JP2005110463A - Motor actuator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive motor actuator which can be assembled easily. <P>SOLUTION: A stator of a stepping motor is made into a two-phase stack structure by laminating a material made by combining yokes 4 having the same shapes which are made by bending a plurality of rectangular outer periphery forming members 24 radially protruded to the outside in the radial direction of a doughnut-shaped sheet metal and a plurality of claw poles 25 radially protruded to the inside in the radial direction in the same direction, so that the outer periphery forming members 24 and the claw poles 25 are engaged with each other, thus forming a two-phase stack structure. Positioning between phases is executed by mutually fitting a positioning pin and a positioning hole formed to a bobbin via a positioning hole formed at the yoke. The stator core is composed by combining one kind of yoke. Accordingly, components are made to be used in common, and components made by drawing are eliminated. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a motor actuator, and more particularly, to a motor actuator provided with a stepping motor for driving a door that opens and closes or switches an air flow path in an automotive air conditioner.

  In an automotive air conditioner, several doors for opening and closing an air flow path are provided. For example, a door for switching the inside / outside air for introducing outside air into the vehicle interior or circulating air inside the vehicle interior, mixing air cooled by a cooler and air heated by a heater, There is a mixing door for setting the air to a predetermined temperature, and a mode selection door for setting the air distribution mode at the outlet. Each of these doors is provided with a motor actuator, and by controlling the opening of these doors, the temperature of the air blown into the passenger compartment and the amount of air blown out are adjusted, and the air outlet is selected.

  A motor actuator used for such an application generally includes a motor portion and a gear box portion having a reduction gear group and an output gear, and has a configuration in which the motor portion is attached to a case of the gear box portion. A DC motor or a stepping motor is used as the motor of the motor unit. As a motor actuator using a stepping motor, for example, the one described in Patent Document 1 is known.

  In the motor actuator described in Patent Document 1, the motor includes a stator core, a magnet rotor, and a yoke. The stator core has a pair of coil bobbins each of which is wound with a coil wire to form an exciting coil, the magnet rotor has a center piece and a magnet magnetized in multiple poles, and the yoke surrounds the coil bobbin. Thus, it is configured by drawing into a bottomed cylindrical shape.

The magnet rotor has a coil bobbin in which one end of a center piece is supported by a bearing, and the other end is inserted into a bearing concave portion formed on the rotation shaft of the center piece by a support convex portion formed by drawing part of the yoke. Is pivotally supported in a hollow portion at the center of the shaft.
Japanese Unexamined Patent Publication No. 2000-209807 (paragraph numbers [0015] to [0020], FIGS. 2 and 3)

  However, in the motor actuator using the conventional stepping motor, the yoke of the stepping motor is drawn into a bottomed cylindrical shape and the supporting convex part is integrally formed by drawing, so that the yoke material is used for drawing. Since a member has to be used and the die for drawing is generally expensive, there has been a problem that the cost of the motor actuator becomes high.

  In addition, in the conventional motor actuator, since the reduction gear group is first assembled, the lid is covered with the gear housing, and then the motor is assembled thereon, it is formed integrally with the rotation shaft of the center piece. The pinion must be inserted into a through-hole provided in the gear housing and arranged so as to mesh with the input gear that is hidden behind the gear housing and cannot be seen. In addition, if the gear teeth are missing or deformed, there is a problem that abnormal noise is generated during the deceleration operation.

  The present invention has been made in view of these points, and an object of the present invention is to provide a motor actuator that is easy to assemble and low in cost.

  In the present invention, in order to solve the above problem, in a motor actuator including a stepping motor having a magnet rotor rotatably supported and a stator having a two-phase stack structure provided around the magnet of the magnet rotor. The stator is formed by bending a plurality of rectangular outer periphery forming members radially projecting radially outward of a donut-shaped sheet metal and triangular claw poles projecting radially radially inwardly in the same direction. There is provided a motor actuator characterized in that a yoke having the same shape is combined so that the outer periphery forming member and the claw pole mesh with each other to constitute a stator core of the first and second phase stacks, respectively.

