JP2009213326A - Electric motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric motor for expanding a terminal pitch in the radial direction under the condition to reduce the cost and number of steps for assembling operation. <P>SOLUTION: A holder stay 30 includes a brush holder with a brush for supplying power to an armature coil housed therein, and a terminal holder 33 extended in the axial direction of a yoke 2 for holding a terminal 42 connecting the brush to an external power source. The holder stay is pressed into the yoke 2, the terminal holder 33 is constituted of a first holder 40 and a second holder 41, and the terminal 42 is held by the first holder 40 and the second holder 41 in the radial direction of the yoke 2. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electric motor.

  In general, an electric motor with a brush includes a cylindrical yoke and an armature that is rotatably supported by the yoke and has a coil wound thereon. The electric motor also includes a brush and a commutator (commutator) for mechanically rectifying a direct current supplied from an external power source and supplying the direct current to the armature. The brush is housed in a brush holder provided on the holder stay so as to be able to appear and retract in a state of being biased via a coil spring. The holder stay is provided with a terminal for connecting the brush and an external power source. For example, as shown in Patent Document 1, this terminal is press-fitted and fixed in a through hole formed in the holder stay along the axial direction of the electric motor. One end of the terminal is connected to the brush inside the yoke, and the other end is connected to a lead wire routed from an external power source outside the yoke.

  By the way, among the electric motors described above, in the case of a small electric motor used for a throttle motor or the like, it is necessary to increase the terminal pitch in the radial direction with respect to the outer diameter of the yoke because of the connection with an external device. There is. In this case, in order to ensure a large terminal pitch, it is conceivable to press-fit a terminal that is bent outward in the radial direction into the brush holder. However, when the bent terminal is press-fitted into the holder stay, the terminal cannot be press-fitted perpendicularly to the holder stay due to the moment acting during the press-fitting, and the terminal pitch accuracy deteriorates. As a result, the terminal must have a straight shape that does not bend and the outer diameter of the motor must be increased to ensure the terminal pitch.

On the other hand, as shown in Patent Document 2, for example, a configuration in which a terminal is insert-molded on a holder stay made of an insulating resin is disclosed. It is also conceivable to increase the terminal pitch by insert molding a terminal that is bent outward in the radial direction of the electric motor.
Japanese Patent Laid-Open No. 06-169550 JP 2004-289934 A

  However, when the terminal is fixed by insert molding, the terminal must be set in the holder stay in advance. For this reason, there is a problem that the number of assembling steps is increased and the production efficiency is reduced as compared with the case where the terminal is press-fitted and fixed. Furthermore, since a molding machine for insert mold molding is required, there is a problem of increasing costs.

  Accordingly, the present invention has been made to solve the above-described problems, and an object thereof is to provide an electric motor capable of expanding the terminal pitch in the radial direction while reducing the number of assembling steps and costs. And

In order to solve the above-described problem, an invention described in claim 1 is an electric motor including a cylindrical yoke, and an armature that is rotatably supported in the yoke and has a coil wound thereon. A holder stay having a brush holder in which a brush for supplying power to the coil is housed, and a terminal holder that extends along the axial direction of the yoke and holds a terminal that connects the brush and an external power source, The terminal holder includes a first holder and a second holder, and the terminal is sandwiched between the first holder and the second holder in the radial direction of the yoke. The terminal may be bent toward the outer side in the radial direction of the yoke.
According to this configuration, since the terminal holder is configured by dividing the first holder and the second holder, the terminal is held only by sandwiching the terminal between the first holder and the second holder. be able to. Thereby, it is not necessary to insert-mold and hold the terminal on the brush holder as in the prior art.
Further, by bending the terminal, the terminal pitch in the radial direction can be increased without changing the outer diameter of the yoke, so that the terminal pitch larger than the outer diameter of the yoke can be easily ensured. And by pinching the formed terminal between the first holder and the second holder, there is no need to press-fit the terminal as in the prior art, and no load is applied to the terminal, so the accuracy of the terminal pitch is not deteriorated. Easy to assemble. That is, the terminal pitch can be set without depending on the outer diameter of the yoke.

