JP3349966B2 - Hybrid type magnet and stepping motor having the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a hybrid type in which a permanent magnet and an electromagnet are combined to control the intensity of a magnetic field applied to the outside by controlling a current supplied to the electromagnet and to efficiently extract the supplied energy. It is about a magnet.

[0002]

2. Description of the Related Art Heretofore, there are few examples of hybrid type magnets in which permanent magnets and electromagnets are combined. As an effect of combining the permanent magnet and the electromagnet, it is generally considered that when a current in a certain direction is applied to the exciting coil of the electromagnet, a total magnetic field of the permanent magnet and the electromagnet is generated, and the opposite direction is applied to the exciting coil. Is to cancel the magnetic field generated by the permanent magnet by the opposite magnetic field generated by the electromagnet.

Therefore, when no current is applied to the exciting coil, a magnetic field is generated only by the permanent magnet, and the current is applied to the exciting coil to increase or decrease the strength of the magnetic field. Become.

[0004]

However, the method of use described above cannot be said to make effective use of the energy of the permanent magnet. At first glance, it seems that the energy of the permanent magnet is used, but since energy must be applied to the electromagnet for canceling the magnetic field, the energy is plus or minus 0.
In order to effectively use the energy of the permanent magnet by exciting the electromagnet, it is necessary to change the way of thinking.

It is an object of the present invention to provide a hybrid magnet having a structure capable of effectively utilizing the energy of a permanent magnet by exciting an electromagnet, and to provide a stepping motor using the magnet.

[0006]

In order to solve the above-mentioned problems, the present invention employs the following means. The hybrid magnet according to claim 1, wherein an electromagnet formed by winding an exciting coil around an iron core formed in a "U" shape by a body and left and right arms having a rectangular cross section, and a permanent magnet from both sides. A rectangular rod-shaped engaging member sandwiched between members and closely joined between both outer ends of the arm portion of the iron core, and wherein the permanent magnet is located between the arm portions of the iron core. The ratio of the width of the permanent magnet to the sum of the widths of the magnetic members is set in a range of 1: 1.6 to 1: 7 , and the iron core is made of pure iron, and the magnetic member is made of pure iron.
It is characterized by a material having higher saturation magnetic flux density and magnetic permeability .

With this configuration, when the excitation coil of the electromagnet is not energized, the lines of magnetic force generated by the permanent magnet form a closed magnetic path consisting of a permanent magnet, a magnetic member, an iron core, a magnetic member, and a permanent magnet. There is almost no leakage of magnetic flux. Next, when a current is generated in the exciting coil of the electromagnet in a direction opposite to the direction of the magnetic field lines of the permanent magnet and generates a magnetic flux number larger than that of the permanent magnet, the magnetic field lines of the permanent magnet are canceled by the magnetic field lines of the electromagnet. Not only that, when the saturation state of the permanent magnet is exceeded, it is released into the air. At that time,
If the number of magnetic fluxes of the electromagnet is sufficiently large, the number of magnetic fluxes discharged into the air is the sum of both the permanent magnet and the electromagnet as appropriate.

For this reason, when a magnetic material is arranged close to the engaging member, the effect is remarkable. When no current is supplied to the exciting coil, the hybrid magnet does not attract the magnetic material.
When a current flows through the exciting coil, a phenomenon occurs in which the current is attracted by the force of the permanent magnet and the electromagnet. That is, the effect of the permanent magnet that does not consume energy can be fully utilized.

The hybrid type magnet according to the second aspect is characterized in that:
An electromagnet formed by winding an excitation coil around two body portions of an iron core formed in an “E” shape by three body portions and three rectangular arm portions, a magnetic member, a permanent magnet,
A magnetic member, a permanent magnet, and a rod-shaped engaging member that is configured in close contact with the magnetic member in the order of the magnetic core and that is closely bonded between both outer ends of the outer arm portion of the iron core, and each of the permanent magnets is A hybrid magnet positioned between the arms, wherein the permanent magnets have the same width, and the ratio of the total width of the permanent magnets to the total width of the magnetic members is 1: 1. 6 to 1: 7 .

[0010] Even in the case of such a configuration, the same function as the invention of the first aspect is exhibited.

[0011] The hybrid magnet according to claim 3 is
In the invention according to claim 1 or 2, the iron core is pure iron,
The permanent magnet is a neodymium magnet.

