JP2012010433A - Brush device and starter motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brush device and a starter motor capable of reducing time to be taken for a brush to make surface contact with a segment after the start of operation, and suppressing change in motor performance associating with a lapse of time.SOLUTION: A brush device includes two anode brushes 32A and two cathode brushes 32B, where one of respective brushes has a sliding contact surface 37, on which an inwardly inclined surface 37a2 inclined to a segment side as proceeding from an inner radial direction to an outer radial direction is formed, while each of the other brushes has a sliding contact surface 37, on which an outwardly inclined surface 37a1 inclined to a segment side as proceeding from an outer radial direction to an inner radial direction is formed.

Description

  The present invention relates to a brush device and a starter motor using the brush device.

  For example, many starter motors used for starting a motorcycle have an armature rotatably provided in a yoke housing having a magnetic pole. The armature includes an armature core around which a winding is wound, and a commutator to which the winding is connected, and power is supplied to the winding by a brush that is in sliding contact with the commutator.

  In addition, this type of starter motor is highly demanded for miniaturization, and a flat so-called disk commutator is used as a commutator. In the disk commutator, a plurality of segments to which windings are connected are provided radially on an end surface which is a rotational sliding surface. Each segment is formed in a substantially fan shape in a plan view so as to expand from the radially inner side toward the radially outer side. And the brush is urged | biased by the spring toward the axial direction segment side (for example, refer patent document 1).

  Here, in Patent Document 1, when the disk commutator rotates as the armature rotates, the brush slightly tilts in the rotation direction due to the frictional resistance generated between the segment and the brush. In such a case, in the initial operation of the starter motor, the brush comes into contact with the segment. That is, the contact area of the brush decreases, and it takes time until the brush wears and comes into surface contact with the segment. For this reason, a technique is disclosed in which an inclined surface that is inclined toward the disk commutator as it goes in the rotational direction of the disk commutator is formed on the sliding surface of the brush (see, for example, Patent Document 2).

  According to this, when the brush is slightly tilted in the counter-rotation direction with the rotation of the disk commutator, the inclined surface and the segment come into surface contact, so the time until the brush comes into surface contact with the segment is shortened. Is possible.

JP 2004-304946 A JP 2007-209119 A

  However, in Patent Document 2 described above, the number of segments that the brush contacts changes between when the starter motor first moves and after a predetermined time has elapsed. This will be described in more detail with reference to FIG.

7A and 7B show a conventional segment and a brush. FIG. 7A is an explanatory diagram showing a contact state between the segment and the brush at the initial movement, and FIG. It is explanatory drawing.
As shown in FIG. 7A, the sliding contact surface 101a of the brush 101 is inclined so as to incline toward the disk commutator 102 as it goes in the rotation direction of the disk commutator 102 (see arrow Y101 in FIG. 7A). A surface 101b is formed. Therefore, when the starter motor is initially moved, only the rotation direction front side edge 104 (see the shaded portion in FIG. 7A) of the sliding contact surface 101a of the brush 101 is in contact with the segment 103 of the disk commutator 102. It has become. That is, the radially outer side of the brush 101 is in contact with one of the two adjacent segments 103 (see P101 in FIG. 7A). Further, the other side in the radial direction of the brush 101 is in contact with the other (see P102 in FIG. 7A).

  On the other hand, as shown in FIG. 7B, when the brush 101 slightly tilts in the rotation direction as the disk commutator 102 rotates, the sliding contact surface 101 a of the brush comes into surface contact with the segment 103. It becomes a state. In such a state, since the segment 103 of the disk commutator 102 is formed in a fan shape in a plan view, the segment is in contact with one segment 103 on the radially outer side of the brush 101 (in FIG. 7B). P103). On the other hand, on the radially inner side of the brush 101, the brush 101 is in contact with the three adjacent segments 103, 103, 103 (see P104 in FIG. 7B).

