JPH01174261A - Linear pulse motor - Google Patents

Abstract

PURPOSE:To reduce the number of components and assembling processes by using the upper surface of a base as the track surface of a roller and forming coil cores together with yokes as a unit. CONSTITUTION:A flat linear pulse motor is constituted of a stator 15 and a mover 1. The stator 15 is equipped with a base 11 having a rectangular hole 11a on the central part thereof, and two yokes 12 constituted of magnetic materials and a permanent magnet 13 are located into the rectangular hole 11a of the base 11. Two projecting coil cores 12a are formed on each yoke 12 as a unit, and flat pole teeth 10b and 10d are secured on the upper surfaces of these coil cores 12a. Driving coils 5b and 5d are mounted on the peripheries of coil cores 12a. The mover 1 is placed in the inside of a retainer 6A, and is so supplied that the mover 1 is capable of running through a sphere 6b and a roller 6c. The roller shaft 6c is supported on the upper surface of the base 11.

Description

[Detailed Description of the Invention] Summary of the Invention The upper surface of the base of the stator is a roller raceway surface for supporting and guiding the movable element, the yoke and the coil core are integrally formed, and a hole is formed in the center of the base. Ake.

By inserting and fixing the yoke into this hole, the number of assembly steps can be reduced by two parts, the overall thickness can be made thinner, and the structure can be made stronger.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear pulse motor, and more particularly, to a flat linear pulse motor that is applied to a head drive of a magnetic head for reading and writing a floppy disk of a word processor.

Prior art and its problems Flat linear pulse motors generally have a stator with a plurality of magnetic pole teeth, and a plurality of magnetic poles arranged in pairs, each facing the magnetic pole teeth of the stator. It consists of a movable element that has teeth and is movably supported by a stator. The stator is a permanent magnet that generates bias magnetic flux and magnetizes the paired magnetic pole teeth of the stator and the magnetic pole teeth of the mover so that they have different polarities, and is excited in order to move the mover. A plurality of drive coils and a permanent magnet are wound around a coil core that sequentially generates magnetic flux in a direction that strengthens the bias magnetic flux between the paired magnetic pole teeth of the stator and the magnetic pole teeth of the mover. These permanent magnets include a yoke forming a magnetic path between the coil core and the
A drive coil (coil-core) and yoke are assembled on the base.

In conventional linear pulse motors.

Since the yoke and the coil core are separate parts and are assembled on the base, there is a problem that the number of parts per unit and the number of assembly steps are large. Moreover, the magnetic path length becomes long, and the magnetic efficiency is not necessarily sufficient.

In addition, since the yoke, coil core, permanent magnets, etc. are assembled on the base, the overall thickness of the linear pulse motor is thick.In particular, if the base is made thicker to provide strength, the overall thickness becomes even thicker. There is a problem that increases.

Furthermore, since the yoke is joined to the top surface of the base,
The magnetic attraction force acting between the movable element and the movable element acts upward on the yoke, and this acts in a direction to separate the bond between the base and the yoke, thereby reducing the adhesion between the two.

SUMMARY OF THE INVENTION OBJECTS OF THE INVENTION An object of the present invention is to provide a high-strength linear pulse motor that reduces the number of parts, the number of assembly steps, and the overall thickness.

Structure and Effects of the Invention The present invention is composed of a solid element and a movable element movably supported by the stator, and the stator and the movable element are formed with magnetic pole teeth facing each other. A permanent magnet that generates a bias magnetic flux, a drive coil wound around a coil core that sequentially generates magnetic flux in the direction of increasing the bias magnetic flux in order to move the mover, and a magnetic flux between the permanent magnet and the coil core. A linear type in which a stator is constructed by assembling a yoke that forms a magnetic path on a base.
In a pulse motor, a hole is formed in the center of the base, and a yoke with an integrally formed coil core is inserted into this hole from the bottom side of the base, and is bonded and fixed to the bottom surface of the base, and the above-mentioned hole on the top surface of the base is inserted into the hole from the bottom side of the base. It is characterized in that both sides of the movable member are roller raceway surfaces that support and guide the mover.

