JP2007006646A - Motor with reduction gear mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor with reduction gear mechanism in which occupation ratio of a substrate can be reduced while enhancing the yield, and a space for arranging other component can be ensured on a brush holder. <P>SOLUTION: An armature shaft 14 is supported rotatably between a motor case 11 and a gear case 21, a brush holder 30 is fixed to the gear case 21, a commutator 19 and a sensor magnet 41 are fixed, respectively, to predetermined positions of an armature shaft 14, a brush 35 contained retractibly in a brush holder 30 is provided to come into press contact with the commutator 19 freely, a substrate 40 is fixed to a position opposing the sensor magnet 41 of the brush holder 30, and a magnetic sensor 42 for detecting variation in magnetic field of the sensor magnet 41 is fixed to the substrate 40. In such a motor 10 with reduction gear mechanism, the substrate 40 is fixed to the brush holder 30 such that the substrate 40 erects vertically. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a small motor with a speed reduction mechanism in which a substrate on which a magnetic detection sensor such as a Hall IC (Hall element) is mounted is integrated with a brush holder that holds a brush.

  As a brush holder used in this type of motor with a speed reduction mechanism, there is one shown in FIGS. 8 and 9 (see, for example, Patent Document 1). The brush holder 1 is made of resin and has an elliptical plate shape, and is fitted into an opening of a yoke (not shown).

  As shown in FIGS. 8 and 9, a substantially cylindrical bearing holding portion 2 is formed at the center of the brush holder 1, and the armature shaft 8 is rotated via the bearing 5 held by the bearing holding portion 2. It is supported freely. A ring-shaped sensor magnet 9 magnetized in the circumferential direction is fixed to the armature shaft 8. Further, a pair of brush holding portions 1c and 1c are projected from the lower surface 1b of the brush holder 1 so as to face each other with the bearing holding portion 2 therebetween. A brush (not shown) is slidably accommodated in each brush holding portion 1c.

  Further, the upper part of the substantially cylindrical bearing holding part 2 of the brush holder 1 is a boss part 3 for fixing the substrate 6, and this boss part 3 is divided into a plurality of boss pieces 3a, 3b. Further, as shown in FIGS. 8 and 9, a columnar protrusion 4 for fixing the substrate 6 is provided in the vicinity of the boss 3 on the upper surface 1 a of the brush holder 1. The substrate 6 is fixed to the upper surface 1 a of the brush holder 1 in a horizontal state (sideways state) by the boss portion 3 and the protrusion 4. Further, at a position facing the sensor magnet 9 of the substrate 6, a pair of rotation information such as the number of rotations and the rotation speed of the armature shaft 8 is detected based on a change in the magnetic field of the sensor magnet 9 that rotates together with the armature shaft 8. Hall elements 7 are mounted.

JP 2003-61311 A

  However, in the conventional motor with a speed reduction mechanism, since the substrate 6 is fixed in a horizontal state along the upper surface 1a of the brush holder 1, the ratio (area) of the substrate 6 to the upper surface 1a of the brush holder 1 is Due to the increase in size, it was difficult to arrange other parts such as terminals other than the substrate 6 on the upper surface 1 a of the brush holder 1. Further, since the circular insertion hole 6a fitted into the boss pieces 3a and 3b of the boss portion 3 is indispensable at the center of the substrate 6, the entire area of the substrate 6 is increased correspondingly and the yield of the substrate 6 is poor. Thus, the cost of the substrate 6 was increased.

  Therefore, the present invention has been made to solve the above-described problems, and by arranging the substrate in a vertically placed state with respect to the brush holder, the ratio of the substrate can be reduced and the yield can be improved. An object of the present invention is to provide a motor with a speed reduction mechanism that can secure a space for arranging other components on the brush holder.