  According to such a motor actuator, the stator cores of the first and second phase stacks are configured by combining four yokes having the same shape by bending. This makes it possible to reduce the types of parts by sharing parts, and not only to reduce the management cost of each type of parts, but also to molds and equipment by eliminating drawing parts. Eliminates the need for significant costs.

  Further, the present invention includes a lower case that accommodates the stepping motor, an upper case that accommodates the gear portion, and a bracket disposed between the lower case and the upper case, and the lower case is a rotating shaft of the magnet rotor. A shaft that rotatably supports the shaft, a fixing portion for positioning and fixing the stator of the stepping motor together with the bracket, and a housing forming portion that constitutes the connector housing are integrally formed. The upper case is integrally provided with another bearing portion that rotatably supports the other end of the output shaft of the output gear, and an intermediate shaft that rotatably supports the plurality of intermediate gears. Another shaft that rotatably supports the gear and a shaft holding portion that holds the tip of each shaft that supports the rotating shaft of the magnet rotor are integrally provided.

  With this configuration, the lower case, stepping motor, bracket, gear group, and upper case are assembled in this order, so the gear can be assembled while checking the meshing state of each gear, and the gear can be unidirectionally without scratching the gear. They can be assembled sequentially, which facilitates the assembly of the motor actuator.

  In the motor actuator of the present invention, the stator cores of the first and second phase stacks are constituted by a single type of common yoke, and the yoke is formed not by drawing but by bending, so that the manufacturing cost of parts And there is an advantage that the management cost can be reduced. In addition, since the parts are shared, there is no variation due to the combination of the parts, so that the positioning dimension tolerance can be relaxed and a stable product can be supplied. Furthermore, since the connector housing is formed by the lower case and the bracket, the dedicated connector parts are not required, and the cost can be further reduced.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings, taking as an example a motor actuator having a stepping motor having 24 poles in each phase stack and a step angle of 7.5 °.

FIG. 1 is a central longitudinal sectional view showing the configuration of a stepping motor.
The stepping motor of the motor actuator according to the present invention has a rotating shaft 1 at the center thereof, and a magnet 2 magnetized with 24 poles is fixed around it to constitute a magnet rotor. The rotating shaft 1 has a hollow structure, and can be rotatably supported by being inserted through a shaft formed integrally with the lower case when the stepping motor is assembled. The rotary shaft 1 is also integrally formed with a pinion 3 at one end thereof.

  A stator having a two-phase stack structure is disposed on the outer periphery of the magnet 2. In each phase stack, a pair of yokes 4 and 5 and yokes 6 and 7 form a stator core. Bobbins 8 and 9 are disposed in each stator core, and coils 10 and 11 are wound around the respective bobbins 8 and 9 by bifilar winding. The stack of each phase must be staggered so as to act alternately on one magnet 2 in order to increase the step resolution. For that purpose, the positioning of the stack of each phase is performed by bobbins 8 and 9. That is, the bobbins 8 and 9 are provided with bosses 12, 13, 14 and 15 at positions symmetrical with respect to the bobbin center, and positioning holes 16 provided at corresponding positions of the adjacent yokes 5 and 6. , 17, 18, and 19 to position the bobbins 8 and 9 and the yokes 5 and 6, and positioning pins 20 and 21 provided on the boss 12 of the bobbin 8 and the boss 14 of the bobbin 9, and the bobbin By positioning the boss 13 of 8 and the holes 22 and 23 provided in the boss 15 of the bobbin 9, the stack of each phase is positioned. Next, the yokes 4, 5, 6, and 7 constituting the stator core will be described.

