JPH01136550A - Stepping motor - Google Patents

Abstract

PURPOSE:To improve the starting efficiency and the control function and to make it compact and lightweight by placing yoke members equipped with stator teeth and an electromagnetic coil on both sides of a multipolar anisotropic orientation magnet rotor 1 having a dichroic construction in opposite directions. CONSTITUTION:An anisotropic orientation resin magnet rotor 1 having a dichroic construction is such that its periphery is formed of a resin magnet material with a thickness of 1/2-1/3 of a pitch between poles, and that its inside is made of thermoplastic resin. Yoke members 5L1, 5L2, 5R1, 5R2 equipped with stator teeth 4 are placed on both sides of the rotor 1 in opposite directions. Electromagnetic coils 6A and 6B to generate magnetic field at the stator teeth 4 are mounted on yoke members 5L1, 5L2, 5R1 and 5R2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a stepping motor, and more particularly to a small, multipolar stepping motor having a rotor, a stator yoke, and an electromagnetic coil.

[Prior Art] In a conventional stepping motor having a magnetic field in the radial direction around the outer circumference of the rotor, the radial orientation is formed using a sintered ring-shaped magnet, the outer circumference is magnetized and oriented, and the shaft member is press-fitted or bonded. Generally, the rotor is constructed by being fixed at

[Problems to be solved by the invention] Recently, there has been a demand for miniaturization of this type of motor. Rotor magnetic pole pitch (2~3m
Since the disassembly performance deteriorates with spacing of m), a rotor with a smaller diameter is also required to have a similar number of magnetic poles. However, as the number of disassembled rotor magnetic poles with a reduced outer circumferential diameter increases, the pitch between the poles (1.4 to 1.8 mm) becomes narrower, making it impossible to manufacture using conventional techniques.

Therefore, resin-molded magnets have been studied in the past, but there has been a problem that magnetization is incomplete and the magnetic force is weak for rotors with a small pitch between poles (1.4 to 1.8 mm).

The present invention attempts to solve these problems.

In other words, the present invention provides a small rotor with a small diameter and a two-color molding with a sufficient axial length and multipole anisotropic orientation so as to obtain sufficient torque and disassembly performance. The purpose of this invention is to provide a stepping motor.

[Means for solving the problem] In a stepping motor having an anisotropically oriented resin magnet rotor made of a cross-wire material of thermoplastic resin and magnetic powder, the final interpolar pitch P due to magnetization of the rotor is 1/2 to 1/3
A resin magnet rotor having a thickness of a yoke member arranged in the rotor, stator teeth serving as a stator arranged from the yoke member in the axial direction of the rotor, and an electromagnetic coil attached to the yoke member to generate a magnetic field in the stator teeth. It is assumed that

[Function] According to the present invention, the rotor can be made longer in the axial direction and can be configured in two-color molding by applying multi-pole anisotropic orientation, and the rotor thus configured can be fixed at left and right opposing positions. By arranging the child teeth and the stator yoke, and by fixing the electromagnetic coil that generates a magnetic field to the stator, the entire stepping motor can be made lighter and smaller, and it also has sufficient torque. The rotor is made of two-color molding, which reduces the inertia, making it lightweight and compact, which allows the moment of inertia to be kept small. It has excellent performance and responsiveness, and can improve controllability. Furthermore, by using a material in which thermoplastic resin and magnetic powder are kneaded, a necessary and sufficient magnetic force can be obtained by molding orientation, and the material can be manufactured at low cost.

[Example] FIG. 1 is an exploded perspective view showing an embodiment of the present invention.

In Fig. 1, 1 has a plurality of magnetic fiN and S on the outer peripheral surface.
A multi-pole anisotropically oriented resin magnet rotor is alternately magnetized, and IA is its rotor axis. The rotor shaft IA is pivotally supported by a bearing portion 2A of a motor support plate 2 and a bearing portion 3A of a bearing plate 3. Furthermore, the motor support plate 2 and the bearing plate 3 are provided with a plurality of comb-shaped grooves. An iron core 7 around which yoke members 5L1, 5L2 and an electromagnetic coil 6A having a stator 4 of It is fixed by a stopper or the like.

In addition, 2B and 3B are holes drilled in the motor support plate 2 and the bearing plate 3 in order to penetrate the iron cores 7 and 8 and caulk their tips, and 5A is the hole drilled in the yoke member 5L.
1 (5), 5 L 2 (5).

These are caulking holes for fixing 5 R1 (5) and 5 R2 (5).

FIG. 2 is an enlarged perspective view of the rotor, and FIG. 3 is a two-color structure multipole anisotropically oriented resin magnet rotor 1 constructed as described above.
The operation of a stepping motor with That is, in the stepping motor of this embodiment, in the four stages of FIG. 3(A) → FIG. 3(B) → FIG. 3(A) → FIG. 3(D) → FIG. , 1/
The rotor 1 rotates by 4P (P is pitch), and FIG. 3(a) shows the electromagnetic coil 6A.

6B shows the state of the motor which is not energized. In this case, since the magnetic poles provided on the rotor 1 form a magnetic path via the stator and the yoke member, the stator teeth of the left yoke member 5L1 4L1 and stator teeth 4L2 of the yoke member 5L2 are stopped facing the magnetic poles S and N of the rotor 1, respectively.

