JP2007089253A - Motor manufacturing method, and motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor for enabling spot welding in at least three positions without a design change in an outer stator core even if an attachment angle between a motor attachment plate and a stator is changed, and enabling an identically structured component to be used for the outer stator core in an output stator group and an opposite output stator group. <P>SOLUTION: In a stepping motor 1, three remaining protrusions can be spot-welded even if one of four protrusions is located in a position in which it can not be welded to the motor attachment plate 6 since four spot welding protrusions for protruding toward the output are formed in the outer stator core 41 of the stator group 4B. There is no problem for assembling even if four protrusions 452 are located in the outer stator core 41 of the stator group 4B since all of four protrusions are spot-welded to a bearing holder 8 and the outer stator core 41 of the stator group 4A. The stator groups 4A, 4B can comprise the identically structured component. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a motor manufacturing method and a motor. More specifically, the present invention relates to a technology for fixing a bearing holder and a motor mounting plate to a stator.

Stepping motors used in digital cameras, digital video cameras, FDDs, ODDs, etc. generally have a rotor arranged inside a rotor arrangement hole that opens in the motor axis direction in a cylindrical stator, and one of the rotation axes. The end is supported by a bearing through a sphere. Here, the bearing is inserted into the through hole of the bearing holder, and is urged toward the rotating shaft by the leaf spring portion of the pressurizing member disposed further on the one end side than the bearing holder. Here, the pressurizing member is provided with two claws extending on the pressurizing member, while the pressurizing member is overlapped with the output side end surface of the bearing holder on the counter output side end surface of the bearing holder. An engagement portion is formed in which the claw portion is hooked when the is rotated, and the pressurizing member is held by the bearing holder by such a claw portion and the engagement portion. In addition, a motor mounting plate used when the motor is mounted on the device is fixed to the output side end surface of the stator. The motor mounting plate is connected to the vertical plate from the end of the horizontal plate extending in the motor axial direction. The portion is bent vertically (see Patent Document 1).
JP 2003-299298 A

  In such a motor, a projection is provided on the output side end surface of the stator, the current is applied with the vertical plate portion of the motor mounting plate superimposed on the output side end surface of the stator, and spot welding is performed using the projection to mount the motor. A structure in which a plate is fixed to a stator is often employed. In this case, the welding between the motor mounting plate and the stator needs to be performed at at least three places in order to ensure the stability, so that the projections are formed at three places. Here, the motor mounting plate is used for mounting the motor to various devices. For this reason, depending on the equipment to which the motor is mounted depending on the terminal position of the motor, the mounting angle of the motor mounting plate to the motor and the shape of the motor mounting plate may change. For example, one of the three protrusions is When the vertical plate portion and the horizontal plate portion are located at the bent portion, a notch is formed therein and the vertical plate portion is overlapped on the output side end surface of the stator. Positioning and welding can be performed only in two places. Therefore, conventionally, it is necessary to change the formation position of the protrusion for each model, and such a design change has a problem on the output side that causes an increase in manufacturing cost.

  On the other hand, the stator is composed of an output-side stator set and a counter-output-side stator set that are arranged so as to overlap in the motor output axis direction, and each of the output-side stator set and the counter-output-side stator set is an outer side in the motor axis direction. An outer stator core, a coil, and an inner stator core sandwiched between the outer stator core and the coil on the inner side in the motor axial direction. Further, since the output side end face of the stator is constituted by the outer stator core of the output side stator assembly, when the projection is provided on the output side end face of the stator, the projection is formed on the outer stator core of the output side stator assembly.

  Here, in the output-side stator assembly and the non-output-side stator assembly, if the outer stator cores, the coils, and the inner stator cores arranged on the outer side in the motor axial direction are each composed of parts having the same structure, the manufacturing cost is reduced. In addition to being able to reduce, the output-side stator group and the counter-output-side stator group can be configured with parts of the same lot, and the magnetic balance is improved.

  However, when the output side stator set and the counter output side stator set have the same structure as the outer stator cores, if three protrusions are formed on the outer stator core of the output side stator set, the outer stator core of the counter output side stator set also has Three protrusions will be formed, and when fixing the bearing holder to the outer stator core of the output side stator assembly, the protrusions will interfere, so the outer stator core, coil, In addition, it is difficult to configure the inner stator core with parts having the same structure.

  In view of the above problems, an object of the present invention is to perform spot welding at least at three locations without changing the design of the outer stator core even if the mounting angle between the motor mounting plate and the stator is changed. An object of the present invention is to propose a motor manufacturing method and a motor that can use parts having the same structure as the outer stator core in the output side stator group and the non-output side stator group.

