JP2008092642A - Motor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor device which can simplify the manufacturing process of the motor device, and can position a sub-yoke to a regular position of a main yoke with respect to the axial direction. <P>SOLUTION: When press-molding the main yoke 13, the shape of the internal side face of each edge supporting part 15, 15 is formed into a shape so as to copy the shape of the external side face of the edge 16a of the sub-yoke 16. By this, a cutting process for forming a tapered face on the sub-yoke which has been necessary hitherto can be eliminated, and the manufacturing process of a wiper motor 10 can be simplified while suppressing an increase in the number of machining man-hours of the main yoke 13. Since the shape of the internal side face of the edge 16a of the sub-yoke 16 and the shape of the external side face of each edge supporting part 15, 15 of the main yoke 13 can firmly be joined with each other by being formed into the same shapes, the sub-yoke 16 can be positioned at the regular position of the main yoke 13 with respect to the axial direction. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a motor device in which a sub yoke to which a magnet is fixed is press-fitted inside a main yoke.

As a motor device mounted on a vehicle such as an automobile, there is a motor device that is used in a wiper device, a power window device, a sliding door opening / closing device, etc., and has a reduction mechanism that can obtain a relatively large output. The motor device mounted on the vehicle is desired to be mounted on the vehicle body frame and to be reduced in weight as an energy saving measure. In order to solve such a problem, for example, a motor device described in Patent Document 1 is known. In the motor device described in Patent Document 1, a sub-yoke having a C-shaped cross section that can be elastically deformed in the radial direction is mounted inside a main yoke constituting the motor device, and a magnetic path of a magnet is formed in the sub-yoke. Thus, the thickness of the main yoke is reduced to reduce the weight of the entire motor device. Then, the positioning of the sub yoke in the axial direction with respect to the main yoke is performed by abutting the end surface on the tip side in the mounting direction of the sub yoke with respect to the main yoke against the bottom surface formed on the bottom side of the main yoke.
JP 2001-309586 A

  However, according to the motor device described in Patent Document 1 described above, although the sub yoke can be positioned at a normal position with respect to the axial direction of the main yoke, an arc-shaped curved portion is formed on the outer peripheral side of the bottom of the main yoke at the time of press molding. Therefore, a tapered surface for avoiding the curved portion is formed on the outer peripheral side of the end surface of the sub yoke. Therefore, in order to form the sub-yoke, in addition to the bending process for forming the steel plate to have a C-shaped cross section, a cutting process for forming a tapered surface on the outer peripheral side of the end surface of the sub-yoke is required, and the manufacturing process of the motor device Was complicated.

  An object of the present invention is to provide a motor device capable of simplifying the manufacturing process of the motor device and positioning the sub yoke at a normal position with respect to the axial direction of the main yoke.

  The motor device according to the present invention includes a bottomed cylindrical main yoke, a sub-yoke having a C-shaped cross section that is elastically deformable in a radial direction and press-fitted inside the main yoke, and is fixed to the inner side of the sub-yoke. A motor device having a first magnet and a second magnet, wherein the edge portion is provided on one end side in the axial direction of the sub yoke, and is provided to protrude radially inward on the bottom portion side of the main yoke. An edge support portion that contacts the main yoke with respect to the axial direction and the radial direction, and the inner side surface shape of the edge support portion is the outer surface shape of the edge portion during press molding of the main yoke. It is characterized in that it is formed in a shape following the above.

  The motor device of the present invention is characterized in that at least two edge support portions are provided at equal intervals in the circumferential direction of the main yoke.

  The motor device according to the present invention is characterized in that slits formed in the sub-yoke having a C-shaped cross section are arranged at positions away from the edge support portions in the circumferential direction of the main yoke.

  According to the present invention, an edge portion provided on one end side in the axial direction of the sub yoke, and a protruding portion provided radially inward on the bottom portion side of the main yoke, are brought into contact with the edge portion in the axial direction and the radial direction, and the main yoke of the sub yoke. An edge support portion for positioning with respect to the main yoke, and at the time of press molding of the main yoke, the inner side surface shape of the edge support portion is formed to follow the outer surface shape of the edge portion, thereby suppressing an increase in the man-hours for processing the main yoke. Cutting for forming a tapered surface in the sub yoke can be omitted. Therefore, the manufacturing process of the motor device can be simplified. Since the inner side surface shape of the edge portion of the sub yoke and the outer surface shape of the edge support portion of the main yoke can be made the same shape, both can be brought into close contact with each other, so that the sub yoke is positioned at a proper position with respect to the axial direction of the main yoke. Can do.

