JPH0145263Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a single-phase step motor of rotating iron piece type.

A single-phase step motor of the iron piece rotating type depends on whether the magnetic pole generated in the iron piece rotor at the time of starting is the N pole or the S pole.For example, if the former rotates in the forward direction, the latter rotates normally. It had a drawback that it rotated in the forward direction after rotating backwards for one pulse. Furthermore, since the rotational torque of the rotor is determined only by the exchange of magnetic flux generated between the rotor and the magnets,
The drawbacks were that the torque at startup was small and the startup characteristics were poor.

This invention aims to rectify the shortcomings mentioned above.
It is an object of the present invention to provide a single-phase step motor in which the direction of rotation can be regulated and the starting torque can be improved by providing new magnetic pole teeth.

The present invention will be explained below with reference to examples. In FIG. 1, 1 is a rotor shaft, and the shaft 1 is rotatable through a bearing 2 with respect to a first soft magnetic boss 3, and is connected to an iron piece rotor through a second boss 4. 5 are integrated. An annular excitation coil 6 is fixed to the first boss 3, a soft magnetic yoke 7 is fixed to cover the upper side of the excitation coil 6, and eight outer magnetic pole teeth are attached to the inner circumference of the yoke 7. 8 are integrally formed. Reference numeral 9 denotes an annular magnet whose upper surface faces the iron piece rotor 5 with a slight gap therebetween, and is fixed by a non-magnetic mounting member 10.

As shown in FIG. 2, the above-mentioned magnet 9 is magnetized with 8 N poles and S poles alternately arranged at equal pitches in the circumferential direction so as to form a radial pattern, and the magnetized surface faces the iron piece rotor 5. so that it is fixedly placed.

Moreover, the iron piece rotor 5 is, as shown in FIG.
An inner circumferential flange 5 ₃ is formed as a fixing portion to the second boss 4, and the first magnetic pole tooth 5 ₁ and the second magnetic pole tooth 5 ₂ are formed.
and are alternately extended from the inner peripheral collar ₅₃ .
The first magnetic pole tooth 5 ₁ is connected to the inner peripheral flange 5 ₂ via a small cross-sectional area portion 5 ₄ and has a longer circumferential length than the second magnetic pole tooth 5 ₂ . On the other hand, the second magnetic pole tooth 5 ₂ extends from the inner peripheral flange 5 ₃ with the same width as the magnetic pole tooth 5 ₂ . Furthermore, each magnetic pole tooth 5 ₁ , 5 ₂
have an unexpanded shape, and are formed of four pieces each, and the first magnetic pole teeth ₅₁ and the second magnetic pole teeth ₅₂ have the same pitch as the N and S poles of the magnet 9. It is formed.

Further, the outer magnetic pole teeth 8 are arranged at the same pitch as the magnetic pole pitch of the magnet 9, as shown in FIG.
As shown in FIG. 5, the magnets 9 are arranged so as to have a phase difference such that they are offset by a slight angle α counterclockwise from the polar center of the magnet 9.

Furthermore, as shown in FIG. 6, the excitation coil 6 is of a type in which a DC voltage +B is applied to the intermediate tap 6a, and when a positive pulse is applied to the first control terminal 11, the first transistor 12 is activated. When conductive, a current flows through the excitation coil 6 in the direction of the arrow shown by the solid line.On the other hand, when a positive pulse is applied to the second control terminal 13, the second transistor 14 becomes conductive, and the current flows through the excitation coil 6 in the direction indicated by the dashed arrow. Current is now flowing through. When a magnetic flux is generated in the excitation coil 6 due to this, the magnetic flux is
Loop 15 indicated by the broken line in the figure, that is, the first boss 3←→
It flows through the yoke 7←→outer magnetic pole tooth 8←→gap g←→iron piece rotor 5←→second boss 4←→first boss 3. As a result, opposite magnetic poles are induced in the first magnetic pole tooth 5 ₁ and the second magnetic pole tooth 5 ₂ of the iron piece rotor 5, and the longer first magnetic pole tooth 5 ₁ exerts an attractive force on the outer magnetic pole tooth 8. will begin to receive

Next, the operation will be explained. A pulse signal shown in FIG. 7A is applied to the first control terminal 11, and a pulse signal shown in FIG. 7B is applied to the second control terminal 13, but both pulse signals A and B are on duty. The cycle is less than 50% and the phase difference is 180 degrees. Therefore, a rest time t ₀ occurs in which no current flows through the exciting coil 6.