  In order to solve the above problems, in the present invention, a cylindrical stator having a rotor arrangement hole that opens in the motor axial direction, a rotor arranged in the rotor arrangement hole, and the non-output side in the motor axial direction A bearing for supporting one end of the rotating shaft of the rotor, a bearing holder provided with a through hole in which the bearing is mounted, and disposed on the one end side further than the bearing holder; In a manufacturing method of a motor having a pressurizing member having a leaf spring portion biased toward the motor and a motor mounting plate stacked on the output side end surface of the stator, the stator is stacked in the motor output shaft direction. The output-side stator set and the counter-output-side stator set are arranged, and the output-side stator set and the counter-output-side stator set are arranged outside in the motor axial direction. The stator cores, the coils, and the inner stator cores sandwiching the coils between the outer stator cores on the inner side in the motor axial direction are composed of parts having the same structure, and the rotor is disposed on the end surface of the outer stator core. Four or more spot welding projections projecting toward the outside in the motor axial direction around the arrangement hole are formed, and the bearing holder is provided on the outer stator core that constitutes the non-output side end face by the counter output side stator assembly. A bearing holder fixing step in which spot welding is performed using all of the four or more protrusions by energizing in a pressed state, and the motor mounting plate is pressed against the outer stator core constituting the output side end face by the output side stator assembly The motor mounting plate is fixed so that spot welding is performed using at least three of the four or more protrusions. And performing the step.

  In the motor manufactured by such a method, the stator is composed of an output-side stator set and a counter-output-side stator set that are stacked in the motor output shaft direction, and the output-side stator set and the counter-set In the output side stator assembly, the outer stator cores arranged on the outside in the motor axial direction, the coils, and the inner stator cores sandwiching the coil between the outer stator cores on the inner side in the motor axial direction have the same structure. The outer stator core and the bearing holder, which are composed of parts and constitute the counter-output side end face by the counter-output side stator set, are spot welded at four or more locations around the rotor arrangement hole, and the output-side stator set The outer stator core and the motor mounting plate constituting the output side end face are arranged around the rotor arrangement hole. Te, of the above four positions corresponding to the welding portion at the opposite output side, wherein the spot welding is applied at least three places.

  In the present application, the side on which the rotating shaft protrudes is referred to as an output side, and the side opposite to the side on which the rotating shaft protrudes is referred to as a non-output side.

  In the present invention, since four or more spot welding projections projecting to the output side are formed on the outer stator core constituting the output side end face of the output side stator assembly, welding at at least three locations is possible. . That is, even when the mounting angle of the motor mounting plate with respect to the stator is changed and a part of the protrusion is located at a place where welding cannot be performed, four or more spot welding protrusions are formed on the outer stator core. Therefore, welding can be performed using the remaining three protrusions. Therefore, various motor mounting plates can be fixed in a stable state without changing the design of the outer stator core. Here, if the outer stator cores, the coils, and the inner stator cores constituting the output side stator set and the counter output side stator set are respectively configured from components having the same structure, the counter output side end surface is formed by the counter output side stator set. However, in the present invention, all of the four or more protrusions are formed between the outer stator core constituting the counter-output side end surface of the stator and the bearing holder. Spot welding is performed using For this reason, since the bearing holder can be stacked on the non-output side end face of the stator, the outer stator cores, the coils, and the inner stator cores that constitute the output side stator set and the non-output side stator set are each of the same structure. It can consist of

  In the present invention, in the motor mounting plate fixing step, when spot welding is performed using a part of the four or more projections, the four or more projections are applied to the motor mounting plate. Of these, a notch may be formed at a position overlapping with a protrusion not used for spot welding. In a motor employing such a manufacturing method, the outer stator core and the motor mounting plate that constitute the output-side end face of the output-side stator set are welded on the counter-output side around the rotor arrangement hole. Spot welding is performed in a part of the corresponding four or more locations, and in the remaining locations, spot welding projections protruding from the outer stator core to the output side remain, while the motor mounting plate A cutout is formed at a position overlapping the protrusion.

  In the present invention, the motor mounting plate includes a horizontal plate portion extending in the motor axial direction and a vertical plate portion bent vertically from an end portion of the horizontal plate portion, and the vertical plate portion is an output of the stator. When the spot welding is performed by being overlapped on the side end face, the notch may be formed in a bent portion between the vertical plate portion and the horizontal plate portion. That is, when the motor mounting plate has a horizontal plate portion and a vertical plate portion, spot welding cannot be performed at the bent portion between the vertical plate portion and the horizontal plate portion, so that even if a protrusion is located at the bent portion, there is no problem. It is preferable to form a notch in the bent portion so that there is no occurrence.

