JP6343331B2 - Stepping motor - Google Patents

Description

  The present invention relates to a stepping motor characterized by a structure for fixing to a circuit board.

  A stepping motor that is directly fixed to a circuit board is known (for example, see Patent Document 1). In this structure, an energizing terminal pin for energization is arranged on an end face of the stepping motor, and the energizing terminal pin is fixed to the circuit board by direct soldering, thereby fixing the stepping motor to the circuit board.

JP 2001-66161 A

  When the arrangement of the energizing terminal pins described in the cited document 1 is adopted, the distance between the energizing terminal pins is increased, and the routing of the wiring from the stator coil to the energizing terminal pins is restricted. This leads to poor workability at the time of manufacturing, problems of disconnection due to unreasonable wiring, problems of design restrictions, and the like. In view of such a background, an object of the present invention is to provide a structure in which a stepping motor can be securely fixed to a circuit board, and there is no restriction on wiring routing in the motor.

The invention according to claim 1 is a stator, a front plate that contacts one end side in the axial direction with respect to the stator and is joined to a circuit board, and an end plate that contacts the other end side in the axial direction with respect to the stator. When the front plate and the bridged outer periphery of the stator a between the end plates, and a band to be bonded to each other in a state in which the said front plate and said end plate to sandwich the stator, the front The plate is located on a side surface of the stator and extends to the end plate side, and includes a plurality of band coupling portions formed with engaging portions on the outside, and the band is disposed on the end plate side. A plurality of arms extending in the direction of the front plate and engaging with the engaging portions in each of the plurality of band coupling portions. Comprising a beam portion, the engagement to the engaging portion of the arm portion, in a state sandwiched between the end plate and the stator, and coupled to the front plate, the front plate, a rotary shaft on the inside A boss portion that fits into the circuit board, and that protrudes in the axial direction, an energizing terminal pin that projects in the axial direction and is soldered to the circuit board, and a position that sandwiches the boss portion between the energizing terminal pins disposed, are soldered to the circuit board, e Bei a fixing pin which does not function as an electrode, the boss portion is integrally molded with the front plate, the said boss split is formed, the boss portion A stepping motor, wherein the stepping motor is press-fitted into a boss hole formed in the circuit board and is fitted into the boss hole by a repulsive force by the split function .

According to the first aspect of the present invention, the energizing terminal pin and the fixing pin at a position sandwiching the boss portion at the center of rotation are fixed to the circuit board by soldering. According to this structure, the boss portion at the rotation center position is fixed by being fitted into the circuit board, and the energizing terminal pin and the fixing pin are fixed to the circuit board by soldering at a position sandwiching the boss portion. In the case of a structure in which soldering to the circuit board is performed only with the energizing terminal pins, the load is concentrated on the energizing terminal pins. However, in the structure of the present invention, the soldering is performed at two positions sandwiching the boss portion. Therefore, the concentration of the load on the energizing terminal pin can be avoided. In addition, since the stepping motor is fixed to the circuit board using the fixing pin in addition to the energizing terminal, the degree of freedom of arrangement of the energizing terminal is high, and there is a restriction on the wiring of the stator coil to the energizing terminal pin. Absent. Further, it is possible to fix the state in which the front plate and the end plate are coupled with the stator sandwiched by the band.

According to a second aspect of the present invention, in the first aspect of the present invention, the rotating shaft is passed through holes provided in the front plate and the end plate, and is in contact with inner peripheral surfaces of the holes. It is characterized by being rotatably supported. The invention according to claim 3 is the invention according to claim 1 or 2, wherein the front plate includes a positioning pin for positioning the stepping motor with respect to the circuit board.
In the present invention, the energizing terminal pin and the fixing pin are provided at equal angular positions. According to this feature, since the arrangement balance of the fixing mechanism to the circuit board by the energizing terminal pins and the fixing pins is good, the concentration of the load on the energizing terminal pins can be suppressed. Further, a stable structure for fixing the stepping motor to the circuit board can be obtained.

  ADVANTAGE OF THE INVENTION According to this invention, in the structure which can fix a stepping motor to a circuit board reliably, the structure where a restriction | limiting does not arise in the routing of wiring in a motor is provided.

It is a perspective view (A) and (B) of a stepping motor of an embodiment. It is sectional drawing of the stepping motor of embodiment. It is a perspective view (A) and (B) of a front plate in an embodiment. It is a perspective view (A) and (B) of other front plates in an embodiment.

