JPH0311184B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a stepping motor, and more particularly to a configuration in which a coil wound around a bobbin is wound around four poles formed on a stator core in a square hybrid stepping motor. Conventional permanent magnet hybrid type mini angle stepping motors are 1.8° or
Many types have step angles such as 3.6°, but the
As shown in the figure, there are 8
poles 2 are protruded, and each pole 2
In this structure, when the core 1 has a rectangular outer shape, there is a portion 3 at each corner that does not function as a core, and eight poles 2 are formed on the inner periphery of the core. Pole 2 to protrude
The area of the slits around which the coils are wound becomes smaller, and since the poles 2 face the center of the core 1, the gaps 5 between the tips of the poles 2, which are the openings of the slits 4 around which the coils are wound, are The narrow structure makes it difficult to wind the coil around each pole 2, resulting in poor workability and increased costs, as well as making it impossible to increase production quantity. Therefore, as shown in FIG. 2, a configuration has been considered in which poles 9 are made to protrude from the inner edge 8 of each side 7 of the square core 6, and the gap between the poles 9 is widened to facilitate winding of the coil. However, since each pole 9 is offset according to the step angle,
If the coils 10 are wound around each pole 9 instead of being formed symmetrically on the inner edge 8 of each side 7, wasted space 11 will be formed, and in particular, the recesses of the rotor corresponding to the step angles will have an odd number of recesses. In this case, this tendency is particularly noticeable, and the disadvantage is that the amount of coils relative to the core is small, the electrical load is small, and the torque is also small. Conventionally, a coil conductor wire with an insulating coating is wound around the pole 9 of the core 6 in a ring shape, or an insulating cylinder divided into two parts is fitted around the pole 9, and the coil conductor wire is wound around the pole 9. This structure has the disadvantage that the coil installation workability is poor. The present invention has been made in view of the above points, and it is an object of the present invention to provide a stepping motor that has the largest number of coils and can obtain the most efficient mechanical output as a stepping motor of the same size. The structure of the present invention includes a rectangular stator core in the form of a substantially square frame, which has poles protruding from the center of the inner edge of each side, each having a plurality of convex portions at the tips corresponding to the step angle. four coils wound around bobbins that are fitted together and respectively disposed along the inner edge of each side of the core;
A rotor is provided in a space surrounded by each of the coils and has a convex portion formed around the circumference according to a step angle corresponding to the convex portion of the pole, and the rotor is provided with a rotor having a convex portion formed around the circumference according to a step angle corresponding to the convex portion of the pole, and the width of the pole and the outer diameter of the rotor and the height of the pole is 0.24 to 0.5 of the outer diameter of the rotor.
It will be doubled. Next, an embodiment of the present invention will be described with reference to a four-phase stepping motor having a step angle θ of 3 3/14 degrees and a rotor having 28 convex portions formed at equal intervals on the circumferential surface. 3 to 6, reference numeral 20 denotes a laminated or integrally molded stator core, which is formed into an approximately square frame shape, and approximately at the center of the inner edge 22 of each side 21, 21, 21, 21. Paul 23, respectively.
24, 25, and 26 are protruded. The height h of each of the poles 23, 24, 25, 26 is set to 0.24 to 0.5 times the outer diameter D of the rotor 27, which will be described later. , 29, 30, and 31 are each formed into a tooth shape. The first pole 23 has four convex portions 28, 29, 30, and 31 formed evenly in the center of the edge 22 so as to be symmetrical with respect to the vertical center line _l1 - _l1 . Furthermore, four convex portions 28, 29, 30, and 31 are formed on the left and right second and third poles 24 and 25, respectively, symmetrically from the vertical center line _l1 - _l1 of the core 20. Convex part 2
8, 29, 30, and 31 are formed offset from the horizontal center line _l2 - _l2 of the core 20 by a step angle θ° in a direction closer to the first pole 23 side. Further, the fourth pole 26 facing the first pole 23 has four convex portions 28, 29, 30, 31 at an angle 2θ° which is twice the step angle θ° from the vertical center line _l1 - _l1 . is deviated toward the third pole 25 by an angle of . And each of these poles 23, 24, 25, 2
The convex portions 28, 29, 30, and 31 of 6 are formed toward the center of the core 20, and the first pole 2 of the second pole 24 and the third pole 25 are deviated by θ°.