  According to the present invention, since at least two edge support portions are provided at equal intervals in the circumferential direction of the main yoke, the sub yoke can be moved by bringing the edge portion of the sub yoke into contact with each edge support portion of the main yoke. It can be mounted on the same axis without being twisted with respect to the main yoke. Therefore, the sub yoke and the main yoke can be brought into close contact with each other to obtain stable motor characteristics, and variations between products can be suppressed.

  According to the present invention, the slits formed in the sub-yoke having a C-shaped cross section are arranged at positions away from the respective edge support portions in the circumferential direction of the main yoke. Therefore, the portions corresponding to the respective edge support portions of the sub-yoke are provided. When pressing from the axial direction and press-fitting into the main yoke, the torsional deformation of the sub yoke can be further suppressed, and the sub yoke can be attached to the main yoke with high accuracy.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  1 is a front view showing a wiper motor according to an embodiment of the present invention, FIG. 2 is a partially enlarged view of a broken line circle A portion of FIG. 1, and FIG. 3 is a view of the main yoke of FIG. FIG. 4 is a perspective view showing a sub-yoke to which a magnet is fixed, and FIG. 5 is a partially enlarged cross-sectional view showing a connecting portion between the sub-yoke and the gear case.

  The wiper motor 10 serving as a motor device is used as an actuator for a wiper device that secures the driver's field of view by wiping rain attached to a front windshield of a vehicle (not shown) or splashes of a front vehicle. The wiper motor 10 is provided in an engine room of a vehicle (not shown), and wipes a wiper arm provided via a link mechanism or the like within a predetermined wiping range on the windshield.

  The wiper motor 10 has an electric motor 11 and a gear case 12, which are connected to each other by screws (not shown). The electric motor 11 includes a main yoke 13 as a housing that forms an outer shell thereof. The main yoke 13 is closed at one end (right side in the drawing) and opened at the other end (left side in the drawing). Is formed. The main yoke 13 is formed by applying a pressing means such as press working to a plate material (steel plate) made of steel, and a yoke body 13a and a flange portion 13b integrally formed on the left side of the yoke body 13a in the drawing. And a stepped bottom portion 13c that forms the bottom side of the main yoke 13.

  The stepped bottom portion 13c has an annular flat surface portion 14 whose outer peripheral side is connected to the yoke body 13a. The outer peripheral side of the annular flat surface portion 14 protrudes toward the left side and the radial inner side of the main yoke 13 in the figure. A pair of edge support parts 15 and 15 are formed. As shown in FIGS. 1 and 3, the edge support portions 15, 15 are arranged to face each other at regular intervals along the circumferential direction of the main yoke 13, that is, so as to have an arrangement relationship of 180 degrees with each other. ing. The edge support portions 15 and 15 are formed simultaneously with the yoke main body 13a, the flange portion 13b, and the stepped bottom portion 13c when the main yoke 13 is press-molded.

  Each edge support portion 15, 15 has an inner peripheral wall portion 15a on the stepped bottom portion 13c side of the yoke body 13a, and an axial wall portion 15b facing the flange portion 13b side, and the inner peripheral wall portion 15a and the axial direction are provided. The wall portions 15b are connected so as to be perpendicular to each other. As shown in FIG. 2, the inner surface shape of the inner peripheral wall portion 15a and the axial direction wall portion 15b is a shape that follows the outer peripheral surface shape of the edge portion 16a formed on one axial end side (right side in the drawing) of the sub yoke 16, That is, the edge portion 16a is formed in the same shape as the edge portion 16a so that the edge portion 16a can be in close contact with the edge support portions 15 and 15.

  Inside the main yoke 13, a sub-yoke 16 formed in a cylindrical shape by bending or the like while punching a plate material (steel plate) made of steel by pressing or the like is fixed. Since the sub yoke 16 is formed in a cylindrical shape having a C-shaped cross section as shown in FIG. 4, a slit 16 b extending in the axial direction is formed in a part of the circumferential direction, thereby elastically deforming in the radial direction. It has become. As shown in FIG. 2, an edge having an outer peripheral side surface 16c and an axial end surface 16d connected to each other so as to be perpendicular to each other when punched by press working or the like is provided on one end side (right side in the drawing) of the sub yoke 16. A portion 16a is formed.

