JPH0611182B2 - Stepping motor - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a stepping motor, in which a coil wound around a bobbin is wound around four balls formed in a stator core of a rectangular hybrid type stepping motor. Regarding things.

[Technical background of the invention and its problems]

Conventional permanent magnet hybrid type mini-angle stepping motors often have a step angle of 1.8 ° or 3.6 °, but as shown in FIG. 1, the inner peripheral edge of the core (1) is Eight poles (2) are projected in a symmetrical position on each of the poles, and a coil is wound around each pole (2). In this configuration, if the outer shape of the core (1) is square, There is a part (3) that does not function as a core in the corner portion, and the slit area around which the coil is wound between the poles (2) is made to project the eight poles (2) on the inner peripheral edge of the core (1). Since the pole (2) is smaller, and the pole (2) faces the center of the core (1), the gap (5) between the tips of the poles (2), which is the opening of the slit (4) around which the coil is wound, is Narrow, it is difficult to wind the coil around each pole (2), workability is poor,
Not only was it a cost-up, but we could not increase the production quantity.

Therefore, as shown in FIG. 2, the poles (9) are projected from the inner side edges (8) of the sides (7) of the rectangular core (6), and
It is conceivable to expand the gap between (9) to facilitate the winding of the coil, but since the convex portion formed at the tip of each pole (9) is displaced according to the step angle, Paul (9)
Is deviated and each pole (9) is not formed symmetrically on the inner side edge (8) of each side (7), and it is useless when the coil (10) is wound around each pole (9). When the space (11) is formed and the number of concave portions of the rotor corresponding to the step angle is odd, this tendency is particularly remarkable, and there is a drawback that the coil amount to the core is small, the electric load is small, and the torque is small. .

[Object of the Invention]

The present invention has been made in view of the above point, and the bobbin of the coil wound around each pole of the core reduces the space generated inside the core, and the stepping of the same size as compared with the size of the core is performed. It is intended to provide a stepping motor capable of obtaining the most efficient mechanical output as a motor.

[Outline of Invention]

The structure of the present invention is a square frame-shaped rectangular stator core in which a pole having a plurality of convex portions corresponding to the step angle is projectingly provided at the central portion of the inner side edge of each side portion, and each pole of this core. 4 wound around bobbins respectively fitted along the inner edges of the sides of the core.
Each of the poles is provided with a plurality of coils and a rotor provided in a space surrounded by the coils and having a convex portion formed on a circumferential surface according to a step angle corresponding to the convex portion of the pole. Cut the side edge of the pole with the convex portion of the tip displaced according to the step angle and cut it parallel to the center line in the width direction of the pole, and make the concave portion adjacent to this convex portion on the cut side of the pole It is deviated toward the center line in the width direction.

Example of Invention

Next, in one embodiment of the present invention, the step angle .theta. A stepping motor in which 28 convex portions are formed on the peripheral surface of the rotor at equal intervals will be described.

In FIG. 3 to FIG. 6, (20) is a laminated or integrally formed stator core, which is formed into a square shape in a substantially square frame shape and has inner side edges ((21) (21) (21) (21)). The poles (23), (24), (25) and (26) are respectively projected in the substantially central portion of the (22). The height (h) of each pole (23) (24) (25) (26) is the rotor (27) described later.
0.24 to 0.5 times the outer diameter (D) of this pole (2
3) (24) (25) (26) has four protrusions (28) (29) (30) (3
1) is formed in a tooth shape. This first pole
(23) is uniform so that the four convex parts (28) (29) (30) (31) are symmetrical to the center of the edge (22) with respect to the vertical center line (l ₁ −l ₁ ). Is formed in. The left and right second poles (24) and third poles (25) have four convex portions (28) (29) (30) (3).
1) is formed, and the convex portions (28), (29), (30), and (31) are divided by the step angle θ ° from the horizontal center line (l ₂ −l ₂ ) of the core (20). It is formed so as to be displaced in the direction close to the pole (23) side. A fourth pole facing the first pole (23).
(26) is four convex parts (28) (29) (30) (31) are vertical center lines
(l ₁ −l ₁ ) is offset to the side of the third pole (25) by an angle of 2θ ° which is twice the step angle θ °, and the second pole (24),
The third pole (25) and the fourth pole (26) are formed so as to be offset from the center. And this each pole (2
3) The protrusions (28), (29), (30) and (31) of (24), (25) and (26) are formed toward the center of the core (20), and the second pole is offset by θ °.
(24) and the third pole (25) on the side of the first pole (23), and the third pole (25) of the fourth pole (26) deviated by 2θ.
For the side, cut the part indicated by the chain line in FIG.
Parallel to the center line (l ₂ −l ₂ ) (l ₁ −l ₁ ) of the poles (24) (25) in the width direction, the concave portion (32) forming this convex portion (31) is (24) It is deviated toward the center line in the width direction of (25) and (26).