(Constitution)
1 and 2 show a stepping motor 100 according to an embodiment. The stepping motor 100 is a claw pole type stepping motor. As shown in FIG. 2, the stepping motor 100 has a structure in which a front side stator assembly 200 and an end side stator assembly 300 are coupled in the axial direction as a structure on the stator side. The rotor 400 is housed in a rotatable state inside a structure in which the front side stator assembly 200 and the end side stator assembly 300 are coupled in the axial direction.

  The front stator assembly 200 includes a front plate 210, an outer stator 220, a bobbin 230, and an inner stator 240. The front plate 210 is a substantially disk-shaped member that constitutes the front-side housing, and is made of injection-molded resin. FIG. 3 shows perspective views (A) and (B) of the front plate. The front plate 210 has a band coupling portion 211 extending in the axial direction from a substantially disc-shaped edge portion. The band coupling portion 211 includes a claw portion 212 protruding outward. In addition, a band coupling portion 217 and a claw portion 218 having a similar structure are provided on the opposite side across the shaft. The band coupling unit 211 is coupled to a band 500 described later. When the band coupling portion 211 is coupled to the band 500, the coupling state in the axial direction of the front side stator assembly 200 and the end side stator assembly 300 is fixed.

  The front plate 210 has a terminal portion 213 formed integrally with the front plate 210. In the terminal portion 213, four metallic energizing terminal pins 214 that function as energizing terminals for the circuit board 600 are embedded. The energizing terminal pin 214 has an end portion 214 a that protrudes in the axial direction inserted into the contact hole 602 of the circuit board 600, and an end portion 214 b that contacts the terminals 233 and 333 to which wiring from the stator coils 231 and 331 is connected. doing. FIG. 2 shows a stage in the middle of fixing the stepping motor 100 to the circuit board 600 or a stage in the middle of separating the stepping motor 100 from the circuit board 600. Moreover, although various electronic devices are mounted on the actual circuit board 600, those descriptions are omitted in FIG.

  The front plate 210 includes a fixed pin arrangement portion 313 formed integrally. The fixed pin arrangement portion 313 is provided at a position symmetrical to the terminal portion 213 around the boss portion 216. That is, the boss portion 216 (the shaft 403 serving as the rotation axis) is located near the center (not strictly the center) on the line connecting the terminal portion 213 and the fixed pin arrangement portion 313. Two fixing pins 314 protruding in the axial direction are arranged in the fixing pin arrangement portion 313. The fixing pin 314 is a substantially U-shaped metal member, and is fixed by being inserted into a hole provided in the fixing pin arrangement portion 313. The fixing pin 314 is made of a solderable material and is a member that fixes the stepping motor motor 100 to the circuit board 600, but does not function as an energizing terminal.

  The front plate 210 includes a boss portion 216 that is integrally formed and protrudes in the axial direction. The boss portion 216 is formed with a plurality of slits (slits) 216a extending in the axial direction, has a substantially cylindrical shape, and the rotor-side shaft 403 is housed in a rotatable state inside the boss portion 216. . Further, the front plate 210 includes positioning pins 219 (see FIGS. 1 and 3) for positioning the circuit board 600. The positioning pin 219 is a resin member formed integrally with the front plate 210, and the positioning pin 219 is fitted into a positioning hole (not shown) provided on the circuit board 600 side, so that the stepping motor Positioning with respect to 100 circuit boards 600 is performed.

  The outer stator 220 and the inner stator 240 are portions that function as a stator yoke in which a magnetic path is formed, and are made of a magnetic material such as electromagnetic soft iron or rolled steel plate. The structure of the outer stator 220 and the inner stator 240 is the same as that of a normal claw pole type stator.

  The bobbin 230 is made of resin, and a stator coil 231 is wound around the bobbin 230. The bobbin 230 around which the stator coil 231 is wound is disposed in a donut-shaped space (annular space) surrounded by the inside of the outer stator 220 and the inner stator 240. The bobbin 230 includes two terminal portions 232. Each of the terminal portions 232 is embedded with a metal terminal 233 to which the end of the winding of the stator coil 231 is tangled and connected.