  In the present invention, when the number of the protrusions formed on the stator core is four, the pressurizing member is formed with four claw portions protruding from the outer peripheral edge toward the output side at positions separated in the circumferential direction. On the other hand, the bearing holder is formed with an engagement concave portion in which the outer peripheral side region of the output side end surface is recessed toward the non-output side so that the claw portion can be engaged, and the engagement concave portion has four circumferential directions. In the bearing holder fixing step, the spot welding is preferably performed in the region formed between the engagement recesses by the division. If comprised in this way, since the area which an engagement recessed part occupies is small in the outer peripheral side of a bearing holder, it is a spot welding location between the engagement recessed parts divided into four, or between the engagement recessed parts divided into four. Can be secured.

  In the present invention, when the bearing holder has a substantially rectangular shape when viewed from the motor axial direction, the engaging recess is formed in a part of a region corresponding to the side of the rectangular shape, and the bearing In the holder fixing step, it is preferable to perform the spot welding in a region corresponding to the square corner. If comprised in this way, since a wide space can be ensured between the engagement recessed parts of a bearing holder, a spot welding location can be ensured in the outer peripheral side area | region of a bearing holder.

  In the present invention, even when the mounting angle of the motor mounting plate to the stator is changed and a part of the protrusion is positioned at a place where welding cannot be performed, four or more spot welding protrusions are formed on the outer stator core. Therefore, welding can be performed using the remaining three protrusions. Therefore, various motor mounting plates can be fixed in a stable state without changing the design of the outer stator core. Here, if the outer stator cores, the coils, and the inner stator cores constituting the output side stator set and the counter output side stator set are respectively configured from components having the same structure, the counter output side end surface is formed by the counter output side stator set. However, in the present invention, all of the four or more protrusions are formed between the outer stator core constituting the counter-output side end surface of the stator and the bearing holder. Spot welding is performed using For this reason, since the bearing holder can be stacked on the non-output side end face of the stator, the outer stator cores, the coils, and the inner stator cores that constitute the output side stator set and the non-output side stator set are the same in structure. It can consist of Therefore, the cost of the motor can be reduced. Further, since the output side stator group and the counter output side stator group can be constituted by parts of the same lot, the magnetic balance is improved.

  Embodiments of the present invention will be described below with reference to the drawings.

(overall structure)
FIG. 1 is a sectional view of a stepping motor to which the present invention is applied.

  As shown in this figure, a motor 1 of this embodiment is a small PM type stepping motor used for a digital camera, a digital video camera, an FDD, an ODD, and the like. And a stator 3 having a rotor arrangement hole 30 whose base end side is coaxially arranged.

  The stator 3 is composed of an anti-output-side stator set 4A and an output-side stator set 4B (output-side stator set). These stator sets 4A and 4B are stacked in the direction of the motor axis L to form a two-phase structure. It is arranged. Each of the stator sets 4A and 4B includes an outer stator core 41, an annular bobbin 43 around which a coil 42 is wound, and an inner stator core 44 sandwiching the bobbin 43 between the outer stator core 41. The end faces of are fixed. A plurality of pole teeth 411 and 441 are erected from the inner peripheral edges of the outer stator core 41 and the inner stator core 44, and these pole teeth 411 and 441 are alternately arranged in the circumferential direction along the inner peripheral surface of the bobbin 43. It has a configuration. Thus, the cylindrical stator 3 provided with the rotor arrangement hole 30 is configured, and the proximal end side of the rotor 2 is coaxially arranged inside the rotor arrangement hole 30. The rotor 2 includes a rotor magnet 22 that is polarized and magnetized in the circumferential direction around the base end side of the rotating shaft 21, and the rotor magnet 22 is disposed inside the rotor arrangement hole 30 and has stator pole teeth 411. , 441 are opposed to each other with a predetermined interval. In this embodiment, a cylindrical case 10 is configured by the outer peripheral portion and the bottom portion of the outer stator core 41, and the stator 3 including the coil 42, the inner stator core 44, and the outer stator core 441 in the case 10, and the rotor 2. The base end side of the is arranged.

  Here, in the stator set 4A on the counter-output side and the stator set 4B on the output side, parts having the same structure are used for the outer stator cores 41, the coils 42, the bobbins 43, and the inner stator cores 44, respectively. It has been.

  In the counter output side stator assembly 4A, a counter output side bearing 7 is arranged on the counter output side of the outer stator core 41. The counter output side bearing 7 is connected to the counter output side of the rotary shaft 21 via a steel ball 71. Supports the end. Further, a plate-like bearing holder 8 made of a sintered body is disposed on the side opposite to the stator 3 so as to at least partially overlap the stator 3, and the counter-output side bearing 7 corresponds to the bearing holder 8. It is in a state of being inserted into the through hole 80. Further, a spring member 9 made of a thin metal plate is disposed further on the side opposite to the output side than the bearing holder 8, and a leaf spring portion 90 cut and raised in the spring member 9 is provided on the counter output side bearing 7 in the through hole 80. The end is biased toward the rotating shaft 21. Here, the leaf spring portion 90 is in contact with a position shifted from the center of the non-output side bearing 7.