According to a third aspect of the present invention, the terminal has a through-hole penetrating in the radial direction of the yoke, and extends in the radial direction in either the first holder or the second holder. And a boss portion to be inserted into the through hole is formed, and a receiving portion for receiving the boss portion is formed on the other side.
According to this configuration, the relative position of the terminal with respect to the first holder and the second holder is determined by inserting the boss formed on either the first holder or the second holder into the through hole and the accommodating portion. Is done. Even when a force acts in a direction (axial direction) perpendicular to the radial direction with respect to the terminal, the boss portion can be prevented from being caught in the through hole, and the boss portion can be prevented from coming out of the through hole.

The invention described in claim 4 is characterized in that an engagement portion for engaging the first holder and the second holder is formed in the second holder.
According to this configuration, by engaging the first holder and the second holder, the relative position between the first holder and the second holder is determined, and the terminal is sandwiched therebetween. And even if force is applied to the terminal in the radial direction, it is possible to prevent the terminal from coming off the terminal holder.

The invention described in claim 5 is characterized in that a rib is formed on a contact surface of the first holder or the second holder with the yoke.
According to this configuration, since the rib is crushed and assembled by assembling the holder stay, the holder stay can be stably held without rattling.

  According to the first aspect of the present invention, since the terminal holder is divided into the first holder and the second holder, the terminal is simply sandwiched between the first holder and the second holder. Can hold the terminal. Thereby, since it is not necessary to insert-mold and hold | maintain a terminal to a brush holder like the past, it can reduce an assembly man-hour and cost.

  According to the second aspect of the present invention, the terminal pitch in the radial direction can be increased without changing the outer diameter of the yoke by bending the terminal. Can be easily secured. And by pinching the bent terminal between the first holder and the second holder, there is no need to press-fit the terminal as in the prior art, and no load is applied to the terminal, so the accuracy of the terminal pitch is not deteriorated. Easy to assemble. That is, the terminal pitch can be set without depending on the outer diameter of the yoke. Therefore, it is possible to improve the degree of freedom in designing after downsizing the apparatus.

According to the invention described in claim 3, the relative position of the terminal with respect to the first holder or the second holder is determined by inserting the boss formed on the first holder or the second holder into the through hole of the terminal. Is done. Therefore, since positioning can be performed easily, assembly efficiency can be improved.
Even when a force acts in a direction (axial direction) perpendicular to the radial direction with respect to the terminal, the boss portion can be prevented from being caught in the through hole, and the boss portion can be prevented from coming out of the through hole. Therefore, the holding force of the terminal holder can be improved.

According to the invention described in claim 4, by engaging the first holder and the second holder, the relative position between the first holder and the second holder is determined, and the terminal is sandwiched therebetween. . Therefore, assembly efficiency can be improved.
And even if force is applied to the terminal in the radial direction, it is possible to prevent the terminal from coming off the terminal holder. Therefore, the holding force of the terminal holder can be improved.

  According to the invention described in claim 5, since the rib is crushed and assembled by assembling the holder stay, the holder stay can be stably held without rattling.

Next, embodiments of the present invention will be described with reference to the drawings. In the following description, the left side in FIG. 1 is the front side (the other end side), and the right side in FIG. 1 is the rear side (the one end side).
As shown in FIG. 1, the electric motor 1 is a motor with a brush used for, for example, a throttle motor, and an armature 3 is rotatably supported in a bottomed cylindrical yoke 2.

  The yoke 2 is formed by integrally forming a cylindrical portion 10 and a bottom portion 11, and a bearing housing 12 that protrudes outward in the axial direction is formed at the radial center portion of the bottom portion 11. A bearing 13 is press-fitted inside the bearing housing 12, and one end of a shaft 20 is rotatably supported by the bearing 13. A plurality of tile-shaped permanent magnets 4 divided in the circumferential direction are fixed to the inner peripheral surface 10a of the cylindrical portion 10 at equal intervals and so that the polarities of adjacent permanent magnets 4 are opposite to each other.