  The end side stator assembly 300 includes an end plate 310, an outer stator 320, a bobbin 330, and an inner stator 340. Here, the outer stator 320 is the same component as the outer stator 220 and is used in a state where the direction in the axial direction is reversed. The bobbin 330 is the same component as the bobbin 230 and is used in a state where the direction in the axial direction is reversed. The inner stator 340 is the same component as the inner stator 240 and is used in a state where the direction in the axial direction is reversed.

The end plate 310 is a substantially disc-shaped member that constitutes the housing on the end side, and is made of injection-molded resin. The end plate 310 has a band contact portion 311 (see FIGS. 1 and 3) that contacts the arm portion 501 of the band 500 from the inside. The band contact portion 311 contacts the arm portion 501 from the inside and supports the arm portion 501 from the inside so that the arm portion 501 is deformed after being assembled and the arm portion 501 is not detached from the front plate 210. A band contact portion 312 having a similar function and contacting the arm portion 502 of the band 500 is also provided on the opposite side of the band contact portion 311 and the shaft.

  The band 500 is a substantially U-shaped member made of a metal material having a spring property. As shown in FIGS. 1 and 3, the band 500 includes arm portions 501 and 502 extending in the axial direction at both ends. The arm portions 501 and 502 are provided with rectangular holes. The claw portions 212 and 218 of the band coupling portions 211 and 217 included in the front plate 210 are caught in this hole portion, and the band 500 is engaged with the front plate 210.

  A rotor 400 shown in FIG. 2 includes a cylindrical rotor magnet 401. The rotor magnet 401 is fixed to the outer periphery of the rotor member 402 and has a magnetic pole structure magnetized alternately with NSNS in the circumferential direction. A shaft 403 serving as a rotation shaft is fixed to the center of the rotor 400 (rotor member 402). The shaft 403 is passed through holes provided in the front plate 210 and the end plate 310, and is rotatably supported by directly contacting the inner peripheral surface thereof. It is also possible to hold the shaft 403 in a freely rotatable state on the front plate 210 and the end plate 310 via a bearing device such as a rolling bearing.

  Rubber washers 404 and 405 having a cylindrical shape made of rubber are attached to the shaft 403. The rubber washer 404 is located between the rotor 400 and the front plate 210, and the rubber washer 405 is located between the rotor 400 and the end plate 310. The rubber washers 404 and 405 absorb the impact caused by the backlash in the axial direction of the rotor 400.

(How to fix the stepping motor to the circuit board)
Hereinafter, an example of a procedure for fixing the stepping motor 100 to the circuit board 600 will be described. First, the positional relationship between the stepping motor 100 and the circuit board 600 is as shown in FIG. Then, the stepping motor 100 is pressed against the circuit board 600, the boss portion 216 is pushed into the boss hole 601 for fixing the motor, and the boss portion 216 is press-fitted into the boss hole 601 for fixing the motor. At this time, the boss portion 216 is reduced in diameter by the function of the split 216a formed on itself, and the boss portion 216 is fitted into the boss hole 601 for fixing the motor by a repulsive force to be increased in diameter generated at that time. .

  Here, with the stepping motor 100 pressed against the circuit board 600, the end portions 214 a of the four energizing terminal pins 214 are inserted into the contact holes 602 of the circuit board 600. Further, the fixing pin 314 is inserted into the pin fixing hole 604 of the circuit board 600. A copper foil pattern (print pattern) 603 constituting a circuit pattern is formed around the contact hole 602, and the copper foil pattern 603 and the energizing terminal pin 214 are joined by solder. Further, a soldering pattern 605 using a copper foil constituting the copper foil pattern 603 is formed around the pin fixing hole 604, and the soldering pattern 605 and the fixing pin 314 are joined by soldering. To do. Thus, the four energizing terminal pins 214 and the two fixing pins 314 are fixed to the circuit board 600 by soldering. Here, the soldering pattern 605 uses the copper foil pattern of the circuit board 600, but does not function as an electrode.

(Superiority)
A structure in which the load is not concentrated on the energizing terminal pin 214 can be achieved. Further, since the arrangement of the energizing terminal pins 214 is not limited, the wiring from the stator coils 231 and 331 to the terminals 233 and 333 can be performed without difficulty. Further, since the soldering pattern 605 on the circuit board 600 side is configured using the copper foil pattern provided in the circuit board 600, an increase in cost can be suppressed.

