JP2012257380A - Mold motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable protection of a temperature fuse used in a mold resin motor.SOLUTION: Plural projections 9 are provided to one of two resin plates (resin holders 3a, 3b) sandwiching a temperature fuse 2 therebetween, and fitting holes 10 in which the projections 9 are fitted are provided to the other resin plate. Projection openings 1b through which the projections 9 penetrate are formed around a temperature fuse opening 1a provided on a print substrate 1, and the inner surface side of the resin holder 3a is fitted to the shape of the temperature fuse 2 to form a temperature fuse groove 12. The inside of the resin holders 3a, 3b are kept to be hermetically sealed to prevent flow-in of mold resin, the temperature fuse 2 can be protected from pressure under flow-in of the mold resin, and the inside of the resin holders 3a, 3b is processed to be fitted to the shape of the temperature fuse 2, whereby the mount position of the temperature fuse 2 can be stabilized and the temperature fuse 2 can be normally operated.

Description

  The present invention relates to protection of thermal fuses used in molded resin motors.

  A conventional mold resin motor in which a thermal fuse is built in a mold resin will be described with reference to FIG. FIG. 5 is a partial sectional side view of a conventional molded resin motor.

  In FIG. 5, a mold resin motor 101 includes a stator 103 around which a winding 102 is wound and a printed circuit board 104 attached to one side surface of the stator 103, using a molding material such as resin or premix. It is formed by molding.

  The mold resin motor 101 includes a rotor 105 housed in a mold resin 110, two bearings 106 that support and rotate the rotor 105, and a bearing housing 107 that houses the bearing 106. Has been.

  The printed circuit board 104 is equipped with a thermal fuse 108 for preventing the motor from igniting, and is connected in series to the winding 102. That is, when a problem such as the rotor 105 being restrained by the motor due to an external action during driving of the motor occurs, there is a possibility that the inside of the motor becomes hot and the driving coil is reared, and smoke or ignition is caused accordingly. . In order to prevent these problems, a thermal fuse 108 is installed.

  The thermal fuse 108 is housed in a box-shaped housing portion 109 and covered with a mold resin 110 by molding. The storage unit 109 is provided on the printed circuit board 104a.

JP 2000-175398 A

  In such a conventional mold motor with a built-in temperature fuse, since the temperature fuse is exposed, the temperature fuse directly touches the resin that flows in at the time of molding, so that the temperature fuse can withstand the inflow pressure. Had a structure to be installed in the storage section provided. However, such a structure has a problem that the temperature corresponding to the space in the storage portion cannot be accurately determined, and the flow of the mold resin is hindered during molding.

  Therefore, the present invention is intended to solve the above-described conventional problems, and aims at normal operation of the thermal fuse and thinning of the holder.

In order to achieve this object, the present invention
A stator core having a plurality of slots;
A drive coil wound around the stator core via an insulator;
A printed circuit board on which electronic components including drive circuit components are mounted;
A rotor held rotatably against the stator core;
A mold motor in which the printed circuit board, the stator iron core, and the drive coil are integrally molded and solidified by injection molding with a thermosetting resin having electrical insulation, and a stator is formed.
The printed circuit board is provided with an opening for mounting a thermal fuse,
The thermal fuse is mounted in the opening and sealed so as to be sandwiched between two plate-like resin holders from the front and back of the printed circuit board.

  According to the present invention, an opening is provided in the printed circuit board, and a thermal fuse is attached to the opening, so that the height in the direction of the rotation axis is reduced, contributing to the miniaturization of the motor, and the resin holder from the front and back of the printed circuit board Therefore, the thermal fuse is not exposed to the inflowing mold resin during molding, and the fuse can be stably installed. Further, since the resin holder is placed on the printed circuit board in a plate shape, it is difficult to inhibit the inflow of the mold resin.

  By having these structures, it is possible to obtain an effect that the thermal fuse installation position can be stabilized and operated normally, and the thermal fuse can be protected from the pressure at the time of mold resin inflow.

Side cross-sectional view when motor is installed The front view which shows resin holder attachment to the board | substrate of Embodiment 1 of this invention Side view before mounting the resin holder on the board Resin holder of Embodiment 2 of the present invention (a) Upper triangular view, (b) Lower triangular view Side sectional view of a conventional molded motor

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is a detailed cross-sectional view of a main part of a molded electric motor 8 according to the present embodiment. The mold motor 8 has a stator 5 provided with a rotor hole in the center and a winding (drive coil 6), a rotor 7 inserted in the center, and a drive for driving the mold motor 8. The printed circuit board 1 is mounted with a circuit, and the whole is molded with a mold resin 20.

  The stator 5 is obtained by winding a winding serving as a drive coil 6 through an insulator (not shown) around a stator core in which electromagnetic steel plates provided with a plurality of slots are laminated. The rotor 7 is rotatably inserted into a rotor hole provided at the center of the stator 5.

  The printed circuit board 1 is provided with an opening having a size that allows at least the rotation shaft of the rotor 7 to pass through at the center thereof, and is arranged in close contact with the rotation shaft direction of the stator 5. In the present embodiment, the insulator attached to the stator 5 is provided with a fixing pin and is attached to the stator 5. The printed circuit board 1 is mounted with a drive IC for driving an electric motor, a resistor, a capacitor, a thermal fuse 2, and the like.