A stepping motor according to a fourth aspect of the present invention
4. An engaging member for a hybrid magnet, comprising a plurality of hybrid magnets according to any one of claims 1 to 3, which are integrally formed at equal angles so that arm portions are radially centered around the trunk portion. The magnetic body is arranged at equal intervals on the outside of the rotor to constitute a rotor.

[0013] The stepping motor according to claim 5 is
A plurality of stepping motors according to claim 4 are connected in series with a phase difference.

[0014] With this configuration, the pulse current is applied to each of the exciting coils, so that the energy of the input electromagnet is reduced.
The over, so that can be taken out as efficiently output by utilizing permanent magnets.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment of a hybrid magnet 10 according to the present invention,
(A) is a plan view, (b) is a front view, and (c) is a side view. The hybrid magnet 10 is roughly composed of two components. One is an electromagnet 16 configured by winding an exciting coil 14 around an iron core 12 formed in a "U" shape by a body 12a and left and right arms 12b, 12b having a rectangular cross section, and the other is a permanent magnet ( neodymium). Magnetic member 20 made of a soft magnetic material from both sides.
And an engagement member 22 in the form of a square bar which is tightly joined between both outer ends of the arm portion 12 b of the iron core 12. At this time, the permanent magnet 18 is located between the left and right arm portions 12b, 12b of the iron core 12.

The iron core 12 constituting the electromagnet 16 is formed by laminating plates of pure iron, which is a soft magnetic material. In this embodiment, as shown in FIG.
Has a width F of 10 mm, a height D (height from the upper end of the body 12a) of 10 mm, and a thickness H of 10 mm. Therefore, the cross-sectional area of the arm portion 12b is 100 mm ² .

On the other hand, the longitudinal section of the engaging member 22 is
Both the magnet 18 and the magnetic member 20 form the same rectangle.
And the height C of the permanent magnet 18 is
15mm, width B is 5mm, thickness H is 10mm
The height C of the magnetic members 20 arranged on the left and right is 15 m.
m, width A is 17.5 mm, thickness H is 10 mm
You. Therefore, both the permanent magnet 18 and the magnetic member 20
Has a vertical cross-sectional area of 150 mm ²Becomes In addition, this magnetic part
As a material of the material 20, for example, pure iron may be used.
Or more saturated magnetic than pure iron such as permalloy or silicon steel.
Those having high flux density and high magnetic permeability may be used.

The exciting coil 14 wound around the iron core 12 of the electromagnet 16 is made of a copper wire having a wire diameter of 0.6 mm.
This is 0 turns.

Next, the characteristics of the hybrid magnet 10 will be described. First, the excitation coil 14 of the electromagnet 16
When no power is supplied to the
A closed magnetic path is formed from a permanent magnet N pole → a magnetic material 20 → an iron core 12 → a magnetic material 20 → a permanent magnet S pole, and there is almost no leakage of magnetic flux into the air. Therefore, a strong attraction force is generated between the arm portion 12b of the iron core 12 and the engaging member 22, and even if the magnetic material is brought close to the outside of the engaging member 22, the magnetic material that is brought close is affected. Absent.

Next, an experiment will be made as to what happens when a current for generating a magnetic flux is applied to the exciting coil 14 of the electromagnet 16 in the direction opposite to the direction of the magnetic field lines of the permanent magnet 18.
First, a movable member made of a magnetic material (width 40 mm × height 15
(mm × thickness 10 mm, also referred to as a piece) 30 is brought into contact with the engaging member 22 and, as shown in FIG. For comparison, when there is no permanent magnet 18 only (FIG. 3), when there is no engaging member 22 (FIG. 4), the permanent magnet (in a state sandwiched by the magnetic members 20) 1
When the number is only 8 (FIG. 5), the maximum value of the force for separating the movable member 30 is checked. The data as shown in Table 1 below was obtained. The movable member 30 is made of ferropalm (manufactured by NKK).
In the case of, the case of pure iron is appended.