  As described above, in Patent Document 2 described above, the number of segments that the brush contacts changes between the initial start of the starter motor and after a lapse of a predetermined time, so that the windings connected to the segments are effective. The number of conductors will change. For this reason, there exists a subject that the performance of a starter motor will change a lot by the time of the initial motion of a starter motor, and after progress for a predetermined time.

  Therefore, the present invention has been made in view of the above-described circumstances, and can shorten the time from the initial movement until the brush comes into surface contact with the segment, and suppresses the change in motor performance with the passage of time. A brush device and a starter motor are provided.

  In order to solve the above-mentioned problems, the invention described in claim 1 slidably contacts a plurality of segments arranged along the circumferential direction on the rotational sliding surface of the flat disk commutator, and is connected to the segments. Have two anode brushes and two cathode brushes for supplying power to the windings, and these anode brushes and cathode brushes are opposed to each other with the opposite poles sandwiching the rotation axis of the disk commutator. And the two anode brushes and the two cathode brushes are arranged on the sliding contact surface of one of the brushes, respectively, so that the same poles are arranged adjacent to each other in the circumferential direction. A first inclined surface that is inclined toward the segment side from the radially inner side toward the radially outer side is formed, and on the sliding contact surface of the other brush, from the radially outer side to the radially inner side. Wherein the second inclined surface inclined to the segment side is formed according to buy.

By configuring in this way, at the time of initial movement, two brushes of the same polarity are in contact with the segment on the radially outer side, and the other brush contacts the segment on the radially inner side. . That is, each brush contacts the segment over the entire circumferential width. In particular, in the other brush in contact with the radially inner side of the segment, the number of segments with which the brush contacts is the same. For this reason, it can suppress that the number of effective conductors of a coil | winding changes with a time-dependent change compared with the past, As a result, it becomes possible to suppress the change of motor performance.
Further, at the time of initial movement, the contact pressure with respect to each brush segment can be increased as much as the contact area with each brush segment decreases. For this reason, it is possible to promote wear of the brush at the time of initial movement, and it is possible to shorten the time from the initial movement to the time when each brush comes into surface contact with the segment.

  In the invention described in claim 2, each segment is formed in a fan shape in a plan view so as to spread from the radially inner side toward the radially outer side, and the two anode brushes and the two cathode brushes are It is characterized by being formed in a quadrangular cross section.

By configuring in this way, one side in the rotation direction of each segment is in a state of extending obliquely with respect to one side in the width direction of the brush. For this reason, since switching to the next segment in a brush is performed gradually, it becomes possible to improve rectification | straightening property.
Moreover, it becomes possible to form a brush easily by making each brush into cross-sectional square shape.

  According to a third aspect of the present invention, a shared inclined surface is formed on the sliding contact surface of the rectangular parallelepiped-shaped shared brush so as to be inclined toward the segment side toward either the radially inner side or the radially outer side. One of the supply brushes is configured as the two anode brushes and the two cathode brushes by changing the direction of the inclined surface.

  By comprising in this way, two anode brushes and two cathode brushes can be shared. For this reason, the number of parts can be reduced and parts management becomes easy.

  According to a fourth aspect of the present invention, there is provided the brush device according to any one of the first to third aspects, an armature including the winding that is fed by the brush device, and the armature rotatably supported. And a starter motor comprising a yoke housing having a magnetic pole.

  With such a configuration, it is possible to provide a starter motor that can shorten the time from the initial movement until the brush comes into surface contact with the segment and can suppress a change in motor performance due to a change with time.

According to the present invention, at the time of initial movement, two brushes of the same polarity have one brush in contact with the segment at the radially outer side and the other brush in contact with the segment at the radially inner side. That is, each brush contacts the segment over the entire circumferential width. In particular, in the other brush in contact with the radially inner side of the segment, the number of segments with which the brush contacts is the same. For this reason, it can suppress that the number of effective conductors of a coil | winding changes with a time-dependent change compared with the past, As a result, it becomes possible to suppress the change of motor performance.
Further, at the time of initial movement, the contact pressure with respect to each brush segment can be increased as much as the contact area with each brush segment decreases. For this reason, it is possible to promote wear of the brush at the time of initial movement, and it is possible to shorten the time from the initial movement to the time when each brush comes into surface contact with the segment.

