JP2006278722A - Coil bobbin structure and stepping motor equipped therewith - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coil bobbin structure wherein coil bobbins are precisely linked together and a precision deterioration hardly occurs in the coil bobbins after they are linked together. <P>SOLUTION: The coil bobbin structure is equipped with a first and a second coil bobbins which are each provided with a hollow shaft which is wound with a coil and has flanges that extend vertically from both its ends as enlarged and linked together in the axial direction of the coils. The first and second coil bobbins are linked together at the one ends of the shafts so as to enable the flanges of the coil bobbins to have a prescribed gap between them. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fan driving stepping motor mounted on a dehumidifier, insect repellent or the like, and a coil bobbin structure used as a stator in a stepping motor.

  A coil bobbin generally has a structure having a hollow shaft portion around which a coil is wound and flange-shaped flange portions that are enlarged from both ends of the shaft portion.

  When the ends of the two coil bobbins are connected to each other in the coil winding axis direction, the projection provided on the flange of one coil bobbin is engaged with the recess provided on the flange of the other coil bobbin for positioning. However, both buttocks are butted and connected.

Patent Document 1 describes a structure in which two coil bobbins are connected with a magnetic pole plate interposed therebetween.
JP-A-4-298008

  Usually, after the coil is wound around the flange portion of the coil bobbin, a force that causes the coil to spread in the direction of the winding axis acts, so that the flange portion of the coil bobbin tends to easily fall.

  In this case, it is sufficient if the thickness of the collar portion of the coil bobbin is strong enough to withstand the collapse, but if the coil has a large number of windings or if the thickness of the collar portion is reduced for miniaturization, the strength is high. It is easy to fall down because it is not enough. When the flanges that have collapsed are brought into contact with each other, not only the entire length of the coil bobbin is increased, but also the centering (positioning with respect to the winding axis) accuracy of both coils is reduced.

  In addition, when the hook part falls after being connected, it may interfere with parts such as a magnet arranged in the hollow part, or a desired magnetic field may not be obtained, which may affect the characteristics of the final product and the manufacturing process.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a coil bobbin structure in which coil bobbins are accurately connected to each other and the accuracy of assembly after assembly does not occur and a stepping motor including the coil bobbin structure.

  In order to solve the above-described problems and achieve the object, the coil bobbin structure of the present invention has a hollow shaft portion around which a coil is wound, and a flange-shaped flange portion that is enlarged from an end portion of the shaft portion. A coil bobbin structure in which the first and second coil bobbins are connected in the winding axis direction of the coil, and the first and second coil bobbins are arranged on the shafts so that the flanges of the respective coil bobbins have a predetermined gap. Connected at the end of the part.

  Preferably, the end of each coil bobbin is provided with a protrusion protruding outward from the end face of the flange with respect to the winding axis direction of the coil, and a recess recessed inside the end face of the flange. The first coil bobbin and the second coil bobbin are engaged by engaging the convex portion of the first coil bobbin with the concave portion of the second coil bobbin.

  Preferably, each coil bobbin has the same shape.

  Preferably, each coil bobbin is a resin molded product, and a terminal electrically connected to the coil is integrally formed.

  A stepping motor according to the present invention includes any one of the coil bobbin structures described above, and a rotor having a magnet is pivotally supported at a connection portion between the first and second coil bobbins, and the magnet is a shaft at the connection portion. Each coil bobbin is used as a stator, and the rotor is rotationally driven by changing the magnetic pole of the stator by energizing each coil.

  As described above, according to the present invention, the coil bobbins are connected to each other at the end of the shaft portion that is stronger than the collar portion, so that the coil bobbins can be connected with high accuracy.

  In addition, since the flanges of the coil bobbin are connected so that the flanges do not come into contact with each other, even if the flanges fall down, the gap becomes a space that absorbs the fall, so the accuracy after connection It can be configured so as not to cause any madness.

  Hereinafter, a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

  The embodiment described below is an example as means for realizing the present invention, and the present invention can be applied to a modified or modified embodiment described below without departing from the spirit of the present invention.

  1 is an exploded perspective view of a stepping motor and a fan device having a coil bobbin according to an embodiment of the present invention, FIG. 2 is a side sectional view of the fan device of FIG. 1 assembled, and FIG. 3 is a diagram of the fan device of FIG. It is the top view which fractured | ruptured a part. FIG. 4 is a front view (a), a side view (b), a rear view (c), a bottom view (d), and a sectional view (e) taken along line XX of the coil bobbin around which no coil is wound. FIG. 5 is a front view (a), a side view (b), and a rear view (c) of a coil bobbin around which a coil is wound. FIG. 6 is a side view showing a state in which a pair of coil bobbins each having a coil wound thereon are connected.