The measuring device is: AT-10TE SHIMADZU LOAD CELL TYPE SBL-1kN Resolution MAX 100 kgf, MIN 10 gf

[0022]

[Table 1]

Referring to Table 1, it can be said that, for the electromagnet and the permanent magnet, the force required for separation even at a current of 0 A is due to the leakage magnetic flux. At a current of 0.2 A, the separation force is lower in the case of the electromagnet and the permanent magnet than in the case of the permanent magnet alone, presumably because the magnetic flux of the permanent magnet cannot be canceled with a current of this magnitude. When the current exceeds 0.4 A, a force is required for sudden separation, and the value approximates the total value of the case of only the electromagnet and the case of only the permanent magnet. In the case of the configuration shown in FIG.
Since a magnetic path is formed between the magnetic members 20 through an air gap, the movable member 3 disposed outside the structure shown in FIG.
It can be seen that the suction force for 0 becomes weaker.

Next, the maximum separation value when the thickness of the movable member 30 was changed was measured. Table 2 shows when the thickness of the movable member 30 is 5 mm, Table 3 shows when the thickness is 7.5 mm, and Table 4 shows
Table 5 shows data at a time of 15 mm when the distance is 2.5 mm. Table 1 shows the case of a thickness of 10 mm.

[0025]

[Table 2]

[0026]

[Table 3]

[0027]

[Table 4]

[0028]

[Table 5]

An overview of Tables 2 to 5 shows that when the thickness of the movable member 30 is 5 mm or less, the separating force is weakened, but the movable member 30 has a thickness of 7.5 m.
It seems that there is almost no change from m to 15 mm.

In any case, according to the above-described hybrid magnet 10, by controlling the current flowing through the electromagnet, the energy of the permanent magnet, which is considered not to decrease in energy even when used, is added to the energy of the electromagnet. It has been found that when the current can be applied to the outside without affecting the outside, the current can be simply set to zero.

Next, for this hybrid magnet 10,
An experiment was conducted on the influence of the magnetic material on the magnetic material at that time. FIG. 6 shows the experimental method. For comparison, a case where the permanent magnet 18 was removed, that is, a case where only the electromagnet was used and a case where only the permanent magnet 18 was used were performed. The configuration
7 and 8.

As shown in FIG. 6, two hybrid magnets 10 are installed so as to face left and right, and a sliding member 40 that slides perpendicularly to the plane of FIG. 4 sliding members
Numeral 0 has a quadrangular prism base 42 made of a non-magnetic material at the center, and holes 44 are provided at upper and lower portions of the base 42, and rails (not shown) pass through the holes 44. A mounting plate 46 also made of a non-magnetic material is provided on each of the left and right sides of the base 42, and the movable member 30 made of a magnetic material is mounted on both ends of the mounting plate 46. The movable member 30 and the hybrid magnet 1
A gap G is formed with the zero engaging member 22.

In the experiment, the gap G was set to 0.2, 0.3,
By changing the current flowing through the exciting coil 14 of the electromagnet 16 from 0 to 2.0 A, the sliding member 40 slides from the front side of the drawing to the rear side of the drawing to change the hybrid current. What kind of attraction force works when passing the magnet 10 was examined. The results are shown in Tables 6, 7, 8, and 9. Tables 6, 7, 8, and 9 similarly show the case where only the electromagnet 16 is used and the case where only the permanent magnet 18 is used. In addition, each shows the maximum value.

[0034]

[Table 6]

[0035]

[Table 7]

[0036]

[Table 8]

[0037]

[Table 9]

From these tables, it can be seen that the current is from 0.2 A to 2.0 A.
Within the range of A, it can be seen that at any current value, the attractive force exerted by the hybrid magnet 10 on the passing magnetic body is greater than when only the electromagnet is used. That is, the permanent magnet 18
This means that the energy possessed is effectively used.

It has also been found that it is more important.
That is the relationship between the attractive force received when the sliding member 40 passes the hybrid magnet 10 and the distance. The measured values when the current flowing through the excitation coil is 2.0 A for the gap G = 0.2, 0.3, 0.4, 0.5 mm are shown in FIGS.
0, 11, and 12. It should be noted that the current value is irrelevant when only the permanent magnet is used.

As is apparent from the figure, the maximum value is almost 10
mm, but the hybrid magnet 10
It can be seen that in the case of, not only the maximum value is larger than in the case of only the electromagnet, but also the overall attractive force is strong. That is,
Since the integral value of the distance and the suction force is large, it can be seen that the energy applied to the sliding member 40 is large.

