JPH0432630B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a stepping motor, and more particularly to a structure in which a coil wound around a bobbin is wound around four poles formed on a stator core in a square hybrid stepping motor. (Prior Art) Conventional permanent magnet hybrid type mini-angle stepping motors often have a step angle of 1.8° or 3.6°.
As shown in FIG. 1, eight poles 2 are projected at symmetrical positions from the inner peripheral edge of the core 1, and a coil is wound around each pole 2. In this configuration, when the outer shape of the core 1 is square, there is a portion 3 at each corner that does not function as a core, and
Since eight poles 2 protrude from the inner peripheral edge of the core, the area of the slit for winding the coil between the poles 2 becomes smaller, and since the poles 2 face toward the center of the core 1, the slit area for winding the coil becomes smaller. The gap 5 between the tips of each pole 2, which is the opening of the section 4, becomes narrow, making it difficult to wind the coil around each pole 2, resulting in poor workability and increased costs, as well as a reduction in production quantity. There was a problem that could not be increased. For this reason, as shown in FIG. 2, 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. Conceivable. (Problems to be Solved by the Invention) In the square core 6 shown in FIG.
are not formed symmetrically on the inner edge 8 of each side 7,
When a coil 10 is wound around each pole 9, a wasted space 11 is formed, and this tendency is particularly noticeable when the rotor has an odd number of recesses corresponding to the step angle. The problem is that the loading 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 tube divided into two parts is fitted around the pole 9, and the coil conductor wire is wound around the pole 9. Although such a structure is known, it has a problem that the coil installation workability is poor. The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide a rectangular stepping motor in which coils can be easily attached and assembly workability is improved. (Means for Solving the Problems) The stepping motor of the present invention has a substantially square shape having a pole 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. A frame-shaped rectangular stator core, four coils wound around bobbins that are fitted into each pole of this core and arranged along the inner edge of each side of this core, and each of these coils. a rotor disposed in a space surrounded by a rotor, the rotor having a protrusion formed on its circumferential surface according to a step angle corresponding to the protrusion of the pole; The distance between a straight line drawn perpendicular to the protrusion direction and the side edge of the pole adjacent to this pole is made equal, and the width of the bobbin is determined from the distance between the opposing inner edges of each side of the core. Thickness 2
The height of each pole is made substantially equal to the value obtained by subtracting the multiplication factor, and the height of each pole is greater than the thickness of each coil. (Function) In the stepping motor of the present invention, when a bobbin wound with a coil is attached to each pole of the core, the thickness of the bobbin is the same as that of the straight line drawn from the tip of the pole in a direction perpendicular to the protruding direction and adjacent to this pole. The width of this bobbin is approximately equal to the distance between the opposite inner edges of each side of the core minus twice the thickness of the bobbin, so they are opposite to each other. Two bobbins to be attached to the poles can be simultaneously inserted into the spaces between the poles, and these two bobbins can be fitted to each pole by moving in opposite directions. Therefore, even if the height of each core pole is greater than the thickness of each bobbin, two coil bobbins can be attached to each opposing pole at the same time. (Example) Next, an example of the present invention will be explained about a stepping motor with four phases, a step angle θ of 33/14 degrees, and a rotor with 28 convex portions formed at equal intervals on the circumferential surface. do. 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 23,2
4, 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. This first pole 23 has four convex parts 2
8, 29, 30, and 31 are evenly formed at the center of the edge 22 so as to be symmetrical with respect to the vertical center line ( _l1 - _l1 ). Further, the left and right second poles 24 and third poles 25 each have cores 20.
4 symmetrically from the vertical center line (l ₁ − l ₁ ) of
Three convex portions 28, 29, 30, 31 are formed, and these convex portions 28, 29, 30, 31 extend from the horizontal center line (l ₂ - l ₂ ) of the core 20 by a step angle θ°. It is formed to be offset in a direction closer to the pole 23 side. Further, the fourth pole 26 facing the first pole 23 has four convex portions 28, 29, 3.