  Here, the most characteristic part of the present embodiment will be described.

  As shown in FIG. 2, the thermal fuse 2 is mounted in a thermal fuse opening 1 a provided in the printed circuit board 1. The thermal fuse opening 1 a is preferably located in the vicinity of the drive coil 6 when the printed circuit board 1 is mounted on the stator 5. When mounted on the printed circuit board 1, the thermal fuse 2 protrudes from the front surface (or back surface) of the printed circuit board 1. In this mounted state, the printed board 1 is hermetically sealed by being sandwiched by two resin holders 3 (resin holder 3a, resin holder 3b) from the front and back sides.

  3 and 4 show details of the resin holder 3.

  The resin holder 3 is two rectangular plates (resin holder 3a, resin holder 3b) formed of resin, for example, polybutylene terephthalate (PBT) which is an insulator material provided on the stator 5. First, the resin holder 3a is provided with protrusions 9 in the vicinity of the four corners, and provided with a temperature fuse groove 12 on the surface on which the protrusion 9 is provided in accordance with the shape of the temperature fuse 2. And the other resin holder 3b is provided with fitting holes 10 into which the projections 9 are fitted at the four corners. Further, the printed circuit board 1 is provided with a projection opening 1b corresponding to the projection 9 around the thermal fuse opening 1a.

To explain the mounting process in more detail,
1) A thermal fuse 2 is mounted in a thermal fuse opening 1a provided in the printed circuit board 1 and soldered.
2) Seal from the front and back of the thermal fuse 2 so as to be sandwiched between the resin holder 3a and the resin holder 3b.
At this time, the resin holder 3a is mounted such that the protrusion 9 of the resin holder 3a penetrates the protrusion opening 1b provided on the printed circuit board 1. One resin holder 3b fits the penetrating protrusion 9 into the fitting hole 10 and seals it so that there is no gap between the printed board 1 and the resin holder 3b.
Since the thermal fuse 2 is provided so as to protrude to the front side (or back side) when mounted on the printed circuit board 1, the resin holder 3 a provided with the temperature fuse groove 12 is placed on the protruding side.
3) Finally, resin molding is performed.

  According to such a configuration, since the thermal fuse 2 is mounted so as to be provided in the printed board 1 with an opening (thermal fuse opening 1a), the size in the height direction can be kept small, The mold motor 8 can be thinned. In addition, since the thermal fuse 2 inserted into the thermal fuse opening 1a is sandwiched between the plate-shaped resin holder 3 from the front and back and sealed with the printed circuit board 1 and the resin holder 3, the mold resin is prevented from flowing in during resin molding, It can withstand the pressure of the mold resin. Further, the resin holder 3 is provided with a temperature fuse groove 12 to reduce the thickness of the resin at that portion. That is, it has a structure in which the ambient temperature can be easily detected.

  In addition, the resin holder 3a and the resin holder 3b are mounted without being displaced due to the fitting between the protrusion 9 and the fitting hole 10, and the resin holder 3a and the resin holder 3b are not displaced even when the resin flows in. The fuse 2 can be operated more accurately.

  Moreover, since the resin holder 3 is formed of a resin having higher heat resistance than the resin temperature that flows in at the time of molding, it does not deform.

  Further, the side surface of the resin holder 3 is an inclined surface, and has a structure that hardly inhibits the inflow of resin.

  In the present embodiment, the temperature fuse groove 12 is provided in the resin holder 3a provided with the protrusions 9, but may be provided in the other resin holder 3b.

  The thermal fuse protection holder according to the present invention can protect the thermal fuse from the pressure when the mold resin flows in the molded resin motor to which the thermal fuse is attached, and can stably operate the thermal fuse installation position. Therefore, it is useful for accurately installing an electronic component having a low withstand voltage used at the time of molding without destruction or breakage.

DESCRIPTION OF SYMBOLS 1 Printed circuit board 1a Thermal fuse opening 1b Protrusion opening 2 Thermal fuse 3 Resin holder 3a Resin holder 3b Resin holder 5 Stator 6 Drive coil 7 Rotor 8 Mold electric motor 9 Protrusion 10 Fitting hole 11 Slope 12 Thermal fuse groove 20 Mold resin

Claims (6)

A stator core having a plurality of slots;
A drive coil wound around the stator core via an insulator;
A printed circuit board on which electronic components including drive circuit components are mounted;
A rotor held rotatably against the stator core;
A mold motor in which the printed circuit board, the stator iron core, and the drive coil are integrally molded and solidified by injection molding with a thermosetting resin having electrical insulation, and a stator is formed.
The printed circuit board is provided with a fuse opening for mounting a thermal fuse,
The thermal fuse is a molded electric motor which is mounted in the opening and sealed so as to be sandwiched between two plate-like resin holders from the front and back of the printed circuit board. One resin holder is provided with a plurality of protrusions,
The mold motor according to claim 1, wherein the other resin holder is provided with a fitting hole into which the protrusion is fitted. The mold motor according to claim 2, wherein a protrusion opening through which the protrusion penetrates is provided around the fuse opening. The mold motor according to any one of claims 1 to 3, wherein a recess is provided in which the inner surface side of the resin holder is matched to the shape of the thermal fuse. The mold motor according to claim 1, wherein a side surface of the resin holder is a slope. The mold motor according to claim 1, wherein the resin holder uses a resin having higher heat resistance than the mold resin.

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