  The invention of claim 1 includes a motor case that houses an armature that rotates when energized, and a gear case that is connected to the motor case and houses a reduction mechanism that decelerates the rotation of the armature. The armature shaft is rotatably supported between the brush case, a brush holder is attached to at least one of the motor case and the gear case, and a commutator and a sensor magnet are respectively attached to predetermined positions of the armature shaft so that the brush holder can be moved in and out. Deceleration in which the stored brush is press-contacted to the commutator, a substrate is attached to the brush holder at a position opposite to the sensor magnet, and a magnetic detection sensor for detecting a change in the magnetic field of the sensor magnet is attached to the substrate. For motor with mechanism Te, characterized in that attached to the standing vertically the substrate to the brush holder.

  The invention according to claim 2 is the motor with a speed reduction mechanism according to claim 1, wherein a through-hole through which the armature shaft and the sensor magnet are inserted is formed at the center of the brush holder, and the upper surface of the brush holder A substrate mounting surface is formed in the vicinity of the through hole, and the substrate is mounted on the substrate mounting surface in a vertically mounted state.

  As described above, according to the first aspect of the present invention, the substrate occupying the brush holder can be reduced by attaching the magnetic detection sensor to the brush holder so as to stand vertically. The space for arranging other parts on the brush holder can be secured.

  According to the second aspect of the present invention, the through hole through which the armature shaft and the sensor magnet are inserted is formed at the center of the brush holder, and the substrate mounting surface is formed in the vicinity of the through hole on the upper surface of the brush holder. By attaching the substrate vertically to the mounting surface, it is not necessary to form a circular hole in the substrate with respect to the through-hole of the brush holder as in the conventional case, and accordingly, the yield of the substrate is improved. In addition, the cost of the substrate can be reduced.

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

  1 is a plan view showing a motor with a speed reduction mechanism according to an embodiment of the present invention, FIG. 2 is a plan view showing a state where a gear case cover of the motor with the speed reduction mechanism is removed, and FIG. 3 is a cross-sectional view of the motor with the speed reduction mechanism 4 is a plan view of a brush holder used in the motor with the speed reduction mechanism, FIG. 5 is a left side view of the brush holder, FIG. 6 is a bottom view of the brush holder, and FIG. 7 is a line XX in FIG. It is sectional drawing which follows.

  As shown in FIGS. 1 to 3, the motor 10 with a speed reduction mechanism includes a substantially cylindrical yoke (motor case) 11 having an open end, and a flange portion 11 b around the open end 11 a of the yoke 11 with screws 20 a. And a synthetic resin gear case 21 fastened and fixed thereto.

  As shown in FIG. 3, a pair of magnets 12 and 12 are fixed to the inner peripheral surface 11c of the yoke 11 with an adhesive or the like. The other end portion 14d of the armature shaft 14 is rotatably supported via a bearing 13c fitted to the bottomed cylindrical portion 11d at the other end of the yoke 11, and in the vicinity of both ends of the shaft hole 22 of the gear case 21. The one end 14a and the intermediate portion 14c of the armature shaft 14 are rotatably supported via the bearings 13a and 13b fitted to the shaft.

  The armature shaft 14 has a worm 15 formed in the vicinity of one end 14b thereof. In addition, a recess (not shown) for housing half of the steel ball 16b is formed at the center of the end face of the other end 14d of the armature shaft 14. The steel ball 16b is in contact with a bearing plate 17b fitted and fixed to the bottomed cylindrical portion 11d of the yoke 11. Further, a recess (not shown) for accommodating half of the steel ball 16a is formed at the center of the end surface of the one end 14a of the armature shaft 14. The steel ball 16 a is in contact with a bearing plate 17 a disposed on the bottom side of the shaft hole 22 of the gear case 21.

  An armature 18 is attached to a position of the armature shaft 14 facing the pair of magnets 12 and 12. The armature 18 is composed of an armature core 18a fixed to the armature shaft 14 and having a coil winding portion having a predetermined number of slots, and an armature coil 18b wound around the coil winding portion of the armature core 18a. Yes.