  In the output side stator set 4B, a metal motor mounting plate 6 having a U-shaped cross section is disposed on the output side of the outer stator core 41. The motor mounting plate 6 is a horizontal plate extending in the motor axial direction. Portion 63, a base end side vertical plate portion 61 bent vertically at the opposite end portion of the horizontal plate portion 63, and a base end side vertical plate portion bent vertically at the output end portion of the horizontal plate portion 63. The rotating shaft 21, which includes a front end side vertical plate portion 62 that opposes 61, passes through a hole 610 formed in the base end side vertical plate portion 61, and the front end portion thereof passes through the steel ball 51. It is supported by the output side bearing 5 held by the front end side vertical plate portion 62. In the motor attachment plate 6, the horizontal plate portion 63 is used as a fixed plate for attaching the motor to various devices. A lead screw groove 25 is formed in the outer peripheral surface portion of the output side of the rotating shaft 21, and a device-side fed object (not shown) that engages with the lead screw groove 25 is moved along with the rotation of the rotating shaft 21. It is made to move in the direction of the axis L (thrust direction).

(Detailed configuration on the non-output side)
2 (a) and 2 (b) are an exploded perspective view showing the disassembled output side of the stepping motor 1 shown in FIG. 1 and a perspective view showing the structure of the output side end face of the bearing holder 8. FIG. FIGS. 3A to 3C are a plan view, a longitudinal sectional view, and a bottom view showing a configuration of the output side end face of the bearing holder 8 of the stepping motor 1 shown in FIG. . FIGS. 4A to 4C are plan views showing the spring member 9 of the stepping motor 1 shown in FIG. 1, a longitudinal sectional view taken along line II, and a cross section of the leaf spring portion 90. FIG. FIG.

  In this embodiment, the following structure is adopted when fixing the bearing holder 8 and the spring member 9 to the counter-output side of the stator 4.

  First, as shown in FIG. 2A, the outer stator core 41 includes a substantially annular bottom plate portion 412 that constitutes the non-output side end surface of the case 10, an outer peripheral surface portion 413 that contacts the outer peripheral surface of the case 10, and a bottom plate portion. And a plurality of pole teeth 411 standing at the inner peripheral edge of the central hole 412.

  Here, on the bottom plate portion 412 of the outer stator core 41 (the end face on the counter-output side of the stator 3), four protrusions 451 (protrusions for spot welding) protruding in the counter-output direction are formed around the rotor arrangement hole 30. Yes. These protrusions 451 are formed at intervals of approximately 90 degrees with the motor axis L as the center.

  Next, as shown in FIGS. 2A and 2B and FIGS. 3A to 3C, the bearing holder 8 is a sintered body, and its planar shape is in two directions orthogonal to the motor axis L. It has a substantially square shape with sides. Here, the substantially quadrangular shape means that a shape with R added to the corner as in the present embodiment is included. In the center of the bearing holder 8, a circular through hole 80 into which the non-output-side bearing 7 is inserted is formed. A groove 81 extends radially outward from the bearing holder 8. When spot welding is performed between the outer stator core 41 of the stator assembly 4 </ b> A on the opposite output side and the bearing holder 8, a groove is formed between the adjacent pole teeth 411 of the outer stator core 41. By inserting a positioning pin (not shown) into 81, the bearing holder 8 can be positioned with respect to the outer stator core 41. In addition, the thickness (outer diameter) of the positioning pin is set to be smaller than the interval between the pole teeth 411 so as not to contact the pole teeth 411 during positioning.

  On the outer peripheral side of the output side end face of the bearing holder 8, four engagement recesses 821, 822, 823, and 824 that are recessed on the counter-output side are divided in the circumferential direction at the center of the portion corresponding to the square side Is formed. Further, in the bearing holder 8, a portion between the engaging recesses 821, 822, 823, and 824 (a square corner portion) of the periphery of the through hole 80 (that is, the periphery of the rotor arrangement hole 30) is outside. Four planned welding areas 85 for spot welding using the protrusions 451 of the stator core 41 are secured as flat surfaces.

  Therefore, when the motor 1 is assembled, the bearing holder 8 is placed on the outer stator core 41 so that the four projections 451 of the outer stator core 41 abut each of the four planned welding areas 85 of the bearing holder 8, and energized while applying pressure to both. For example, spot welding can be performed using all of the four protrusions 451, whereby the bearing holder 8 can be fixed to the stator 3.

  As shown in FIGS. 2 and 4A to 4C, the spring member 9 includes a substantially circular end plate portion 91, and the bearing holder 8 is located in the central portion of the end plate portion 91. The leaf spring 90 is cut and raised toward the side. The leaf spring 90 is bent at the tip, and its urging force and urging direction are adjusted.