It is a partial sectional view of a starter motor in an embodiment of the present invention. It is a top view which shows schematic structure of the commutator in embodiment of this invention. It is the top view which looked at the rear bracket in embodiment of this invention from the front bracket side. It is sectional drawing which follows the AA line of FIG. It is sectional drawing which follows the BB line of FIG. It is explanatory drawing which shows the contact state of the segment and brush in embodiment of this invention. The conventional segment and a brush are shown, (a) is explanatory drawing which shows the contact state of the segment at the time of initial movement, and a brush, (b) is explanatory drawing which shows the contact state of the segment and brush after progress for a predetermined time. .

(Starter motor)
Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a partial cross-sectional view of a starter motor.
As shown in the figure, the starter motor 1 is, for example, a so-called inertia dive starter motor for generating a rotational force necessary for starting a marine engine (not shown). The starter motor 1 includes a front bracket 2 (upper side in FIG. 1), a cylindrical stator 3 having one end fixed to the front bracket 2, and a rear bracket 4 (lower in FIG. 1) closing the other end. Side), an armature 5 disposed in the stator 3 and rotatably supported by the front bracket 2 and the rear bracket 4, and one end side (upper end side in FIG. 1) of the rotary shaft 10 of the armature 5 The pinion mechanism 60 is provided.

  The front bracket 2 is formed in a substantially disc shape by, for example, aluminum die casting, and has a through hole 15 through which the rotary shaft 10 can be inserted in the center in the radial direction. One end of the rotating shaft 10 protrudes from the front bracket 2 through the through hole 15. A bearing 16 that rotatably supports one end of the rotary shaft 10 is press-fitted and fixed to the stator 3 side of the through hole 15. An oil seal 17 is provided on the through-hole 15 on the pinion mechanism 60 side.

Further, a ring-shaped fitting portion 2a into which one end of the stator 3 is fitted is provided on the outer peripheral edge of the front bracket 2 so as to project toward the stator 3 side.
Further, an insertion hole (not shown) through which the bolt 19 can be inserted is formed on the outer peripheral portion of the front bracket 2. The front bracket 2 is fixed to the stator 3 by inserting bolts 19 into the insertion holes and fastening the bolts 19 to the rear bracket 4 via the stator 3.

The stator 3 is formed of, for example, iron, and includes a substantially cylindrical yoke 21 having a cylindrical portion 21A. A fitting portion 3a that can be fitted to the fitting portion 2a is formed on the periphery of the yoke 21 on the front bracket 2 side. On the other hand, a fitting portion 3b that can be fitted into the rear bracket 4 is formed on the periphery of the yoke 21 on the rear bracket 4 side.
Further, a plurality of magnets 22 formed in the shape of roof tiles for field are fixed to the inner peripheral side of the yoke 21 along the circumferential direction. As the magnet 22, for example, a neodymium rare earth magnet can be used.

  In the armature 5, an armature core 11 and a commutator 12 are externally fitted and fixed to a rotary shaft 10. The armature core 11 is manufactured, for example, by stacking iron core pieces, and has a plurality of teeth 6 that extend radially about the rotation shaft 10. Between each tooth 6, a slot 7 having a long dovetail shape is formed in the axial direction, and a winding 13 is wound around the tooth 6 through the slot 7.

FIG. 2 is a plan view showing a schematic configuration of the commutator.
As shown in FIGS. 1 and 2, the commutator 12 is a so-called disk-type commutator formed in a substantially disk shape, and is located on the other end side (lower end side in FIG. 1) from the armature core 11 of the rotating shaft 10. The outer fitting is fixed. A surface of the commutator 12 on the rear bracket 4 side is set as a rotational sliding surface with which a brush 32 described later is in sliding contact, and a plurality of segments 14 are radially arranged around the rotation shaft 10.
Each segment 14 is formed in a substantially fan shape in an axial plan view so as to gradually widen toward the radially outer side from the radial center. Between the segments 14 adjacent to each other in the circumferential direction, a slit 18 is formed for ensuring insulation. Each segment 14 is connected to one end of a winding 13.