Next, a description will be given of a second embodiment of the hybrid magnet according to the present invention. As shown in FIG. 13, the hybrid magnet 50 is roughly composed of two elements. One element is the two torso 62
a, and an iron core 62 formed in an “E” shape by an arm portion 62b having a rectangular cross section on both left and right sides and a central arm portion 62c.
An electromagnet 60 comprising an excitation coil 64 wound around each of the two body portions 62a;
1, a square rod-shaped engaging member 70 which is in close contact with the permanent magnet 72, the magnetic member 73, the permanent magnet 74, and the magnetic member 75 in this order, and is tightly joined between both outer ends of the arm portion 62b outside the iron core 62. It is composed of The permanent magnet 72 is connected to the left and center arm portions 62 b and 62 of the iron core 62.
and the other permanent magnet 74 is located between the center of the iron core 62 and the right arm portions 62c and 62b.

The iron core 62 constituting the electromagnet 60 is made of soft magnetic material.
This embodiment is made by laminating pure iron plates as materials.
As shown in FIG. 13, the left and right arm portions 62
b has a width F of 10 mm and the center arm 62c has a width I of 2 mm.
0 mm, the height D of the arm portions 62b and 62c (the body portion 62a
Is 10 mm, and the thickness H is 10 mm.
You. Therefore, the cross-sectional area of the arm portions 62b and 62c is
100mm each² , 200mm²Becomes

In contrast, an experiment was conducted with five types of engaging members 70 prepared. In the case shown in FIG. 13, the longitudinal section of the engaging member 70 has the permanent magnets 72 and 74 and the magnetic members 71, 73 and 7.
5 have the same rectangular shape and are in the shape of a single square bar. The height C of the permanent magnets 72 and 74 is 15 mm, the width J is 2.5 mm, and the thickness H is 10 mm. The height C of the magnetic members 71, 73, 75 arranged at the center is 15 mm, and the widths are 18.75 mm, 37.5 m, respectively.
m, 18.75 mm, and the thickness H is 10 mm.
Therefore, the permanent magnets 72, 74 and the magnetic members 71, 7
Both 3, 75 have a vertical cross-sectional area of 150 mm ² . As a material of the magnetic members 71, 73, 75, for example, pure iron may be used, or a material having a higher saturation magnetic flux density and magnetic permeability than pure iron such as permalloy or silicon steel may be used. . The exciting coil 64 wound around the iron core 62 of the electromagnet 60 is formed by turning a copper wire having a wire diameter of 0.6 mm into 420 turns.

FIG. 14 shows a case where the width of each of the permanent magnets 72 and 74 is set to 5 mm, and FIG.
FIG. 16 shows the permanent magnets 72 and 74 each having a width of 15 mm, and FIG. 16 shows the permanent magnets 72 and 74 each having a width of 20 mm. For these five types, a movable member made of a magnetic material (width 80 mm × height 15 mm × thickness 1
A 0 mm ferropalm (80) is brought into contact with the engaging member 70, and the force is measured by pulling it apart in the direction of the arrow.
For comparison, when only the electromagnet 60 is used (FIG. 18), the permanent magnets 72 and 7 are in a state sandwiched by the magnetic members 71, 73 and 75.
In the case of only 4 (FIG. 19), it is also checked. Data as shown in Table 10 were obtained.

[0045]

[Table 10]

The data in Table 10 is shown in FIG. 20 as a line graph so that the data can be easily viewed. Table 10 and FIG.
, The width of each of the permanent magnets 72 and 74 is 2.
In the range of 5 mm to 20 mm and a current of 0.2 A to 2.0
In any of the ranges A, this hybrid magnet 5
0 was found to have a greater attractive force than the electromagnet alone. In particular, the width of each of the permanent magnets 72 and 74 is 5 mm.
It was found that the suction force in the range of １５15 mm was large.
Considering this, the ratio of one width of the permanent magnet to the sum of the widths of the magnetic members may be configured to be in the range of 1: 1 to 1:15, and particularly in the range of 1: 1.6 to 1: 7. It was found that the effect was greater in the range. Note that in the first embodiment, no experiment was performed to examine the separation force by changing the width of the permanent magnet, but a similar effect can be estimated from the second embodiment. Further, in the second embodiment, no experiment is performed on the suction force due to the passing of the magnetic members, but the same effect can be inferred from the first embodiment.