  Further, at four positions on the edge portion of the end plate portion 91, four claw portions that protrude to the output side and wrap around the outer peripheral side surface of the bearing holder 8, and then engage with the engagement recesses 821, 822, 823, and 824. 921, 922, 923, and 924 are formed. Here, since the four claw portions 921, 922, 923, and 924 are provided with bent portions inward at the end portions, the four claws are overlapped when the end plate portion 91 of the spring member 9 is overlapped with the bearing holder 8. The portions 921, 922, 923, and 924 wrap around the outer peripheral side surface of the bearing holder 8, and the bent portions engage with the engaging recesses 821, 822, 823, and 824. In this state, the four claw portions 921, 922, 923, and 924 are elastically engaged with the four engagement recesses 821, 822, 823, and 824, so that the spring member 9 is fixed to the bearing holder 8. It becomes a state. On the counter-output side of the bearing holder 8, portions corresponding to the four engaging recesses 821, 822, 823, and 824 are tapered surfaces, and the spring member 9 is fixed to the bearing holder 8 and the spring The roots of the claw portions 921 to 924 of the member 9 are not brought into contact with the bearing holder 8. Further, since the bearing holder 8 and the spring member 9 have the same dimensions in two directions orthogonal to the motor axis L, the spring member 9 can be fixed to the bearing holder 8 regardless of the front, rear, left or right direction.

(Detailed configuration on the output side)
FIG. 5 is an exploded perspective view showing the output side of the stepping motor 1 shown in FIG. 1 in an exploded manner. 6A to 6D are a plan view, a longitudinal sectional view, a bottom view, and a side view showing a motor mounting plate of the stepping motor 1 shown in FIG.

  In this embodiment, the following structure is adopted when fixing the motor mounting plate 6 to the output side.

  First, as shown in FIG. 5, the outer stator core 41 used in the output-side stator set 4B has the same configuration as the outer stator core 41 of the counter-output-side stator set 4A described above. Although omitted, the bottom plate portion 412 constituting the output side end face of the case 10 is formed with four protrusions 452 (protrusions for spot welding) protruding around the rotor arrangement hole 30 and projecting these protrusions 452. Are formed at intervals of approximately 90 degrees around the motor axis L.

  As shown in FIGS. 5 and 6 (a) to 6 (d), in the motor mounting plate 6, the front end side vertical plate portion 62 has a substantially semicircular shape, and the output side bearing 5 is provided at the center thereof. A holding hole 620 is formed. The horizontal plate portion 63 is an attachment portion for attaching the motor 1 to various devices, and a plurality of attachment holes 631 for attachment to various devices are formed.

  The base end side vertical plate portion 61 has a substantially semicircular shape having substantially the same contour as the bottom plate portion 412 of the outer stator core 41. A circular hole 610 for allowing the rotation shaft 21 to pass is formed in the central portion of the base end side vertical plate portion 61. Further, a pin hole 68 is formed in the base end side vertical plate portion 61, and the pole teeth 411 adjacent to the outer stator core 41 are spot-welded between the outer stator core 41 of the output side stator set 4B and the motor mounting plate 6. The motor mounting plate 6 can be positioned with respect to the outer stator core 41 by inserting a positioning pin (not shown) between the pin and the pin hole 68. In addition, the thickness (outer diameter) of the positioning pin is set to be smaller than the interval between the pole teeth 411 so as not to contact the pole teeth 411 during positioning.

  Furthermore, in the base end side vertical plate portion 61, spot welding is performed using the three protrusions 452 of the four protrusions 452 of the outer stator core 41 around the hole 610 (that is, around the rotor arrangement hole 30). These three scheduled welding areas 65 are secured as flat surfaces. Further, in a bent portion between the base end side vertical plate portion 61 and the horizontal plate portion 63, a notch 66 is formed at a position overlapping the remaining one protrusion 452 so that the protrusion 452 does not hit. .

  Therefore, when the motor 1 is assembled, the motor mounting plate 6 is stacked on the outer stator core 41 so that the three positioning projections 452 of the outer stator core 41 abut on the three planned welding regions 65 of the motor mounting plate 6 respectively. If the current is applied while pressure is applied, spot welding can be performed using the three protrusions 452 of the four protrusions 452, whereby the motor mounting plate 6 can be fixed to the stator 3. At this time, the protrusion 452 positioned at the bent portion of the motor mounting plate 6 is in a position where a welding scheduled region cannot be formed. However, since the notch 66 is formed there, the protrusion 452 is released by the notch 66. Can do. Therefore, the motor mounting plate 6 can be fixed to the stator 3 by spot welding in a state where the motor mounting plate 6 is stacked on the outer stator core 41.