FIG. 3 is a plan view of the rear bracket as seen from the front bracket side.
As shown in FIGS. 1 and 3, the rear bracket 4 is formed in a bottomed cylindrical shape by, for example, aluminum die casting or the like, and the bolt 19 is screwed into the female screw portion 23 engraved on the outer peripheral portion. By being inserted, it is fixed to the stator 3. On the bottom portion 4A of the rear bracket 4, a boss portion 25 protrudes toward the stator 3 side at the radial center. A bearing 26 for pressurizing and supporting the other end of the rotary shaft 10 of the armature 5 is press-fitted into the boss portion 25.

(Brush device)
A brush device 29 is provided inside the bottom portion 4A of the rear bracket 4. The brush device 29 is for supplying electric power from an external power source (not shown) to the winding 13 via the commutator 12, and has a brush holder 30 fixed to the inner surface side of the rear bracket 4. .
The brush holder 30 is a substantially annular resin molded product, and a holder boss 30A formed so as to cover the outer peripheral surface of the boss portion 25 of the rear bracket 4 protrudes from the center in the radial direction. That is, the boss portion 25 projecting from the rear bracket 4 and the holder boss 30A projecting from the brush holder 30 constitute a bearing boss that rotatably supports the other end of the rotary shaft 10 of the armature 5. ing.

  The rear bracket 4 is integrally provided with four holder portions 31 so as to surround the holder boss 30A. The holder part 31 is formed in a square cylinder shape, and is disposed along the axial direction. Further, the four holder portions 31 are arranged so that two of them face each other around the rotation shaft 10. Each holder portion 31 accommodates a conductive brush 32 slidably in contact with the segment 14 of the commutator 12 constituting the armature 5 one by one.

4 is a cross-sectional view taken along line AA in FIG. 3, and FIG. 5 is a cross-sectional view taken along line BB in FIG.
As shown in detail in FIGS. 3 to 5, the brush 32 is formed in a substantially rectangular parallelepiped, and is housed in the holder portion 31 such that the longitudinal direction of the cross section is along the radial direction of the commutator 12. Yes. The brush 32 is urged toward the commutator 12 by a spring 33 disposed in the holder portion 31. One end of the pigtail 34 is fixed to the side surface of the brush 32 in the lateral direction of the cross section by welding or the like. The pigtail 34 is pulled out from a slit (not shown) formed in the side portion of the holder portion 31.

  Here, an inclined surface 37 a that is inclined along the radial direction of the commutator 12 is formed on the slidable contact surface 37 with respect to the segment 14 of each brush 32. And it arrange | positions so that the inclination direction of the inclined surface 37a may become alternate in the circumferential direction. Further, of the four brushes 32, among these, the upper two brushes 32, 32 in FIG. 3 are configured as anode brushes 32A, 32A, and the lower two brushes 32, 32 in FIG. It is configured as 32B.

That is, the anode brush 32A and the cathode brush 32B are arranged so that the different poles face each other around the rotation axis 10, and the same poles are adjacent to each other in the circumferential direction.
Further, of the two anode brushes 32A and 32A, the inclined surface 37a of one (left side in FIG. 3) of the anode brush 32A is outwardly inclined toward the segment 14 side from the radially outer side toward the radially inner side. It becomes the inclined surface 37a1. Further, the inclined surface 37a of the anode brush 32A on the other side (the right side in FIG. 3) becomes an inwardly inclined surface 37a2 that is inclined toward the segment 14 side from the radially inner side toward the radially outer side.

Further, of the two cathode brushes 32B and 32B, the inclined surface 37a of one (left side in FIG. 3) of the cathode brush 32B is inwardly inclined toward the segment 14 side from the radially inner side toward the radially outer side. It becomes the inclined surface 37a2. Further, the inclined surface 37a of the other (right side in FIG. 3) cathode brush 32B becomes an outwardly inclined surface 37a1 inclined to the segment 14 side from the radially outer side toward the radially inner side.
Each brush 32 arranged in this way has a different contact state with the segment 14. This will be described more specifically with reference to FIG.