FIG. 8 shows the first magnetic pole tooth ₅₁ and the second magnetic pole tooth of the iron piece rotor 5.
magnetic pole tooth 5 ₂ , outer magnetic pole tooth 8 , and magnet 9
FIG.

At the time shown in FIG. 7, the magnet is in a non-excited state, and the first magnetic pole tooth 5 ₁ and the second magnetic pole tooth 5 ₂ have the lowest magnetic resistance in the magnetic flux path from the N pole of the magnet 9 to the S pole. It is stationary at a position where it is, that is, an intermediate position straddling the north and south poles. At this time, Figure 8a
As shown in , the first magnetic pole tooth ₅₁ stands still between the poles running from the north pole toward the south pole in the counterclockwise direction, and the second magnetic pole tooth 51 stands between the poles running from the south pole toward the north pole in the counterclockwise direction. 5
Suppose that ₂ is at rest.

Next, at the time shown in FIG. 7, the exciting coil 6 is excited in one direction, and the first magnetic pole tooth 51 is the N pole, and the second magnetic pole tooth ₅₁ is the N pole.
When the magnetic pole tooth ₅₂ becomes the S pole, the first tooth becomes the N pole due to the magnetic action of attraction and repulsion, as shown in Figure 8b.
The magnetic pole tooth ₅₁ is attracted onto the south pole of the magnet 9, and the second magnetic pole tooth ₅₂ , which has become the south pole, is attracted onto the north pole of the magnet 9, and the magnetic pole tooth 51 is attracted to the north pole of the magnet 9 in the counterclockwise direction.
It rotates by two magnetic pole pitch angles, and this state continues until the pulse signal applied to the first control terminal 11 becomes zero. Note that at this time, the outer magnetic pole tooth 8 attracts the first magnetic pole tooth 5 ₁ by transferring magnetic flux. For this reason, the first
The magnetic pole tooth ₅₁ is not the top of the S pole of the magnet 9,
The position is shifted by a slight angle β (<α) toward the outer magnetic pole tooth 8 (counterclockwise direction), and the starting torque becomes large.

Next, at the time shown in FIG. 7, the excitation coil 6 becomes non-excited, and the magnetic poles of the first magnetic pole tooth 5 ₁ and the second magnetic pole tooth 5 ₂ disappear. Just before this, both magnetic poles 5 as mentioned above
₁ and ₅₂ are offset counterclockwise by β from the top of the pole of magnet 9, so when the magnet 9 is de-energized, the action of the north and south poles of magnet 9 causes the magnet 9 to move in that direction. It rotates by 1/2 the magnetic pole pitch angle and comes to rest in the middle between the north and south poles (Figure 8c).

Next, when the time shown in FIG. 7 is reached, the exciting coil 6 is excited in the opposite direction to the time, and the first magnetic pole tooth 5
₁ becomes the S pole, and the second magnetic pole tooth 5 ₂ becomes the N pole, and due to the attraction and repulsion with the magnetic pole of the magnet 9, it further rotates counterclockwise as shown in FIG. 8 d, and as shown in FIG.
The situation is the same as shown in .

Thereafter, the above operation is repeated as time passes, and the iron piece rotor 5 rotates counterclockwise in steps of one magnetic pole pitch of the magnet 9 for each period of the pulse signal applied to the first control terminal 11 and the second control terminal 13. Rotate in the circumferential direction.

By the way, the above is a case where the iron piece rotor 5 is stationary at the position shown in FIG. 8a and the time shown in FIG. 7 is reached, but as shown in FIG. The first magnetic pole tooth 5 ₁ is stationary between the poles going from the S pole to the N pole in the clockwise direction, and the second magnetic pole tooth 5 ₂ is stationary between the poles going from the N pole to the S pole in the counterclockwise direction. If so, the rotation is restricted at the next time shown in FIG.

That is, a positive pulse is generated at the first control terminal 11 and the excitation coil 6 is excited in one direction, so that the first magnetic pole tooth 5 ₁ becomes the N pole and the second magnetic pole tooth 5 ₂ becomes the N pole, as in the previous case.
is rotated counterclockwise by attraction and repulsion with the magnetic poles of the magnet 9, and comes to the position shown in FIG. 8b'. This state is the same as that shown in FIG. 8b, and the state shifts to FIG. 8c due to subsequent de-energization, after which step rotation continues in the counterclockwise direction as in the previous case.