According to this invention, since the upper surface of the base is used as the roller raceway surface and the coil core is formed integrally with the yoke, there is no need to separately manufacture and install raceway surface parts and core parts, and it requires only 2 parts and 1 assembly man-hour. can be reduced. In addition, the yoke is located in the hole formed in the base, and the coil is inserted through this hole.
Since the core is configured to protrude in the direction of the mover, there is no need to increase the thickness of the entire motor even if the base is thickened, and sufficient strength can be ensured even if the entire motor is made relatively thin. Can be done. Furthermore, since the part of the yoke that passes through the hole in the base is joined and fixed to the lower surface of the base, an upward force acts on the yoke due to the magnetic attraction force that acts between the yoke and the mover.

Since this force acts in the direction of pressing the yoke against the base, the adhesion between the joint surfaces of the yoke and the base increases, resulting in a favorable balance between the two strengths.

DESCRIPTION OF EMBODIMENTS FIGS. 1 to 7 show embodiments of the present invention. Of these, FIG. 1 is a perspective view of a flat linear pulse motor, showing the mover and locking member in an exploded view. FIG. 2 is a cross-sectional view of the linear pulse motor with the mover and locking member assembled. FIG. 3 is an exploded perspective view of the motor. FIG. 4 is a perspective view of a flat magnetic pole tooth.

Referring to Figures 1 to 3, the flat linear pulse
The motor is composed of a stator 15 and a movable element 1.

The stator 15 includes a base [1;
A rectangular hole 11a is bored in the center of the hole 11a, and the upper surfaces of both sides of the hole 11a are roller raceway surfaces. Two yokes 12 and a permanent magnet 13 made of a magnetic material are located in the square hole 11a of the base 11. A pair of left and right yokes 12 are fixed together using adhesive, for example, with a square bar-shaped permanent magnet 13 sandwiched in the center.

These are fixed from the lower surface of the base 11 to the lower surface of the front and rear edges of the square hole 11a. There is a gap between the left and right edges of the square hole 11a and the yoke 12.

Two protruding coil cores 12a are integrally formed on the yoke 12, and flat magnetic pole teeth 10a, 10b, 10c, and lOd are fixed to the upper surface of these coil cores 12a. The permanent magnet 13 has N and S magnetic poles on both sides in contact with the yoke 12.

As shown in an enlarged view in FIG. 4, the flat magnetic pole teeth 10a-10d have a shape in which protrusions and grooves are alternately formed at a constant pitch P, and are made of a magnetic material. As will be described later, the permanent magnet 13 attaches N or S to the above convex strip.
Because the pole appears, the name magnetic pole tooth is used. However, it is also possible to use magnetic pole teeth that are most magnetized and become permanent magnets. The flat magnetic pole teeth 10a and toe have the same pitch and the same phase, and the same goes for lOb and lOd, and the magnetic pole teeth 10a and 10b have the same pitch and are formed with a phase shifted by 1/2 pitch. In order to correctly adjust the phase of the magnetic pole teeth 1.0a-10d as described above, the flat magnetic pole teeth 10a-10d are formed into a single flat plate as shown in Figure IJ3.

It is preferable to fix this flat plate IO to the coil core 12a of the yoke 12 and then separate it into four pieces by one machining or electric discharge machining. Coil core 12a and magnetic pole teeth 10
Around a-10d are insulating film 4A, drive coils 5a, 5b, 5c, 5d and insulating film 4B, respectively.
are provided for each.

A substrate 14 for wiring for the drive coils 5a to 5d is fixed to the lower surface of the base 11. This substrate 14 also has holes into which the yoke 12 and the permanent magnet 13 are inserted.

A traveling reference guide 7a is fixed to one side of the base 11 by welding. This guide 7a
The inner surface thereof is exactly perpendicular to the direction of the magnetic pole teeth 10a-lod. A mounting piece 9 is fitted to the front and back of the other side of the base 11, and a part of the preload guide 7b is inserted into the hole defined by the piece 9 and the base 11, so that the guide 7b can be attached to the side. It is movable within a small range in one direction. piece 9 and base 1
A preload spring 8 whose both ends are inserted into the hole formed by the guide 7b urges the guide 7b inward.

A traveling support mechanism 6 for the movable element 1 is provided between these guides 7a and 7b. The running support mechanism 6 includes a retainer 6A, and a square hole is bored in the center of the retainer 6A.

