JPH01103153A - Flat linear pulse motor - Google Patents

Abstract

PURPOSE:To reduce the power to position a needle by absorbing a lock member made of a magnetic material mounted on a moving section by means of a spring into a fixed section by a permanent magnet when driving coils are not reactive magnetism and reducing the absorption force when driving coils are excited. CONSTITUTION:A rectangle of hole is made on the central part of a base 11 of a stator 15, a roller orbital surface is formed on the upper surface of the both sides of the base 11. Two yokes 12 made of a magnetic material and a permanent magnet 13 are placed into the hole. A lock member 3 made of a magnetic material mounted by means of a flat spring 2 is provided to a needle 1. Pole teeth 1a and 1b of the needle 1 are corresponded to pole teeth 10a & 10b and 10c & 10d of the yokes 12. Pole teeth 10a & 10c have the same pitch and phase as those of 10b & 10d, and 10a and 10b are shifted 1/2 pitches. When driving coils 5a-5d of pole teeth 10a-10d are not excited, the needle 1 is locked strongly by the permanent magnet 13, but the locking force is reduced in case of exciting. According to the constitution, the needle is positioned accurately by low power.

Description

[Detailed Description of the Invention] Summary of the Invention A locking member made of a magnetic material is attached to the movable part by a spring, and the locking member is arranged so that it is attracted to the fixed part by a permanent magnet for generating bias magnetic flux when the drive coil is not energized. However, since the attraction force is weakened when the drive coil is energized, the movable element can be firmly positioned and fixed without power consumption, and is resistant to shock and vibration.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat 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 Conventional flat plate linear pulse motors typically have a stator with multiple magnetic pole teeth, and a plurality of magnetic pole teeth arranged in pairs, each facing the magnetic pole teeth of the stator. The mover has magnetic pole teeth and is movably supported by the stator. It generates bias magnetic flux and magnetizes the paired magnetic pole teeth of the stator and the mover so that they have different polarities. and a plurality of permanent magnets that sequentially generate 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 movable element by being excited to move the movable element. It is composed of a drive coil (see, for example, Japanese Patent Laid-Open No. 82-84252).

In such a linear pulse motor.

In a non-excited state where the drive coil is not energized, the mover is stopped by the force (this is called cogging force) that acts between the magnetic pole teeth of the mover and stator, which are magnetized by the bias magnetic flux generated from the permanent magnet. and fixed. Since this cogging force is not very strong, if an external force such as a shock or vibration is applied, the movable element may move and its stopping position may change. In particular, when a linear φ pulse motor is used to drive the head and the head is mounted on a movable element, if the head suddenly moves, the head will not be able to operate normally (reading and writing). In some cases, linear pulse conflict may lead to damage to the motor or head.

In order to firmly fix the movable element, it is necessary to apply current to one of the drive coils to strengthen the attraction force, which increases power consumption.

SUMMARY OF THE INVENTION OBJECT OF THE INVENTION The object of the present invention is to provide a flat linear motor that has a relatively simple configuration and can firmly fix a mover in any position without consuming electric power. .

Structure of the Invention This invention provides a stator having a plurality of magnetic pole teeth, a mover having a plurality of magnetic pole teeth arranged to face the magnetic pole teeth of the stator and movably supported by the stator, and a bias. A permanent magnet that generates magnetic flux and magnetizes the magnetic pole teeth of the stator and the magnetic pole teeth of the mover that face each other so that they have different polarities, and is energized to move the mover. A flat plate-shaped linear motor equipped with a plurality of drive coils that sequentially generate magnetic flux in a direction to strengthen the bias magnetic flux between the magnetic pole teeth of the stator and the magnetic pole teeth of the mover, which face each other.
In a motor, a position where part of the bias magnetic flux of the permanent magnet forms part of the magnetic closed circuit, and is biased through the magnetic closed circuit by the magnetic flux generated by energizing (excitation) the drive coil. When the drive coil is disposed in a position where the magnetic flux is weakened and is attached via an elastic body to a movable part including a movable element and a member that moves in conjunction with the movable element, and the drive coil is not energized (in a non-excited state), the above-mentioned The present invention is characterized in that a locking member made of a magnetic material is provided, which attracts the fixed portion including the stator and the members coupled thereto by the attractive force of the bias magnetic flux against the restoring force of the elastic material.

Effects of the Invention According to this invention, in the non-excited state of the drive coil,
A locking member provided on the movable part is attracted to the fixed part by a force generated based on the bias magnetic flux of the permanent magnet.

Therefore, the movable part can be locked without energizing the drive coil, that is, without consuming power.

Moreover, since the locking member is attracted to the fixing part in a state where there is no gap between them, that is, in a close contact state, a firm fixation can be obtained, and the locking member is resistant to shocks, vibrations, etc. Even when this linear pulse motor is applied to a head drive and the head is mounted on a movable element, normal operation of the head is ensured, and there is no risk of damage to the linear pulse motor, head, etc.