The armature 3 includes a shaft 20, an armature core 21 that is externally fixed to the shaft 20, and a commutator (commutator) 23 that is externally fixed to the shaft 20.
The armature core 21 is manufactured by laminating iron core pieces and has a plurality of teeth 24 extending radially around the shaft 20. An armature coil (coil) 22 is wound around the teeth 24.

  The commutator 23 has a cylindrical shape that is externally fitted and fixed to the other end of the shaft 20, and a plurality of segments 25 made of a conductive material are disposed on the surface of the commutator 23 along the circumferential direction. These segments 25 are arranged radially at equal intervals around the shaft 20 in an exposed state, and adjacent segments 25 are insulated from each other. A riser 26 is integrally formed at the end of each segment 25 on the armature core 21 side so as to project outward in the radial direction and the tip is bent inward in the radial direction. The riser 26 is for connecting the armature coil 22 to the segment 25. The winding start end and the winding end end of the winding 27 drawn from the armature coil 22 are respectively wound around and fixed by fusing. ing. Thereby, the segment 25 and the armature coil 22 corresponding to this are electrically connected.

  As shown in FIGS. 1 and 2, a resin holder stay 30 is provided on the open end (other end) side of the yoke 2 so as to close the yoke 2. The holder stay 30 includes a disc-shaped holder stay main body 31, and a brush holder 32 and a terminal holder 33 along the circumferential direction of the holder stay main body 31.

  The brush holder 32 has a box shape having an opening formed integrally with the holder stay main body 31, and is formed so as to protrude from the holder stay main body 31 toward the inner side in the axial direction. Two brush holders 32 are provided at equal intervals along the circumferential direction of the holder stay main body 31. In each brush holder 32, a brush 34 is housed so as to be able to protrude and retract in the radial direction while being urged via a torsion spring 35 (see FIG. 2). The tips of the brushes 34 are slidably contacted with the commutator 23 by being urged by a torsion spring 35. A wiring hole 36 is formed on the end surface of the brush holder 32 on the armature core 21 side. A pigtail 37 is inserted into the wiring hole 36 toward the brush holder 32, and the brush 34 and one end of the pigtail 37 are connected in the brush holder 32.

  The terminal holder 33 is provided at two locations along the circumferential direction of the holder stay main body 31, and each terminal holder 33 is provided adjacent to each brush holder 32. The terminal holder 33 is configured by dividing the first holder 40 and the second holder 41, and the terminal 42 is sandwiched between the first holder 40 and the second holder 41 in the thickness direction (radial direction). Yes.

  As shown in FIG. 3, the terminal 42 is a flat plate-like member, and is bent at two points toward the radially outer side and the axially outer side at a midway portion in the longitudinal direction. Further, at one end side of the terminal 42, two through holes 43 penetrating in the thickness direction of the terminal 42 are formed along the longitudinal direction (axial direction). One end of the terminal 42 is connected to the other end of the pigtail 37 in the yoke 2, and the other end is connected to a lead wire routed from an external power source (not shown) outside the yoke 2. As a result, a direct current supplied from an external power source is supplied to the commutator 23 via the brush 34.

  The first holder 40 is an L-shaped member that is integrally formed on the outer peripheral portion of the holder stay main body 31 described above, and includes an extending portion 44 that extends along the axial direction, and an axial direction of the extending portion 44. It is comprised by the flange part 45 projected over the radial direction outer side from the front-end | tip of an outer side.

  The extending portion 44 extends to both sides in the thickness direction (axial direction) of the holder stay main body 31, and the axial direction inside portion across the holder stay main body 31 is in the thickness direction (radial direction) of the extending portion 44. Two through-holes (accommodating portions) 48 penetrating therethrough are formed. The through hole 48 is formed corresponding to the through hole 43 of the terminal 42 described above, and receives a boss portion 51 described later.