FIG. 6 is an explanatory diagram illustrating a contact state between a segment and a brush. In FIG. 6, for easy understanding, only two brushes 32 having the same polarity (two anode brushes 32 </ b> A and 32 </ b> A or two cathode brushes 32 </ b> B and 32 </ b> B) and a part of the plurality of segments 14 are shown. The interval between adjacent homopolar brushes is shown to be narrower than that of FIG.
As shown in the figure, brushes of the same polarity, that is, one of the two anode brushes 32A and 32A or the two cathode brushes 32B and 32B has an outwardly inclined surface 37a1 (on the right side in FIG. 6). Brushes 32A and 32B). The other of the two anode brushes 32A and 32A or the two cathode brushes 32B and 32B has an inwardly inclined surface 37a2 (see the left brushes 32A and 32B in FIG. 6).

  For this reason, one side (the left side in FIG. 6) of the anode brush 32 </ b> A and the cathode brush 32 </ b> B in the longitudinal direction of the cross section is in a state of being entirely in contact with the radially outer side of the segment 14. Further, the other side in the longitudinal direction of the cross section of the other (right side in FIG. 6) anode brush 32A and cathode brush 32B is in a state of being entirely in contact with the radially inner side of the segment 14.

Here, each segment 14 is formed in a substantially fan shape in an axial plan view so as to gradually widen from the radial center toward the radial outer side. In other words, the circumference on the inner circumference side of the segment 14 is set shorter than the circumference on the outer circumference side. On the other hand, since the anode brush 32A and the cathode brush 32B are each formed in a substantially rectangular parallelepiped, the lengths of the sides facing each other are set to be substantially the same.
For this reason, for example, in this embodiment, one anode brush 32A and cathode brush 32B will be in the state which contacted one segment 14 (refer P1 part in FIG. 6). Further, the other anode brush 32A and cathode brush 32B are in contact with each other across the three segments 14 (see P2 portion in FIG. 6).

As shown in FIG. 3, the pigtail 34 having one end connected to each of the anode brushes 32 </ b> A and 32 </ b> A is connected to a terminal bolt 36 via a power supply plate 35. That is, the other end of the pigtail 34 is connected to the power supply plate 35 by welding or the like. The pigtail 34 is arranged in a divergent shape from the power supply plate 35 and is connected to the two plus-side brushes 32A. The power supply plate 35 is bent in a substantially L shape and is insert-molded in the brush holder 30.
On the other hand, the other end of the pigtail 34 whose one end is connected to the cathode brushes 32 </ b> B and 32 </ b> B is connected to the ground terminal 40.

The terminal bolt 36 is for electrically connecting an external power source (not shown) and the power supply plate 35, and is provided at the base end of the bolt main body 51 and the bolt main body 51 and disposed in the brush holder 30. And a head 41.
The bolt main body 51 protrudes from the inner surface side to the outer side through terminal insertion holes 42 and 43 formed in the brush holder 30 and the rear bracket 4 respectively. A male screw portion 52 is engraved on the front end side of the bolt main body 51, and a nut 47 is screwed therein.

An O-ring 44 is inserted into the terminal insertion holes 42 and 43 provided in the brush holder 30 and the rear bracket 4 respectively. As a result, the gap between the bolt body 51 of the terminal bolt 36 and the terminal insertion holes 42 and 43 is sealed.
On the other hand, on the outside of the rear bracket 4, the nut 47 is tightened after passing the resin bush 45 and the stopper washer 46 through the terminal bolt 36. In this way, the brush holder 30 and the rear bracket 4 are sandwiched between the terminal bolt 36 and the nut 47. An insulating ring member 48 is integrally formed on the resin bush 45 so as to surround the nut 47.

