JPS61285063A - Linear pulse motor - Google Patents

Abstract

PURPOSE:To reduce the height and the width of the entirety by disposing the magnetic core of a stator at the poles in a direction perpendicular to the moving direction of a movable element and disposing permanent magnets on the sides of the poles and a back yoke on the side of the magnet. CONSTITUTION:Magnetic cores 11, 12 are so disposed that poles 21, 22, 23, 24 are aligned in one row in a direction perpendicular to the moving direction A of a movable element 16. A permanent magnet 14 for generating bias magnetic fluxes having different polarities to the cores 11, 12 is bonded to the sides of the cores 11, 12 at the pole side. A back yoke 15 having the same length as the magnet 14 is secured by bonding to the other side of the magnet 14. With such a construction, the height and the width of the entirety can be reduced to decrease the thickness and the size of a linear pulse motor.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a linear pulse motor suitable for application to, for example, a magnetic head drive system of a Frembie disk in a word processor or the like.

(Summary of the Invention) The linear pulse motor according to the present invention has the magnetic core of the stator arranged with its magnetic pole part perpendicular to the direction of movement of the mover, and permanent magnets and permanent magnets on the sides of the pole part. It is constructed with a pack yoke placed on the side, and the overall design is thin and compact, allowing for effective use of space.

(Prior art) As a flat linear pulse motor, for example,
The one described in Japanese Patent No. 9-89565 is known. As shown in FIG. 5, this consists of a stator 10 and a mover 16. On the back surface of the mover 16, magnetic pole teeth 16a of the same pitch are arranged in the direction of movement of the mover 16 as shown by arrow A. A large number of them are provided in orthogonal directions. The stator 10 includes a pair of nearly U-shaped magnetic cores 1 with open ends facing each other.
1゜12, and each open end has a magnetic pole part 21゜2.
2 and 23.24. Each U-shaped magnetic core 1
Coils 31 and 32 for generating magnetic flux are wound around the phase portions 11a and 12a of 1.12. Each magnetic pole part 2
On the upper surface of 1.22.2'3.24, magnetic pole parts 23.22.24.2 are arranged at the same pitch as the magnetic pole teeth 16a of the mover 16.
Magnetic pole teeth 21a, 22a, 23a, and 24a having a relative phase change of 1/4 pitch are formed in the order of 1, and constitute a magnetic pole tooth group. On the back surface of each magnetic pole part 21, 22, 23, 24, a permanent magnet 14 with an N pole and an S pole magnetized on the traveling direction A side of the mover 16 is fixed in a direction perpendicular to the traveling direction A. There is.

Further, a back yoke 15 is fixed to the back surface of the permanent magnet 14. The mover 16 is movably held relative to the stator 10 with a predetermined gap maintained by a guide mechanism (not shown). By sequentially switching the energization to the coils 31.32 and the direction of the current, each magnetic pole portion 23.22.24.21 is sequentially excited, and the mover 1
6 is stepped relative to the stator 10 by 1/4 pitch of the magnetic pole teeth.

(Problems to be Solved by the Invention) However, in such a conventional linear pulse motor, the permanent magnet 14 and the back yoke 15 are stacked on the back of the magnetic core 11, 12, so the overall height is It becomes thick. Particularly, problems arise when a linear pulse motor is used to drive a magnetic head of a floppy disk. For example, when using a head system mounting structure as shown in FIG. 6, the magnetic head 17 is a head? The moving element 1 of the linear pulse motor is connected via the mount 18.
6, the height H from the base 19 to the floppy disk 20 is determined by the height of the linear pulse generator, and the height of the magnetic head 17 determines the height of the diskette and the floppy disk device. Its height is determined. Therefore, if the linear pulse motor itself becomes thick, there is a problem in that it becomes extremely difficult to reduce the thickness of the floppy disk drive device itself.

In addition, as shown in FIG. 7, within the movable range of the mover 16,
When the mover 16 is located at the most extreme position (a) and when it is located at the most extreme position (b), empty spaces as shown by diagonal lines are created. Since these empty spaces are distributed on both sides in the direction of movement of the mover 16, there is a problem in that these empty spaces cannot be used effectively, such as for arranging other parts.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a linear pulse motor in which the stator is made as thin and compact as possible to effectively utilize space.