  Further, a commutator 19 is fixed at a position facing the boundary between the yoke 11 and the gear case 21 of the armature shaft 14. The commutator 19 includes the same number of commutator pieces 19a as the coil winding portion of the armature core 18a, and each commutator piece 19a and the armature coil 18b are electrically connected to each other.

  Furthermore, the opening end of the shaft hole 22 of the gear case 21 is a large-diameter hole portion 22a, and a pair of brushes are disposed at positions facing the commutator 19 in the large-diameter hole portion 22a via a brush holder 30 described later. 35 and 35 are attached so as to contact each commutator piece 19a of the commutator 19. Each brush 35 is electrically connected to a motor control circuit (not shown). When the switch of the motor control circuit is switched from OFF to ON, a current flows through the armature 18 and the armature shaft 14 rotates.

  As shown in FIG. 3, a shaft hole 22 is formed substantially at the center of the gear case 21, and a concave reduction mechanism housing portion 23 is formed in communication with the shaft hole 22. As shown in FIG. 2, a circular recess 23 a is formed at a predetermined position on the bottom wall of the speed reduction mechanism housing portion 23 facing the worm 15. A lower portion of a metal-made pin-shaped support shaft 25 is fitted into the recess 23a by press-fitting or the like, and a worm wheel 26 is rotatably supported on the support shaft 25. Further, as shown in FIG. 2, a cylindrical portion 23 b is integrally formed at a position on the right side in FIG. 3 of the one end 14 a of the armature shaft 14 on the bottom wall of the speed reduction mechanism housing portion 23. In the cylindrical portion 23b, the cylindrical lower end portion of the output shaft portion 28 having a through hole shape of the output gear 27 is rotatably supported via a radial bearing (not shown).

  As shown in FIG. 3, a through-hole-shaped output shaft portion 28 located at the center of the output gear 27 is disposed at a position close to the one end 14 a side of the armature shaft 14 of the gear case 21. The small-diameter gear 26 b of the worm wheel 26 is disposed at a position away from the armature shaft 14 from the through-hole-shaped output shaft portion 28 of the output gear 27.

  Further, as shown in FIGS. 1 and 3, the opening of the speed reduction mechanism housing portion 23 of the gear case 21 is covered with a metal plate-like gear case cover 29 fastened to the gear case 21 with screws 20 b. A circular recess 29 a is formed at a position of the gear case cover 29 that faces the recess 23 a of the speed reduction mechanism housing 23. The upper portion of the support shaft 25 is fitted into the recess 29a by press fitting or the like. A circular hole 29 b is formed at a position of the gear case cover 29 that faces the cylindrical portion 23 b of the speed reduction mechanism housing portion 23. In the circular hole 29b, a cylindrical upper end portion of the output shaft portion 28 having a through hole shape of the output gear 27 is rotatably supported via a thrust / radial bearing (not shown). The worm 15, the worm wheel 26, and the output gear 27 are housed in a speed reduction mechanism housing portion 23 of the gear case 21, and constitute a speed reduction mechanism 24.

  As shown in FIGS. 2 and 3, the worm wheel 26 is made of a synthetic resin and includes a large diameter gear 26a and a small diameter gear 26b. That is, the worm wheel 26 has a large-diameter gear 26a and a small-diameter gear 26b that is concentric with the large-diameter gear 26a and rotates integrally therewith. The large diameter gear 26 a of the worm wheel 26 meshes with the worm 15. Further, the small diameter gear 26 b of the worm wheel 26 is engaged with the output gear 27. An output shaft (not shown) is fixed in the output shaft portion 28 having a through-hole shape of the output gear 27, and a part of the output shaft protrudes outward from the gear case 21 so that torque is taken out to the outside. ing. That is, when the motor 10 with a speed reduction mechanism is applied to, for example, a reclining motor for a power seat of an automobile, the portion of the output shaft that protrudes outward from the gear case 21 is connected to a reclining seat mechanism (not shown). Yes.