3 side and the third pole 25 side of the fourth pole 26 which is deviated by _{2θ °} , the portion shown by the chain line in _{FIG .} This convex part 3
The concave portion 32 forming the pole 1 is connected to the pole 2 from the chain line position.
4, 25, and 26 toward the center in the width direction. Next, numerals 33, 34, 35, and 36 are bobbins each having a coil 37 wound thereon, which are fitted into each of the poles 23, 24, 25, and 26 of the core 20. This first and fourth pole 2
A-phase and phase coils 37 are wound by bi-filer winding on the bobbins 33 and 36 attached to the second and third poles 24 and 26, and bi-filer coils 37 are wound on the bobbins 34 and 35 attached to the second and third poles 24 and 25. B-phase and phase coils 37 are wound. The thickness a of each bobbin 33, 34, 35, 36
is the distance between the vertical line perpendicular to the protruding direction of the pole from the tip of the pole and the adjacent side edge of the pole adjacent to this pole, for example, the distance between the vertical line from the tip of the second pole 24 and the second pole 24 The side edge 38 of the fourth pole 26 adjacent to the second pole 24
The distance b is approximately equal to the distance b between the bobbins 33 and 3.
4, 35, 36 from the distance d between the inner edges 22 of each side 21 of the core 20, the bobbins 33, 34,
The thickness should be approximately equal to the value obtained by subtracting twice the thickness a of 35 and 36. Further, the width c of each bobbin 33, 34, 35, 36 is made approximately equal to the distance between the leading edges of opposing poles, for example, the distance e between the leading edges of the second pole 24 and the third pole 25. In other words, the distance d between the opposing inner edges 22 of the core 20 minus the sum of the heights h of the opposing poles, for example, the distance between the edges 22 and the first pole 23 and the fourth pole 26 It is formed approximately equal to the distance e obtained by subtracting the height 2h from the
Further, the thickness a of each bobbin 33, 34, 35, 36 is thinner than the outer diameter D of the rotor 27, which will be described later, and
It may be formed to be approximately equal to the height h of 3, 24, 25, and 26. Next, the rotor 27 is moved to each pole 23, 2.
The rotor 27 is arranged in a space 39 surrounded by a coil 37 wound around the coils 4, 25, and 26, and the rotor 27 includes a disk-shaped permanent magnet 40 and a disk-shaped magnetic magnet placed between the permanent magnets 40. 28 convex portions 43 are formed at equal intervals on the outer peripheral surface of the magnetic bodies 41 and 42, and the convex portions 43 of the upper and lower magnetic bodies 41 and 42 are formed by the convex portions 43. It is offset in the circumferential direction by one-half of the step angle θ°, that is, one-half of the step angle θ°. Further, the rotation shaft 44 of this rotor 27 is connected to bearings 45 and 4 provided in frames 52 and 53, which will be described later.
6 and is rotatably supported. Further, the upper side of each bobbin 33, 34, 35, 36 is provided with a bobbin 33, 34, 35, 36, respectively.
The terminal pin 64 to which the lead wire of the coil 37 wound is connected is inserted into the connection hole 48 of the printed wiring board 47 and connected. Further, terminal pins 50 of the connector 49 are connected to this wiring board 47. Further, each pole 23, 24, 2 of the core 20
Bobbins 33, 34, 35, 3 fitted to 5, 26
6 at least diagonally, for example between the first pole 23 and the second pole 24 and the third pole 25
Both ends of a film-like slip-off preventing piece 51 are respectively locked between the fourth pole 26 and the fourth pole 26 to prevent each bobbin 33, 34, 35, and 36 from falling off. Reference numerals 52 and 53 designate motor frames, which are fitted onto the upper and lower surfaces of the core 20. Furthermore, a holding protrusion 54 that engages with the inner surface of the bobbins 33, 34, 35, and 36 is protruded from the inner surface of the lower motor frame 53. Note that when the conductor is directly connected to the lead wire of the coil 37 without using the wiring board 47, the upper motor frame 52
Projections are also provided on the inner surfaces of the bobbins 33, 34, 35, 36 to engage with the inner surfaces of the bobbins 33, 34, 35, 36 to keep them from moving. The upper and lower frames 52, 53 are fastened and fixed with bolts 55 passing through the core 20. Reference numeral 56 denotes a shield plate made of a magnetic material such as an iron plate, which is formed into a substantially cross shape and includes a base plate 59 having an insertion hole 58 formed in the center thereof through which the output shaft 57 of the rotating shaft 44 is inserted. Each protrusion 60 of 59
The protruding piece 61 extending and bent from the protruding piece 6
1 except for one projecting piece 61 and an engaging piece 62 extending and bent, and the base plate 59 of this shield plate 56 is brought into contact with the outer surface of the lower frame 53,