(Means for Solving the Problems) In the linear pulse motor according to the present invention, the stator moves each magnetic pole portion having magnetic pole teeth having the same pitch as the magnetic pole teeth of the mover and shifted in phase by a predetermined bit to move the mover forward. A plurality of magnetic cores arranged in a line perpendicular to the direction, a coil wound around each magnetic core for generating magnetic flux, and a plurality of magnetic cores arranged on the side surface of each magnetic core on the magnetic pole side. The magnet includes a permanent magnet for generating bias magnetic fluxes of different polarities, and a back yoke disposed on the side surface of the permanent magnet opposite to the magnetic core.

(Embodiment) FIG. 1 shows an embodiment of the present invention, and the reference numerals used in the description of the conventional example in FIG. 5 are used for similar members and parts. The stator 10 has a pair of substantially U-shaped magnetic cores 11.12 arranged in parallel, each of which has magnetic pole parts 21.22 and 23.24 at its open end. Phase portion 118 of each cone-shaped magnetic core 11.12
．． 12a includes a coil 31.3 for generating magnetic flux.
2 is wound. Each magnetic core 11.12 is connected to each W1
The pole parts 21.22, 23.24 are arranged in a line in a direction perpendicular to the moving direction A of the mover 16, and the upper surface of each magnetic pole part 21.22, 23.24 is provided with a mark of the mover 16. At the same pitch as the magnetic pole teeth 16a formed on the back surface, the magnetic pole part 2
Magnetic pole teeth 21a, 22a, 23a having a relative phase displacement of 1/4 pitch in the order of 1, 23.22°24
.

24a is formed. A single permanent magnet 14 for generating bias magnetic fluxes of different polarities for each magnetic core 11.12 is fixed by adhesive or the like to the side surface of each magnetic core 11.12 on the magnetic pole side. This permanent magnet 14 is magnetized with polarity divided into two in its longitudinal direction,
The magnetic pole portions 21.22 are fixed to the south pole of one side surface, and the magnetic pole portions 23.24 are opposite to the north pole. A back yoke 15 having the same length as the permanent magnet 14 is fixed to the other side surface of the permanent magnet 14 by adhesive or the like. The mover 16 has a narrow gap with respect to the stator 10, e.g.
It is movably held by a linear bearing or the like while maintaining a force of about 0μ.

Next, the operation will be explained. Now, when the coil 31 is energized to excite the magnetic pole part 21, a strong attractive force is generated between the peaks of the magnetic pole teeth 21a of the magnetic pole part 21 and the peaks of the magnetic pole teeth 16a of the slider 16, and the two The mover 16 moves relatively to the opposing stable point. Next, when the coil 31 is de-energized and the coil 32 is energized to excite the magnetic pole part 23, the peaks of the magnetic pole teeth 23a of the magnetic pole part 23 and the peaks of the magnetic pole teeth 16a of the slider 16 are connected. A strong suction force acts between them to relatively move the mover 16 to a stable point where the two face each other. Since the magnetic pole teeth 21a and the magnetic pole teeth 23a are out of phase by 1/4 pitch, the mover 16 has advanced by 1/4 pitch during this period. Next, a current is applied in the opposite direction to the coil 31 to make the peaks of the magnetic pole teeth 22a and 16a face each other, and a current is applied in the opposite direction to the coil 32 to cause the magnetic pole teeth 24a and the magnetic poles [116a and 116a to By sequentially arranging the peaks of the movable member 16 to face each other, it becomes possible to advance the mover 16 by one pitch in four steps. When moving the mover 16 in the opposite direction, the coils 31 and 32
The excitation of each magnetic pole portion may be performed in the reverse order to the above.

As shown in FIG. 2(a), when the mover 16 is located at the most extreme position in the movable range of the mover 16, there is an empty space below the mover 16 and in front of the stator 10 shown by the shaded area. The mover 1 shown in FIG. 2(b)
6 is located at the rearmost position, no empty space is formed. Since the empty space formed ahead of the stator 10 is relatively large, the space can be used effectively by arranging other parts in this space, resulting in improved space efficiency.

FIG. 3 shows an example in which the linear pulse motor according to the present invention is applied to a floppy disk magnetic head drive system to effectively utilize empty space, and the symbols used in the explanation of FIG. Used for similar parts.

A head mount 18 is attached to the tip of the mover 16 of the linear pulse motor via a connecting fitting 18a.
A magnetic head 17 is attached to the upper surface of the head mount 18. As shown in FIG. 3(b), the mover 16
By moving in the direction of the arrow, writing to and reading from the floppy disk 20 is performed. In this way, the head mount 18 can be placed using the empty space formed ahead of the stator 10, so that the permanent magnet 14 of the stator 10 and the back yoke 1
5 on the side of the magnetic cores 11, 12, the height H of the floppy disk 20 and the height of the floppy disk drive itself can be further reduced.