0 and 31 are offset toward the third pole 25 by an angle 2θ°, which is twice the step angle θ°, from the vertical center line (l ₁ −l ₁ ). The convex portions 28, 29, 3 of each of the poles 23, 24, 25, 26
0 and 31 are formed toward the center of the core 20, and are formed toward the first pole 23 side of the second pole 24 and third pole 25 which are deviated by θ°, and the fourth pole which is deviated by 2θ°. The third pole 25 side of the pole 26 is the seventh
Cut the part shown by the chain line in the figure to find the center line (l ₂ −l ₂ )
(l ₁ −l ₁ ), and the concave portion 32 forming the convex portion 31 is offset from the position of the chain line toward the center in the width direction of the poles 24, 25, and 26. Next, numerals 33, 34, 35, and 36 are bobbins each having a coil 37 wound thereon, which are fitted into the respective poles 23, 24, 25, and 26 of the core 20. This first and fourth pole 2
A-phase and ^A -phase coils 37 are wound on the bobbins 33 and 36 attached to the second and third poles 24 and 26 using bifilar winding, and the bobbins 34 and 35 attached to the second and third poles 24 and 25 are B-phase and ^B -phase coils 37 are wound with bifilar winding. The thickness a of each bobbin 33, 34, 35, 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 distance between the vertical line from the tip of the second pole 24 and the fourth pole adjacent to this second pole 24. The distance b from the side edge 38 of the pole 26 on the second pole 24 side is approximately equal to the distance b, and the overall width c of the bobbins 33, 34, 35, 36 is set to the inner edge of each side 21 of the core 20. 2
2 from the distance d between bobbins 33, 34, 35, 36
The thickness should be approximately equal to the value obtained by subtracting twice the thickness a. Further, from the thickness a of the bobbins 33, 34, 35, 36, each pole 23, 24 of the core 20,
The heights of 25 and 26 are increasing. Further, the height h of the poles 23, 24, 25, 26 is set lower than the extension line of the adjacent side edges of the poles 23, 24, 25, 26, and
As shown in the table below, the widths c of Nos. 3, 24, 25, and 26 are set to be sufficiently smaller than the width of the bobbin. Next, the rotor 27 is moved to each pole 23, 2.
The rotor 27 is disposed 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 permanent magnet 40 sandwiched between the coils 37. 28 convex portions 43 are formed at equal intervals on the outer peripheral surface of the magnetic bodies 41, 42, and half of the convex portions 43 of the upper and lower magnetic bodies 41, 42 It is offset in the circumferential direction by one half of the step angle θ°. Further, the rotation shaft 44 of the rotor 27 is supported by bearings 4 provided in frames 52 and 53, which will be described later.
5 and 46 so as to be rotatable. Further, the upper side of each bobbin 33, 34, 35, 36 is provided with a bobbin 33, 34, 35, 3, respectively.
The terminal pin 64 connected to the lead wire of the coil 37 wound around the coil 37 is inserted into the connection hole 48 of the printed wiring board 47 and connected. Furthermore, terminal pins 59 of the connector 49 are connected to this wiring board 47. Further, each pole 23, 24, 2 of the core 30
Bobbins 33, 34, 35, 3 fitted to 5, 26
at least one diagonal position of 6, e.g. the first pole 2
3 and the second pawl 24 and between the third pawl 25 and the fourth pawl 26, respectively, by locking both ends of the film-shaped retaining prevention piece 51 to each bobbin 33, 34, 35, 36 is prevented from coming off. Further, reference numerals 52 and 53 denote motor frames, and these frames 52 and 53 are adapted to be fitted onto the upper and lower surfaces of the core 20. Furthermore, a holding protrusion 54 is provided on the inner surface of the lower motor frame 53 so as to protrude from the inner surface of the bobbin 33 , 34 , 35 , 36 . Note that the coil 37 can be used without using the wiring board 47.
If the conductor is connected directly to the lead wire of the bobbin 33,
The bobbins 33, 3 are engaged with the inner surfaces of the bobbins 4, 35, 36.
4, 35, and 36 are protruded from each other to maintain their movement. The upper and lower frames 52 and 53 are fastened and fixed by a pole 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 in which an insertion hole 58 through which the output shaft portion 57 of the rotating shaft 44 is inserted is formed in the center. Each protrusion 6 of section 59
The shield plate 64 consists of a protruding piece 61 extending and bent from 0 and an engaging piece 62 extending and bent from each protruding piece 61 except for one protruding piece 61.
A base plate portion 59 is provided to protrude from the outer surface of the lower frame, and each protruding piece portion 60 is attached to each outer circumferential surface of the upper and lower frames 52 and 53 and each outer circumferential surface of the core 20.
3, 24, 25, and 26, and engages with the engaging grooves 63 formed on the upper outer 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, for example, the first pole 23 becomes the S pole,
The fourth pole 26 becomes the N pole, and the first pole 26
3 includes a 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 fourth pole 26, rotated by a step angle θ°, and then attached to the second pole 24 and the third pole 25. When the B phase of the coils 37, 37 are excited, the second pole 24 becomes the N pole, the third pole 25 becomes the S pole, and the second pole 24 has the other magnetic body 42 of the rotor 27. The convex portion 43 is attracted and the rotor 27 is attached to the third pole 25.