Each protruding piece 60 is attached to each outer circumferential surface of the upper and lower frames 52, 53 and each outer circumferential surface of the core 20 to each of the poles 2.
3, 24, 25, and 26, and engages with the engaging grooves 63 formed on the outer periphery of the upper surface of the upper frame 52 except for the position of the connector 49. The mating piece part 62 is locked to prevent magnetic leakage due to magnetic saturation in the poles 23, 24, 25, and 26, particularly on the output shaft part 57 side. Next, the operation of this embodiment will be explained. First, when the A phase of the coils 37, 37 attached to the first pole 23 and the fourth pole 26 are excited, the first pole 23 becomes the S pole, the fourth pole 26 becomes the N pole, and the first The convex portion 43 of one of the magnetic bodies 41 of the rotor 27 is attracted to the pole 23, and the convex portion 43 of the other magnetic body 42 of the rotor 27 is attracted to the fourth pole 26, and the step angle θ° is When the motor rotates and then the B phase of the coils 37, 37 attached to the second pole 24 and the third pole 25 are excited, the second pole 24 becomes the north pole and the third pole 25 becomes the south pole. , second pole 24
The convex portion 43 of the other magnetic body 42 of the rotor 27 is attracted, and the convex portion 43 of one of the magnetic bodies 41 of the rotor 27 is attracted to the third pole 25, and the rotor 27 rotates by θ°. Next, when the phases of the coils 37, 37 of the first pole 23 and the fourth pole 26 are excited,
The first pole 23 becomes the N pole, and the fourth pole 2
6 becomes the S pole, and the rotor 2 is attached to the first pole 23.
The convex portion 43 of the other magnetic body 42 of the rotor 27 is attracted to the fourth pole 26, and the one magnetic body 4 of the rotor 27 is attracted to the fourth pole 26.
The convex portion 43 of No. 1 is attracted and rotated by a step angle θ°,
When the phases of the coils 37, 37 of the second pole 24 and the third pole 25 are subsequently excited, the second pole 24 becomes the S pole, the third pole 25 becomes the N pole, and the second pole 24 becomes the N pole. The convex portion 43 of one magnetic body 41 of the rotor 27 is attracted, and the convex portion 43 of the other magnetic body 42 of the rotor 27 is attracted to the third pole 25.
is attracted, the rotor 27 rotates θ°, and this operation is repeated, causing the rotor 27 to rotate in steps. The leakage magnetic flux concentrated on the output shaft portion 57 side of the rotating shaft 44 due to the magnetic saturation occurring in each of the poles 23, 24, 25, and 26 is prevented from leaking by the base plate portion 59 of the shield plate 56 and each projection portion 61. Prevented. Also, when assembling, each bobbin 33, 34,
By inserting the terminal pins 64 protruding from the terminal pins 35 and 36 into the connection holes 48 of the printed wiring board 47 and connecting them by soldering, the bobbins 33, 34, 35, and 36 are held in position, and wiring can be easily performed.
There is no risk of incorrect wiring and connection failures can be prevented. Furthermore, by connecting the connector 49 to the wiring board 47, external conductor wires can be connected reliably. Furthermore, the retaining prevention pieces 51 are provided at both ends of adjacent poles located diagonally, for example, at the side edges of the first pole 23 and the second pole 24 and at the side edges of the third pole 25 and the fourth pole 26. Each bobbin 33, 34, 35, 36 is securely fixed by simply locking the bobbin. Further, the holding protrusion 54 of the frame 53 fitted to the core 20 is engaged with the inner surface of the bobbin 33, 34, 35, 36, so that the bobbin 33, 34, 35, 36 is positioned and held. Also, each pole 23, 24, 25, 2 of the core 20
6, the pole 23 whose center is deviated by θ° or 2θ°,
24, 25, 26 are each pole 23, 24 by notching the side edge of the protrusion 31 on the deviation side of the tip edge and making it parallel to the central axis, and deflecting the recess 32 forming the protrusion 31 toward the center. , 25, 26, the space created when winding the coil 37 can be reduced. Next, the thickness a of each of the bobbins 33, 34, 35, 36 is defined as the distance b between the vertical line from the tip of the opposing pole 23, 24, 25, 26 and the adjacent side edge of the pole adjacent to this pole. The width c of the bobbins 33, 34, 35, and 36 is calculated from the distance d between the inner edges 22 of each side 21 of the core 20.
The relationship between the height h of the pole and the outer diameter D of the rotor when the height h of the pole is approximately equal to the value obtained by subtracting twice the thickness of 3, 34, 35, and 36 will be explained. The inner edge 22 of each opposing edge 21 of the core 20
The distance d between them is 34 mm, and the poles 23, 24, 2
The ratio of the width f of 5, 26 and the outer diameter D of the rotor 27 is
0.45, and looking at the storage area of 1/2 of the coil stored between adjacent poles, the following table and 8th
As shown in FIGS. 1 to 16.