Next, an embodiment of the stepping motor according to the present invention will be described. As shown in FIG. 21, this stepping motor 100 has four hybrid-type magnets 50 as described above, and the arm portions 62b and 62c are equiangular (here, at the center of the trunk portion 62a of the iron core 62). 90 °), and further provided with a phase difference (here, 30 °) in the upper and lower directions (in the figure, 30 °) to form three stages in series to form a stator 110. The rotor 120 is configured by disposing the magnetic members 80 at equal intervals (here, 90 °) at the inside thereof. In this case, the motor rotates in steps of 30 degrees.

FIG. 22A is a sectional view taken along line AA 'of FIG.
(B) is a sectional view taken along the line BB ′,
(C) is a sectional view taken along line CC ′.

The efficiency of the motor 100 is apparent from the effect of the above-described hybrid magnet, but is significantly improved as compared with a normal motor. In this example, four hybrid-type magnets 50 are radially arranged as the stator 110, and a phase difference is provided to form three stages in series. However, if eight stators are used, the motor rotates in 15 ° steps, and the number of stages is reduced. Obviously, it can be rotated in finer steps with more.

[0050]

As described above, according to the hybrid magnet of the present invention, a large attractive force can be obtained with low power consumption by utilizing the effect of the permanent magnet which does not consume energy. it can.

Further, according to the stepping motor according to the present invention, the input energy can be efficiently taken out as an output by using the permanent magnet, and energy can be saved.

[Brief description of the drawings]

1 shows an embodiment of a hybrid magnet according to the present invention, wherein (a) is a plan view, (b) is a front view, and (c) is a side view.

2A and 2B are diagrams for measuring a separating force of the hybrid magnet shown in FIG. 1, wherein FIG. 2A is a front view and FIG. 2B is a side view.

3A and 3B are diagrams for measuring a detaching force in a state where a permanent magnet is removed from a hybrid magnet, wherein FIG. 3A is a front view and FIG. 3B is a side view.

4A and 4B are diagrams for measuring a detaching force in a state where an engaging member is removed from the hybrid magnet, wherein FIG. 4A is a front view and FIG. 4B is a side view.

FIGS. 5A and 5B are diagrams for measuring a separating force when only a permanent magnet is used, where FIG. 5A is a front view and FIG. 5B is a side view.

FIG. 6 shows a configuration for examining an attractive force acting when a hybrid magnet passes a magnetic member.

FIG. 7 shows a configuration in which a permanent magnet is removed from a hybrid magnet, and an attractive force acting when passing a magnetic member is examined.

FIG. 8 shows a configuration for examining an attractive force acting when passing a magnetic member when only a permanent magnet is used.

FIG. 9 (a) shows the relationship between the attractive force and the distance acting when the hybrid magnet passes the magnetic member when the gap G is 0.2 mm and the current flowing through the exciting coil is 2.0A. FIG. 3B is a diagram showing a relationship between an attractive force and a distance acting when passing a magnetic member when the permanent magnet is removed from the hybrid magnet, and FIG. It is a figure which shows the relationship between the suction force and the distance which act when passing each other.

10A is a diagram showing a relationship between an attractive force and a distance acting when a hybrid magnet passes a magnetic member when a gap G is 0.3 mm, and FIG. 10B is a diagram showing a relationship between a hybrid magnet and a permanent magnet. A diagram showing the relationship between the suction force and the distance acting when passing the magnetic member in a state in which is removed,
(C) is a diagram showing the relationship between the attractive force and the distance acting when passing the magnetic member when only the permanent magnet is used.

11A and 11B are diagrams illustrating a relationship between an attractive force and a distance acting when a hybrid magnet passes a magnetic member when a gap G is 0.4 mm, and FIG. 11B illustrates a relationship between the hybrid magnet and a permanent magnet. A diagram showing the relationship between the suction force and the distance acting when passing the magnetic member in a state in which is removed,
(C) is a diagram showing the relationship between the attractive force and the distance acting when passing the magnetic member when only the permanent magnet is used.

12A and 12B are diagrams illustrating a relationship between an attractive force and a distance acting when a hybrid magnet passes a magnetic member when a gap G is 0.5 mm, and FIG. 12B illustrates a relationship between a hybrid magnet and a permanent magnet. A diagram showing the relationship between the suction force and the distance acting when passing the magnetic member in a state in which is removed,
(C) is a diagram showing the relationship between the attractive force and the distance acting when passing the magnetic member when only the permanent magnet is used.