On the other hand, the stator teeth 4R1 of the right yoke member 5R1 and the stator teeth 4R2 of the yoke member 5R2 do not face the magnetic poles S and N of the rotor 1, but are half poles, that is, 1/2.
In this way, the yoke phase on the right side and the yoke phase on the left side are set to be deviated by 172P.

That is, the pitch P is the magnetized magnetic pole pitch in the rotor 1, and therefore, in this case, the angle θ shown in FIG.
Also, the pitch between the stator teeth 4L1 and 4L2 constituted by the yoke members 5L1 and 5L2 and the yoke member 5R1.
, 5R2, the pitch between the stator teeth 4R1 and 4R2 corresponds to the pitch P described above.

Next, the electromagnetic coil 6A is energized in the opposite direction (this state is changed to B) as shown in FIG. 3(B) from the state of FIG.
), when the electromagnetic coil 6B is energized in the positive direction (this state is shown by A), an N pole is generated in the stator tooth 4L1, an S pole is generated in the stator tooth 4L2, and then the fixed An S pole is generated in the child tooth 4R1, and an N pole is generated in the stator tooth 4R2. In this way, the rotor 1 can be rotated in a counterclockwise direction due to mutual repulsion and attraction between the poles on the rotor 1 and the poles generated on the individual stators. That is, at this time, the left stator teeth 4L1, 4
Since L2 and the stator teeth 4R1 and 4R2 on the right side are shifted by 1/2P, the poles on the rotor 1 and the poles on the yoke side are reversed from the state shown in Fig. 3 (A) in order to maintain balance. After moving 1/4 point in the clockwise direction, it stably stops.

Next, in the state shown in FIG. 3 (b), the electromagnetic coil 6A
When the energization is stopped and the energization A is continued only to the electromagnetic coil 6B to achieve the state shown in FIG. Due to the suction operation between the opposing poles of the rotor 1, the rotor 1 further rotates by 1/4P in the counterclockwise direction.

Next, in the state shown in FIG. 3 (8), the electromagnetic coil 6A
As shown in FIG. 3(d), by applying current B in the positive direction, the rotor 1 is further moved to 1/4P using the same principle.
It can only be rotated counterclockwise.

The series of operating procedures explained above will be further described with reference to FIG. Here, a step sequence is shown in the horizontal direction, and furthermore, the electromagnetic coils 6A and 6 are shown for each step.
The energization state to B is shown. That is, step 3
There are eight combinations of energization from BA to B through steps 1 to S8, and sequence control is performed using these eight steps as one pulse, and by repeating this, the rotor 1 can be moved to any desired angle. It can be rotated. Furthermore, by controlling the energization so that the combination of energizations described above proceeds in the opposite direction, the rotor 1 can be rotated in the clockwise direction.

[Effects of the Invention] As explained above, according to Raiko, stator teeth are formed at opposing positions on both sides of a small, two-color structured, multi-pole, anisotropically oriented resin magnet rotor. By arranging the yoke members in combination and further providing electromagnetic coils on these stator teeth to generate a magnetic field via the yoke members, excellent starting performance and control function can be maintained. At the same time, it has become possible to provide a small and lightweight stepping motor with high torque. Moreover, forming a multipolar anisotropically oriented resin magnet rotor with a two-color structure with the internal thermoplastic resin to be long in the axial direction,
This is very easy, and by combining it with a stator of opposing length, it is possible to provide a stepping motor that is not only small and has high torque, but also has a small moment of inertia.

Also, 1/2 to 1/2 of the final pitch P due to magnetization of the rotor
Since 1/3 of the thickness is formed on the outer periphery of the resin magnet rotor using resin magnet material, it is easy to make the rotor smaller in diameter and smaller in inertia, and sufficient magnetic force can be obtained, making it possible to manufacture the rotor at low cost. In addition, it is possible to provide a stepping motor with good followability suitable for a high-speed type.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view showing an embodiment of the present invention, FIG. 2 is an enlarged perspective view of a rotor, and FIG. 3 (A). (B), (8), and (D) are explanatory views showing the operating principle of the stepping motor shown in FIG. 1, and FIG. 4 is an explanatory view of the timing of the excitation sequence. 1... Anisotropically oriented resin magnet rotor IA... Rotor shaft 2... Motor support plate 3.
・・Bearing plate 4・Stator 4L1, 4L
2, 4R1, 4R2... Stator teeth 5L1, 5L2, 5
R1, 5R2... Yoke members 6A, 6B... Electromagnetic coil 7.8... Iron core (B) (C) (D)

Claims (1)

[Claims] In a stepping motor having an anisotropically oriented resin magnet rotor made of a kneaded material of thermoplastic resin and magnetic powder,
A two-color anisotropic structure in which a thickness of 1/2 to 1/3 of the final pole-to-pole pitch P due to magnetization is formed on the outer periphery of the resin magnet rotor using resin magnet material, and the inside thereof is formed from thermoplastic resin. a yoke member comprising a oriented resin magnet rotor and disposed opposite to each other on both sides of the rotor; stator teeth serving as a stator arranged from the yoke member in the axial direction of the rotor; A stepping motor comprising: an electromagnetic coil attached to the stator teeth to generate a magnetic field.