JPH0419791B2 - - Google Patents

Description

[Detailed description of the invention] [Table of contents] ●Overview ●Field of industrial application ●Prior art (Figure 6) ●Problems to be solved by the invention ●Means for solving the problems ●Operations ●Example (Figures 1 to 5) ●Effects of the invention [Summary] It is an oscillating moving coil type motor,
A coil lead wire is passed through the inside of the rotating shaft of the motor and fixed onto the end surface of the rotating shaft via a terminal fixing plate, and a ribbon-shaped intermediate lead wire having spring properties is wound in a spiral shape around the outer periphery of the terminal fixing plate. By connecting and fixing the inner terminal of the intermediate lead wire to the coil lead wire and fixing the outer terminal to the motor case side, the repetitive stress caused by rocking rotation is absorbed by the intermediate lead wire, thereby reducing fatigue due to the repeated stress. This makes it possible to improve strength (improve durability) and reduce the wiring space for coil lead wires.

[Industrial application field]

The present invention relates to an oscillating moving coil motor, and particularly to a structure for drawing out lead wires of a moving coil.

Conventionally, most oscillating motors with a large oscillating angle (for example, 30° to 360°) have been of the moving magnet type. However, recently, in order to save energy and increase efficiency, moving coil type motors have become necessary, and their development is progressing. Moving coil type motors have a structure in which the coil side performs oscillating motion, so the drawing structure of the coil lead wire is important. )
In other words, it is required to be highly reliable.

[Conventional technology]

FIG. 6 is a diagram showing a conventional example, and is a sectional view of an oscillating moving coil type motor. Note that this motor is formed as an encoder motor with a built-in encoder section.

In FIG. 6, reference numeral 1 denotes a motor case consisting of a case body 1a and a lid 1b fixed to the case body 1a;
2 is a rotating shaft (output shaft) supported in the center of the motor case 1 via bearings 3A and 3B so as to be able to rotate freely in forward and reverse directions; 4 is arranged inside the case body 1a and fixed to the rotating shaft 2 in a cantilevered manner. Each bobbin is shown below. The bobbin 4 has a hollow hole 4a that penetrates in the circumferential direction.
has. 5 is a coil wound around the outer periphery of the bobbin 4 in the same direction as the axis α of the rotating shaft 2 (indicated by a dotted line in the figure); A core is shown that loosely fits through the hollow hole 4a and is fixed to the case body 1a side. 5a is a lead wire of the coil 5, which is connected to the encoder demodulator printed board 13 with a sufficient length.
As this lead wire 5a, a normal flexible wire, a flexible printed board, or the like is used. 7A and 7B are magnets (permanent magnets) arranged opposite to both outer end surfaces of the bobbin 4 perpendicular to the axis α and with a slight gap between them, and fixed on the support plate 1c and the bottom wall 1d of the case body 1a, respectively. ), 8 is one end 2a of the rotating shaft 2
The capstan is shown inserted and fixed in the figure.

11 is the support plate 1c and the lid 1 inside the motor case 1.
12 is a light source (for example, an LED) disposed opposite to one plate surface of the code wheel and mounted on the encoder demodulator printed board 13; shows. Note that the printed board 13 is fixed to the case body 1a side. Reference numeral 14 designates a phase plate disposed facing the other plate surface of the code wheel 11 (opposed to the light source 12), and reference numeral 15 designates a light receiving section (photodiode matrix) disposed facing the phase plate 14. show. The encoder section is mainly formed by the above-mentioned parts.

This conventional example is formed with a built-in encoder section as described above, and by passing current in the forward and reverse directions through the coil 5, the rotating shaft 2 is connected to the capstan 8 and the code wheel 11 through the bobbin 4. Rotates forward and backward within a predetermined rotation angle (swing angle) range. A steel belt (not shown) or the like is wound around the outer periphery of the capstan 8, and the positioning of the driven object (for example, positioning of the magnetic head in a magnetic disk device) is performed via this steel belt.
Control operations such as the following are performed. In the encoder section, as the code wheel 11 rotates, the slit patterns provided on the code wheel 11 and the phase plate interfere with each other, and the amount of transmitted light from the light source 12 changes. is received by the light receiving unit 15, photoelectrically converted, and finally converted to 90° as the cold wheel 11 rotates.
It is formed to demodulate and output a two-phase sine wave output with a phase difference (1/4 pitch phase difference). This two-phase sine wave output signal is fed back to the coil 4 via a control section (non-rotating), etc., and a control operation is performed.