When the drive coil is excited to move the movable element, the attraction force of the locking member is weakened or almost eliminated, so that the movable element is unlocked.

It becomes possible to drive the mover to move.

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 11.
A rectangular hole is drilled in the center of the hole, and the upper surfaces of both sides of the hole are roller raceway surfaces. Two yokes 12 and a permanent magnet 13 made of a magnetic material are located in the square hole of the base 11. A pair of left and right yokes 12 are fixed together using adhesive, for example, with a square rod-shaped permanent magnet 13 sandwiched in the center, and these are fixed to the front and rear edges of the square hole from the lower surface of the base 11. There is a gap between the left and right edges of the square hole and the yoke 12. Two protrusions 12a are formed on each yoke 12, and these protrusions 12
a Flat magnetic pole teeth on the top surface 1. Oa, 10b, 10
c, lOd is fixed. 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 to 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 lOc have the same pitch and the same phase, and the same goes for lOb and lOd.The magnetic pole teeth 10a and lOb 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 10a-10d as described above, the flat magnetic poles m1Oa-10d are formed into a single flat plate as shown in FIG.

It is preferable that this flat plate 10 is fixed to the protruding portion 12a of the yoke 12 and then separated into four pieces by two-way machining or electric discharge machining. Around the protrusion 12a and the magnetic pole teeth 10a to lOd, an insulating film 4A, a drive coil 5a,
5b, 5c, 5d and an insulating film 4B are provided, respectively.

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 of the pole teeth 10a-106 is exactly perpendicular to the direction of the pole teeth 10a-106. 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 of the base 11. A plurality of holes are formed in the horizontal portion of the retainer 6A, and the roller shaft 6C is housed in the hole 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 movable element 1 is formed from a plate-shaped magnetic material, and has two rows of magnetic pole teeth 1a and 1b formed on its lower surface. These magnetic pole teeth 1a, lb are also formed with alternating protrusions and grooves,
The pitch 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.

Such a movable element 1 is housed in a retainer 6A and is supported so as to be freely movable via nine spheres 6b and roller shafts 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 of the base 11 and in contact with these. Magnetic pole tooth 1 of mover 1
A faces the magnetic pole teeth 10a and lOb with a certain gap between them, and the magnetic pole tooth 1b faces the magnetic pole teeth IC and 1d with a certain gap between them.

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 e-motor drive method is unipolar drive.

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

1b, 10a-10d, and magnetic poles appear on their protrusions as shown in FIG.

First, in a state where the magnetic poles 110a and 1a are shifted by 1/4 pitch, the drive coil 5a corresponding to the magnetic pole tooth 10a 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 LQa most strongly attracted the magnetic pole tooth 1a of the mover 1, and the mover 1 moved by 1/4 pitch, so that these magnetic pole teeth 1a and the ridges of lOa (which are magnetized with different polarities) faced each other. stable in the state. This is the state shown in FIG. The magnetic pole tooth 1b and IOc are shifted by 1/4 pitch.

Next, the power supply to the drive coil 5a is stopped, and the 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 IQc pulls the movable element 1 most strongly until both the magnetic pole teeth 1b and 10c of 1 are opposed to each other and become stable (that is, 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, 10a~
Finally, it is moved by the attractive force between the magnetic poles generated at 10d and 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 show a part of FIG. 2 in an enlarged manner, but the cross-sectional position is different from 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 LOc,
Magnetic pole teeth LOa, 1 (lc) 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 teeth 10a (and 10b
), magnetic pole tooth 1a, mover 1. Magnetic pole tooth lb, magnetic pole tooth 10C
(and 1Od), 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 lb
, magnetic pole teeth 10c (depending on the position of the lock member 3, magnetic pole teeth 10d and 10b also pass through), yoke 12. Lock member 3.
It passes through the 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 13, the attraction force of the lock member 3 is weakened. When the attraction force of the locking member 3 becomes smaller than the restoring force of the leaf spring 2, the locking member 3 separates from the yoke 12 as shown in the figure, and the lock is released.

As described above, the movable element 1 moves by 1/4 pitch when the coil 5a is energized.

The above occurs in the same way when a 5 dL current is passed through the drive coils 5b, 5c.

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 10c), the magnetic pole of the mover l5iala (
and 1b), the magnetic pole teeth 10b (and 10d), and the yoke 12, flowing in the same direction as the moving direction of the movable element 1.

In a linear pulse motor with this configuration,
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 phase, and the stator magnetic pole teeth 10a and 10b are 1
/2 pitch phase shifted, magnetic pole teeth 10a and 10c are +1
/4 pitch phase shifted, magnetic pole teeth 10a and lOd are -1
It is preferable to shift the phase by /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 locking member 3, the movable element 1 changes from rolling contact to sliding contact with the stator system, and can be fixed. In this way, the dead weight of the locking mechanism including the locking member 3 is not added to the movable element 1, so that 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. 2 are the same as those shown in FIG. 3 and the like. FIG. 11 is a cross-sectional view.