【table】

[Table] Height h of each pole 23, 24, 25, 26
is the inner edge 22 of each opposing edge 21 of the core 20
It is assumed that the distance d between them is one half of the difference in the outer diameter D of the rotor 27, that is, h=(34-D)÷2. As a result, the bobbin storage area s reaches its maximum value of 39.7 cm ² when the outer diameter D of the rotor 27 is 17 mm, and at this time, the height h of the pole is 0.5 of the outer diameter D of the rotor 27.
It is clear that the amount will be doubled. At this time, the motor has the largest electrical load among motors using cores 20 of the same size. On the other hand, in order to maximize the torque obtained with a core of the same size, the product of the bobbin storage area s, which is proportional to the electrical load, and the rotor outer diameter D, which is proportional to the magnetic load, must be maximized. All you need to do is determine the outer diameter of the rotor 27, and the height h of the pole as shown in the table above.
The torque is maximum when is 0.24 times the outer diameter D of the rotor 27. Also, in the table above, poles 23, 24, 25, 26
The ratio of the width f of the rotor 27 to the outer diameter D of the rotor 27 is set to 0.45, but the same result can be obtained by setting this ratio to 0.3, 0.35, 0.4, or 0.5 as shown in the following table.

【table】

[Table] In both cases, the bobbin storage area s reaches its maximum value when the pole height h is 0.5 times the outer diameter D of the rotor 27, and the bobbin storage area s reaches its maximum value when the pole height h is 0.5 times the outer diameter D of the rotor 27.
The torque is maximum when it is 0.24 times. In addition, when the width c of the bobbin is approximately equal to the distance between the tip edges of opposing poles, and the thickness a of the bobbin is formed to be thinner than the outer diameter D of the rotor and approximately equal to the height of the pole, the height h of the pole and the rotation The relationship with the outer diameter D of the child is shown in the following table and FIG. 9.

[Table] In this way, the bobbin storage area s reaches its maximum value when the height h of the pole is 0.5 times the outer diameter D of the rotor 27.
The torque is maximum when it is 0.24 times. Moreover, as shown in FIG. 8, each bobbin 33, 34,
The poles 23 and 2 facing each other with a thickness a of 35 and 36
The distance b between the vertical line from the tip of the bobbin 6, 24, 25 and the adjacent side edge of the pole adjacent to this pole is approximately equal, and the width c of the bobbin 33, 34, 35, 36 is determined.
If it is made approximately equal to the value obtained by subtracting twice the thickness a of the bobbins 33, 34, 35, and 36 from the distance d between the inner edges 22 of each side 21 of the core 20, the core 2
Two sets of two bobbins can be fitted inside the 0 at the same time and wound around each opposing pole. In the above embodiment, the step angle θ° is 3 3/14°.
Although the motor described above is not limited to this, the step angle may be set to an appropriate step angle such as 1.8° or 3.6°. Further, in the above embodiment, a 4-phase 1-excitation method has been described, but the present invention can also be applied to a 4-phase 2-excitation method or a 4-phase 1-2 excitation method. According to the present invention, the ratio between the width of the poles protruding from the inner edge of each side of the rectangular stator core having a substantially square frame shape and the outer diameter of the rotor is set to 0.3 to 0.5, and the height of the poles is set to 0.3 to 0.5. Since the height of the pole is 0.24 to 0.5 times the outer diameter of the rotor, the space for storing the bobbin is maximized when the pole height is 0.5 times the outer diameter of the rotor. The torque is maximum when it is 0.24 times the outer diameter of the rotor, and the most efficient mechanical output can be obtained by setting the height of the pole within the range of 0.24 to 0.5 times the outer diameter of the rotor.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a stator core of a conventional stepping motor, FIG. 2 is a plan view of a stator core of another conventional stepping motor, and FIG. 3 is a perspective view of a stepping motor showing an embodiment of the present invention. ,
Figure 4 is a partially cutaway front view of the same as above, Figure 5 is a bottom view with the lower frame removed, Figure 6 is a plan view of the core of the same, Figure 7 is an enlarged view of a part of the same as above, Figure 8
9 are explanatory diagrams showing a comparison between the height of the pole and the outer diameter of the rotor. 20...Core, 21...Side part, 22...Inner edge, 2
3, 24, 25, 26...pole, 27...rotor,
28, 29, 30, 31...Convex portion of pole, 33,
34, 35, 36...Bobbin, 37...Coil, 43
...Convex part of the rotor.

Claims (1)

[Scope of Claims] 1. A rectangular stator core in the shape of a substantially square frame, which has poles protruding from the center of the inner edge of each side, each having a plurality of convex portions at the tips corresponding to the step angle; There are four coils wound around bobbins that are fitted into each pole and arranged along the inner edge of each side of the core, and a coil that is arranged in a space surrounded by each of the coils and that is arranged along the inner edge of each side of the core. a rotor having protrusions formed on its peripheral surface according to step angles corresponding to the protrusions; the ratio of the width of the pole to the outer diameter of the rotor is 0.3 to 0.5; and the height of the pole is A stepping motor characterized in that the outer diameter of the rotor is 0.24 to 0.5 times.