Downwardly directed stopper pieces 6d are formed in horizontal portions located on both sides of this hole, and these stopper pieces 6d are inserted into the rectangular hole 11a of the base 11. A plurality of holes are made in the horizontal portion of the retainer 6A.

A roller shaft 6C is housed here and rotatably supported. Also, a plurality of holes are made in the vertical portions rising from both sides of the horizontal portion, and the spheres 6b are housed in these holes.

The mover 1 is formed from a plate-shaped magnetic material, and has two rows of magnetic poles ff1la and 1b formed on its lower surface. These magnetic poles i1a, lb also have protrusions and grooves formed alternately, and the pitch thereof is the same as the pitch P of the magnetic pole teeth 10a to 10d. The magnetic pole teeth 1a and 1b are out of phase by 1/4 pitch.

The movable element 1 as described above is housed in a retainer 6A and is supported so as to be freely movable via a sphere 6b and a roller shaft 6c. The sphere 6b is in contact with the side surface of the movable element 1 and the guides 7a, 7b, and the roller shaft 6c is located between the lower surface of the movable element 1 and the upper surface (roller raceway surface) of the base 11 and in contact with these. The magnetic pole tooth 1a of the mover 1 faces the magnetic pole teeth 10a and 10b with a fixed gap therebetween, and the magnetic pole tooth 1b faces the magnetic poles @lOc and 10d with the same fixed gap as above.

The lock member 3 is made of a magnetic material, has a groove in the center, and has protrusions 3a on both sides of the groove.

This locking member 3 is fixed to the lower surface of one end of the leaf spring 2,
The other end of the leaf spring 2 is fixed to the central lower surface of the movable element 1 by a screw or other fixing means. As will be described later, the lock member 3 is attracted by the permanent magnet 13 against the force of the leaf spring 2, and its protrusion 3a is in contact with the yoke 12 so as to straddle the permanent magnet 13.

Next, the operation of such a flat linear pulse motor will be explained with reference to FIG. FIG. 5 shows the positional relationship between the magnetic pole teeth 1a and 1b of the movable element 1 and the magnetic pole teeth 10a to 10d of the stator 15. This planar linear pulse motor drive method is unipolar drive.

The bias magnetic flux generated by the permanent magnet 13 is applied to the magnetic pole tooth 1a.

lb, lOa to 10d, and magnetic poles appear on these protrusions as shown in FIG.

First, in a state where the magnetic pole teeth 10a and 1a are shifted by 1/4 pitch, the drive coil 5a corresponding to the magnetic pole tooth LOa is
Then, a current is passed in a direction that generates magnetic flux in a direction that strengthens the bias magnetic flux generated by the permanent magnet 13 in the magnetic pole tooth 10a. Then, the magnetic pole tooth 10a attracts the magnetic pole tooth 1a of the mover 1 most strongly, and the mover 1 moves by 1/4 pitch, causing these magnetic poles @1a+! : The convex stripes (magnetized with different polarities) of lOa are stabilized in a facing state. This is the state shown in FIG. The magnetic pole teeth 1b and 10c are also magnetic pole teeth 1b and l.
od are shifted by 1/4 pitch.

Next, the power supply to the drive coil 5a is stopped, and the second drive coil 5c is
A current is passed through the magnetic pole teeth 10c so as to generate magnetic flux in a direction that mutually strengthens the bias magnetic flux of the permanent magnet 13. Then, the magnetic pole tooth 10c pulls the mover 1 most strongly until both the magnetic pole teeth 1b and the IOC face each other and become stable (i.e. 1
/4 pitch) Mover 1 moves.

Similarly, when the coils 5b and 5d are energized in order, the mover 1
moves in 1/4 pitch increments.

When none of the drive coils is energized, the permanent magnet 13 drives the magnetic pole teeth 1a, 1b, loa~1
The magnetic poles are finally moved by the attractive force generated between the magnetic poles at 0d, and are held in a stable positional relationship (for example, the positional relationship as shown in FIG. 5). The force acting on the mover 1 at this time is the cogging force.

Next, the locking operation by the locking member will be explained. FIG. 6 shows a state in which the movable element 1 is locked, and FIG. 7 shows a state in which the lock is released and the movable element 1 moves as described above. These drawings are enlarged views of a part of FIG. 2, but the cross-sectional position is different from that of FIG. 2. That is, for convenience of explanation, the drive coil 5
b.

