JP2541801B2 - Step Motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] [Industrial field of application] The present invention relates to a step motor used in various control devices and the like.

"Prior Art" A conventional stepping motor is shown in FIG. This is a motor housing 4 containing two stators 1 and 2 necessary to perform the function as a step motor, and a bearing plate 10 having an inner bearing 8 for supporting a rotor shaft 6 integrated by bolts 12. Have been concluded.
The outer ring of the outer bearing 16 is fitted in the central portion of the motor housing so as to be pressed to the bearing plate 10 side by the leaf spring 14, and the rotor shaft 6 is fixed to the inner ring of the outer bearing 16. ing. A rotor 18 having a permanent magnet on the outer periphery is integrally attached to the rotor shaft 6. A pulse signal is given to the stators 1 and 2, and the rotor shaft 6 is rotated by a predetermined angle by an electromagnetic force.

Each of the stators 1 and 2 is a coil 2 wound around a bobbin.
0, an insulating tape that presses the coil 20 toward the center to prevent winding snag, and a slightly large diameter lead wire 22 soldered to each end of each winding of the coil 20. An insulating tape that presses these lead wires 22 toward the center and stator cores 1a and 2a that are outer frames that surround the bobbin, and each lead wire 22 is provided with a rubber packing 24. It extends through the hole 26 to a connector not shown.

The stator cores 1a and 2a are superposed as shown in the drawing, but at the time of superposition, a means such as fitting a protrusion provided on the other stator core into a hole provided on either one of the stator cores is provided. Positioning of both stator cores in the circumferential direction is performed. As shown in the figure, both stator cores 1a and 2a are pressed against the bearing plate 10 side by a corrugated plate spring 28 via a seat 29.

"Problems to be Solved by the Invention" However, the above step motor has the following problems.

Since the connector portion for connecting to the drive power source is located away from the motor housing 4, it is not preferable to extend the end portion of the winding (diameter of about 0.2 mm) of the coil 20 to the connector portion because of the possibility of disconnection. Therefore, the stator core
Inside 1a and 2a, the end of the winding is
In addition to being connected by soldering or the like, the connecting portion is covered with a short insulating pipe or the like for insulation, and then the covered portion is bent and fixed by winding it with an insulating tape toward the center. Further, the lead wire is passed through the through hole 26, covered with a relatively long insulating pipe, and extended to the connector portion. Furthermore, when a waterproof plug is inserted into the tip of each lead wire and connected to the corresponding connection terminal, a troublesome work is required, the number of parts is large, and a great amount of assembly time is required.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and to provide a step motor having a compact structure, a small number of parts, and easy assembling.

[Structure of Invention]

"Means for Solving Problems" A step motor according to the present invention is a step motor including a motor housing integrally formed by enclosing a main portion of a motor, and a cylindrical portion 52 forming a stator housing and an integral portion of the cylindrical portion. Two ring-shaped stators 1'on the cylindrical portion of the first resin molded product 50 having a connector housing 56 containing a plurality of connecting terminals 54 parallel to the axis of the cylindrical portion. After the 2's are stacked and housed and fixed, the ends of the windings of the coils of the ring-shaped stator are connected to the corresponding connection terminals 54, respectively.
64 and the shaft center of the stator 1 ', 2'and the shaft center of the bearing hole 80 for bearing one end of the rotor shaft 6 which fixes the rotor housed inside the stator are aligned and integrally molded with each other. And a motor housing 70 that has been formed.

[Examples] Examples of the present invention will be described below with reference to Figs. For convenience of description, first, referring to FIGS. 3 to 4, the first resin molded product 50 is made of, for example, thermoplastic resin PBT, 6 or the like.
6 Nylon, glass fiber reinforced resin, etc., cylindrical part 52
And a connector housing 56 integrally molded with the cylindrical portion 52 so as to include a plurality (usually 6) of connection terminals 54 arranged in a direction parallel to the axis of the cylindrical portion 52. Have and.