[Problem that the invention seeks to solve]

In the above-mentioned conventional oscillating-type moving coil motor, the lead wire 5a of the coil 5 is wired with a sufficient length, but due to the oscillating motion of the coil 5 (bobbin 4), the lead wire 5a of the coil 5 cannot be directly connected. There is a problem in that it is subject to repeated stress and is prone to early fatigue failure. For example, the lead wire 5a does not have the durability to withstand 100 million to 1 billion oscillations as required in a magnetic disk device, and may break due to fatigue. Furthermore, the lead wire 5a occupies a large space, making it difficult to downsize the motor. Furthermore, since the lead wire 5a influences the rotational movement of the rotary shaft 2, the offset force around the rotary shaft 2 due to the lead wire 5a is unstable, which tends to cause control problems.

The present invention was created in view of these problems, and has a drawer structure in which repeated stress does not directly act on the coil lead wire, which can significantly improve fatigue strength against repeated stress, and is also compact. The object of the present invention is to provide an oscillating moving coil motor that can improve controllability.

[Means for solving problems]

In order to solve the above problems, the present invention provides an oscillating moving coil motor, in which the rotation shaft 22 of the motor has a rotation center axis α.
A radial insertion hole 22c is provided in the hole 22b along the hole 22b and a radial insertion hole 22c is provided in the middle part of the hole 22b to communicate with the hole 22b. A predetermined space is provided in the motor case portion corresponding to the end surface 22d of the shaft 22, and the terminal fixing plate 26 fixed to the end surface 22d is positioned in this predetermined space, and the coil lead wires 25A-1, 25B of the moving coils 25A, 25B are -1 to the insertion hole 2
2c and hole 22b from the end surface 22d side of the rotating shaft 22, and penetrates through the terminal fixing plate 26 fixedly provided on the end surface 22d.
A ribbon-shaped intermediate lead wire 27 having spring properties and conductivity is wound like a clockwork around the outer periphery corresponding to the radial direction of the terminal fixing plate 26, and the intermediate lead wire 27 is fixed to the terminal fixing plate 26. The inner terminals 27a and 27b are connected and fixed to the lead wires 25A-1 and 25B-1, respectively, and the outer terminals 27c and 27d are fixed to the motor case 21 side so that they can be connected to the external lead wire 30. shall be.

[Effect]

The coil lead wires 25A-1 and 25B-1 are drawn out from the end face 22d side through the inside of the rotating shaft 22, pass through a terminal fixing plate 26 fixedly disposed on the end face 22d, and are fixed onto this fixing plate 26. Therefore, the moving coils 25A, 25B and the rotating shaft 22 rotate in a rocking manner, and there is no effect of repeated stress due to the rocking rotation. The repeated stress caused by the oscillating rotation acts on the intermediate lead wire 27 which is wound in a clockwise manner, but the intermediate lead wire 27 absorbs this repeated stress by dispersing it over the entire lead wire 27 within the elastic limit range. do. As a result, the fatigue strength of the intermediate lead wire 27 against repeated stress can be significantly improved, and sufficient durability can be obtained even for, for example, one billion oscillations. Also coil lead wires 25A-1, 25B
-1 is housed inside the rotating shaft 22, and the rotating shaft 22
By adopting a structure that oscillates and rotates together, the motor can be made smaller, and the influence of the coil lead wire on the rotational movement of the rotating shaft 22 can be completely eliminated, so that the offset force can be stabilized. I can do it.

〔Example〕

1 to 5 are diagrams for explaining embodiments of the present invention.

1a, b, and c are views showing an embodiment of the oscillating-type moving coil type motor according to the present invention, in which a is a front view thereof, b is a cross-sectional view taken along the line _A1 - _A2 of a,
c is a bottom view of arrow B in b. Note that this example is formed as an encoder motor with a built-in encoder section. The motor case 21 is formed by integrating an outer wall 21a, a bottom wall 21b, and an inner cylindrical wall 21c. This motor case 21 also serves as a yoke for the magnetic circuit. The rotating shaft (output shaft) 22 has an output end 22a protruding from the motor case 21, and has bearings 23A, 23.
It is supported via B in the center of the motor case 21 so as to be rotatable in forward and reverse directions. The rotating shaft (output shaft) 22 is formed in a hollow shape with a through hole 22b provided along the rotation center axis α, and a radial insertion hole 22c is provided in the longitudinally intermediate portion thereof to communicate with the through hole 22b. It is being Note that the through hole 22b may be formed as a non-through hole with a solid output end side. The bearings 23A and 23B are integrally formed with the rotating shaft 22, with their inner rings being formed integrally with the rotating shaft 22, and are called shaft bearings. This shaft bearing has
Furthermore, a compression spring 2 is provided for applying a preload in the direction of the axis α to the outer ring of each of the bearings 23A and 23B.
3-1, and a cylindrical outer ring support sleeve 23-2 for fitting and fixing both outer rings at the same time. Therefore, by fitting and fixing the sleeve 23-3 into the inner cylindrical wall 21c of the motor case 21 as shown, the rotating shaft 22 and the bearings 23A, 23B are attached at the same time.