  The sub yoke 16 is press-fitted toward the edge support portions 15 and 15 in the main yoke 13 from the edge portion 16a side in a state of being elastically deformed (reduced diameter) inward in the radial direction. Then, the outer peripheral side surface 16c and the axial end surface 16d of the edge portion 16a are in close contact with the inner peripheral wall portion 15a and the axial wall portion 15b of each edge support portion 15, 15 so that the sub yoke 16 is in the normal axial direction with respect to the main yoke 13. It is positioned at the position and the radial position.

  The slit 16b of the sub-yoke 16 is, as shown by a broken line in FIG. 3, a portion away from the edge support portions 15 and 15 in the circumferential direction of the main yoke 13, here, 90 degrees with respect to the edge support portions 15 and 15. Placed in position. Thus, when the sub yoke 16 is press-fitted into the main yoke 13, the portions corresponding to the edge support portions 15 and 15 of the sub yoke 16 (pressed portions C indicated by black circles in the figure) are pressed. By pressing the sides in a well-balanced manner, the torsional deformation of the sub yoke 16 is suppressed.

  Here, the “position away from each edge support portion” in the present invention refers to the position of the slit in the circumferential direction of each edge support portion that can suppress torsional deformation of the sub yoke when the sub yoke is press-fitted into the main yoke. Say that. For example, when the thickness of the sub-yoke is relatively thick and the sub-yoke is difficult to torsionally deform, the sub-yoke may be arranged so as to be at a position of 60 degrees from one edge support part (120 degrees from the other edge support part). it can.

  As shown in FIG. 1, on the other end side (left side in the figure) of the sub yoke 16, an annular projecting portion 16e projecting to the gear case 12 side from the flange portion 13b of the main yoke 13 is provided. By fitting 16e into the gear case 12, the main yoke 13 and the gear case 12 are arranged coaxially (alignment). As shown in FIGS. 4 and 5, the annular projecting portion 16e is integrally provided with an engaging convex portion 16f that projects further toward the gear case 12 than the annular projecting portion 16e. By engaging the protrusion 16 f with the engagement recess 12 a formed in the gear case 12, relative rotation between the sub yoke 16 and the gear case 12 is prevented.

  The main yoke 13 and the sub yoke 16 are in contact with each other over the entire surface, and the sub yoke 16 functions as a yoke member for securing the magnetic flux together with the main yoke 13. Thus, since the sub yoke 16 functions as a yoke member, a housing made of a synthetic resin material such as a hard plastic material is formed in the same shape as the main yoke 13 instead of the steel main yoke 13. In this case, the electric motor 11 can be driven to rotate. Further, the housing is not limited to a synthetic resin material, and can be molded from other light non-magnetic materials.

  Inside the sub yoke 16, a pair of first and second magnets (permanent magnets) 17 a, 17 b having a substantially arc shape in cross section are disposed at positions avoiding the slits 16 b of the sub yoke 16. It is fixed by the adhesive means. As shown in FIG. 1, an armature 18 is rotatably provided opposite to the first and second magnets 17 a and 17 b via a predetermined gap (air gap). The armature 18 has a rotation shaft 18a so as to pass through the central axis thereof, and one end side (right side in the figure) of the rotation shaft 18a is interposed via a bearing 19 attached to the stepped bottom portion 13c of the main yoke 13. Are supported by the stepped bottom 13c. The bearing 19 is fixed at a predetermined position of the stepped bottom portion 13c by a pressing member 19a that is press-fitted and fixed to the stepped bottom portion 13c.

  A commutator 18b (broken line in the figure) is integrally provided on the rotating shaft 18a of the armature 18, and a plurality of brushes 20 and 20 (two in the broken line in the figure) have a predetermined elastic pressure. It comes in sliding contact. Further, worms 21a and 21b are integrally formed on the other end side of the rotary shaft 18a, and the worms 21a and 21b have a relationship in which the forming directions (twisting directions) of the helical teeth are opposite to each other. It is formed to become.