The connector housing 56 is provided with a connection portion space 58 in which one end portion of the connection terminal 54 is exposed and communicates with the inside of the cylindrical portion 52, and a socket insertion space 60 in which the other end portion (tip portion) is exposed. There is. The connection space 58 will eventually be filled with resin as described later.

After the ring-shaped stators 1'and 2'similar to the stators 1 and 2 shown in FIG. 7 (conventional example) are stacked and housed in the cylindrical portion 52 of the first resin molded product 50, the cylindrical portion The stators 1 ′ and 2 ′ are fixed to the cylindrical portion 52 by heating the fixing portion 62 provided at the edge of 52 with a soldering iron or the like and bending it inward.

When the two stators 1'and 2'are superposed, the ends of the windings of both coils are aligned so that they are on the side of the superposed planes, and the stators 1'and 2'are superposed on each other. The ends of these windings should be
It is better to position it so that it comes closest to.

When the stators 1'and 2'are stored and fixed in this manner, the tip ends of the coil windings are passed through the connecting portion space 58 and soldered to the corresponding connecting terminals 54. To form a stator assembly 64 in this manner.

Next, a mold for resin molding as shown by a chain double-dashed line in FIG.
Motor housing 70 for stator assembly 64 using 66, 68
And the second resin molding.

That is, the molds 66, 68 are opened, the stator assembly 64 is inserted into either one of the molds, and then the molds are closed to fit the shaft center of the stator 1 ', 2'and the inner side of the stator 1', 2 '. Rotor 18
The motor housing 70 is injection-molded so that it is aligned with the shaft center of the bearing hole 80 for bearing the rotor shaft 6 (Fig. 1) on which the motor is fixed, surrounds the first resin molded product 50, and fills the connecting portion space 58. It is integrally molded by.

At this time, if the resin inflow port 88 is provided in the stator cores 1a ′ and 2a ′, the resin flows into the stator core and fills the voids outside the coil, so that the heat generated by energizing the coil is dissipated. Can contribute.

When the step motor manufactured in this manner is used for a flow control valve or the like, for example, as shown in FIG. 1, an intermediate portion of the rotor shaft 6 to which the rotor 18 is fixed is supported by an inner bearing 8. It is preferable that the tip end is supported by the hole 80 formed at the time of resin molding. Further, it is preferable to insert a ball 82 and a spring 84 for pressing the ball in the hole 80. Alternatively, another bearing member 81 can be inserted into the hole 80 as shown in FIG. 1a.

FIG. 6 shows another embodiment of the present invention. In this embodiment, a partition wall 76 is provided in the connecting portion space 58 so as to form a groove in which the ends of the windings of the coil 20 can be separately wired, whereby each of the stators 1'and 2'is separated. Connection terminal 54
It is possible to prevent entanglement, disconnection and the like that are likely to occur during the second resin molding of the winding end portion extending up to the end.

Alternatively, it is also possible to protect the winding end by fitting the heat-resistant wire protection member 74 into the connection space 58 before resin molding and suppressing the winding end.

Alternatively, the winding end (thin wire) that passes through the connection space 58
The thin wire can be protected by covering it with a pipe material or the like.
Further, it is of course possible to use the above respective means together.

According to the embodiment, (1) the concentricity between the inner diameter of the stator and the bearing hole or the bearing material of the rotor shaft can be accurately obtained, so that the performance can be improved.

(2) Since the outer periphery of the stator and the upper and lower end surfaces of the stator core are hermetically integrated during the second resin molding, that is, during molding of the motor housing 70, the vibration resistance and airtightness can be improved.

Further, since the stator assembly is constructed and the rotor with the rotor shaft is integrally molded with the stator assembly, workability is good.