  A through hole 46 penetrating in the axial direction is formed in the flange portion 45, and the other end side of the terminal 42 is inserted into the through hole 46. On the rear surface of the flange portion 45, a stepped portion 47 is formed in which the thickness of the base portion is thinner than the thickness of the tip portion, and the bent portion 39 of the terminal 42 abuts against the stepped portion 47. It has been. Therefore, the rear surface of the front end portion of the flange portion 45 and the rear surface of the bent portion 39 of the terminal 42 are flush with each other in a sectional view (see FIG. 3).

The second holder 41 is attached to the first holder 40 from the radially outer side, and includes a support piece 49 extending along the axial direction and a flange portion 50 projecting radially outward from one end of the support piece 49. It is configured.
As shown in FIGS. 3 and 4, the support piece 49 has a flat plate shape, and two boss portions 51 rising vertically toward the radially inner side are formed on the surface of the support piece 49. The boss portion 51 is formed corresponding to the through hole 48 formed in the extending portion 44 of the first holder 40 and the through hole 43 of the terminal 42, and the boss portion 51 is inserted into each through hole 48, 43. ing. Thereby, the position of the terminal 42 in the axial direction is determined.

  On both sides along the longitudinal direction of the support piece 49, tongue piece portions 52 are formed that rise vertically toward the inside in the radial direction. The tongue piece 52 has a flat plate shape, and is formed to be thinner than the thickness of the support piece 49 so that it can be bent and deformed along the thickness direction. A claw portion 53 is formed at the tip of the tongue piece portion 52 so as to stand in the thickness direction from the surface of the tongue piece portion 52. The claw portion 53 is formed such that a side surface 54 along the insertion direction of the boss portion 51 is inclined with respect to the surface of the tongue piece portion 52, and in a direction opposite to the insertion direction of the boss portion 51 (drawing direction). A side surface 55 is formed substantially perpendicular to the surface of the tongue piece 52. Note that the tongue piece portion 52 and the claw portion 53 constitute an engaging portion 56 of the present embodiment, and this engaging portion 56 is configured to be able to engage with the extending portion 44 in the first holder 40 in the thickness direction. Has been.

  4 and 5, two rows of ribs 57 are formed along the longitudinal direction of the support piece 49 on the back surface side of the support piece 49, that is, on the contact surface side with the inner peripheral surface 10 a of the cylindrical portion 10. Yes. The rib 57 has a triangular shape in cross-sectional view and protrudes radially outward from the back surface of the support piece 49, and serves as a press-fitting allowance when the holder stay 30 is press-fitted into the yoke 2.

  As shown in FIGS. 3 and 4, the flange portion 50 has a flat plate shape that is orthogonal to the extending portion toward the radially outer side, and the surface thereof is the rear surface of the flange portion 45 of the first holder 40 and the terminal 42. It is in contact with the rear surface of the bent portion 39. Further, the back surface of the flange portion 50 is abutted against the flange portion 14 of the yoke 2. That is, the flange portion 50 of the second holder 41 is sandwiched between the flange portion 45 of the first holder 40 and the flange portion 14 of the yoke 2. Thus, the terminal 42 is clamped by the first holder 40 and the second holder 41.

  As shown in FIG. 1, a bracket 58 is provided on the open end (other end) side of the yoke 2 with the holder stay 30 interposed therebetween. The bracket 58 is substantially disk-shaped, and the back surface of the bracket 58 is abutted against the flange portion 14 of the yoke 2. A plurality of through holes 65 are formed in the bracket 58 along the circumferential direction, and the other end side of the terminal holder 33 is inserted into the through holes 65. Around the bracket 58, two mounting pieces 59 projecting radially outward are formed along the circumferential direction (see FIG. 2). The mounting piece 59 has a triangular shape in plan view, and a bolt hole 60 penetrating in the thickness direction of the bracket 58 is formed at the center thereof. The electric motor 1 is attached to an external device by fastening a bolt (not shown) in the bolt hole 60.