Next, (33), (34), (35) and (36) are bobbins wound with coils (37), respectively, and are fitted to the respective poles (23) (24) (25) (26) of the core (20). It is being worn. This first and fourth
The coils (37) of the A phase and the phase are wound around the bobbins (33) (36) mounted on the poles (23) (26) of the No. 2 by the Bi-Failer winding, and the second and third poles (24) ( The B-phase and phase coils (37) are wound around the bobbins (34) (35) mounted on the coil (25) by bifilar winding. Each bobbin (33) (34) (35)
The thickness (a) of (36) is the distance between the vertical line from the tip of the opposing pole and the adjacent side edge of the pole adjacent to this pole, for example, the vertical line from the tip of the second pole (24) and this first line. The second pole (2) of the fourth pole (26) adjacent to the second pole (24)
4) side edge (38) and the distance (b) is almost equal, and the width (c) of the bobbins (33) (34) (35) (36) is set to each side (21) of the core (20). ) The distance (d) between the inner edges (22) of the bobbin (33) (34) (35) (36)
Thickness (a) is subtracted from the value to make it approximately equal.

Next, the rotor (27) is arranged in a space (39) surrounded by a coil (37) wound around each of the poles (23) (24) (25) (26). (27) is formed by a disk-shaped permanent magnet (40) and disk-shaped magnetic bodies (41) and (42) sandwiching the permanent magnet (40). ), 23 convex portions (43) are formed at equal intervals on the outer peripheral surface of the magnetic body (41).
One half of the convex portion (43) of (42), that is, two of the step angle θ °
It is deviated in the circumferential direction by a fraction.

Further, the lead wires of the coils (37) wound around the bobbins (33) (34) (35) (36) are connected to the upper sides of the bobbins (33) (34) (35) (36). The terminal pin (64) is protruding and this terminal pin
The (64) is inserted into the connection hole (48) of the printed wiring board (47) for solder connection.

Also, on this wiring board (47), the terminal pins (50) of the connector (49)
Connect.

Also, at least diagonal positions of the bobbins (33) (34) (35) (36) fitted to the respective poles (23) (24) (25) (26) of the core (20), for example, the first pole (23 ) And the second pole (24) and the second
The bobbin is formed by locking both ends of the film-like retainer blocking piece (51) between the pole (25) and the fourth pole (26).
(33) (34) (35) (36) are prevented from coming off and blocked.

Also, (52) (53) is a motor frame, and this frame (52) (5
3) is adapted to be fitted on the upper and lower surfaces of the core (20).

Further, the rotating shaft (44) of the rotor (27) is attached to the frame (52) (53).
Bearing bearings (45) and (46) for rotatably supporting the shaft are provided.

Further, the bobbin (3
3) Holding projections (54) that engage with the inner surface sides of (34), (35) and (36) are provided in a protruding manner. It should be noted that the coil (3
When the lead wire is directly connected to the lead wire of (7), the inner surface of the upper motor frame (52) is also engaged with the inner surface of the bobbin (33) (34) (35) (36). Protrusions are provided to hold the movement of 34, 35, and 36. This upper and lower frame (52) (53) core (20)
Tighten and fix it with the bolts (55) that pass through.