13A and 13B show another embodiment of the hybrid magnet according to the present invention, in which an experiment is conducted to separate the movable member when the width of the permanent magnet is 2.5 mm, and FIG.
(B) is a side view.

FIG. 14 shows an example in which the width of the permanent magnet is 5 mm in the example of FIG.
(A) is a front view, and (b) is a side view.

FIG. 15 is a front view and FIG. 15B is a side view in which the width of the permanent magnet is changed to 10 mm in the example of FIG.

16 (a) is a front view and FIG. 16 (b) is a side view in which the width of the permanent magnet is changed to 15 mm in the example of FIG.

17A and 17B are diagrams in which the width of the permanent magnet is changed to 20 mm in the example of FIG. 13, (a) is a front view, and (b) is a side view.

FIGS. 18A and 18B are diagrams illustrating an experiment in which the movable member is separated from the hybrid magnet according to the present invention with the engagement member removed, FIG. 18A is a front view, and FIG.

19A and 19B are diagrams illustrating an experiment in which a movable member is separated when only a permanent magnet is used. FIG. 19A is a front view, and FIG. 19B is a side view.

FIG. 20 is a diagram showing a line graph of Table 10 displaying the experimental data of FIGS.

FIG. 21 is a longitudinal sectional view showing an embodiment of a stepping motor according to the present invention.

FIG. 22A is an end view taken along line AA ′ of FIG. 20;
(B) is an end view along line BB ', and (c) is an end view along line CC'.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Hybrid type magnet 12 Iron core 12a Body part 12b Arm part 14 Excitation coil 16 Electromagnet 18 Permanent magnet 20 Magnetic member 22 Engaging member 30 Moving member 40 Sliding member 50 Hybrid type magnet 60 Electromagnet 62 Iron core 62a Body 62b Arm part 62c Arm Part 64 exciting coil 70 engaging member 71, 73, 75 magnetic member 72, 74 permanent magnet 80 movable member 100 stator 110 rotor

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuya Oguri 5-6-1 Kamizuruma, Sagamihara-shi, Kanagawa A-111 Rune Higashi-Rinkan (72) Inventor Sanshiro Ogino 2--20-1 Futaba, Shinagawa-ku, Tokyo 2 Umeda Building 405 (72) Inventor Hiroyuki Makabe 6714 Tamura, Hiratsuka-shi, Kanagawa (56) References JP-A-4-271103 (JP, A) JP-A-4-286103 (JP, A) JP-A-61-177154 (JP, A) Japanese Utility Model Hei 2-118478 (JP, U) Special Table Hei 1-502705 (JP, A)

Claims (5)

(57) [Claims] 1. An electromagnet formed by winding an exciting coil around an iron core formed in a U-shape by a body and left and right arms having a rectangular cross section, and a permanent magnet sandwiched between magnetic members from both sides by the magnetic core. A rectangular rod-shaped engaging member that is tightly joined between both outer ends of the arm portion, and wherein the permanent magnet is located between the arm portions of the iron core, wherein the width of the permanent magnet is The ratio of the width of the magnetic member to the total width is in the range of 1: 1.6 to 1: 7 , and the iron core is made of pure iron, and the magnetic member is made of pure iron.
A hybrid magnet made of a material having a high saturation magnetic flux density and a high magnetic permeability . 2. An electromagnet formed by winding an exciting coil around two body portions of an iron core formed in an "E" shape by two body portions and three rectangular arm portions, and a magnetic member. A permanent magnet, a magnetic member, a permanent magnet, a magnetic rod, and a square rod-shaped engaging member that is in close contact with the outer surface of the arm portion of the iron core and that is tightly joined between both outer ends of the arm portion outside the iron core. A hybrid magnet positioned between the arm portions of the iron core, wherein the permanent magnets have the same width, and the ratio of the total width of the permanent magnets to the total width of the magnetic members is 1: 1.6 to 1:
7. A hybrid type magnet comprising: 3. The hybrid magnet according to claim 1, wherein the core is pure iron, and the permanent magnet is a neodymium magnet. 4. A hybrid type magnet comprising a plurality of hybrid type magnets according to any one of claims 1 to 3, which are integrally formed at equal angles so that arm portions are radially centered on the trunk portion. A stepping motor, wherein magnetic members are arranged at equal intervals outside an engaging member of a magnet to constitute a rotor. 5. A stepping motor comprising a plurality of stepping motors according to claim 4, which are connected in series with a phase difference.