  A bearing housing 61 protruding outward in the axial direction is formed at the radial center of the bracket 58. The bearing housing 61 is formed with a through hole 62 penetrating in the thickness direction of the bracket 58 at the center thereof, and the other end of the shaft 20 is inserted into the through hole 62. Further, a bearing 63 is press-fitted inside the bearing housing 61 in the radial direction, and the other end of the shaft 20 is rotatably supported by the bearing 63. A gear 64 is attached to the other end of the shaft 20 outside the bracket 58 in the axial direction. By engaging the gear 64 with a gear of an external device (not shown), the power output from the electric motor 1 can be transmitted to the external device.

Next, a method for assembling the terminal holder in the holder stay will be described with reference to FIG.
First, the other end side of the terminal 42 is inserted into the through hole 46 formed in the flange portion 45 of the first holder 40. Specifically, the bent portion 39 of the terminal 42 is abutted against the stepped portion 47 of the first holder 40 and inserted to a position where the through hole 48 of the extending portion 44 and the through hole 43 of the terminal 42 overlap in plan view. To do.

  Subsequently, the second holder 41 is attached to the first holder 40 in which the terminal 42 is inserted. Specifically, the boss part 51 of the second holder 41 is inserted into the through hole 48 of the extension part 44 and the through hole 43 of the terminal 42. Then, the peripheral edge along the longitudinal direction of the extending portion 44 of the first holder 40 and the side surface 54 formed on the claw portion 53 come into contact with each other. When the second holder 41 is further pushed in, the tongue piece portion 52 of the second holder 41 is bent and deformed so as to follow the shape of the extending portion 44, and the side surface 54 of the claw portion 53 is moved to the peripheral edge of the first holder 41. The boss part 51 is inserted while sliding. At this time, since the side surface 54 of the claw portion 53 is formed to be inclined, the second holder 41 can be smoothly mounted while the tongue piece portion 52 is bent and deformed. And the 1st holder 40 and the 2nd holder 41 are engaged by the vertex of the nail | claw part 53 getting over the periphery of the extension part 44, and the tongue piece part 52 restoring | restoring to an original position.

As a result, the second holder 41 is mounted on the first holder 40, and the terminal 42 is sandwiched between the first holder 40 and the second holder 41 in the thickness direction. Specifically, the terminal 42 is sandwiched in the thickness direction (radial direction) by the extending portion 44 of the first holder 40 and the support piece 49 of the second holder 41, so that there is no backlash in the thickness direction of the terminal 42. Be regulated. At this time, since the first holder 40 and the second holder 41 are engaged by the engaging portion 56 of the second holder 41, the thickness of the terminal 42 can be increased only by mounting the second holder 41 on the first holder 40. The holding force in the vertical direction is improved.
On the other hand, when the bent portion 39 of the terminal 42 is sandwiched between the flange portion 45 of the first holder 40 and the flange portion 50 of the second holder 41, the backlash in the axial direction of the terminal 42 is restricted. At this time, by inserting the boss portion 51 of the second holder 41 into the through hole 43 of the terminal 42 and the through hole 48 of the first holder 40, the relative position of the terminal 42 with respect to the terminal holder 33 is determined, and the axial direction Holding power is improved.

Finally, the holder stay 30 to which the terminal 42 and the brush 34 are attached is press-fitted into the yoke 2. At this time, since the rib 57 is formed on the second holder 41, it becomes a press-fitting margin when the rib 57 is press-fitted. That is, when the holder stay 30 is press-fitted, the top of the rib 57 is crushed and press-fitted.
Thereby, the holder stay 30 can be assembled to the yoke 2.

Therefore, according to the present embodiment, since the terminal holder 33 is divided into the first holder 40 and the second holder 41, the terminal 42 is interposed between the first holder 40 and the second holder 41. The terminal 42 can be held only by pinching. Thereby, since it is not necessary to insert-mold and hold | maintain a terminal to a brush holder like the past, it can reduce an assembly man-hour and cost.
Further, since the terminal 42 is bent, the pitch of the terminal 42 in the radial direction of the yoke 2 can be increased without changing the inner diameter of the yoke 2. Then, the terminal 42 formed by bending is sandwiched between the first holder 40 and the second holder 41, so that it is not necessary to press-fit the terminal as in the prior art, and no load is applied to the terminal 42. Can be assembled easily without deteriorating. In other words, the pitch of the terminals 42 that is equal to or larger than the outer diameter of the yoke 2 can be ensured without depending on the inner diameter of the yoke 2. Therefore, it is possible to improve the degree of freedom in designing after downsizing the apparatus.