  Here, the mounting angle of the motor mounting plate 6 to the stator 3 is changed according to the device to which the motor is mounted depending on the terminal position of the stepping motor 1 and the like. Therefore, when any of the four protrusions 452 is located in a region where the bent portion is avoided in the base-end-side vertical plate portion 62 of the motor mounting plate 6, four welding schedules are provided at positions where these four protrusions 452 overlap. The region 65 may be formed.

(Motor manufacturing method)
Since the motor 1 of the present embodiment has the above-described configuration, in the manufacturing method thereof, the stator 4 is configured by an output-side stator set 4B and a counter-output-side stator set 4A that are arranged so as to overlap in the motor output shaft direction. In addition, in the stator sets 4A and 4B, the outer stator cores 41, the coils 42, and the inner stator cores 44 are each composed of parts having the same structure, and the end surface of the outer stator core 41 is surrounded by a rotor arrangement hole. Thus, four spot welding projections 451 and 452 projecting outward in the motor axial direction are formed, and spot welding is performed in the bearing holder fixing step and the motor mounting plate fixing step. At that time, positioning pins (not shown) are inserted into the grooves 81 of the bearing holder 8 and the pin holes 68 of the motor mounting plate 6 to position the bearing holder 8 and the motor mounting plate 6 with respect to the stator 4.

  That is, in the bearing holder fixing step, the positioning pin is inserted into the groove 81 of the bearing holder 8 from the non-output side, and the tip end portion of the positioning pin is inserted between the pole teeth 411 so that the stator assembly 4A on the non-output side is removed. The stator core 41 and the bearing holder 8 are positioned, and thereafter, the outer stator core 41 is energized with the bearing holder 8 being pressed, and spot welding is performed using all of the four or more protrusions 451. After spot welding, the positioning pin is pulled out.

  On the other hand, in the motor mounting plate fixing step, the positioning pin is inserted into the pin hole 68 of the motor mounting plate 6 from the output side, and the tip end portion of the positioning pin is inserted between the pole teeth 411, so that the stator assembly 4B on the output side is The outer stator core 41 and the motor mounting plate 6 are positioned, and thereafter, the outer stator core 41 is energized with the motor mounting plate 6 pressed, and spot welding is performed using at least three protrusions 451. After spot welding, the positioning pin is pulled out.

  After completion of the bearing holder fixing step and the motor mounting plate fixing step, the rotor 2 is inserted into the rotor arrangement hole 30 from the opposite output side through the through hole 80 of the bearing holder 8, and the rotor 2 is inserted inside the rotor arrangement hole 30. After the base end side is disposed, the steel ball 71, the non-output-side bearing 7, and the spring member 9 are attached.

(Effect of this embodiment)
As described above, in the stepping motor 1 according to the present embodiment, the outer stator core 41 constituting the output side end face of the output side stator assembly 4B is formed with the four protrusions 452 protruding to the output side. Even when the mounting angle of the motor mounting plate 6 with respect to the stator 3 changes depending on the equipment to be mounted and a part of the four protrusions 452 is located at a place where welding cannot be performed, spot welding is performed using the remaining three protrusions 452. It can be performed. Further, when using the motor attachment plate 6 that can secure the four planned welding regions 65 in the region where the bent portion is avoided in the base end side vertical plate portion 61, the projection 452 is used in each of the four planned welding regions 65. Spot welding may be performed. Therefore, the stepping motor 1 can be mounted on various devices without changing the design of the outer stator core 41.

  In this embodiment, since the bearing holder 8 is welded to the outer stator core 41 using all of the four protrusions 451, the four protrusions are formed on the outer stator core 41 constituting the output side end face by the output side stator assembly 4B. Even if 452 is formed, the stator assembly 4B can be fixed in a state where the bearing holder 8 is overlapped on the output side end face. Therefore, in the stator assembly 4A on the counter-output side and the stator assembly 4B on the output side, the outer stay cores 41, the coils 42, the bobbins 43, and the inner stator cores 44 may each be composed of parts having the same structure. It is possible to standardize parts. In addition, the magnetic balance can be improved.

  Here, in the pressurizing member 9, four claw portions 921, 922, 923, and 924 protruding from the outer peripheral edge toward the output side are formed at positions separated in the circumferential direction. Engaging recesses 821, 822, 823, and 824 that can engage the portions 921, 922, 923, and 924 are formed, but the four engaging recesses 821, 822, 823, and 824 are the sides of the bearing holder 8. Of these, only a portion corresponding to about 2/3 is divided and formed. For this reason, the area occupied by the engaging recesses 821, 822, 823, and 824 is small on the outer peripheral side of the bearing holder 8, and a wide space is secured between the four engaging recesses 821, 822, 823, and 824. ing. For this reason, there are few restrictions with respect to the formation position etc. of the protrusion 451, such as being able to ensure the welding planned area | region 86 in the position near the outer periphery of the bearing holder 8 among the area | regions equivalent to a square-shaped corner, and freedom of design Is expensive.

