JPH0428221Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention relates to a step motor used in pointer type watches and the like.

[Prior art and its problems] In general, a step motor used in an electronic watch includes a coil 1 that generates a magnetic field, a coil core 2 around which the coil 1 is wound, as shown in FIGS. 5 and 6. It consists of a stator 3 attached to both ends of this coil core 2, and a cylindrical rotor 4 rotatably disposed within a circular hole 3a of this stator 3. In this case, the stator 3 is attached to the lower surface of the base plate 5, as shown in FIG. 5b. Further, the rotor 4 has an upper end of its shaft 4a supported by a bearing 5a provided on a base plate 5, and a lower end supported by a bearing 7a of a rotor support 7 below through a gear train bearing 6. An intermediate wheel 8 of the wheel train mechanism is engaged with the pinion 4b. However,
When the rotor 4 is rotated by the stator 3, the rotation is transmitted to the wheel train mechanism by the intermediate wheel 8 that meshes with the pinion 4b of the rotor 4. As a result, the time is indicated by moving the hour hand, minute hand, second hand, and other hands.

In such a step motor, the rotor must be stopped so that the direction of the magnetic flux of the rotor magnet is inclined with respect to the direction of the excitation magnetic flux of the stator so that the rotor rotates in one direction every time the stator is excited. No. Therefore, methods for determining the resting position of the rotor 4 include a method of shifting the stator 3 as shown in FIG. 5a, or a method of providing recesses 3b, 3b in the stator 3 as shown in FIG. .

However, the former method of shifting the stator 3 is to divide the stator 3 into left and right parts using the circular hole 3a, and while adjusting one of the stators 3 using the eccentric pin 9, shift the opposing parts of the stator 3 back and forth. This deviation determines the resting position of the rotor 4, but since the amount of deviation of the stator 3 must be adjusted with an accuracy of 1/100 mm or less, the processing and assembly are extremely troublesome, and mass production is difficult. There was a problem that it was bad.

The latter method of providing the recesses 3b, 3b in the stator 3 is to form a pair of recesses 3b, 3b on the inner circumferential surface of the circular hole 3a of the stator 3;
b determines the resting position of the rotor 4, but the recess 3
b and 3b must be formed at symmetrical positions and at positions inclined at a predetermined angle with respect to the excitation magnetic flux generated within the circular hole 3a, which is not only cumbersome to process, but also must be formed at positions that are symmetrical with respect to the center of the circular hole 3a. It is necessary to align the center of the rotor 4, and center accuracy is required between the bearing 5a of the base plate 5, which pivotally supports the upper end of the shaft 4a of the rotor 4, and the bearing 7a of the rotor bearing 7, which pivotally supports the lower end. ,
There is a problem that assembly work is troublesome.

[Purpose of the invention] This invention was made in consideration of the above-mentioned circumstances, and its purpose is to create a step motor that can easily and reliably determine the resting position of the rotor and that can be easily assembled. It is about providing.

[Main points of the invention] In order to achieve the above-mentioned purpose, this invention has a linear positioning mechanism on the upper shaft of the rotor, which has a conical magnet rotatably arranged in the conical hole of the stator. In addition to providing a convex portion, a linear locking recess is provided in the rotor holder along a direction inclined to the excitation magnetic flux generated in the conical hole of the stator, so that when the stator is energized, the rotor is moved toward the bearing member by the stator's magnetic flux. The rotor is moved and rotated, and when the stator is not energized, the rotor is moved to the rotor receiving side by the magnetic force of the magnet, and the positioning protrusion is engaged with the locking recess of the rotor receiver to determine the resting position of the rotor. It is something.

[Embodiment] An embodiment of this invention will be described below with reference to FIGS. 1 to 4.

In FIGS. 1 and 2, 10 is a stator and 11 is a rotor. The stator 10 provides magnetic flux to the rotor 11, and is made of permalloy or the like in the form of a strip. Both ends of the stator 10 are connected to both ends of a coil core, and are attached to the lower surface of the main plate 12. A conical hole 10a is formed in the center of the stator 10, and recesses 10b, 10b are formed in opposing outer wall surfaces with the conical hole 10a in between.

The rotor 11 is arranged in a conical hole 10a of the stator 10 and rotates, and has a magnet portion 11a.
, a rotor pinion 11b, and a shaft portion 11c, and the magnet portion 11a is connected to the conical hole 10a of the stator 10.
It is sintered into the same conical shape and magnetized into two poles, and has a small diameter surface 11e, a large diameter surface 11f, and a tapered surface 1.
It has 1g. The rotor pinion 11b is the magnet part 1
It is provided below 1a and transmits its rotation to the wheel train mechanism, and is engaged with the intermediate wheel 13 of the wheel train mechanism. The shaft portion 11c rotatably supports the rotor 11, and its upper end is supported by the rotor bearing 12a of the base plate 12, and its lower end is supported by the bearing 14a of the train wheel bearing 14. That is, the lower end of the shaft portion 11c is rotatably supported by the bearing 14a of the gear train bridge 14, and is movable slightly in the vertical direction. Further, a mountain-shaped positioning portion 1 is provided at the upper end of the shaft portion 11c.
1d is provided on a straight line (on the diameter) passing through the center of the magnet part 11a, and this positioning part 11d is a locking part 1 formed on the rotor receiver 12a of the main plate 12.
2b in a removable manner.
The locking portion 12b is a groove in which the positioning portion 11d engages and disengages in response to de-energization and excitation of the stator 10, and as shown in FIG.
It is formed in a direction inclined with respect to the excitation magnetic flux generated at 0a.