Furthermore, the relative position of the terminal 42 with respect to the terminal holder 33 is determined by inserting the boss portion 51 formed in the second holder 41 into the through hole 43 of the terminal 42 and the through hole 48 of the first holder 40. Therefore, since positioning can be performed easily, assembly efficiency can be improved.
In addition, since the boss portion 51 is inserted into the through holes 43 and 48, the boss portion 51 is caught by the through holes 43 and 48 even when a force is applied to the terminal 42 in the axial direction, and the terminal 42 is pulled out. Can be prevented. Therefore, the holding force of the terminal holder 33 can be improved.

Further, by engaging the first holder 40 and the second holder 41 by the engaging portion 56 formed on the second holder 41, the relative position between the first holder 40 and the second holder 41 is determined. The terminal 42 is held between them. Therefore, assembly efficiency can be improved.
Furthermore, even when force is applied to the terminal 42 in the radial direction, the terminal 42 can be prevented from coming off from the terminal holder 33. Therefore, the holding force of the terminal holder 33 can be improved.

  Moreover, since the rib 57 is formed in the support piece 49 of the 2nd holder 41, when the holder stay 30 is assembled | attached, the top part of the rib 57 will be crushed and assembled | attached. Therefore, when the holder stay 30 is assembled to the yoke 2, the holder stay 30 can be stably held without rattling.

It should be noted that the technical scope of the present invention is not limited to the above-described embodiments, and includes those in which various modifications are made to the above-described embodiments without departing from the spirit of the present invention.
In the above-described embodiment, the case where the terminal is bent is described, but the terminal may be formed straight.

It is sectional drawing of the electric motor in embodiment of this invention. It is a top view of the bracket and holder stay in the embodiment of the present invention. FIG. 3 is a cross-sectional view corresponding to the line AA in FIG. 2. It is a perspective view of the 2nd holder in the embodiment of the present invention. It is the B section enlarged view of FIG. FIG. 4 is an exploded cross-sectional view of FIG. 3.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Electric motor 2 ... Yoke 3 ... Armature 22 ... Armature coil (coil) 30 ... Holder stay 32 ... Brush holder 33 ... Terminal holder 34 ... Brush 40 ... 1st holder 41 ... 2nd holder 42 ... Terminal 43 ... Through-hole 48 ... Through-hole (accommodating portion) 51 ... boss portion 56 ... engaging portion 57 ... rib

Claims (5)

A cylindrical yoke,
An electric motor comprising an armature rotatably supported in the yoke and wound with a coil;
A holder stay having a brush holder in which a brush for supplying power to the coil is housed, and a terminal holder that extends along the axial direction of the yoke and holds a terminal for connecting the brush and an external power source are disposed in the yoke. Pressed into
The electric motor according to claim 1, wherein the terminal holder includes a first holder and a second holder, and the terminal is sandwiched between the first holder and the second holder in a radial direction of the yoke.   2. The electric motor according to claim 1, wherein the terminal is bent toward the outer side in the radial direction of the yoke.   The terminal is formed with a through-hole penetrating in the radial direction of the yoke, extending in either the first holder or the second holder in the radial direction, and inserted into the through-hole. The electric motor according to claim 1, wherein a boss portion is formed and a housing portion that receives the boss portion is formed on the other side.   4. The electric motor according to claim 1, wherein the second holder is formed with an engaging portion that engages the first holder with the second holder. 5. motor.   The electric motor according to any one of claims 1 to 4, wherein a rib is formed on a contact surface of the first holder or the second holder with the yoke.

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