In this embodiment, a plate-shaped permanent magnet 13 is used, and with the center line as the boundary, the upper surface of this plate-shaped permanent magnet 13 has an N pole and an S pole, and the lower surface has opposite magnetic poles. It is magnetized. 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. In this embodiment as well, the locking member 3 is attracted to the central portion of the yoke 12.

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 the yoke 12 and the side surface of the back yoke 17, which are located above and below with the two sides in between. In this embodiment, since two locking members 3 can be provided, the movable element 1 can be more firmly fixed.

FIGS. 14 to 16 show still other embodiments, and FIG. 14 is an assembled perspective view showing only the mover disassembled;
FIG. 15 is a sectional view, and FIG. 18 is an exploded perspective view.

In this embodiment, the yoke 12 provided in contact with the permanent magnet 13 is divided into four pieces, and each yoke 12 is formed with a protrusion 12a extending in the direction of movement of the mover l, on which the coils 5a to 5d are attached. provided. The axial direction of the coils 58 to 5d coincides with the moving direction of the movable element 1. The permanent magnet 13 and the yoke 12, which are fixed together, are fixed to a reinforcing plate 18 made of a non-magnetic material.

And this reinforcing plate 18. The coils 5a to 5d, the front and rear yokes 19, and the reference guide 7a on the left side in the drawing are fixed together. A guide 7b is provided on the right side so as to be movable laterally, and one guide 7a, ? A retainer 6A is arranged between b, and the movable element 1 is movably supported by the retainer 6A. Both ends of the preload spring 8 are inserted into a hole 19A made in the yoke 19, and the preload spring 8 is inserted into a hole 19A made in the yoke 19, and is connected to the guide 7b and one retainer 6.
Press A. The linear pulse motor of this embodiment is characterized in that it can be made thin because the thickness of the coils 5a to 5d does not affect the thickness of the motor.

The locking member 3 is rod-shaped, and has downward protrusions 3a formed at both ends thereof. This locking member 3 is a spring 2
is attached to one side of the movable element 1. Then, at the protrusion 3a, the side portion 19a (first
(see Figure 5). Also in this example, m1
As shown in FIG. 4, bias magnetic flux φB due to the permanent magnet 13 passing through the lock member 3 and magnetic flux φ due to the coils 5a to 5d. The direction of is opposite.

The locking member 3 is attached to the yoke 1 as shown at 19b in FIG.
It may be made to adsorb to the side surface of 9. Further, two locking members 3 may be provided at two locations on both sides of the yoke 9.

[Brief explanation of the drawing]

Figures 1 to 7 show embodiments of the present invention; Figure 1 is a partially exploded perspective view of a flat linear pulse φ motor, and Figure 2 is a cross-sectional view of the assembled state. , 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 diagrams for explaining the locking operation. It is an enlarged cross-sectional view. 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. □ Figure 1O and Figure 11rI! J shows still another embodiment, and FIG. 1O shows a flat linear pulse
FIG. 11 is a partially exploded perspective view of the motor, and FIG. 11 is a cross-sectional view of the assembled motor. 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. FIGS. 14 to 16 show still other embodiments. FIG. 14 is a partially exploded perspective view of the flat linear pulse motor, and FIG. 15 is a cross-sectional view of the assembled state.
FIG. 16 is an exploded perspective view. l...Movable element. la, 1b, 10a to lOd - magnetic pole teeth. 2... Spring, 3... Lock member. 3a... Protrusion of lock member. 5a to 5d... Drive coils. 6... Traveling support mechanism. 6A...retainer. 7a, 7b...Guide. 8... Preload spring, 11... Base. 12... York. 12a...Yoke protrusion. 13...Permanent magnet, 17...Back yoke. 19...York. that's all

Claims (1)

[Scope of Claims] A stator having a plurality of magnetic pole teeth, a mover having a plurality of magnetic pole teeth arranged to face the magnetic pole teeth of the stator and movably supported by the stator, and a bias magnetic flux. A permanent magnet that magnetizes the magnetic pole teeth of the stator and the magnetic pole teeth of the mover, which face each other, so that they have different polarities. A plurality of drive coils that sequentially generate magnetic flux in a direction that strengthens the bias magnetic flux between the facing magnetic pole teeth of the stator and the magnetic pole teeth of the movable element, and magnetic closure of a part of the magnetic flux of the bias magnetic flux of the permanent magnet. A position that forms part of a circuit and is located at a position where the bias magnetic flux passing through the magnetic closed circuit is weakened by the magnetic flux generated by excitation of the drive coil, and includes a movable element and a member that moves in conjunction with the movable element. It is attached to the movable part via an elastic body, and when the drive coil is in a non-excited state, the attractive force of the bias magnetic flux causes the fixed part, including the stator and the members connected thereto, to resist the restoring force of the elastic body. A flat linear pulse motor equipped with a locking member made of a magnetic material that attracts and attracts.