is a portion suitable for providing a pool for the reactor device that generates magnetic flux.

  The invention according to claim 2 is characterized in that the outer periphery of the core part constituting the side surface of the filler reservoir is shorter than the outer periphery of the core part constituting the contact surface with the adhesive part.

  According to the present invention, since the outer periphery of the central core portion constituting the side surface of the filler reservoir portion is shorter than the outer periphery of the central core portion constituting the contact surface with the adhesive portion, the capacity of the filler reservoir portion can be increased. And it becomes easy to perform position alignment and fitting of a reactor using the core part whose outer periphery became short.

  The invention according to claim 3 is characterized in that the inner circumference of the hollow portion constituting the side surface of the filler reservoir is longer than the inner circumference of the hollow portion constituting the contact surface with the adhesive portion.

  According to the present invention, the capacity of the filler reservoir is increased by making the inner periphery of the hollow part constituting the side surface of the filler reservoir part longer than the inner periphery of the hollow part constituting the contact surface with the adhesive part. can do.

  In the invention according to claim 4, the central core portion has a top portion located above the filler reservoir portion and a fitting hole formed downward from the top portion, and the hollow portion is fitted. A through hole located right above the hole, and having a screw for fitting the fitting hole and the through hole, the height from the bottom surface to the top is longer than the length of the through hole in the penetration direction. It is characterized by that.

  According to the present invention, since the through hole of the reactor and the fitting hole of the case are fixed with screws, it is possible to realize a strong joint between the reactor and the case. Since the top part is formed at a position where the height from the bottom surface to the top part is higher than the length of the through hole in the penetration direction, the situation where the filler crawls up to the top part of the core part is reduced. Can do. In addition, the contact area between the reactor and the case is increased by extending the core portion upward, and heat dissipation is improved.

In the invention according to claim 5, the case includes a hollow portion that is recessed downward on the upper surface of the surrounding wall,
It is characterized by providing.

  According to the present invention, since the filling material in which the hollow part formed in the upper surface of the surrounding wall overflows is absorbed, it can reduce that a filling material overflows outside and causes appearance defect. In addition, it is possible to prevent the filler from adhering to a screw hole or the like located in the case outer edge direction with respect to the recess.

  In a sixth aspect of the present invention, the reactor has a middle shaft portion made of a metal having a higher thermal conductivity than the dust core between the dust core and the central shaft.

  According to the present invention, since the dust core of the reactor device is in contact with the metal having higher thermal conductivity than the dust core, it is possible to achieve efficient heat dissipation of the reactor.

  FIG. 1 is a longitudinal sectional view of a reactor device according to an embodiment of the present invention.

  The reactor device 1 is formed by accommodating a reactor 12 including a coil 13 and a dust core 14 inside a case 11. The reactor 12 used in the present invention is separately molded with a mold and then placed in the case 11. In order to fix the reactor 12 in the case 11 and to dissipate heat from the reactor 12 to the case 11, a filler 15 having excellent thermal conductivity and adhesive strength is applied between the case 11 and the reactor 12. Is done.

  The reactor 12 includes a coil 13 that generates a magnetic flux when energized, and a dust core 14 that serves as a magnetic path of the magnetic flux generated by the coil 13. The dust core 14 is a resin mixed with magnetic powder, and is filled inside and outside the coil 13. In the reactor 12, both ends of the end portion of the wire rod of the coil 13 protrude from the dust core 14, and both ends of the end portion of the wire rod are used as terminals 24 for connection to an electronic device. Further, the reactor 12 has a middle shaft portion 21 made of a metal having a higher thermal conductivity than the dust core 14 inside the dust core 14 and a hollow portion 22 in which a hole extending in the central axis direction of the coil 13 is formed. The middle shaft portion 21 is surrounded by the dust core 14 and the hollow portion 22. The middle shaft portion 21 is a reverse-concave type and has a large opening in the center axis direction, and a portion where the coil 13 is opened serves as a hollow portion 22. The middle shaft portion 21 is made of a metal material having high heat dissipation such as aluminum and absorbs heat from the reactor 12. A through hole 23 through which the screw hole is passed is formed above the hollow portion 22.

  The case 11 has an open top surface, has a bottom surface 31 and a surrounding wall 32 forming a side surface, and the reactor 12 is accommodated in the case 11 so as to be surrounded by the bottom surface 31 and the surrounding wall 32. From the bottom surface 31 of the case 11, a core portion 33 facing the hollow portion 22 extends upward. The outer periphery of the central core portion 33 that forms the side surface of the filler reservoir 42 is shorter than the outer periphery of the central core portion 33 that forms the contact surface with the adhesive portion 41, and the shape with the shorter outer periphery is the filling described later. The material reservoir 42 is formed. Since the middle core portion 33 is provided to fit with the central axis of the reactor 12, it is formed closer to the center of the case 11 than the outer edge of the case 11. A screw hole 35 for attaching a screw facing downward is formed in the top 34 of the core 33.

