JPS62233059A - Miniature linear pulse motor - Google Patents

Abstract

PURPOSE:To improve positioning precision and output torque, by arranging a yoke and a mover having minute teeth in a chemical etching process, and by setting the yoke on the side of a stator to be wound up with an exciting coil. CONSTITUTION:A linear pulse motor is provided with a yoke 1, an exciting coil 2, a mover 3, a permanent magnet 4, a retainer 5, a yoke base 6, rollers 7, and plate springs 8. At the tips four rectangular parallelopiped sections of the yoke 1, teeth 11 processed by chemical etching are respectively formed. In the same manner, also on the mover 3, teeth 31 with the same shape as the teeth 11 are formed in a comblike form by chemical etching. Besides, on both the side sections of the retainer 5, a plurality of hard balls 51 are arranged, and a slight space between the yoke 1 and the mover 3 is retained. Then, by excitation of the exciting coil 2, the mover 3 is linearly moved, and by the retainer 5, an optimum gap between the yoke 1 and the mover 3 is kept.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a small linear pulse motor, and more particularly to a small linear pulse motor that linearly moves a head of a disk device or the like.

[Conventional technology]

FIG. 4 is a principle configuration diagram showing an example of a conventional small linear pulse motor.

Traditionally, disk devices have come in 8-inch, 5-inch,
3.5-inch type, 3-inch type, etc. have been proposed, but the linear drive method used for these converts the carriage into linear drive using a voice coil motor, linear pulse motor, or rotary pulse motor. is common. In particular, in linear pulse motors, the teeth at the tip of the slider yoke, which determine the step pitch distance and accuracy, are formed by slicing with a grindstone, or by machining using a milling machine or press machine. Similarly to the above, the flat plate type stator with the opposing composition was formed by stone slicing or machining.

In the conventional example shown in FIG. 4, a yoke 9 and a stator 10 coupled by permanent magnets are arranged as shown in FIG. The wires are reversed and connected in series. When the coil 91 is excited, a magnetic force is generated between the pole I of the yoke 9 and @m of the stator 10, and the positional relationship tal in the figure is maintained. next,
When the coil 92 is excited, the pole ■ of the yoke 9 and the stator 1
A magnetic force is generated between teeth n of 0, resulting in the positional relationship shown in FIG. Next is Koku■ and V2
The yoke 9 moves further in the B direction due to the magnetic force between the coils 91 and 92, and by the sequential excitation of the coils 91 and 92, the yoke 9 moves linearly.

[Problems to be Solved by the Invention] According to the above-described conventional drive method using a mechanism that converts the carriage into linear drive using a voice coil motor and a rotary pulse motor, the disk device etc. becomes large and heavy. The drawbacks are that it is heavy, has a complicated mechanism, and is expensive to manufacture.

In the IJ near-pulse motor as well, the moving parts are the yoke, coil, and related parts, so not only are the moving parts heavy and the mechanism complicated, but also the teeth at the tip of the mover yoke and their teeth are heavy. The comb-like flat plate type stator Δ facing the is grinded and machined.
Machining ability and machining accuracy up to fM width of about 0.4H are ±1
The accuracy is poor, ranging from 0 μIn to ±30 μm, and therefore there is a problem in positioning accuracy.Furthermore, there is a drawback that a beam or a warp of the workpiece occurs during processing, requiring post-work. However, as disk devices and the like have become smaller, linear drive mechanisms have also become smaller, requiring high positioning accuracy, and conventional methods cannot satisfy the requirements of small feed, high precision positioning, and miniaturization.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned drawbacks, and to provide a small linear pulse motor with a relatively simple mechanism, small size, good positioning accuracy, and high torque.

[Means to solve all problems]

The small linear pulse motor of the present invention has a yoke base which is fixed so as not to move, and first teeth are provided at nine equal intervals over the entire length of the back surface of the plate made of a plate-shaped magnetic material. a linearly movable mover, and a second lug at the tip that meets the first lug and is equally spaced from the first lug.
A plurality of rectangular parallelepiped parts provided with i&l are arranged on a plate-like part so that the installation intervals of the rectangular parallelepiped parts are slightly different, and a permanent magnet is placed approximately in the center of the plate-like part and fixed to the yoke base. an excitation coil interposed between the mover and the yoke and winding the rectangular parallelepiped portion, and a thin plate retainer provided around the entire periphery of a plurality of rotatable rolling elements provided on the outer periphery of the excitation coil. and both 1i of the yoke base.
a support mechanism provided on the first surface of the tire, which clamps the slider from both side surfaces with an optimal biasing force, moves the slider linearly by the rolling element, and maintains a minute gap between the first and second teeth. ing.

[Effect]

The present invention solves the conventional problems by making the yoke and coil fixed, making the mover easy to move as a single component, and further micromachining the teeth provided on the mover and stator. did.

First, by chemically etching the teeth at the tip of the yoke containing the excitation coil to form fine grooves, the shape accuracy of the teeth and grooves is less than ±2 μm, and the pitch accuracy of the teeth is ±1 μm.
m or less.

The movable element facing the teeth of this yoke is also chemically etched in the same way as described above to form fine grooves and teeth with high precision, thereby making it possible to carry out short feed and high-precision positioning.

〔Example〕

Next, the present invention will be explained in detail with reference to the drawings.

1 and 2 are an overall perspective view including a partial cross section and an exploded perspective view of one embodiment of the present invention, and FIG. 3 is an enlarged side view showing the relationship between the yoke and the slider in this embodiment.

This embodiment includes a yoke 1, an excitation coil 2, a moving element 3, a permanent magnet 4, a retainer 5, a yoke base 6, a roller 7, and a leaf spring 8. The yoke 1 has teeth 11 processed by chemical etching at the tips of four rectangular parallelepiped parts. The excitation coil 2 is formed by forming a conductive wire into a spiral shape, and is inserted into the yoke 1 with a lead holder 21 provided thereon.