  The gear case 12 is formed by pouring a molten aluminum material into a mold at a predetermined pressure, that is, by die casting. The gear case 12 includes a bottomed case body 12b and brushes 20 and 20. It is comprised from the brush holder part 12c which hold | maintains. Inside the case body 12b, the worms 21a and 21b formed on the rotary shaft 18a are accommodated so as to protrude from the main yoke 13 side (right side in the figure), and the rotation center orthogonal to the rotation center axis of the rotary shaft 18a. A pair of worm wheels 22, 23 having a shaft and a spur gear 24 are accommodated. An output shaft 25 is integrally provided at the center of rotation of the spur gear 24, and the output shaft 25 extends through the bottom of the case body 12 b to the outside of the gear case 12. A link mechanism for swinging a wiper arm (not shown) is connected to an end (not shown) extending to the outside of the output shaft 25.

  A brush holder base 26 (broken line in the figure) is fixed and provided inside the brush holder portion 12c, and the brushes 20 and 20 are provided on the brush holder base 26 so as to be slidable. A flange portion 12d is integrally formed on the opening side (right side in the drawing) of the brush holder portion 12c, and the annular projecting portion 16e of the sub yoke 16 enters and fits inside the flange portion 12d. Yes.

  The pair of worm wheels 22 and 23 mesh with the worms 21a and 21b with the axis of the rotary shaft 18a interposed therebetween, and are accommodated in the case main body 12b. Are provided integrally. Each pinion 22a, 23a is meshed with a spur gear 24, and the rotational force of each worm wheel 22, 23 is transmitted to the spur gear 24 via each pinion 22a, 23a. Therefore, the rotation of the armature 18 is decelerated through the worm wheels 22 and 23, and the decelerated and increased torque is output to the output shaft 25 of the spur gear 24.

  An annular groove 27 is formed on one side surface of the spur gear 24, and a conductive member 28 made of a conductive thin plate member is press-fitted and fixed to a predetermined position in the circumferential direction of the annular groove 27. The conductive member 28 can rotate integrally with the spur gear 24. The conductive member 28 is formed in a substantially crescent shape by stamping and punching a thin plate member, and the conductive member 28 stands up from the bottom side of the annular groove 27 of the spur gear 24 in the upper side in the figure. A pair of contact members 28a and 28b bent in this manner are integrally provided.

  The contact members 28a and 28b are in contact or non-contact with a pair of conductive members mounted on an insulator as an insulating member mounted on a case cover (not shown). Then, the contact members 28a and 28b stop the wiper arm at a predetermined position by detecting that the controller (not shown) detects the wiper switch OFF signal and that the contact members 28a and 28b are short-circuited with the conductive members. A so-called automatic fixed position stop device (not shown) is configured.

  As shown in FIG. 5, a fitting wall portion 29 having a circumferential surface with which the annular protrusion 16e of the sub yoke 16 is fitted is formed on the inner side of the flange portion 12d of the brush holder portion 12c of the gear case 12. A stepped portion 30 that restricts the movement of the sub yoke 16 in the axial direction (downward in the drawing) is formed below the fitting wall portion 29 in the drawing. An engagement recess 12a into which the engagement projection 16f of the sub yoke 16 enters is formed at a predetermined position along the circumferential direction of the stepped portion 30, and the engagement recess 12a is substantially the same as the engagement projection 16f. It is formed in a shape (substantially rectangular shape).

  The engagement recess 12a and the engagement protrusion 16f engage with each other in an uneven manner, whereby the brushes 20 and 20 fixed to the brush holder base 26 and the sub yoke 16 are fixed at predetermined positions along the circumferential direction of the brush holder portion 12c. The relative positional relationship between the first and second magnets 17a and 17b fixed at a predetermined position along the circumferential direction is a predetermined positional relationship, that is, a positional relationship capable of maintaining the advance angle of the wiper motor 10 in an appropriate state. Thus, the wiper motor 10 can generate a normal output.

  Next, a method for manufacturing the main yoke 13 will be described with reference to FIGS. 6 (a) and 6 (b) are explanatory diagrams for explaining the first press molding process by the press molding apparatus, and FIGS. 7 (a) and 7 (b) are for explaining the second press molding process by the press molding apparatus. Each explanatory diagram is shown.

  The press molding apparatus 40 includes a rod-shaped die 41 having a substantially hemispherical tip side (upper side in the drawing), and a slide that is provided so as to surround the rod-shaped die 41 and slides in the vertical direction in the drawing. It has a die 42 and a hollow punch 43 that slides in the vertical direction in the figure by a drive mechanism that uses a hydraulic source or the like (not shown) as a drive source. A gap corresponding to the thickness of the workpiece W that will later become the main yoke 13 is formed between the inner peripheral side of the hollow portion 43 a of the hollow punch 43 and the outer peripheral side of the rod-shaped die 41.