(Other embodiments)
7A and 7B are an exploded perspective view showing an exploded side opposite to the output side of another stepping motor 1 to which the present invention is applied, and a perspective view showing the structure of the output side end face of the bearing holder 8. . FIGS. 8A to 8C are a plan view, a longitudinal sectional view, and a bottom view showing a configuration of the output side end face of the bearing holder 8 of the stepping motor 1 shown in FIG. . The basic configuration of the stepping motor of the present embodiment is the same as that of the stepping motor described with reference to FIGS. 1 to 6, and therefore, common portions are denoted by the same reference numerals and FIGS. 7 and 8. The description thereof will be omitted.

  Also in the stepping motor shown in FIGS. 7 and 8, the bearing holder 8 has a substantially rectangular shape with two sides perpendicular to the motor axis L, and the outer peripheral side of the output side end face of the bearing holder 8 is The four engaging recesses 821, 822, 823, and 824 that are recessed toward the non-output side are formed in a state of being divided in the circumferential direction along the rectangular side. For this reason, the area occupied by the engagement recesses 821, 822, 823, and 824 on the outer peripheral side of the bearing holder 8 is small, and in the vicinity between the engagement recesses 821, 822, 823, and 824 divided into four parts. Four planned welding regions 85 can be formed. Other configurations are the same as those of the stepping motor described with reference to FIGS.

  In the above embodiment, an example in which four protrusions 451 and 452 are formed has been described, but four or more protrusions 451 and 452 may be formed. In the above embodiment, the stepping motor has been described as an example, but the present invention may be applied to other motors.

It is sectional drawing of the stepping motor to which this invention is applied. (A), (b) is a disassembled perspective view which decomposes | disassembles and shows the non-output side of the stepping motor to which this invention is applied, and a perspective view which shows the structure of the output side end surface of the bearing holder 8. FIG. (A) thru | or (c) are the top views which show the structure of the output side end surface of the bearing holder of the stepping motor shown in FIG. 1, a longitudinal cross-sectional view, and the bottom view which shows the structure of a non-output side end surface. (A) thru | or (c) are the top views which show the spring member of the stepping motor shown in FIG. 1, the longitudinal cross-sectional view of the part cut | disconnected by the II line | wire, and sectional drawing of the part of a leaf | plate spring part. It is a disassembled perspective view which decomposes | disassembles and shows the output side of the stepping motor shown in FIG. (A) thru | or (d) are the top views, longitudinal cross-sectional views, bottom views, and side views which show the motor attachment board of the stepping motor shown in FIG. (A), (b) is a disassembled perspective view which decomposes | disassembles and shows the non-output side of another stepping motor to which this invention is applied, and a perspective view which shows the structure of the output side end surface of a bearing holder. (A) thru | or (c) are the top views which show the structure of the output side end surface of the bearing holder of the stepping motor shown in FIG. 7, a longitudinal cross-sectional view, and a bottom view which shows the structure of a non-output side end surface.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stepping motor 2 Rotor 3 Stator 4A Counter output side stator set 4B Output side stator set 5 Output side bearing 6 Motor mounting plate 7 Counter output side bearing 8 Bearing holder 9 Spring member 21 Rotating shaft 22 Rotor magnet 30 Rotor arrangement hole 41 Outer stator core 42 Coil 44 Inner stator cores 451 and 452 Projections (projections for spot welding)
65, 85 Scheduled welding region 80 Through hole 821-824 Engaging recess 90 Leaf spring portion 921-924 Claw portion

Claims (10)