Further, (56) is a shield plate formed of a magnetic material such as an iron plate, which is formed in a substantially cross shape and has an insertion hole (58) formed in the center portion for inserting the output shaft portion (57) of the rotating shaft (44). Substrate part (59)
And a protruding piece portion (61) extending from each protruding portion (60) of the board portion (59) and one protruding piece portion (61) from each protruding piece portion (61). The shield plate (46) is abutted against the outer surface of the lower frame (53) by engaging and extending the engaging pieces (62), and the protruding pieces (60) are moved up and down. Each of the poles (23) (24) on each outer peripheral surface of the frame (52) (53) and each outer peripheral surface of the core (20)
(25) The upper frame (52) is formed corresponding to the positions of (26) and engages with the engaging groove (63) except for the position of the connector (49).
The engaging groove (63) formed on the periphery of the upper outer surface of the engaging piece (6
2) is locked to prevent magnetic leakage due to magnetic saturation at the poles (23), (24), (25) and (26), especially on the output shaft (57) side.

Next, the operation of this embodiment will be described.

First, when the A phase of the coils (37) (37) mounted on the first pole (23) and the fourth pole (26) is excited, for example, the first pole (23) becomes the S pole and the fourth pole (23) The pole (26) becomes an N pole, and the first pole (23) has one magnetic body (4) of the rotor (27).
The convex portion (43) of 1) is sucked, and the rotor is attached to the fourth pole (26).
A coil attached to the second pole (24) and the third pole (25) by attracting the convex portion (43) of the other magnetic body (42) of (27) and rotating by a step angle θ °. (37) When the B phase of (37) is excited, the second pole (24) becomes the N pole and the third pole (2
5) becomes the S pole, the convex portion (43) of the other magnetic body (42) of the rotor (27) is attracted to the second pole (24), and the third pole (2)
The convex portion (43) of one magnetic body (41) of the rotor (27) is attracted to 5), the rotor (27) rotates by θ °, and then the first pole (23)
And the phases of the coils (37) (37) of the fourth pole (26) are excited, the first pole (23) becomes the N pole and the fourth pole (26)
Becomes the S pole, the convex portion (43) of the other magnetic body (42) of the rotor (27) is attracted to the first pole (23), and the fourth pole (26)
The convex portion (43) of one magnetic body (41) of the rotor (27) is attracted to the rotor (27) and rotated by a step angle θ °, and the coil of the second pole (24) and the third pole (25) continues. (37) When excited to the phase of (37), the second pole (24) becomes the S pole and the third pole (25)
Becomes the N pole, the convex portion (43) of one magnetic body (41) of the rotor (27) is attracted to the second pole (24), and the third pole (25)
The convex portion (43) of the other magnetic body (42) of the rotor (27) is attracted to the rotor (27), the rotor (27) rotates by θ °, this operation is repeated, and the rotor (27) is stepped. Is rotated.

The leakage flux concentrated on the output shaft part (57) side of the rotating shaft (44) due to the magnetic saturation occurring in each pole (23) (24) (25) (26) is the substrate part (59) of the shield plate (56). ) And each protrusion (61) prevent leakage.

When assembling, the terminal pins (64) protruding from each bobbin (33) (34) (35) (36) are connected to the connection hole (48) of the printed wiring board (47).
Bobbin (33) (34)
(35) (36) is positioned and held, and wiring can be simplified, there is no risk of incorrect wiring, and connection failure can be prevented. Furthermore, by connecting the connector (49) to the wiring board (47), the connection of the external conducting wire can be surely performed.

Between adjacent poles located on a diagonal line, for example, the side edge of the first pole (23) and the second pole (24) and the third pole (25).
Each bobbin (33) (34) (35) (36) is fixed by engaging both ends of the retaining block (51) with the side edge of the fourth pole (26).

Furthermore, the retaining protrusions (54) of the frame (53) fitted to the core (20)
Is engaged with the inner surface of the bobbin (33) (34) (35) (36),
(33) (34) (35) (36) are positioned and held.

Further, among the poles (23), (24), (25) and (26) of the core (20), the poles (23), (24), (25) and (26) whose centers are displaced by θ ° or 2θ ° are biased at the tip edge. The side edges of the projections (31) on the position side are cut out so as to be parallel to the central axis and the recesses (32) forming the projections (31) are deviated to the center side so that each pole (23) (24) ( The asymmetrical arrangement of (25) and (26) can reduce the space generated when the coil (37) is wound.