The slider 3 is made of a plate-shaped magnetic material, and has teeth 11 that are slightly wider than the yoke 1 by one yen at a portion facing the teeth 11 at the tip of the yoke 1.
Teeth 31 of the same shape are chemically etched into a comb shape. By placing the permanent magnet 4 at the center of the yoke 1, the yoke 1 and the mover 3 form a complete magnetic circuit. The retainer 5 is made of a rectangular plate with a square hole, and has a plurality of hard plates 51 on both sides. −
11 and the teeth 31 of the mover 3. The yoke base 6 fixes the yoke 1 at the center, and is further provided with rotatably supported rollers 7 at both ends, and one side end has a leaf spring 8 attached to the rotatably supported roller 7. It can be moved slightly toward the other end by force, and constitutes a support mechanism that clamps the mover 3 with optimal pressure.

Here, the detailed structure and mutual positional relationship of the yoke 1 and the mover 3 will be explained with reference to FIG. 3.

The yoke 1 has four rectangular parallelepiped parts 12, 13, 14, and 15, and a plurality of 1ills each having a width of 60 .mu.m and a pitch of 120 .mu.m and being chemically etched are provided at the tip of each of the 6 rectangular parallelepiped parts. Also, there are teeth 11 on the mover 3.
Teeth 31 having the same width and pitch are provided over the entire length by chemical etching. As is clear from the figure, the pitch interval between each rectangular parallelepiped part of the yoke 1 is
Pitches P1 and P of rectangular parallelepiped parts 12゜13, 14, 15
3 have the same spacing, but the pitch spacing P2 of the rectangular parallelepiped portions 13.14 is wider than pl and p3 by 1/2 of the width of the tooth 11. Furthermore, the gap H between the teeth 11 and 31 is maintained at a constant minute dimension by the retainer 5.

The operation of this embodiment configured as described above will be described next.

A magnetic circuit is constructed between the yoke 1 and the mover 30 via the water magnet 4 that excites the excitation coil 2. First, in the first state, the magnetic flux of the rectangular parallelepiped portion 12 generates a magnetic force between the pole a of the pole 11 and the pole I of the tooth 31, and the positional relationship shown in FIG. 3 is maintained. Next, in the second state, a magnetic force is generated between the poles C and P due to the magnetic flux of the rectangular parallelepiped portion 14, and the slider 3 moves in the direction of the arrow by 1/2 of the width of the tooth 31. Next, in the third state, between the pole and @U, and the fourth
In this state, magnetic force is generated between the poles d and 2, and the mover 3 begins to move in the direction indicated by the sequential arrow.

In this way, the excitation coil 2 causes the mover 3 to move linearly. During this time, the retainer 5 maintains the optimum gear spacing H between the yoke 1 and the mover 3, and the hard balls 51 This is intended to facilitate the movement of the mover 3. Further, due to the biasing force of the plate springs 8, the slider 3 moves between the roller roughs while being held at an optimal pressure.

Further, according to this embodiment, the teeth 11 and 31 are processed to have a length of 60 μm by chemical etching, so the pitch of the moving steps of the mover 3 is miniaturized to 30 μm.
Moreover, the positioning accuracy can be obtained within ±2 μm, and the output torque can also be obtained, which is about 200 grams cm, which is larger than that of the conventional method.

Furthermore, the overall size of the structure is approximately 172~
The size can be reduced to 1/3.

〔Effect of the invention〕

As explained above, the present invention provides a yoke and a mover having fine teeth formed by chemical etching, uses the yoke as a stator 1i111, winds an excitation coil, and linearly moves the mover via a retainer. , miniaturization of the step pitch, improvement of positioning accuracy and output torque, miniaturization of the mechanism (fR), and simultaneous mass production using chemical etching processing can be carried out easily and inexpensively.

[Brief explanation of drawings]

1 and 2 are an overall perspective view including a partial cross section and an exploded perspective view of an embodiment of the present invention, FIG. 3 is an enlarged side view showing the relationship between the yoke and the slider in this embodiment, and FIG. 4 1 is a principle configuration diagram showing an example of a conventional small linear pulse motor. 1... Yoke, 2... Excitation coil, 3
...Movers, 4...Permanent magnets, 5...
...Retainer, 6...Yoke base, 7.
...Roller, 8...Plate spring, 9...
...Yoke, 10...Stator, 11.31...
... Teeth, 12゜13.14.15 ... Rectangular parallelepiped part, 21 ... Lead wire, corridor l Fig. 2

Claims (1)

[Claims] a yoke base fixed so as not to move; a mover made of a plate-shaped magnetic material and having first teeth provided at equal intervals over the entire length of the back surface and movable linearly with respect to the yoke base; A plurality of rectangular parallelepiped portions are provided in the plate-like portion, and the rectangular parallelepiped portions are provided with second teeth facing the first teeth and having the same spacing as the first teeth, and the rectangular parallelepiped portions are arranged so that the installation intervals are slightly different. a yoke having a permanent magnet substantially in the center of the plate-shaped portion and fixed to the yoke base; an excitation coil interposed between the mover and the yoke and winding the rectangular parallelepiped portion; and the excitation coil. A thin plate retainer is provided on the outer periphery of the yoke base and has a plurality of freely rotatable rolling elements around the periphery; and a thin plate retainer is provided on both side surfaces of the yoke base and holds the mover with an optimal biasing force from both side surfaces. A small linear pulse motor characterized by comprising a support mechanism that allows linear movement by a moving body and maintains a minute gap between the first and second teeth.