  2A and 2B are views showing a lower yoke constituting the stator core of the first phase stack, in which FIG. 2A is a plan view of the yoke and FIG. 2B is a sectional view of the yoke. 3A and 3B are views showing an upper yoke constituting the stator core of the first phase stack, in which FIG. 3A is a plan view of the yoke and FIG. 3B is a sectional view of the yoke. 4A and 4B are views showing a lower yoke constituting the stator core of the second phase stack, in which FIG. 4A is a plan view of the yoke, and FIG. 4B is a sectional view of the yoke. 5A and 5B are views showing an upper yoke constituting the stator core of the second-phase stack, in which FIG. 5A is a plan view of the yoke and FIG. 5B is a sectional view of the yoke. 6A and 6B are views showing the stator cores of the first and second phase stacks, in which FIG. 6A is a plan view of the stator core and FIG. 6B is a cross-sectional view of the stator core.

  Each of the yokes 4, 5, 6, and 7 has the same shape and is designed to share parts, thereby reducing the types of components. That is, each of the yokes 4, 5, 6, and 7 includes a rectangular outer periphery forming member 24 that is radially protruded radially outward and a triangular claw pole 25 that is radially protruded radially inward. The outer periphery forming member 24 and the claw pole 25 are formed by bending in the same direction from a sheet metal punched into a donut shape. The yokes 4, 5, 6, and 7 are also formed with holes for positioning at positions symmetrical with respect to the center thereof. The lower yoke 4 of the first phase stack shown in FIG. 2 is provided with positioning holes 26 and 27 for fitting with bosses (not shown) protruding inside the lower case, as shown in FIG. Positioning holes 16 and 17 are provided in the upper yoke 5 of the first phase stack to fit the bosses 12 and 13 projecting from the bobbin 8, and the second phase stack shown in FIG. The lower yoke 6 is provided with positioning holes 18 and 19 for fitting with the bosses 14 and 15 projecting from the bobbin 9, and the upper yoke 7 of the second phase stack shown in FIG. Positioning holes 28 and 29 are provided for fitting with bosses (not shown) provided on a bracket, which will be described later. Further, as shown in FIG. 6A, the yokes 4, 5, 6, and 7 are provided with the bobbin 8 to draw out the terminals 30 of the coils 10 and 11 of the bobbins 8 and 9 disposed therein. , 9 where the terminal holding part 31 formed integrally is located, as shown in FIG. 3, the outer periphery forming member 24 is removed over a range of about 80 °, and the yokes 4, 5 and the yoke 6 are removed. , 7 are formed so that a cylindrical stator core is formed.

  The stator core is configured by combining yokes 4 and 5 and yokes 6 and 7. That is, the yokes 4 and 5 constitute a stator core of the first phase stack by combining the outer periphery forming member 24 and the claw pole 25 so as to mesh with each other. At this time, the lower yoke 4 is combined with the upper yoke 5 while being rotated by 7.5 ° in the clockwise direction. Similarly, the yokes 6 and 7 constitute a stator core of the second phase stack by combining the outer periphery forming member 24 and the claw pole 25 so as to mesh with each other. At this time, the upper yoke 7 is combined with the lower yoke 6 while being rotated by 7.5 ° counterclockwise. Thereby, as shown in FIG. 6B, a stator core having a two-phase stack structure can be formed, and the stator core is 1/4 of the pitch of the claw pole 25 between the first and second phase stacks. It is configured to be offset. Of course, although not shown in FIG. 6B, the yokes 4, 5, 6 and 7 are assembled in a state where the bobbins 8 and 9 are incorporated therein. Next, the bobbins 8 and 9 will be described.

FIG. 7 is a side view showing the stator core.
The bobbins 8 and 9 also have the same shape and share parts, thereby reducing the types of components. That is, each of the bobbins 8 and 9 has a portion around which the coils 10 and 11 are wound, bosses 12, 13, 14 and 15, positioning pins 20 and 21, holes 22 and 23, and a terminal holding portion 32 and 31 are provided integrally. Since the bobbins 8 and 9 are assembled in a state in which they are opposite to each other, the positioning pins 20 and 21 provided on the bosses 12 and 14 come to positions opposite to each other and the holes 22 provided in the bosses 13 and 15 are provided. , 23 can be fitted.