In place of 5d, drive coils 5a and 5c have magnetic pole teeth 10c,
Magnetic pole teeth 10a and lOc are shown in place of lod.

In FIG. 6, when no drive current is flowing through any of the drive coils 5a to 5d, the bias magnetic flux φB of the permanent magnet 13 is applied to the yoke 12. Magnetic pole tooth 10a (and Job
), magnetic pole tooth 1a, mover 1. Magnetic pole tooth lb, magnetic pole tooth 10c
(and LOd), passes through the yoke 12, a magnetic pole appears on the magnetic pole tooth as described above, and a cogging force is exerted. Also, the leakage magnetic flux φBL of the bias magnetic flux φB passes through the inside of the lock member 3, and a magnetic pole appears on the protrusion 3a, so that the lock member 3 is attracted to the yoke 12 on both sides of the permanent magnet 13 against the restoring force of the spring 2. Ru. In addition to the above-mentioned cogging force, this adsorption force of the locking member 3 acts, so that the movable element 1 is strongly fixed. Since no current is supplied for locking, power consumption can be reduced to zero, and it is resistant to external vibrations and shocks.

Referring to FIG. 7, when a drive current is passed through the drive coil 5a in a direction to strengthen the bias magnetic flux φB caused by the permanent magnet 13 as described above in order to move the movable element 1, the magnetic flux φ generated by this drive current.

The magnetic pole tooth 10a, the magnetic pole tooth 1a, the mover 1. Magnetic pole tooth 1b
, magnetic pole tooth 10C (also passes through magnetic pole tooth 10d and fob), yoke 12. Rock club moon 3. Passes through yoke 12. Since this magnetic flux φC flows in the lock member 3 in the opposite direction to the leakage magnetic flux φBL caused by the permanent magnet [3, the attraction force of the lock member 3 is weakened. The adsorption force of the locking member 3 is
When the restoring force becomes smaller than the restoring force, the locking member 3 separates from the yoke 12 as shown in the figure, and the lock is released. Coil 5a
As described above, the movable element 1 moves by 1/4 pitch when energized.

The above also occurs when current is passed through the drive coils 5b, 5c, and 5d.

As long as the attraction force acting between the lock member 3 and the yoke 12 weakens, the lock can be released even if the lock member 3 does not necessarily separate from the yoke 12. For example, by appropriately setting the restoring force of the leaf spring 2.

The movable element 1 can be moved with the locking member 3 in contact with the yoke 12, and in this case, an appropriate frictional load is applied, so that the stop time of the movable element 1 can be shortened.

FIG. 8 shows another embodiment. In the above embodiment, the permanent magnet 13 extends in the moving direction of the movable element 1, but in this embodiment, the permanent magnet 13 extends in a direction perpendicular to the moving direction of the movable element 1, and the yokes 12 are arranged in front and behind it. .

The bias magnetic flux of the permanent magnet 13 is applied to the yoke 12. magnetic pole tooth 1
0a (and Inc), mover magnetic pole tooth 1a (and 1b), magnetic pole tooth 10b (and 10d), yoke 1
2 and flows in the same direction as the moving direction of the mover 1. A rectangular hole 11a is drilled in the base 11, and the coil core formed integrally with the yoke 12 is inserted into the hole 11a, and the yoke 12 is bonded to the bottom of the base 11.2
As in the above embodiment, the upper surfaces of both sides of the square hole 11a of the base 11 are roller raceway surfaces.

The locking member 3 is made long in the moving direction of the movable element 1, and performs a locking action by being attracted to the yoke 12 across the permanent magnet 13 as shown by the chain line 3A. Spring 2 has been changed to a pantograph type. The locking operation and the unlocking operation are the same as in the embodiment described above.

This linear pulse motor also operates in the same manner as in the above embodiment, except that the magnetic pole teeth 1a of the mover 1.

1b are in the same phase, and the magnetic pole teeth 10a of the stator and the fob are 1
/2 pitch phase shifted, magnetic pole teeth 10a and lOc are +1
It is preferable that the phase of the magnetic pole teeth 10a A 10d be shifted by -1/4 pitch. The drive coils are excited in the order of coils 5a, 5b, 5c, and 5d.