  As shown in FIGS. 1 to 3, in the fan device of this embodiment, an impeller 5 having a plurality of blade portions such as an axial fan and a sirocco fan is connected to an output shaft 7 of a single-phase PM type stepping motor. . In the single-phase PM type stepping motor, a cylindrical rotor magnet (permanent magnet) 12 magnetized to a pair of S poles and N poles is fixed to the output shaft 7 to constitute a rotor (rotor). The output shaft 7 is rotatably supported by a pair of radial bearings 8a combined in the axial direction. One of the bearings 8a is fixed to the center portion of the bottom plate of the housing 1 that forms the outer shape of the motor with the bottomed cylindrical (cup-shaped) cover 4, and the other is fixed to the output shaft. Both ends of 8 are supported in the radial direction. The thrust bearing 8b supports the lower end portion of the output shaft 7 in the thrust direction through a hole formed in the central portion of the bottom plate 1a of the housing 1.

  On the other hand, the stator (stator) includes a pair of hollow coil bobbin bodies 3, and coils such as enameled copper wires are wound around the coil bobbins 3a and 3b by about 2000 turns. Each coil bobbin 3a, 3b is connected along the winding axis direction of the coil (or the longitudinal axis direction of the coil bobbin) L1, and the output shaft 7 of the rotor magnet 12 is pivotally supported by the connecting portion. The rotor magnet 12 is disposed in a hollow space in the connecting portion. That is, the output shaft 7 of the rotor magnet 12 is arranged so as to be orthogonal to the winding axis direction L1 of the coil.

  As shown in FIGS. 4 to 6, the coil bobbins 3 a and 3 b have the same shape, and a shaft portion 13 around which the coil is wound, and flange-shaped flange portions 14 a and 14 b that are enlarged from both ends of the shaft portion 13. And have. The flange portions 14a and 14b are provided to prevent the coil wound around the shaft portion 13 from being collapsed, and have a thickness of about 1 mm.

  On the left half of the central axis Y of the flange portion 14a, a convex surface portion 16a that protrudes outward along the winding axis direction L1 of the coil from the shaft portion 13 is formed so as to surround the hollow portion 17. Similarly, on the right half of the central axis Y of the flange portion 14a, a concave surface portion 16b that is recessed inward so as to surround the hollow portion 17 is formed. When connecting the coil bobbins 3a and 3b, one convex surface portion 16a is engaged with the other concave surface portion 16b, and at the same time, the other convex surface portion 16a is alternately engaged with the one concave surface portion 16b. Combined. Further, on the central axis Y of the flange portion 14a, a groove portion 17 is formed which is slidably in contact with the output shaft 7 of the rotor magnet 12 and is pivotally supported.

  By configuring in this way, each coil bobbin 3a, 3b is not the flange-shaped portion of the flange portion 14a, but the convex surface portion 16a and the concave surface portion 16b formed at the inner edge portion (shaft portion 13) having the highest strength and resistance to deformation. Since it connects, coil bobbins can be accurately connected with respect to the coil winding axis direction L1. The mating surfaces of the coil bobbins 3a and 3b may be integrated by bonding with an adhesive or the like.

  Further, by making the coil bobbins 3a and 3b the same shape, only one mold is required, and there is an advantage that the number of parts and cost can be reduced.

  In addition, in a state where the coil bobbins 3a and 3b are connected, a predetermined gap s is formed in the flange portion 14a facing each other in anticipation of the collapse. The dimensions of the convex surface portion 16a and the concave surface portion 16b are determined by the gap s. As described above, since the flange portions 14a of the coil bobbins 3a and 3b have a predetermined gap s and are connected so that the flange portions do not come into contact with each other, even if the flange portion 14a falls down, the gap absorbs the fall. Thus, after connecting, it can be configured so that an accuracy error after assembly does not occur.

  It should be noted that the amount of collapse of the collar is almost determined from the number of turns of the coil and the material of the collar (coil bobbin), and is about 0.2 to 0.8 mm. Further, the gap s is preferably wide although it is restricted by the total length of the coil bobbin at the time of design. However, it is preferable that the distance between the coil and the magnet is as close as possible because the closer the distance, the better the efficiency.

  In a state where the two coil bobbins 3a and 3b are connected, a pair of terminals 15a and 15b for electrically connecting the start and end of the coil are integrally formed with a resin or the like at the lower end of the flange 14b located at both ends. Molded. The terminals 15a and 15b are inserted into land holes 2a of a circuit board 2 such as a printed wiring board or FPC disposed on the bottom plate 1a of the housing 1 and are electrically connected by soldering or the like. The coil bobbins 3 a and 3 b are excited by energization of the coils to become magnetic poles, and generate Lorentz force between the rotor magnet 12. The coils wound around the coil bobbins 3a and 3b are wound in opposite directions around the winding axis direction L1, and different magnetic poles are generated on the coil bobbins 3a and 3b when energized.