Next, the operation of the step motor configured as described above will be explained with reference to FIGS. 3 and 4.

FIG. 3 shows the state when the stator 10 is not energized, that is, when no magnetic flux is generated in the stator 10. At this time, the rotor 11 is attracted to the stator 10 and pulled up by the magnetic force of the magnet portion 11a. Then,
The magnet portion 11a approaches the tapered surface of the conical hole 10a of the stator 10, and also approaches the shaft portion 11 of the rotor 11.
The positioning part 11d provided at the upper end of the base plate 1
It engages with a groove-shaped locking portion 12b formed on the rotor receiver 12a of No. 2. As a result, the resting position of the rotor 11 is determined, and the rotor 11 comes to rest at a predetermined position.

FIG. 4 shows the state during excitation, that is, when magnetic flux is generated in the stator 10. At this time, rotor 1
The first magnet portion 11a is repelled by the magnetic flux generated in the stator 10 and is pushed down. Then, the positioning part 11d at the upper end of the shaft part 11c of the rotor 11 comes off from the locking part 12b of the rotor receiver 12a, and the rotor 1
1 becomes rotatable and rotates 180 degrees due to the magnetic flux generated in the stator 10.

When the rotor 11 rotates 180 degrees in this way, the rotor 11 returns to the non-excited state shown in FIG.
remains at a predetermined position, and then, as shown in FIG. 4, when magnetic flux is generated in the stator 10 again, the rotor 11 becomes rotatable and rotates 180 degrees.
By repeating this, the rotor 11 rotates.

However, according to the step motor as described above, the positioning portion 11d of the rotor 11 is
is locked to the locking portion 12b of the rotor receiver 12a, so the rotor 11 can be accurately and reliably stopped at the rest position, and during excitation, the positioning portion 11d of the rotor 11 is locked to the locking portion 12 of the rotor receiver 12a.
b, so the rotor 11 can be rotated smoothly.

In addition, in the embodiment described above, the shaft portion 1 of the rotor 11
A mountain-shaped positioning part 11d is provided at the upper end of 1c,
A groove-shaped locking portion 12 is provided on the rotor support 12a of the main plate 12.
b, but the present invention is not limited to this, and the shaft portion 11c of the rotor 11 may be provided with a groove-shaped positioning portion, and the rotor support 12a of the base plate 12 may be provided with a chevron-shaped locking portion. Of course.

[Effects of the invention] As explained above, according to the step motor of this invention, a positioning part is provided on the upper part of the conical rotor rotatably disposed in the conical hole of the stator, and the positioning part Since the locking portion of the rotor support, which is engaged and released in response to de-energization and excitation of the stator, is provided in a direction inclined with respect to the excitation magnetic flux generated in the conical hole of the stator, the stationary position of the rotor can be easily and easily adjusted. It has the advantage of being reliably determined and easy to assemble.

[Brief explanation of the drawing]

Figures 1 to 4 show an embodiment of this invention, with Figure 1 being a sectional view of its main parts, and Figure 2 being A--
A plan view, Fig. 3 shows the state when not energized, Fig. 4 shows the state when energized, Figs. 5 and 6.
The figures show a conventional example: Fig. 5a is a plan view of the step motor when the stator is shifted, Fig. 5b is a sectional view of the main part including a part of the gear train mechanism, and Fig. 6 is a circular hole in the stator. FIG. 3 is a plan view of a step motor provided with a pair of recesses. 10... Stator, 10a... Conical hole, 11...
...Rotor, 11a... Magnet part, 11d... Positioning part, 12a... Rotor holder, 12b... Locking part.

Claims (1)

[Claims for utility model registration] Rotor 11, stator 10, rotor bridge 12a,
The rotor 11 has a bearing member 14, and the rotor 11 has a small diameter surface 11e and a large diameter surface 11f.
and a conical magnet 11a consisting of a surrounding tapered surface 11g, the small diameter surface 11e and the large diameter surface 11.
and a shaft portion 11c protruding from the magnet 1
A shaft portion 11c protruding from the small diameter surface 11e of 1a.
A linear positioning convex portion 11d is provided on the small diameter surface 1.
The stator 10 is provided on a straight line passing through the center of the rotor 11, and a conical hole 10a is formed in the stator 10, with one opening having a small diameter and the other opening having a large diameter. It has a tapered surface with the same inclination as the tapered surface of the magnet 11a, and the rotor receiver 12a has a linear locking recess 1.
2b is formed, a bearing hole is formed in the bearing member 14, the rotor 11 is disposed in the conical hole 10a of the stator 10, and the rotor 11 is disposed on the one opening side of the conical hole 10a of the stator 10. The rotor receiver 12
a is arranged, and the locking recess 12b of the rotor receiver 12a is aligned with the positioning protrusion 1 of the rotor 11.
1d, and the longitudinal direction of the locking recess 12b is along a direction inclined with respect to the excitation magnetic flux generated in the stator 10, and the A bearing member 14 is arranged, and the shaft 11c of the rotor 11 is rotatably supported by the bearing hole of the bearing member 14, and when the stator 10 is energized, the rotor 1
1 is moved toward the bearing member 14 by the magnetic flux generated in the stator 10 and rotated by the magnetic flux of the stator 10, and when the stator 10 is not energized, the rotor 11 is moved to the rotor receiver 12a by the magnetic force of the magnet 11a. A step motor in which the resting position of the rotor 11 is determined by moving the rotor 11 to the side and engaging the positioning protrusion 11d with the locking recess 12b of the rotor receiver 12a.