(Pinion mechanism)
The pinion mechanism 60 includes a clutch 61 and a pinion gear 62, and is attached to the outer periphery of one end side (the upper end side in FIG. 1) of the rotary shaft 10. More specifically, a helical spline 63 is formed in a portion protruding from the front bracket 2 of the rotating shaft 10 and near the front bracket 2, and a bottomed cylindrical shape constituting the clutch 61 is formed here. The clutch housing 64 is screwed.
A helical spline 65 that meshes with the helical spline 63 of the rotary shaft 10 is formed at the bottom 64 </ b> A of the clutch housing 64.

  A clutch inner 66 formed in a cylindrical shape so as to surround the periphery of the rotation shaft 10 is fitted inside the clutch housing 64 so as to be slidable with respect to the rotation shaft 10. The clutch inner 66 is engaged with the clutch housing 64 via the clutch roller 67 so as not to be axially displaceable and relatively rotatable. Further, a holder 68 is provided in the opening 64B of the clutch housing 64 so as to close the opening 64B, and the periphery is covered with a clutch cover 59 from above.

  The holder 68 is for preventing intrusion of dust into the clutch housing 64, and is formed in a substantially annular shape, and a seal ring 68A is provided on the inner peripheral edge. At the center in the radial direction of the holder 68, a clutch inner 66 protrudes outward in the axial direction, and the outer peripheral surface of the clutch inner 66 is in sliding contact with the inner peripheral edge of the seal ring 68A.

  As described above, the clutch 61 mainly includes the clutch housing 64, the clutch inner 66, the clutch roller 67, and the holder 68. When the torque difference and the rotational speed difference generated between the clutch housing 64 and the clutch inner 66 are within a predetermined value, the clutch 61 transmits the rotational force to each other, while the torque difference and the rotational speed difference are a predetermined value. When the value exceeds, the transmission of rotational force is cut off.

A pinion gear 62 is integrally formed at the tip of the clutch inner 66, that is, at the end protruding from the holder 68.
The pinion gear 62 is for engaging the ring gear 69 of the engine (not shown) to transmit the rotational force of the rotary shaft 10 to the ring gear 69 to start the engine. The pinion gear 62 is fitted on the rotary shaft 10 so as to be slidable.

  A stopper 71 is fitted on one end of the rotating shaft 10. The stopper 71 is restricted from moving in the removal direction by a retaining ring 72 attached to one end of the rotary shaft 10. By restricting the removal direction of the stopper 71, the removal direction of the pinion mechanism 60 is also restricted. Further, a return spring 73 formed so as to surround the periphery of the rotary shaft 10 is provided between the stopper 71 and the pinion gear 62. The return spring 73 urges the pinion gear 62 to be constantly pushed back toward the front bracket 2 side.

(Brush manufacturing method, mounting method)
Next, a method for manufacturing the brush 32 will be described.
The brush 32 is formed by cutting a conductive metal square bar into a predetermined length. And the inclined surface 37a along a cross-sectional longitudinal direction is formed in the sliding contact surface 37 side of the cut | disconnected square bar, and manufacture of the brush 32 is completed.
Subsequently, the orientations of the inclined surfaces 37 a of the plurality of brushes 32 are aligned, and the pigtails 34 are welded to the side surfaces of the brushes 32 in the lateral cross-sectional direction. At this time, since the direction of the inclined surface 37a is the same, the connection workability can be improved and the erroneous welding of the pigtail 34 can be prevented.

  Next, after inserting the spring 33 into the holder portion 31 of the brush holder 30 provided on the rear bracket 4, each brush 32 is inserted. At this time, it inserts so that the direction of the inclined surface 37a may become alternate along the circumferential direction, and the cross-sectional longitudinal direction of the brush 32 may be along the radial direction of the commutator 12. By alternately inserting the brushes 32 along the circumferential direction, the pull-out directions of the pigtails 34 of the brushes 32 having the same polarity become the same direction (see FIG. 3). Thereby, the attachment of the brush 32 is completed.