  As shown in FIGS. 3 to 7, the brush holder 30 is formed of a synthetic resin into a substantially rectangular plate shape, and rectangular attachment pieces 30 a are integrally formed at the corners of the four corners. As shown in FIGS. 1 and 2, each mounting piece 30 a of the brush holder 30 is fitted in a rectangular locking hole 21 b formed in the peripheral wall 21 a of the gear case 21. This fitting state is locked by a projection 30b or the like integrally formed on each mounting piece 30a. Thereby, as shown in FIG. 3, the brush holder 30 is positioned and attached at a predetermined position in the large-diameter hole portion 22 a of the shaft hole 22 of the gear case 21.

  As shown in FIGS. 4, 6, and 7, a circular through hole 30c is formed in the center of the brush holder 30. An armature shaft 14 and a ring-shaped sensor magnet 41 attached to the armature shaft 14 are inserted into the circular through hole 30c. Further, a substrate placement surface 31 a is formed at a position facing the sensor magnet 41 in the vicinity of the through hole 30 c on the upper surface 31 of the brush holder 30. The substrate 40 is attached to the substrate placement surface 31a in a vertically placed state in which the substrate 40 stands vertically.

  That is, as shown in FIGS. 4 and 5, a pair of substrate holding walls 33, 33 that hold both side portions 40 b, 40 b of the substrate 40 are erected vertically on both sides of the substrate mounting surface 31 a of the brush holder 30. As shown in FIG. Each of the substrate holding walls 33 is formed in a plane L shape, and a locking convex portion 33b and a substrate receiving portion 33a are integrally formed on the front and rear sides thereof. And it hold | maintains so that the both sides 40b and 40b of the board | substrate 40 may be clamped between each board | substrate receiving part 33a and each latching convex part 33b of a pair of board | substrate holding walls 33 and 33, respectively. Further, a substrate seat wall 34 having a substrate receiving surface 34a is integrally formed so as to stand vertically at a position between the pair of substrate holding walls 33, 33 adjacent to the through hole 30c of the substrate placement surface 31a. It is. Between the pair of substrate holding walls 33, 33 and the substrate seat wall 34, the substrate 40 stands vertically on the substrate mounting surface 31 a while maintaining a vertically placed state.

  As shown in FIG. 4, a pair of power supply terminals (other parts) 36 and 36 for supplying power to the brush 35 and a high-speed drive are disposed around the through hole 30c on the upper surface 31 of the brush holder 30. A terminal (other parts) 37, a low-speed drive terminal (other parts) 38, and the like are arranged. Further, as shown in FIGS. 5 to 7, a pair of brush storage portions 32 a and 32 a are integrally formed on the lower surface 32 of the brush holder 30 so as to sandwich the through hole 30 c. A brush 35 is housed in each brush housing portion 32a so as to be able to move in and out, and the brush 35 is pressed and urged to come into contact with the commutator piece 19a of the commutator 19 by a compression coil spring as urging means (not shown). Yes. As shown in FIGS. 5 and 7, each brush 35 is connected to one end of an electromagnetic noise reducing choke coil 39b including a columnar magnetic core 39a through a pictail 35a. The other end of the choke coil 39b is connected to a power supply terminal 36.

  The sensor magnet 41 is formed in a cylindrical shape that is multipolarly magnetized in the circumferential direction. As shown in FIGS. 3 to 5, a Hall element (magnetic detection sensor) 42 for detecting a change in the magnetic field of the sensor magnet 41 is attached to the center of the surface 40 a of the substrate 40. That is, the Hall element 42 detects rotational information such as the rotational speed and rotational speed of the armature shaft 14 based on a change in the magnetic field of the sensor magnet 41 that rotates together with the armature shaft 14.