  The shape after the reactor 12 is accommodated in the case 11 will be described. The middle core portion 33 faces the hollow portion 22, and the filler 15 is applied to the adhesive portion 41 located between the case 11 and the reactor 12. The hollow portion 22 of the reactor 12 is fitted into the core portion 33 of the case 11, and the reactor 12 is accommodated inside the case 11. The filler 15 is made of a low elastic material excellent in adhesiveness and thermal conductivity, and is used for fixing the reactor 12 to the case 11 and ensuring heat dissipation.

  The region sandwiched between the core portion 33 of the case 11 and the hollow portion 22 of the reactor 12 is composed of the adhesive portion 41 in the lower portion and the filler reservoir portion 42 for accumulating the filler 15 in the upper portion. In the filler reservoir 42, the distance between the inner peripheral surface of the hollow portion 22 and the outer peripheral surface of the core portion 33 is larger than that of the bonding portion 41. The filler reservoir 42 is formed because the outer periphery of the core portion 33 is shorter on the upper side than on the lower side. Further, the filler reservoir portion 42 can also be formed by making the inner circumference above the hollow portion 22 longer than below. Moreover, since the core part 33 is formed long upwards, the contact area of the reactor 12 and the case 11 increases, and heat dissipation improves.

  Since the filler reservoir 42 in the present invention is formed near the central axis of the coil 13, the presence of the filler reservoir 42 receives the pressure from the reactor 12 without disturbing the path of the magnetic flux of the reactor 12. The filler 15 can be absorbed by the filler reservoir 42.

  After bonding the case 11 and the reactor 12 using the filler 15, the same screw is attached to the through hole 23 of the reactor 12 and the screw hole 35 of the case 11. The adhesive force can be increased by using both the filler 15 and the screw together, but only the filler 15 may be used without using the screw.

  Due to the pressure of the reactor 12, the filler 15 crawls up above the core portion 33. However, the filler reservoir 42 can prevent the resin from creeping into the screw hole 35. Further, since the height from the bottom surface 31 to the top portion 34 is designed to be longer than the length of the through hole 23, the situation where the filler 15 adheres to the screw hole 35 formed in the top portion 34 is reduced.

  Furthermore, the upper surface of the surrounding wall 32 of the case 11 has a recess 50 that is recessed downward. When the reactor 12 is accommodated inside the case 11, the hollow portion 50 prevents the filler 15 that has exceeded the surrounding wall 32 from overflowing to the outside due to the pressure of the reactor 12, and suppresses appearance defects. can do. In particular, when there is a screw hole on the upper surface of the surrounding wall 32, it is possible to prevent the filling member from adhering to the screw hole by forming the recessed portion 50 in the case 11 inward direction as seen from the screw hole.

It is a longitudinal cross-sectional view of the reactor apparatus which concerns on Example 1 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Reactor apparatus 11 Case 12 Reactor 13 Coil 14 Dust core 15 Filler 21 Middle shaft part 22 Hollow part 23 Through-hole 24 Terminal part 31 Bottom face 32 Enclosure 33 Core part 34 Top part 35 Screw hole 41 Adhesive part 42 Filling material reservoir part 50 Recessed part

Claims (6)

A reactor comprising a coil that generates a magnetic flux when energized, and a dust core made of a magnetic powder mixed resin filled inside and around the coil;
A bottom surface and a surrounding wall rising from the bottom surface, and a case surrounding the reactor by the bottom surface and the surrounding wall;
In the reactor device having the filler filled between the reactor and the case,
The reactor has a hollow part in which a hole extending in the central axis direction of the coil is formed, and the case has a core part facing the hollow part,
Between the inner peripheral surface of the hollow portion and the outer peripheral surface of the central core portion, an adhesive portion filled with the filler, and an inner peripheral surface of the hollow portion above the adhesive portion above the adhesive portion And a filler reservoir portion having a large distance from the outer peripheral surface of the core portion.   2. The reactor device according to claim 1, wherein an outer periphery of the core part that forms a side surface of the filler reservoir is shorter than an outer periphery of the core part that forms a contact surface with the adhesive part.   The inner circumference of the hollow part constituting the side surface of the filler reservoir is longer than the inner circumference of the hollow part constituting a contact surface with the adhesive part. The reactor apparatus as described.   The center portion includes a top portion located above the upper surface of the filler accommodated in the filler reservoir portion, and a screw hole formed downward from the top portion, and the hollow portion 4. The reactor according to claim 1, comprising a through hole facing the screw hole, and comprising a bolt fastened to the screw hole through the through hole. apparatus. The reactor device according to any one of claims 1 to 4, wherein the case is provided with a hollow portion that is recessed downward on the upper surface of the surrounding wall.   The reactor according to any one of claims 1 to 5, wherein the reactor includes an inner shaft portion made of a metal having a higher thermal conductivity than the dust core inside the dust core.

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