(Starter motor operation)
Next, the operation of the starter motor 1 will be described with reference to FIGS. 1 and 3 to 6.
As shown in FIG. 1, the starter motor 1 is placed vertically on a hull (not shown) so that the pinion mechanism 60 is directed upward in the vertical direction and the rotary shaft 10 is along the vertical direction. That is, the terminal bolt 36 protrudes downward in the vertical direction, and the terminal cover 83 covering the terminal bolt 36 is also positioned vertically downward. Further, the lead-out portion 85 of the terminal cover 83 is in a state in which the opening 95 faces upward in the vertical direction.

  In this state, when an ignition switch (not shown) is turned on to start the marine engine, a voltage is applied to the two anode brushes 32A and 32A of the brush 32 via the terminal bolt 36. Since each brush 32 is in sliding contact with the segment 14, a current is supplied to the winding 13 through the segment 14. Then, a magnetic field is formed in the armature core 11, and a magnetic repulsive force and attractive force act between the yoke 21 and the magnet 22, and the rotating shaft 10 rotates.

Here, as shown in detail in FIG. 6, since the sliding surfaces 37 of the two anode brushes 32A and 32A and the two cathode brushes 32B and 32B are respectively formed with inclined surfaces 37a, the starter motor 1 In the initial movement, the contact area of each brush 32 decreases, and the surface pressure of each brush 32 against the segment 14 increases.
When the rotating shaft 10 rotates in such a state, wear of the sliding contact surface 37 is promoted as the surface pressure of the brush 32 increases. Then, after a predetermined time has elapsed, the brush 32 comes into surface contact with the segment 14 (see FIG. 7B). That is, in this embodiment, the brushes 32 are in sliding contact so as to straddle the three segments 14.

  Further, each segment 14 is formed in a substantially fan shape in a plan view in the axial direction so as to gradually widen from the radial center toward the radially outer side. It will be in the state extended diagonally with respect to the one side 32a in the transversal short direction. For this reason, switching to the next segment 14 in each brush 32 is performed gradually.

  As the rotating shaft 10 rotates, the clutch housing 64 that meshes with the helical spline 63 of the rotating shaft 10 is rotated, and an inertial force acts on the clutch 61. Then, the pinion mechanism 60 is pushed out toward the ring gear 69 side, that is, the upper side opposite to the direction of gravity while rotating along the helical spline 63 against the spring force of the return spring 73 by the inertial force. Then, the pinion gear 62 meshes with the ring gear 69, and the rotational force of the rotary shaft 10 is transmitted to the ring gear 69 via the pinion mechanism 60. Then, the engine starts.

When the engine is started and the rotational speed of the pinion gear 62 exceeds the rotational speed of the rotary shaft 10, the clutch 61 acts to cause the pinion gear 62 to idle. Thereby, it is possible to prevent the rotational force of the ring gear 69 due to the start of the engine from being transmitted to the rotary shaft 10.
Furthermore, when the rotation of the rotating shaft 10 is stabilized, the inertial force acting on the pinion mechanism 60 is weakened. Then, the spring force of the return spring 73 exceeds the inertial force, and the pinion mechanism 60 is pushed back downward in the vertical direction by the weight of the pinion mechanism 60. Thereafter, the starter motor 1 is stopped.

(effect)
Therefore, according to the above-described embodiment, when the starter motor 1 is initially moved, the one anode brush 32A and the cathode brush 32B are in contact with one segment 14, and the other anode brush 32A and the cathode are in contact with each other. Since the brush 32B is in contact with the three segments 14, the change in the number of segments in contact with the brush 32 from the initial movement to the end of a predetermined time can be reduced compared to the conventional case. In particular, the anode brush 32A and the cathode brush 32B on the other side (on the right side in FIG. 6) are in contact with each other across the three segments 14 at the time of initial movement, so that the number of segments in contact at the time of initial movement and after a predetermined time has elapsed. It does not change. For this reason, it can suppress that the number of effective conductors of the coil | winding 13 changes with a time-dependent change compared with the past, As a result, it becomes possible to suppress the change of the motor performance of the starter motor 1. FIG.