  Since the terminals 15a and 15b are soldered, the coil bobbins 3a and 3b should be resistant to heat. However, since heat-resistant materials (PPS and liquid crystal polymer) are expensive, inexpensive POM, A case where PBT or other resin materials are used is also assumed. In this case, since an inexpensive resin material does not have sufficient heat resistance, a metal terminal advantageous in heat resistance is press-fitted, but the collar portion is liable to fall down due to the press-fitting. However, in the present embodiment, such a fall can be absorbed by the gap s, so that an inexpensive material can be actively used.

  Further, in a state where the two coil bobbins 3a and 3b are connected, a projection 15c is integrally formed on the outer edge of the flange 14a that contacts each other, and the hole 2b formed in the circuit board 2 and the housing By engaging with a hole 1b formed in one bottom plate 1a, the circuit board 2 is properly positioned so as to be sandwiched between the bottom plate 1a of the housing 1. In addition, it is preferable to provide these protrusions 15c at positions away from the output shaft 7 and at a thick portion having high strength.

  The coil bobbins 3a and 3b are not limited to a pair (two), but can be applied to a structure in which three or more are connected in series in the winding axis direction L1.

  A drive circuit (not shown) is mounted on the circuit board 2 to generate a pulse voltage waveform applied to the coil.

  A cogging pin 10 made of a magnetic member (stainless steel (SUS420), iron, ferrite, etc.) is fixed in the cover 4 by press fitting or the like in the vicinity of either of the coil bobbins 3a, 3b.

  The cover 4 accommodates therein a stator including the coil bobbins a and 3b and a rotor including the rotor magnet 12 and is fastened and fixed to the bottom plate 1a of the housing 1 with screws 6 or the like.

  The coil bobbins 3a and 3b are excited by energizing each coil to become magnetic poles, and the rotor magnet 12 is rotated by reversing the polarities of these magnetic poles.

  The output shaft 7 is inserted into a shaft hole 5a provided on the rotation center shaft of the impeller 5 so as to be slidable (idling), and the impeller 5 is connected to the output shaft 7 by a connecting means so as to be rotatable. Is done.

  One end of the connecting means is connected to the shaft hole 5 a of the impeller 5, the other end is fixed to a holder 20 that is axially attached to the output shaft 7 by press fitting or the like, and a coil spring 21 wound around the output shaft 7. It is configured.

  The present invention relates to a coil bobbin structure used as a stator in a stepping motor for driving a fan mounted on a dehumidifier or insect repellent.

  The present invention can be applied as a stator to a stepping motor for driving a fan mounted on, for example, an air purifier, a fragrance sprayer, a dehumidifier, an insect repellent or the like.

1 is an exploded perspective view of a stepping motor and a fan device according to an embodiment of the present invention. It is a sectional side view in the state which assembled the fan apparatus of FIG. It is the top view which fractured | ruptured a part of fan apparatus of FIG. It is the front view (a), side view (b), back view (c), bottom view (d), and XX sectional view (e) of a coil bobbin where a coil is not wound. It is the front view (a), side view (b), and rear view (c) of the coil bobbin around which the coil is wound. It is a side view in the state where a pair of coil bobbins where a coil was wound were connected.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Housing 2 Circuit board 3a, 3b Coil bobbin 4 Cover 5 Impeller 6 Screw 7 Output shaft 8a Radial bearing 8b Thrust bearing 10 Cogging pin 12 Rotor magnet 13 Shaft part 14a, 14b Gutter part 15a, 15b Terminal 15c Protrusion part 16a Convex part 16b Concave part 17 Groove 20 Holder 21 Coil Spring

Claims (5)

A coil bobbin structure in which first and second coil bobbins having a hollow shaft portion around which a coil is wound and a flange-shaped flange portion enlarged from an end portion of the shaft portion are coupled in the winding axis direction of the coil. Because
A coil bobbin structure in which the first and second coil bobbins are connected to each other at an end portion of the shaft portion so that a flange portion of each coil bobbin has a predetermined gap.   The end of each coil bobbin is provided with a protrusion protruding outward from the end surface of the flange with respect to the winding axis direction of the coil, and a recess recessed inward from the end surface of the flange, and the first coil bobbin 2. The coil bobbin structure according to claim 1, wherein the protrusion is connected by engaging the recess of the second coil bobbin.   The coil bobbin structure according to claim 1 or 2, wherein each coil bobbin has the same shape.   4. The coil bobbin structure according to claim 1, wherein each coil bobbin is a resin molded product, and a terminal electrically connected to the coil is integrally formed. 5. The coil bobbin structure according to any one of claims 1 to 4,
A rotor having a magnet is pivotally supported at the connection portion of the first and second coil bobbins, and the magnet is disposed in a hollow space of the shaft portion at the connection portion,
A stepping motor, wherein each coil bobbin is a stator and the rotor is driven to rotate by changing the magnetic poles of the stator by energizing each coil.

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