A cylindrical stator having a rotor arrangement hole that opens in the motor axial direction, a rotor arranged in the rotor arrangement hole, and one axial end of the rotation shaft of the rotor on the opposite output side in the motor axial direction A bearing, a bearing holder provided with a through hole in which the bearing is mounted, and a leaf spring portion that is disposed further on one end side than the bearing holder and biases the bearing toward the rotating shaft. In a method of manufacturing a motor having a pressure applying member and a motor mounting plate overlaid on the output side end surface of the stator,
The stator is composed of an output-side stator set and a counter-output-side stator set that are arranged so as to overlap each other in the motor output axis direction, and the output-side stator set and the counter-output-side stator group are outside in the motor axial direction. The outer stator cores arranged between the inner stator cores, the coils, and the inner stator cores sandwiching the coils between the outer stator cores on the inner side in the motor axial direction, respectively, are composed of parts having the same structure, and the end surfaces of the outer stator cores Is formed with four or more spot welding projections projecting outward in the motor axial direction around the rotor arrangement hole,
A bearing holder fixing step of performing spot welding using all of the four or more protrusions by energizing the outer stator core constituting the counter-output-side end face with the counter-output-side stator set while pressing the bearing holder;
Motor mounting for performing spot welding using at least three projections among the four or more projections by energizing the outer stator core constituting the output side end face with the output side stator set while pressing the motor mounting plate A method for manufacturing a motor, comprising performing a plate fixing step. In claim 1, in the motor mounting plate fixing step, spot welding is performed using a part of the four or more protrusions,
The motor mounting plate is characterized in that a cutout is formed at a position overlapping with a projection that is not used for spot welding among the four or more projections. In claim 2, the motor mounting plate includes a horizontal plate portion extending in the motor axial direction, and a vertical plate portion bent vertically from an end portion of the horizontal plate portion,
The vertical plate portion is overlapped on the output side end surface of the stator and subjected to the spot welding,
A method for manufacturing a motor, wherein the notch is formed in a bent portion between the vertical plate portion and the horizontal plate portion. In any one of Claim 1 thru | or 3, the said processus | protrusion formed in the said stator core is four,
On the pressurizing member, four claw portions protruding from the outer peripheral edge toward the output side are formed at positions spaced apart in the circumferential direction,
The bearing holder is formed with an engagement concave portion in which the outer peripheral side region of the output side end surface is recessed toward the opposite output side so that the claw portion can be engaged, and the engagement concave portion is divided into four regions in the circumferential direction. Divided and formed,
In the bearing holder fixing step, the spot welding is performed in a region formed between the engagement recesses by the division. The bearing holder according to claim 4, wherein the bearing holder has a substantially rectangular shape when viewed from the motor axial direction.
The engaging recess is formed in a part of a region corresponding to the rectangular side,
In the bearing holder fixing step, the spot welding is performed in a region corresponding to the square corner. A cylindrical stator provided with a rotor arrangement hole that opens in the motor axial direction, a rotor arranged in the rotor arrangement hole, and one axial end of the rotation shaft of the rotor on the opposite output side in the motor axial direction A bearing, a bearing holder provided with a through hole in which the bearing is mounted, and a leaf spring portion that is disposed further on one end side than the bearing holder and biases the bearing toward the rotating shaft. In a motor having a pressure applying member and a motor mounting plate overlaid on the output side end face of the stator,
The stator is composed of an output-side stator set and a counter-output-side stator set that are arranged so as to overlap each other in the motor output axis direction. The outer stator cores arranged on the outside, the coils, and the inner stator cores sandwiching the coil between the outer stator cores on the inner side in the motor axial direction are each composed of parts having the same structure,
The outer stator core and the bearing holder that constitute the counter-output side end face in the counter-output side stator set are subjected to spot welding at four or more locations around the rotor arrangement hole,
The outer stator core and the motor mounting plate that constitute the output side end face of the output side stator assembly are at least three of the four or more locations corresponding to the welding locations on the counter-output side around the rotor arrangement hole. A motor characterized by spot welding. 7. The outer stator core and the motor mounting plate constituting the output side end face of the output side stator set according to claim 6, wherein the outer stator core and the motor mounting plate are at least four locations corresponding to the welding locations on the non-output side around the rotor arrangement hole. Some of them are spot welded,
In the remaining portions, while spot welding projections protruding from the outer stator core to the output side remain, the motor mounting plate has a notch formed at a position overlapping the projections. Motor. In claim 7, the motor mounting plate includes a horizontal plate portion extending in the motor axial direction, and a vertical plate portion bent vertically from an end portion of the horizontal plate portion,
The vertical plate portion is overlapped on the output side end surface of the stator and subjected to the spot welding,
The motor according to claim 1, wherein the notch is formed in a bent portion between the vertical plate portion and the horizontal plate portion. In any one of Claims 6 thru | or 7, the said outer stator core and the said bearing holder which comprise a counter output side end surface with the said counter output side stator group are spot-welded in four places around the said rotor arrangement | positioning hole,
In the pressurizing member, four claw portions protruding from the outer peripheral edge toward the output side are formed at positions separated in the circumferential direction,
The bearing holder is formed with an engagement recess that allows the claw portion to be engaged by recessing the outer peripheral side region of the output side end surface to the opposite output side,
The engagement recess is formed by being divided into four regions in the circumferential direction, and the spot welding is applied to a region formed between the engagement recesses by the division. motor. The bearing holder according to claim 9, wherein the bearing holder has a substantially rectangular shape when viewed from the motor axial direction.
The engaging recess is formed in a part of a region corresponding to the rectangular side,
A motor characterized in that the spot welding is performed in a region corresponding to the square corner.

Images