As described above, the first magnetic pole tooth 5 ₁ is normally attracted to the top of the magnetic pole of the magnet 9 during excitation, but in this embodiment, the first magnetic pole tooth 5 ₁ is attracted to the top of the magnetic pole of the magnet 9.
Since the first magnetic pole tooth ₅₁ is also attracted to the outer magnetic pole tooth 8, the attracted state continues at a position where the first magnetic pole tooth 51 is deviated by an angle β toward the outer magnetic pole tooth 8. Therefore, by becoming non-energized, it rotates toward the outer magnetic pole tooth 8 side. That is, the iron piece rotor 5 rotates in the direction of the outer magnetic pole teeth 8 which are offset from the top of the magnet 9. In the above embodiment, the rotation is counterclockwise since it is biased in the counterclockwise direction, and as described above, it rotates in the counterclockwise direction, but if it is biased in the clockwise direction, it rotates in the clockwise direction. In other words, the direction of rotation of the iron piece rotor is determined by the direction in which the outer magnetic pole teeth 8 are biased.

In the above embodiment, if the excitation coil 6 does not have an intermediate tap, as shown in FIG. As a result, transistors 15 and 16 become conductive, and a current flows in the direction of the solid arrow in the exciting coil 6.
It is also possible to make the transistors 17 and 18 conductive by a pulse signal applied to the control terminal 13 so that a current flows through the exciting coil 6 in the direction of the dashed arrow.

It is also conceivable that the outer magnetic pole teeth 8 are formed by pressing a magnetic iron plate into a shape that extends individually from the yoke 7, but in this case, the gap g shown in Fig. 1 becomes large and the torque decreases. As shown in FIG. 4, it is preferable to form convex outer magnetic pole teeth 8 on the inner periphery of the cup-shaped magnetic body 7 by compression molding pure iron powder.

Further, in the above embodiment, the number of outer magnetic pole teeth 8 is the same as that of the first magnetic pole teeth ₅₁ , but the number may be 1/2 or 1/4.

Moreover, in the above embodiment, the second magnetic pole tooth 5 ₂
is not necessarily necessary.

Furthermore, the shape of the iron piece rotor 5 is not limited to that of the above-described embodiment, and of course includes all shapes that can perform the same operation as described above.

From the above, according to the present invention, the magnetic pole teeth of the iron piece rotor stand still biased from the top of the magnet pole toward the outer magnetic pole teeth during excitation due to the outer magnetic pole teeth. The rotation direction of the iron piece rotor is now restricted to one direction.

In addition, since the attractive force generated between the outer magnetic pole teeth and the first magnetic pole tooth of the iron piece rotor acts in the direction of adding to the rotational force, a large starting torque is obtained, and therefore a single-phase step motor with the same torque If so, it has the advantage of being extremely compact.

[Brief explanation of drawings]

Fig. 1 is a sectional view of an embodiment of the single-phase step motor of the present invention, Fig. 2 is a plan view of the magnet, and Fig. 3 is a sectional view of an embodiment of the single-phase step motor of the present invention.
The figure is a rear perspective view of the iron piece rotor, Figure 4 is a rear perspective view of the vicinity of the outer magnetic pole teeth, Figure 5 is an explanatory diagram of the positional relationship of the outer magnetic pole teeth with respect to the magnet, Figure 6 is a wiring diagram of the excitation coil, FIG. 7 is a timing chart of a pulse signal to be applied to the excitation coil, FIG. 8 is an operation explanatory diagram, and FIG. 9 is a wiring diagram of another example of the excitation coil. 1... Rotor shaft, 2... Bearing, 3... First boss, 4... Second boss, 5... Iron piece rotor, 5 ₁ ...
...First magnetic pole tooth, 5 ₂ ... Second magnetic pole tooth, 6 ... Exciting coil, 7 ... Yoke, 8 ... Outer magnetic pole tooth, 9 ...
...Magnet, 10...Mounting member.

Claims (1)

[Claims for Utility Model Registration] An iron piece rotor whose center is fixed to the rotor shaft and a plurality of magnetic pole teeth are formed in the circumferential direction, and a plurality of N and S magnetic poles are magnetized in the circumferential direction. An annular magnet fixedly arranged so that its magnetized surface faces the magnetic pole teeth with a gap in between, and an excitation device for causing magnetic flux to flow outward from the center of the iron piece rotor or from the outside toward the center. In a single-phase step motor consisting of a coil, a magnet is generated near the outer peripheral end of the magnetic pole teeth of the iron piece rotor and at an angular position offset by a slight angle from the top of the pole of the magnet, due to the magnetic flux generated by the excitation coil. A single-phase step motor characterized in that another magnetic pole tooth is fixedly arranged to attract the magnetic pole tooth by being guided.