  The terminal holding portions 32 and 31 are formed to have an uneven shape when the bobbins 8 and 9 are opposed to each other. The terminals 30 of the coils 10 and 11 are embedded in the convex portion. As a result, when the bobbins 8 and 9 are opposed to each other so that the concave and convex surfaces are engaged with each other, the terminals 30 protruding from the terminal holding portions 32 and 31 can be arranged in a line.

  FIG. 8 is a plan view showing a state in which a stepping motor is mounted, FIG. 9 is a plan view showing a state in which a gear group is mounted, and FIG. 10 is a cross-sectional view showing a motor actuator. In FIG. 10, a gear center cross section is shown in order to simultaneously show the mounting state of each gear.

  The motor actuator includes a lower case 33 that houses a stepping motor, an upper case 34 that houses a gear group, and a bracket 35 that is disposed between the lower case 33 and the upper case 34. The lower case 33 includes a shaft 36 that rotatably supports the rotating shaft 1 of the magnet rotor, and a fixing portion that positions and fixes the stator, that is, a positioning hole 26 formed in the lowermost yoke 4. 27 is formed integrally with a boss projecting inward so as to be fitted to 27. The lower case 33 also integrally forms a housing forming portion that constitutes a part of the connector housing.

  The bracket 35 has a fixed portion for positioning and fixing the stator on the lower surface thereof, that is, a boss projecting so as to be fitted with positioning holes 28 and 29 formed in the uppermost yoke 7, and a connector housing. A housing forming part constituting a part is integrally formed. Thus, the housing forming portion of the bracket 35 and the housing forming portion formed in the lower case 33 constitute a connector housing, eliminating the need for a connector-dedicated component. The bracket 35 is integrally formed with a bearing portion 38 that rotatably supports the lower end portion of the rotating shaft of the output gear 37 and shafts 41 and 42 that rotatably support the intermediate gears 39 and 40 on the upper surface thereof. doing.

  The upper case 34 includes a bearing portion 43 that rotatably supports the upper end portion of the rotating shaft of the output gear 37, the tips of the shafts 41 and 42 that rotatably support the intermediate gears 39 and 40, and the rotating shaft 1 of the magnet rotor. The shaft holding portions 44, 45, and 46 that hold the tip of the shaft 36 to be supported are integrally formed.

  Further, although not shown, the lower case 33 and the upper case 34 have a snap-fit mechanism that can be coupled to each other using the elastic force of the material, thereby eliminating the need for screws, The number of parts is reduced. The lower case 33 also has a mounting hole 47 on the outer periphery thereof. Although not shown, the lower case 33 also has the same mounting hole at a corresponding position of the upper case 34. When the motor actuator is attached to the door of the automotive air conditioner, it is preferable that the lower case 33 and the upper case 34 are attached together.

  The motor actuator having the above configuration is assembled as follows. First, as shown in FIG. 8, the stator is disposed at a predetermined position in the lower case 33, and the magnet rotor is attached to the shaft 36 erected in the lower case 33. The lower case 33 is covered with a bracket 35 from above. Next, the intermediate gear 39 is attached to the shaft 41 erected on the bracket 35, the output gear 37 is inserted into the bearing portion 38 while meshing with the intermediate gear 39, and the intermediate gear 40 is inserted into the intermediate gear 39 and the pinion 3 of the magnet rotor. And is attached to a shaft 42 erected on the bracket 35. Then, by covering the upper case 34 with the bearing portion 43 and the shaft holding portions 44, 45, 46 aligned with the tips of the output gear 37 and the shafts 41, 42, 36, and further pushing down toward the lower case 33, The upper case 34 is fixed to the lower case 33 by a snap fit mechanism.

  As described above, the motor actuator is configured so that the assembly of the gear box and the assembly of the motor are integrated and the assembly of the gear box is performed after the assembly of the motor, so that each gear can be assembled while checking the meshing state. In addition, it can be assembled in one direction without reversing the assembled parts in the middle of the assembly.