  First, as shown in FIG. 6A, a workpiece W made of a steel plate is set at a predetermined position on the upper surfaces of the rod-shaped die 41 and the slide die 42. Then, the hollow punch 43 is gradually moved downward in the figure by the drive mechanism, and the lower surface of the hollow punch 43 is brought into contact with the workpiece W. After that, the hollow punch 43 is continuously lowered by the drive mechanism, so that the slide die 42 is lowered together with the hollow punch 43 as shown by a one-dot chain line arrow in FIG.

  When the slide die 42 is lowered together with the hollow punch 43, as shown in FIG. 6B, the workpiece W is plastically deformed (press-molded) following the outer shape of the non-moving rod-shaped die 41 to be formed into a substantially cup shape. . Thereafter, the drive mechanism is driven to raise the hollow punch 43 as shown by a one-dot chain arrow in FIG. 6B, whereby the workpiece W formed in a substantially cup shape can be detached from the rod-shaped die 41 (first). 1 press molding process).

  Next, the workpiece W formed in a substantially cup shape after the first press molding step is set in the press molding apparatus 50 shown in FIG.

  The press forming apparatus 50 includes a stepped die 51 whose front end side (upper side in the drawing) is a shape inside the stepped bottom portion 13c (see FIG. 1) of the main yoke 13, and the stepped die 51 is surrounded. A slide die 52 that slides in the vertical direction in the figure relative to the stepped die 51 and a hollow punch 53 that slides in the vertical direction in the figure by a drive mechanism (not shown) are provided. The hollow portion 53 a of the hollow punch 53 has a shape outside the stepped bottom portion 13 c of the main yoke 13, and the main yoke is later formed between the inner peripheral side of the hollow portion 53 a and the outer peripheral side of the stepped die 51. A gap corresponding to the thickness of the workpiece W 13 is formed.

  In the stepped die 51, a pair of concave portions 51a and 51a for forming the edge support portions 15 and 15 shown in FIG. In addition, a pair of convex portions 53 b and 53 b for forming the edge support portions 15 and 15 are arranged to face each other in the hollow portion 53 a of the hollow punch 53. The concave portions 51a and 51a and the convex portions 53b and 53b are arranged so as to be in a state where the phase relations coincide with each other, that is, so as to be coaxial with each other.

  After the workpiece W is set in the press molding apparatus 50, the hollow punch 53 is gradually moved downward in the drawing by the drive mechanism as shown by a one-dot chain arrow in FIG. Contact W. Thereafter, the hollow punch 53 is continuously lowered by the drive mechanism, whereby the workpiece W is plasticized following the outer shape of the stationary step die 51 as the slide die 52 is lowered as shown in FIG. By being deformed (press-molded), the stepped bottom portion 13c and the edge support portions 15 and 15 shown in FIG.

  Thereafter, the workpiece W can be detached from the stepped die 51 by driving the drive mechanism to raise the hollow punch 53 as shown by the one-dot chain line arrow in FIG. 7B (second press forming step). . And the main yoke 13 is completed by cutting the surplus of the workpiece | work W removed from the stepped die 51 using the processing apparatus which is not shown in figure, and forming the flange part 13b etc. which are shown in FIG.

  Next, a method for assembling the wiper motor 10 will be described with reference to FIG. FIGS. 8A, 8B, 8C, and 8D are explanatory diagrams for explaining the assembly procedure of the wiper motor.

  In assembling the wiper motor 10, first, the yoke assembly SA shown in FIG. 8D is assembled. As shown in FIG. 8A, the bearing 19 is disposed at a predetermined position on the stepped bottom 13c of the main yoke 13 from the direction of the arrow. Thereafter, in order to fix the bearing 19 at a predetermined position of the stepped bottom 13c, the pressing member 19a is fitted and fixed to the stepped bottom 13c from the direction of the arrow. Thus, the bearing 19 is disposed at a predetermined position of the stepped bottom portion 13c, and the retaining member 19a prevents the bearing 19 from coming off.