[Effects of the Invention] As described above, according to the present invention, the structure is the cylindrical portion.
52 and a stepping motor including a motor housing integrally formed with the main part of the motor, a plurality of connecting terminals 54 formed integrally with the cylindrical portion forming the stator housing and parallel to the axis of the cylindrical portion. Two ring-shaped stators 1'and 2'are superposed on and housed in the cylindrical portion of the first resin molded product 50 having the enclosed connector housing 56,
A stator assembly 64 which is fixed and connects the ends of the windings of the coils of the ring-shaped stator to the corresponding connection terminals 54, the axial center of the stators 1'and 2'and the inside of the stator. A stepping motor characterized by comprising a motor housing 70 which is integrally molded with the shaft center of a bearing hole 80 for bearing one end of a rotor shaft 6 to which a rotor is fixed. Therefore, the following effects can be obtained.

Since the two stators are fixed by the stator housing and the socket is inserted in the immediate vicinity of the step motor in a safe and workable state, the wiring from the coil to the connection terminal is very easy. That is, the end of the winding extending outward from the stator can be directly connected to the connection terminal, eliminating the trouble of connecting the winding to the lead wire and connecting it to the connector as in the conventional case. You can

[Brief description of drawings]

1 is a vertical sectional view showing an embodiment of the present invention, FIG. 1a is a vertical sectional view showing another embodiment of the outer bearing portion of FIG. 1, and FIG. 2 is a bottom view of FIG. FIG. 3 is a front view of the stator assembly,
FIG. 4 is a side view of FIG. 3, FIG. 5 is a longitudinal sectional view showing an embodiment of the product of the present invention obtained by the second resin molding, and FIG. 6 is a cross sectional view of FIG. 3 and FIG. FIG. 7 is a perspective view showing another embodiment of one resin molded product, and FIG. 7 is a vertical sectional view of a conventional example. 1,1 ′, 2,2 ′ …… stator, 1a, 1a ′, 2a, 2a ′ …… stator core, 4 …… motor housing, 6 …… rotor shaft, 8
...... Inner bearing, 10 ...... Bearing plate, 12 ...... Bolt, 14 ...... Leaf spring, 16 ...... Outer bearing, 18 ...... Rotor, 20 ...... Coil,
22 …… Lead wire, 24 …… Rubber packing, 26 …… Through hole, 28 …… Leaf spring, 29 …… Sheet, 50 …… First resin molded product, 52 …… Cylinder part, 54 …… Connecting terminal, 56 ...... Connector housing, 58 ...... Connection part space, 60 ...... Socket insertion space, 62 ...... Fixed part, 64 ...... Stator assembly, 66, 68 ......
Mold, 70 …… Motor housing, 74 …… Wire protection member, 76
…… Partition wall, 80 …… Bearing hole, 81 …… Bearing material, 82 …… Ball, 84 …… Spring, 88 …… Resin inlet.

Claims (5)

(57) [Claims] 1. A step motor having a motor housing integrally formed with a main portion of a motor, the cylindrical portion 52 forming a stator housing, and the cylindrical portion formed integrally with the cylindrical portion and parallel to the axis of the cylindrical portion. Two ring-shaped stators 1 ′ on the cylindrical portion of the first resin molded product 50 having a connector housing 56 containing a plurality of connecting terminals 54.
After the 2'is superposed and housed and fixed, a stator assembly 64 formed by connecting the ends of the windings of the coils of the ring-shaped stator to the corresponding connection terminals 54, and the stators 1 ', 2 'A bearing hole for bearing one end of the rotor shaft 6 fixed to the shaft center and the rotor inside the stator
A stepping motor comprising a motor housing 70 which is resin-molded so as to be integrally surrounded with the shaft center of 80. 2. The end of the winding of each coil can pass through the connecting portion between the cylindrical portion 52 and the connector housing 56 of the first resin molded product 50, and the motor housing 70 is filled with resin by molding. The step motor according to claim 1, wherein the step motor has a connection portion space 58. 3. The step motor according to claim 2, wherein a partition wall 76 is provided in a connecting portion space 58 between the cylindrical portion 52 and the connector housing 56. 4. The step motor according to claim 2 or 3, wherein an electric wire protection member 74 is fitted in a connection portion space 58 between the cylindrical portion 56 and the connector housing 56. 5. A resin inflow port for the ring-shaped stators 1 ', 2'.
88. The step motor according to any one of claims 1 to 4, wherein 88 is provided.