It is a center longitudinal cross-sectional view which shows the structure of a stepping motor. It is a figure which shows the lower yoke which comprises the stator core of the 1st phase stack, Comprising: (A) is a top view of a yoke, (B) is sectional drawing of a yoke. It is a figure which shows the upper yoke which comprises the stator core of the stack | stuck of a 1st phase, Comprising: (A) is a top view of a yoke, (B) is sectional drawing of a yoke. It is a figure which shows the lower yoke which comprises the stator core of a 2nd phase stack, Comprising: (A) is a top view of a yoke, (B) is sectional drawing of a yoke. It is a figure which shows the upper yoke which comprises the stator core of a 2nd phase stack, Comprising: (A) is a top view of a yoke, (B) is sectional drawing of a yoke. It is a figure which shows the stator core of the stack | stuck of the 1st and 2nd phase, Comprising: (A) is a top view of a stator core, (B) is sectional drawing of a stator core. It is a side view which shows a stator core. It is a top view which shows the state which mounted | wore the stepping motor. It is a top view which shows the state which mounted | wore the gear group. It is sectional drawing which shows a motor actuator.

Explanation of symbols

1 Rotating shaft 2 Magnet 3 Pinion 4, 5, 6, 7 Yoke 8, 9 Bobbin 10, 11 Coil 12, 13, 14, 15 Boss 16, 17, 18, 19 Positioning hole 20, 21 Positioning pin 22, 23 Hole 24 Peripheral forming member 25 Claw pole 26, 27, 28, 29 Positioning hole 30 Terminal 31, 32 Terminal holding portion 33 Lower case 34 Upper case 35 Bracket 36 Shaft 37 Output gear 38 Bearing portion 39, 40 Intermediate gear 41, 42 Shaft 43 Bearing Part 44, 45, 46 Shaft holder 47 Mounting hole

Claims (7)

In a motor actuator comprising a stepping motor having a magnet rotor rotatably supported and a stator having a two-phase stack structure provided around the magnet of the magnet rotor,
The stator is formed by bending a rectangular outer peripheral forming member radially projecting radially outward of a donut-shaped sheet metal and a triangular claw pole projecting radially radially inward in the same direction. A motor actuator characterized in that a yoke having a shape is combined so that the outer periphery forming member and the claw pole mesh with each other to form a stator core of a first and second phase stack, respectively. The yoke is positioned with the bobbin by fitting two positioning holes provided symmetrically with respect to the yoke center and a boss provided on the bobbin;
The motor actuator according to claim 1, wherein the first and second phase stacks are positioned by positioning pins and holes provided in the boss.   3. The motor actuator according to claim 2, wherein the positioning hole of the yoke is formed so as to be shifted by 1/4 of the pitch of the claw pole between the first and second phase stacks.   The motor actuator according to claim 2, wherein the bobbin has a bifilar-wound coil.   The bobbin includes a terminal holding portion having a concavo-convex surface in which a terminal of the coil is embedded in a convex portion, and the concavo-convex surface of the bobbin having the same shape in the first and second phase stacks is provided. 5. The motor actuator according to claim 4, wherein the terminals are arranged in a line when they are engaged with each other.   6. The motor actuator according to claim 5, wherein the outer periphery forming member is formed only in a circumferential direction excluding a place where a terminal holding portion of the bobbin is located. A lower case for accommodating the stepping motor, an upper case for accommodating the gear portion, and a bracket disposed between the lower case and the upper case,
The lower case integrally includes a shaft that rotatably supports the rotating shaft of the magnet rotor, a fixing portion that positions and fixes the stator of the stepping motor together with the bracket, and a housing forming portion that constitutes a connector housing. ,
The bracket integrally includes a bearing portion that rotatably supports one end of a rotation shaft of the output gear and another shaft that rotatably supports a plurality of intermediate gears,
The upper case supports another bearing portion that rotatably supports the other end of the rotation shaft of the output gear, the other shaft that rotatably supports the intermediate gear, and the rotation shaft of the magnet rotor. 2. The motor actuator according to claim 1, further comprising a shaft holding portion for holding each tip of the shaft.

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