  Next, as shown in FIG. 8 (b), a pair of first and second magnets 17a and 17b are inserted inside the sub-yoke 16 formed in a cylindrical shape in advance, as indicated by arrows in the figure. . And it fixes to the predetermined position of the axial direction which left the annular protrusion 16e of the sub yoke 16 using an adhesive agent (not shown).

  The sub-yoke 16 to which the first and second magnets 17a and 17b are attached is elastically deformed (reduced diameter) inward in the radial direction, and in this state, the inner side of the main yoke 13 from the direction of the arrow in FIG. Gradually insert into. At this time, the pressing portions C and C indicated by black circles in FIG. 3 are pressed toward the edge support portions 15 and 15, and the insertion of the sub yoke 16 into the main yoke 13 is continued. Then, the edge portion 16a of the sub-yoke 16 is in close contact with the edge support portions 15 and 15, that is, as shown in FIG. 2, the axial end surface 16d and the axial wall portion 15b, and the outer peripheral side surface 16c and the inner peripheral wall portion 15a contact each other. Then, the insertion is finished, and thereby the yoke assembly SA is completed as shown in FIG.

  Thereafter, the armature 18 is inserted into the completed yoke assembly SA, and the yoke assembly SA is mounted from the opening side of the flange portion 12 d of the brush holder portion 12 c of the gear case 12. At this time, as shown in FIG. 5, the engagement recess 12a and the engagement protrusion 16f are mounted so as to engage with each other. Then, the gear case 12 and the main yoke 13 are connected by screws (not shown).

  Next, as shown in FIG. 1, the worm wheels 22 and 23 are attached to the case main body 12b so as to mesh with the worms 21a and 21b accommodated in the case main body 12b. The worm wheels 22 and 23 are mounted so as to mesh with each other. Then, by attaching a case cover (not shown) to the gear case 12, the wiper motor 10 is completed.

  As described above in detail, according to the wiper motor 10 according to the embodiment of the present invention, when the main yoke 13 is press-molded, the inner surface shape of the pair of edge support portions 15, 15 is changed to the edge portion 16 a of the sub yoke 16. Therefore, it is possible to omit the cutting process for forming the tapered surface on the sub yoke, which has been necessary in the past, while suppressing an increase in the number of processing steps of the main yoke 13. Therefore, the manufacturing process of the wiper motor 10 can be simplified.

  Further, since the inner side surface shape of the edge portion 16a of the sub yoke 16 and the outer surface shape of the edge support portions 15 and 15 of the main yoke 13 can be made to be the same shape, they can be brought into close contact with each other. It can be positioned at a normal position with respect to the axial direction.

  Furthermore, according to the wiper motor 10 according to the embodiment of the present invention, the pair of edge support portions 15, 15 are provided at equal intervals (180 degree intervals) in the circumferential direction of the main yoke 13. By bringing the edge portion 16 a into contact with the edge support portions 15, 15 of the main yoke 13, the sub yoke 16 can be mounted coaxially without being twisted with respect to the main yoke 13. Therefore, the sub yoke 16 and the main yoke 13 can be brought into close contact with each other, so that stable motor characteristics can be obtained, and variations among products can be suppressed.

  Further, according to the wiper motor 10 according to the embodiment of the present invention, the slit 16b formed in the sub-yoke 16 having a C-shaped cross section is separated from the edge support portions 15 and 15 in the circumferential direction of the main yoke 13. Since it is disposed at the position, the torsional deformation of the sub yoke 16 is further suppressed when the pressing portions C, C corresponding to the edge support portions 15, 15 of the sub yoke 16 are pressed from the axial direction into the main yoke 13. Therefore, the sub yoke 16 can be mounted on the main yoke 13 with high accuracy.

  It goes without saying that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention. For example, in the above-described embodiment, the edge support portion 15 that supports the edge portion 16a of the sub yoke 16 is disposed opposite to the main yoke 13. However, the present invention is not limited to this, for example, in the radial direction. In the case of using a sub yoke whose elastic force is set to be small, the sub yoke is easily press-fitted into the main yoke 13 and is not easily twisted. Therefore, only one edge support portion may be formed. On the other hand, in the case of using a sub-yoke having a large elastic force in the radial direction so as to correspond to a relatively large motor device or the like, two or more edge support portions are formed at equal intervals on the main yoke. Also good.