  Further, at the time of the initial movement, the contact pressure of each brush 32 with respect to the segment 14 can be increased by the amount that the contact area of each brush 32 with the segment 14 is reduced. For this reason, the wear of the brush 32 at the time of initial movement can be promoted, and it is possible to shorten the time from the time of initial movement until each brush 32 comes into surface contact with the segment 14.

  Further, each segment 14 is formed in a fan shape in a plan view so as to spread from the radially inner side to the radially outer side, and each brush 14 is formed in a rectangular cross section so that the rotation direction of each segment 14 is uniform. The side 14 a is in a state of extending obliquely with respect to the one side 32 a in the transverse direction of each brush 32. For this reason, switching to the next segment 14 in each brush 32 is performed gradually. As a result, it is possible to improve rectification. Further, each brush 32 can be easily manufactured.

And it arrange | positions so that the direction of the inclined surface 37a currently formed in each brush 32 may become alternate along the circumferential direction, and while configuring the brushes 32 which adjoin each circumferential direction as anode brush 32A, cathode brush 32B. It is configured as. For this reason, when the pigtail 34 is welded to each brush 32, the work can be performed in the state where the directions of the inclined surfaces 37a are the same. The workability of connecting the pigtail 34 to the brush 32 can be improved, and erroneous welding can be prevented. Therefore, it is possible to improve the manufacturing yield, and it is not necessary to manage the anode brush 32A and the cathode brush 32B separately, and the components can be easily managed.
And when the brush 32 is assembled | attached to the holder part 31, the pull-out direction of the pigtail 34 of the brush 32 used as the same polarity can be made into the same direction (refer FIG. 3). For this reason, it is possible to prevent the pigtail 34 from being routed unnecessarily, and the layout in the brush holder 30 is improved.

The present invention is not limited to the above-described embodiment, and includes various modifications made to the above-described embodiment without departing from the spirit of the present invention.
In the above-described embodiment, the case where the starter motor 1 is for generating a rotational force necessary for starting a marine engine (not shown) has been described. However, the present invention is not limited to this, and the starter motor 1 can be used for starting an engine of a motorcycle or the like.

1 Starter motor 5 Armature 10 Rotating shaft 12 Commutator (disc commutator)
13 Winding 14 Segment 21 Yoke (Yoke Housing)
22 Magnet (magnetic pole)
29 Brush device 32 Brush (shared brush)
32A Anode brush 32B Cathode brush 37 Sliding surface 37a Inclined surface (shared inclined surface)
37a1 Outwardly inclined surface (second inclined surface)
37a2 Inwardly inclined surface (first inclined surface)

Claims (4)

Two anode brushes for slidingly contacting a plurality of segments arranged along the circumferential direction on the rotational sliding surface of the flat disk commutator and supplying power to the windings connected to the segments; Two cathode brushes,
The anode brush and the cathode brush are brush devices that are arranged so that different poles face each other across the rotation axis of the disk commutator, and the same poles are adjacent to each other in the circumferential direction,
The two anode brushes and the two cathode brushes are:
A first sloping surface that slopes toward the segment side from the radially inner side toward the radially outer side is formed on the sliding contact surface of each one brush, and the radially outer side is formed on the sliding contact surface of the other brush. A brush device is characterized in that a second inclined surface that is inclined toward the segment side as it goes radially inward is formed. Each segment is formed in a fan shape in a plan view so as to expand from the radially inner side toward the radially outer side,
The brush device according to claim 1, wherein the two anode brushes and the two cathode brushes are formed in a quadrangular cross section. On the sliding contact surface of the rectangular parallelepiped shared brush, a shared inclined surface that is inclined toward the segment side as it goes to either the radially inner side or the radially outer side,
3. The one or more types of the shared brush are configured as the two anode brushes and the two cathode brushes by changing the direction of the shared inclined surface. The brush apparatus as described. The brush device according to any one of claims 1 to 3,
An armature including the winding to be fed by the brush device;
A starter motor comprising a yoke housing that rotatably supports the armature and has a magnetic pole.

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