  According to the motor 10 with the speed reduction mechanism of the embodiment described above, the drive torque output from the motor 10 with the speed reduction mechanism is transmitted to the worm 15 near the one end portion 14b of the armature shaft 14, and the first stage gear is transmitted from the worm 15. And is transmitted from the worm wheel 26 to an output gear 27 as a second-stage gear, and is fixed in the rotational direction within a through-hole-shaped output shaft portion 28 located at the center of the output gear 27. Torque is taken out from the output shaft.

  In the motor 10 with the speed reduction mechanism, as shown in FIGS. 3 to 5 and 7, the substrate 40 with the Hall element 42 attached to the upper surface 31 of the brush holder 30 is attached in a vertical state so as to stand vertically. Thus, the ratio of the substrate 40 to the upper surface 31 of the brush holder 30 can be made as small as possible as compared with a conventional case where the substrate 40 is mounted in the horizontal position. As a result, a sufficient space for arranging other components such as the terminals 36, 37, 38 on the upper surface 31 of the brush holder 30 can be secured. As a result, the layout of other components such as the terminals 36, 37, and 38 attached to the upper surface 31 of the brush holder 30 can be improved.

  In particular, a through hole 30c through which the armature shaft 14 and the sensor magnet 41 are inserted is formed in the center of the brush holder 30, and a substrate mounting surface 31a is formed in the vicinity of the through hole 30c on the upper surface 31 of the brush holder 30, By attaching the substrate 40 vertically to the substrate placement surface 31a, it is not necessary to form a circular hole in the substrate 40 with respect to the through-hole 30c of the brush holder 30 as in the prior art. The yield of the substrate 40 can be improved and the cost of the substrate 40 can be reduced.

  In addition, according to the said embodiment, although the case where the motor with a speed reduction mechanism was applied to the motor for reclining of the power seat of a motor vehicle was demonstrated, the said embodiment was applied to motors with other speed reduction mechanisms, such as a power window motor and a wiper motor. Of course you can.

It is a top view which shows the motor with a reduction mechanism of one Embodiment of this invention. It is a top view which shows the state which removed the gear case cover of the said motor with a reduction mechanism. It is sectional drawing of the said motor with a reduction mechanism. It is a top view of the brush holder used for the said motor with a reduction mechanism. It is a left view of the said brush holder. It is a bottom view of the brush holder. It is sectional drawing which follows the XX line in FIG. It is sectional drawing of the conventional brush holder. It is a top view of the said conventional brush holder.

Explanation of symbols

10 Motor with reduction mechanism 11 Yoke (motor case)
DESCRIPTION OF SYMBOLS 14 Armature shaft 18 Armature 19 Commutator 21 Gear case 24 Deceleration mechanism 30 Brush holder 30c Through hole 31 Upper surface 31a Substrate mounting surface 35 Brush 40 Substrate 41 Sensor magnet 42 Hall element (Magnetic detection sensor)

Claims (2)

A motor case that houses an armature that rotates when energized, and a gear case that is connected to the motor case and houses a reduction mechanism that decelerates the rotation of the armature, the armature shaft being freely rotatable between the motor case and the gear case A brush holder is attached to at least one of the motor case and the gear case, and a commutator and a sensor magnet are respectively attached to predetermined positions of the armature shaft, and the brush accommodated in the brush holder is retractable. In a motor with a speed reduction mechanism in which a substrate is attached to a position opposite to the sensor magnet of the brush holder, and a magnetic detection sensor for detecting a change in the magnetic field of the sensor magnet is attached to the substrate.
A motor with a speed reduction mechanism, wherein the substrate is attached to the brush holder so as to stand vertically. A motor with a speed reduction mechanism according to claim 1,
A through hole through which the armature shaft and the sensor magnet are inserted is formed at the center of the brush holder, and a substrate mounting surface is formed in the vicinity of the through hole on the upper surface of the brush holder. A motor with a speed reduction mechanism, characterized in that the substrate is mounted vertically.

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