Another embodiment of the invention is shown in FIG. In this embodiment, magnetic core 11.
12 are cut off leaving the magnetic pole parts 21.22 and 23.24, respectively, and upwardly shaped magnetic cores 111, 112 are used which connect the lower parts of each set, and each magnetic pole part 2
Similar magnetic pole teeth 21a are provided on the upper surface of 1,22°23.24.
.

22a, 23a, and 24a are formed. The same! ! A permanent magnet 14 is fixedly attached thereto, and a back yoke 15 is further fixedly attached to the side surface of the permanent magnet 14. ! In the pole parts 21, 22 and 23° 24, coils 31 and 32 are wound in the direction of the magnetic pole at each pole part.

In this embodiment as well, the movable element 16 moves 1/4 pitch at a time with respect to the stator 10 by energizing the coils 31 and 32 and sequentially switching the direction of the current.

In this embodiment, since the coils 31.32 are arranged near the magnetic poles 6 of the four phases +21a, 21a, 23a, and 24a, the coils 31.32 are placed near the magnetic cores 11.12 and 21a, 21a, 23a, and 24a, respectively, as in the previous embodiment. Magnetic efficiency is better than winding the wire around the center of the wire. Therefore, the cross-sectional area through which the magnetic flux of the magnetic pole teeth of each phase passes can be reduced, which has the advantage of being able to be made thinner, including the thickness of the coils 31 and 32. Also, magnetic core 111.11
2 does not protrude laterally, there is an advantage that the stator can be made more compact.

In each of the above embodiments, the mover 16 is fixed, and the fixed T1
If the stator 0 is held movable relative to the movable element 16, the stator 10 will similarly move relative to the movable element 16. It should therefore be noted that the terms translator and stator are relative.

(Effects of the Invention) As described above, in the linear pulse motor according to the present invention, the magnetic core of the stator is arranged with its magnetic pole part perpendicular to the direction of movement of the mover, and permanent magnets are attached to the sides of the magnetic pole part. Since the back yoke is placed on the side of the permanent magnet,
The overall height and width can be reduced, and a thin and small linear pulse motor can be realized. Therefore, free space can be used effectively, and if this is used in a floppy disk magnetic head drive system, etc., the floppy disk drive device itself can be made thinner and smaller.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view showing a stator and a mover of a linear pulse motor showing an embodiment of the present invention; FIG.
b) is a schematic diagram showing the movable range of the moving element of the linear pulse motor shown in Fig. 1, and Figs. 3 (a) and (b) show the linear pulse motor shown in Fig. 1 as a floppy disk magnetic head drive system. 4 is an exploded perspective view of a stator and a mover showing another embodiment of the present invention, and FIG. 5 is an exploded perspective view of a stator and a mover showing an example of a conventional linear pulse motor. 6 is a schematic diagram of the linear pulse motor shown in FIG. 5 applied to a magnetic head drive system for a floppy disk, and FIGS. 7(a) and (b) are diagrams of the linear pulse motor shown in FIG. 5. It is a schematic diagram showing the movable range of a mover. 10...Stator, 11.12...Magnetic core, 14.
...Permanent magnet, 15... Back yoke, 16... Mover, 31.32... Coil. Patent applicant Tateishi Electric Co., Ltd. Agent Patent attorney Tetsuji Iwakura (and one other person) Figure 1 10... Stator 16a01. a Tsukiyama 11.12... Ishihirokan core 21-2
4. ,,! Lung part 14...permanent, magnet
21a-24a...a and masochism 15...high 1st yoke 31.32...coil 16...,%
Mover Fig. 2 (a) Fig. 3 17 Magnetic head 19 Base attachment/Head mount 2o-FROM disk 18
a. Connecting fittings

Claims (1)

[Claims] A mover having a large number of magnetic pole teeth with the same pitch on one surface, and a stator disposed opposite to each other on the magnetic pole tooth side of the mover with a predetermined gap therebetween, a plurality of magnetic cores each having magnetic pole teeth having the same pitch as the magnetic pole teeth but shifted in phase by a predetermined pitch in a line in a direction perpendicular to the traveling direction of the slider; a coil for generating rotated magnetic flux; a permanent magnet disposed on the side surface of the magnetic pole side of each of the magnetic cores for generating bias magnetic flux of different polarity for each magnetic core; A linear pulse motor including a back yoke disposed on a side opposite to the magnetic core.