Also, coil (37) on each pole (23) (24) (25) (26) of the core (20)
When winding bobbins (33) (34) (35) (36) wound around, two bobbins to be mounted on bobbins facing each other are provided between poles (23) (24) (25) (26). Each pole can be fitted by inserting it into the space and moving the bobbins in opposite directions.

Next, the thickness (a) of each bobbin (33) (34) (35) (36) is adjacent to the vertical line from the tip of the facing poles (23) (24) (25) (26). The width (c) of the bobbin (33) (34) (35) (36) is set to be approximately equal to the distance from the adjacent side edge of the pole, and the inner edge (22) of each side portion (21) of the core (20) is set. Bobbin (33) (34) (3
5) Regarding the relationship between the pole height (h) and the outer diameter (D) of the rotor when it is made approximately equal to the value obtained by subtracting twice the thickness of (36), each relative of the core (20) Inner side edge (2
The distance (d) between 2) is 34mm, and the poles (23) (24) (25) (26)
The ratio of the width of the rotor to the outer diameter (D) of the rotor (27) is 0.45, and the storage area of one half of the coil stored between the adjacent poles is equal to each pole (23) (24). The height (h) of (25) (26) is the core (20)
1/2 of the difference between the distance (d) between the inner side edges (22) of the opposite side portions (21) of the rotor (27), that is, h = (34-D) ÷ 2 As for the bobbin storage area, the height (h) of the pole is the rotor (2
It is clear that the maximum value is obtained when the outer diameter (D) of 7) is 0.5 times. At this time, the motor having the largest electric load is used as the motor using the cores (20) of the same size.

On the other hand, in order to maximize the torque obtained with cores of the same size, the bobbin storage area is proportional to the electrical mounting.
The outer diameter of the rotor (27) may be determined so that the product of (s) and the outer diameter (D) of the rotor proportional to the magnetic loading is maximized. The torque becomes maximum when the outer diameter (D) of 27) is 0.24 times.

The ratio of the width (f) of the poles (23) (24) (25) (26) to the outer diameter (D) of the rotor (27) was set to 0.45.
Similar results are obtained with 35, 0.4 and 0.5.

〔The invention's effect〕

According to the present invention, of the poles protruding from the central portion of the inner side edge of each side portion of the rectangular stator core, the poles are displaced in accordance with the step angle, and the side of the displaced poles on the displaced side. The edges were cut and ground parallel to the center line in the width direction of the poles, and the concave portion adjacent to the cut side was displaced toward the center line in the width direction of the poles. Due to the asymmetrical arrangement, the space generated when the coil is wound can be reduced, the coil amount can be increased as compared with the core, and a large torque can be obtained.

[Brief description of drawings]

1 is a plan view of a core of a conventional stepping motor, FIG. 2 is a plan view of a core of another conventional stepping motor,
FIG. 3 is a perspective view of a stepping motor showing an embodiment of the present invention, FIG. 4 is a front view with a part thereof cut away, and FIG. 5 is a bottom view of an apparatus without the upper and lower frames thereof. Is a plan view of the core, and FIG. 7 is an enlarged plan view of a part of the core. (20) …… core, (21) …… side, (22) …… inner edge, (23)
(24) (25) (26) …… pole, (27) …… rotor, (28) (29) (3
0) (31) …… Convex part of pole, (32) …… Concave part of pole, (33)
(34) (35) (36) …… bobbin, (37) …… coil, (43) …… rotor protrusion.

Claims (1)

[Claims] 1. A substantially square frame-shaped rectangular stator core in which a pole having a plurality of convex portions corresponding to step angles is projectingly provided at the tip at the center of the inner side edge of each side portion, and each pole of this core. Four coils wound around bobbins that are fitted and arranged along the inner side edges of each side of the core, and the convex portions of the poles arranged in the space surrounded by the coils And a rotor having a convex portion formed on its peripheral surface in accordance with a step angle corresponding to, each pole is displaced in accordance with a step angle, and the side of the displaced pole is displaced. It is characterized in that the edge is cut and ground in parallel with the center line in the width direction of the pole, and the concave portion adjacent to the convex portion on the cut side is displaced toward the center line in the width direction of the pole. Stepping motor.