The convex portion 43 of one of the magnetic bodies 41 is attracted and the rotor 27 rotates θ°, and then the first pole 23 and the fourth pole
When the ^A phase of the coils 37, 37 of the pole 26 is excited, the first pole 23 becomes the N pole, the fourth pole 26 becomes the S pole, and the first pole 23 has the other magnetic material of the rotor 27. 42 is attracted, and the fourth pole 26 attracts the protrusion 43 of one of the magnetic bodies 41 of the rotor 27, rotates by step angle θ°, and then the second pole 24 and the third pole 26 are attracted. Paul 2
When the ^B phase of the coils 37 and 37 of No. 5 is excited, the second
The pole 24 becomes the south pole, the third pole 25 becomes the north pole, the convex part 43 of one magnetic body 41 of the rotor 27 is attracted to the second pole 24, and the third pole 25 is attracted to the rotor The convex portion 43 of the other magnetic body 42 of the rotor 27 is attracted, and the rotor 27 is rotated by θ°. This operation is repeated, and the rotor 27 is rotated 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 leaked by the base plate portion 59 of the shield plate 56 and each protrusion portion 61. is prevented. Also, when assembling, each bobbin 33, 3
4, 35, 36 are inserted into the connection holes 48 of the printed wiring board 47 and connected by soldering to the bobbins 33, 34, 35, 3.
6 can be positioned and held, wiring can be done easily, 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 reliably connected. In addition, retaining prevention pieces 51 are provided between 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 both ends of 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, and the bobbin 33, 34, 35, 36
The positioning is maintained. In addition, each pole 23, 24, 25 of the core 20,
Pole 2 whose center is deviated by θ° or 2θ° among 26
3, 24, 25, 26 are convex portions 3 on the deflection side of the tip edge.
Cut out the side edge of 1 and make this convex part 3 parallel to the central axis.
By deviating the recess 32 housing the coil 37 toward the center, the space created when the coil 37 is wound due to the asymmetric arrangement of the poles 23, 24, 25, and 26 can be reduced. In addition, each pole 23, 24, 25 of the core 20,
bobbins 33, 34, with a coil 37 wound around 26;
35, 36, two bobbins to be attached to poles 23, 24, 25, 26 facing each other are inserted into the space between each pole 23, 24, 25, 26, and the bobbins are wound in opposite directions. It can be fitted to each pole by moving it. Next, the thickness a of each bobbin 33, 34, 35, 36 is approximately equal to the distance 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. Take, bobbin 3
The width c of bobbins 33, 3, 34, 35, and 36 is calculated from the distance 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 in the case where the height h of the pole and the outer diameter D of the rotor are approximately equal to the value obtained by subtracting twice the thickness of 4, 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, it becomes as shown in the following table and FIGS. 8 1 to 16.

〔Effect of the invention〕

According to the present invention, the thickness of each bobbin is made approximately equal to the distance between a straight line drawn from the tip of the pole in a direction orthogonal to the protruding direction of the pole and the side edge of the pole adjacent to this pole, and the width of the bobbin is set to the core. The distance between the opposing inner edges of each side of is approximately equal to the value obtained by subtracting twice the thickness of the bobbin, and the height of each pole of the core is greater than the thickness of each coil. Even if the height of each pole of the core is larger than the thickness, the bobbin of the coil to be wound on each opposing pole can be attached at the same time, and the workability of fixing the bobbin is good. This allows the load to be increased and the torque to be increased.

[Brief explanation of drawings]

FIG. 1 is a plan view of the core of a conventional stepping motor, FIG. 2 is a plan view of the core of another conventional stepping motor, and FIG. 3 is a perspective view of a stepping motor showing an embodiment of the present invention. , Fig. 4 is a partially cutaway front view of the above, Fig. 5 is a bottom view of the device with the lower frame removed, Fig. 6 is a plan view of the core of the above, and Fig. 7 is an enlarged plan view of a part of the above. , FIG. 8 is an explanatory diagram of the relationship between the core and the coil. 20... Core, 21... Edge, 22... Edge,
23, 24, 25, 26...Pole, 27...Rotor, 28, 29, 30, 31...Protrusion of pole, 33, 34, 35, 36...Bobbin, 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; Four coils are wound around bobbins which are respectively fitted to the poles and arranged along the inner edge of each side of the core, and the coils are arranged in a space surrounded by each of the coils. a rotor having protrusions formed on its peripheral surface according to step angles corresponding to the protrusions of the poles; The width of the bobbin is approximately equal to the distance between the opposing inner edges of each side of the core minus twice the thickness of the bobbin. A stepping motor characterized in that the height of each of the poles is greater than the thickness of each of the coils.