  In the above embodiment, the first and second magnets 17a and 17b are fixed to the sub yoke 16 before the slit 16b of the sub yoke 16 is avoided and the sub yoke 16 is press-fitted into the main yoke 13. However, the present invention is not limited to this, and the magnet may be fixed at a position straddling the slit 16 b of the sub yoke 16 after the sub yoke 16 is press-fitted into the main yoke 13. In this case, since the slit can be disposed at a place where the influence on the magnetic path reduction of the magnet is small and the armature reaction is difficult to obtain, the performance reduction of the motor device can be suppressed.

  Furthermore, in the above-described embodiment, the shape of the engagement convex portion 16f of the sub yoke 16 and the engagement concave portion 12a of the gear case 12 is shown as a substantially rectangular shape along the circumferential direction. For example, the engaging convex portion and the engaging concave portion having a substantially semicircular arc shape may be used. In short, the shape is not limited as long as they are engaged with each other and become non-rotatable. Further, the concave / convex relationship can be reversed by forming the engaging convex portion in the gear case and the engaging concave portion in the sub yoke.

  Further, in the above embodiment, the wiper motor 10 as the motor device is applied to the front wiper device for wiping the front windshield. However, the present invention is not limited to this, and the rear windshield is wiped. The present invention can also be applied to a rear wiper device.

  Moreover, in the said embodiment, although the thing used as the wiper motor 10 used for a wiper apparatus was shown as a motor apparatus, this invention is not limited to this, The other used for a power window apparatus, a slide door opening / closing apparatus, etc. The present invention can also be applied to a motor device.

  Furthermore, in the said embodiment, although what was a motor apparatus with a brush was shown as a motor apparatus, this invention is applicable not only to this but a brushless motor etc.

It is a front view which shows the wiper motor which is one embodiment of this invention. It is the elements on larger scale of the broken-line circle | round | yen A part of FIG. FIG. 2 is an arrow view of the main yoke of FIG. 1 viewed from the direction of arrow B. It is a perspective view which shows the sub yoke to which the magnet was fixed. It is a partial expanded sectional view which shows the connection part of a sub yoke and a gear case. (A), (b) is explanatory drawing explaining the 1st press molding process by a press molding apparatus. (A), (b) is explanatory drawing explaining the 2nd press molding process by a press molding apparatus. (A), (b), (c), (d) is explanatory drawing explaining the assembly procedure of a wiper motor.

Explanation of symbols

10 Wiper motor (motor device)
DESCRIPTION OF SYMBOLS 11 Electric motor 12 Gear case 12a Engagement recessed part 12b Case main body 12c Brush holder part 12d Flange part 13 Main yoke 13a Yoke main body 13b Flange part 13c Stepped bottom part 14 Annular plane part 15 Edge support part 15a Inner peripheral wall part 15b Axial wall part 16 Sub yoke 16a Edge portion 16b Slit 16c Outer peripheral side surface 16d Axial end surface 16e Annular protrusion 16f Engaging convex portion 17a First magnet 17b Second magnet 18 Armature 18a Rotating shaft 18b Commutator 19 Bearing 19a Holding member 20 Brush 21a, 21b Worm 22, 23 Worm wheel 22a, 23a Pinion 24 Spur gear 25 Output shaft 26 Brush holder base 27 Annular groove 28 Conductive member 28a, 28b Contact member 29 Fitting wall portion 30 Step portion 40, 50 Press forming device 41 Rod die 42, 52 Slide die 43, 53 Hollow punch 43a, 53a Hollow part 51 Step die 51a Concave part 53b Convex part C Press part SA Yoke assembly W Workpiece

Claims (3)

A bottomed cylindrical main yoke, a sub-yoke having a C-shaped cross section that is formed to be elastically deformable in the radial direction and press-fitted inside the main yoke, and first and second magnets fixed to the inside of the sub-yoke A motor device comprising:
An edge portion provided on one end side in the axial direction of the sub yoke;
An edge support portion that protrudes radially inward on the bottom side of the main yoke, and that contacts the edge portion from the axial direction and the radial direction to position the sub yoke relative to the main yoke;
The motor device, wherein the inner side surface shape of the edge support portion is formed to follow the outer surface shape of the edge portion during press molding of the main yoke.   The motor device according to claim 1, wherein at least two of the edge support portions are provided at equal intervals in a circumferential direction of the main yoke.   3. The motor device according to claim 2, wherein slits formed in the sub-yoke having a C-shaped cross section are arranged at positions away from the respective edge support portions in the circumferential direction of the main yoke. .

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