(Other)
FIGS. 1 to 3 show an example in which the energizing terminal pin 214 and the fixing pin 314 are arranged at positions where the rotation center is sandwiched, but the fixing pin is added to the left and right positions when viewed from the axial direction. A structure in which the metal pins are fixed to the circuit board by soldering at four positions at an angular interval of 90 degrees when viewed from the axial direction is also possible. Further, the numbers of the energizing terminal pins 214 and the fixing pins 314 are not limited to the numbers shown.

  FIG. 4 shows another example of the front plate. In the example illustrated in FIG. 4, the front plate 701 includes a terminal portion 702. The terminal portion 702 is provided with a hole 703 for fixing an energizing terminal pin (not shown). Further, the front plate 701 includes a boss portion 704 protruding in the axial direction at the center thereof. The boss part 704 has the same function as the boss part 216. In this example, a protrusion 704a extending in the axial direction is provided on the outer periphery of the boss portion 704, and the protrusion is pressed into a hole on the circuit board side (not shown). A fixing pin 705 is embedded on the opposite side of the terminal portion 702 across the boss portion 704. The function of the fixing pin 705 is the same as that of the fixing pin 314.

  The aspect of the present invention is not limited to the individual embodiments described above, and includes various modifications that can be conceived by those skilled in the art, and the effects of the present invention are not limited to the contents described above. That is, various additions, modifications, and partial deletions can be made without departing from the concept and spirit of the present invention derived from the contents defined in the claims and equivalents thereof.

  The present invention can be used for a stepping motor.

  DESCRIPTION OF SYMBOLS 100 ... Stepping motor, 200 ... Front side stator assembly, 210 ... Front plate, 211 ... Band coupling part, 212 ... Claw part, 213 ... Terminal part, 214 ... Energizing terminal pin, 214a ... One end part of energizing terminal pin, 214b: the other end of the energizing terminal pin, 216: boss, 216a ... split (slit), 217 ... band coupling part, 218 ... claw part, 219 ... positioning pin, 220 ... outer stator, 230 ... bobbin, 231 ... Stator coil, 232... Terminal portion, 233... Terminal, 240 .. inner stator, 300... End side stator assembly, 310... End plate, 311 ... band contact portion, 312 ... band contact portion, 313. Fixed pin, 314a ... Fixed pin end, 320 ... Outer stator, 331 ... Stator coil 333: Terminal, 330 ... Bobbin, 340 ... Inner stator, 400 ... Rotor, 401 ... Rotor magnet, 402 ... Rotor member, 403 ... Shaft, 404 ... Rubber washer, 405 ... Rubber washer, 500 ... Band, 501 ... Arm part, 502 ... arm portion, 600 ... circuit board, 601 ... motor fixing boss hole, 602 ... contact hole, 603 ... copper foil pattern, 605 ... soldering pattern.

Claims (3)

A stator,
A front plate that contacts one end side in the axial direction with respect to the stator and is joined to a circuit board;
An end plate in contact with the other end side in the axial direction with respect to the stator;
A band extending between the front plate and the end plate and spanning the outer periphery of the stator, and coupling the front plate and the end plate to each other with the stator sandwiched therebetween,
The front plate is provided on a side surface of the stator and includes a plurality of band coupling portions that extend toward the end plate and have engaging portions formed on the outside.
The band includes a plurality of arm portions that are disposed on the end plate side, extend in the direction of the front plate, and engage with the engagement portions in each of the plurality of band coupling portions. In the state where the end plate and the stator are sandwiched between them by the engagement with the engaging portion, the front plate is coupled,
The front plate is
A boss part for accommodating the rotation shaft inside, protruding in the axial direction, and fitting into the circuit board;
Current-carrying terminal pins protruding in the axial direction and soldered to the circuit board;
The energization is disposed at a position sandwiching the boss portion between the terminal pins are soldered to the circuit board, e Bei a fixing pin which does not function as an electrode,
The boss part is integrally formed with the front plate, and a split is formed in the boss part. The boss part is press-fitted into a boss hole formed in the circuit board. A stepping motor characterized by being fitted into a hole by a repulsive force .   2. The rotary shaft according to claim 1, wherein the rotary shaft is passed through holes provided in the front plate and the end plate, and is rotatably supported in contact with inner peripheral surfaces of the holes. Stepping motor.   The stepping motor according to claim 1, wherein the front plate includes a positioning pin that positions the stepping motor with respect to the circuit board.

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