FIG. 9 shows yet another embodiment, in which the leaf spring 2 with the locking member 3 attached is connected to the retainer 6A at one end thereof.
is fixed. The other configurations are the same as those shown in FIG.

As the mover 1 moves, the retainer 6A
Move. By fixing the retainer 6A with the opening/clip member 3, the movable element 1 changes from rolling contact to sliding contact with the stator system, thereby making it possible to fix the movable element 1. In this way, the dead weight of the locking mechanism including the two openings and the locking member 3 is reduced to the movable element 1.
Since this is not added to the movable element 1, the responsiveness of the movable element 1 is improved.

FIGS. 10 and 11 show still other embodiments. FIG. 10 is an exploded perspective view of members disposed below the base 11, and other members not shown in FIG. 1 are the same as those shown in FIG. 3. FIG. 11 is a cross-sectional view.

In this embodiment, a plate-shaped permanent magnet 13 is used, and an N pole and an S pole are arranged on the upper surface of the plate-shaped permanent magnet 13 with the center line as the boundary. Opposite magnetic poles are respectively magnetized on the bottom surface. A back yoke 17 is fixed to the lower surface of the permanent magnet 13 to form a magnetic flux path through the permanent magnet 13.

FIGS. 12 and 13 show still another embodiment, which corresponds to a modification of the embodiment shown in FIGS. 10 and 11. FIG. 12 shows the movable member 1 with a part thereof cut away, and FIG. 13 is a cross-sectional view.

Lock members 3 are attached by springs 2 at positions below the lower surface of the movable element 1 on both sides thereof.

The spring 2 and the locking member 3 are directed downwardly through the gap existing between the sides of the yoke 12 and the side edges of the square hole in the base 11. The protrusion 3a of the locking member 3 is the magnet 13
It is attracted to the side surface of yoke 2 and the side surface of back yoke 17, which are located above and below with the yoke 2 in between. In this embodiment, since two locking members 3 can be provided, the movable element 1 can be more firmly fixed.

[Brief explanation of the drawing]

1 to 7 show embodiments of the present invention. FIG. 1 is a partially exploded perspective view of a flat linear pulse motor, and FIG. 2 is a cross-sectional view of the assembled flat linear pulse motor. Figure 3 is an exploded perspective view, Figure 4 is a perspective view of magnetic pole teeth, Figure 5 is an explanatory diagram of the operating principle of a linear pulse motor, and Figures 6 and 7 are explanations of rotary operation. FIG. FIG. 8 shows another embodiment, and is a partially exploded perspective view of a flat linear pulse motor. FIG. 9 shows still another embodiment, and is a perspective view of a flat linear pulse motor with the movable element removed. Fig. 10 and Fig. 11 show still other embodiments, Fig. 1O is a partially exploded perspective view of the flat linear pulse motor, and Fig. 11 is a cross section of the assembled state. It is a diagram. 12 and 13 show a modification of the above embodiment, in which FIG. 12 is a partially cutaway perspective view of the mover, and FIG. 13 is a cross-sectional view of the entire flat linear pulse motor. It is a diagram. 1...Movable element. 1 a, 1 b, loa ~ 1Od-...Magnetic pole teeth. 5a to 5d... Drive coils. 6... Traveling support mechanism. 6A...retainer, 6c...roller shaft. 7a, 7b...Guide. 8... Preload spring, 11... Base. 11a...square hole, 12...yoke. 12a...Coil core. 13...Permanent magnet, 15...Stator. that's all

Claims (1)

[Claims] Consisting of a solid element and a movable element movably supported by the stator, the stator and the movable element are formed with magnetic pole teeth facing each other, and a bias magnetic flux is generated between these magnetic pole teeth. A permanent magnet that generates magnetic flux, a drive coil that is wound around a coil core that sequentially generates magnetic flux in the direction of increasing the bias magnetic flux to move the mover, and a magnetic path between the permanent magnet and the coil core. In linear pulse motors, where the stator is constructed by assembling the yoke to form the base, a hole is formed in the center of the base, and the yoke, with which the coil core is integrally formed, is inserted into the base. A linear pulse motor, which is inserted from the lower surface side and is joined and fixed to the lower surface of the base, and wherein both sides of the hole on the upper surface of the base serve as roller raceway surfaces for supporting and guiding the movable element.