A capstan 22 - 1 is inserted and fixed to an output end (projection) 22 a of the rotating shaft 22 . A code wheel 31 is fixed concentrically with the rotating shaft 22 on the inner end surface 22-1a of the capstan 22-1. A cylindrical bobbin 24 is fixed on the inner plate surface of the code wheel 31 so as to be concentric with the rotating shaft 22. The bobbin 24 is, for example, molded,
The cylindrical wall 24a and the bottom wall 24b are integrally formed, and the bottom wall 24b is fixed (adhesive, screwed, etc.) to the code wheel 31.

Moving coils 25A and 25B are arranged on the outer peripheral surface of the cylindrical wall 24a of the bobbin 24. The coils 25A and 25B are each formed from a rectangular (square) loop flat coil into a semi-cylindrical shape, and the effective length portions (winding portions parallel to the axis α) of the respective rotational effective torque generating portions are opposed to each other. Bobbin 2
It is fixed on the outer peripheral surface of 4. A pair of magnets (permanent magnets) 21-1 and 21-2 are mounted on the inner surface of the outer wall 21a of the motor case 21, with a slight gap between them and the outer circumferential surface of the bobbin 24 in the radial direction, and facing each other in the radial direction. will be permanently installed. Either one of these magnets 21-1 and 21-2 is N.
pole, and the other is set to the south pole. Coil 25A, 2
5B are electrically connected to each other, and the respective lead wires (coil lead wires) 25A-1, 25B
-1 is the insertion hole 22c of the rotating shaft 22 and the through hole 22
b to one end surface 22d of the rotating shaft 22, that is, in this example, to the lower end surface opposite to the output terminal 22a in FIG. 1b.

A terminal fixing plate 26 is mounted on one end surface 22d of the rotating shaft 22.
is fixed. This terminal fixing plate 26 is molded from an insulating material such as resin as shown in FIG. In FIG. 2, 26a is the main body part, 26b
26c is an insertion portion, 26c is a terminal fixing recess provided in the main body portion 26a, 26d is a pair of axial insertion holes which are cut out from a part of the insertion portion 26d and penetrate through the terminal fixing recess, 26e and 26f are respective holes. Each side of the recess 26c is shown. The insertion portion 26b of the fixed plate 26 is inserted into the through hole 22b (FIG. 1b) of the rotary shaft 22 and fixed, and the coil lead wires 25A-1 and 25B-1 are drawn out through the through hole 26d.

As shown in FIGS. 1b and 1c, an intermediate lead wire 27 formed into a ribbon shape from a conductor having spring properties (for example, beryum copper, etc.) is arranged around the outer periphery of the terminal fixing plate 26 in a spiral shape. It is wound around and arranged. Although the intermediate lead wire 27 shown in FIG. 1c is shown with a reduced number of turns for the sake of clarity, it actually has a large number of turns. The lead wire fixing case 2 is configured to surround the outer periphery of this spirally wound intermediate lead wire 27.
8 is arranged, and the bottom wall 21 of the motor case 21
It is fitted into and fixed to the inner surface of the inner cylinder wall 21c corresponding to b.

The intermediate lead wire 27 is formed as shown in FIGS.
FIG. In Figure 3, 27-1, 27
-2 indicates a ribbon-like conductor (eg, beryllium copper). Ribbon conductors 27-1, 27 as shown
-2 are arranged in parallel on an insulating film (e.g., polyimide film), and both are fixed together through the film, and then an insulating outer cover (e.g., polyimide) 27-3 is baked on this. However, a ribbon-shaped intermediate lead wire 27 is formed as a whole. The lengths of the ribbon conductors 27-1 and 27-2, which are the inner sides of the spiral, are formed with a predetermined difference in length, and each end is bent, and this bent portion is the coil lead wire. 25A
Connection terminals (inner terminals) 27a, 27 for connecting to -1, 25B-1 (Fig. 1 a, b), respectively
b. These connection terminals 27a,
27b is the side surface 26e, 26f of each terminal fixing recess 26c in the terminal fixing plate 26 shown in FIG. 2 mentioned above.
are fixed to each. On the outer periphery of this terminal fixing plate 26, a connection terminal 2 of the intermediate lead wire 27 is provided.
A collar 29 (see FIG. 1c) is fixed to ensure fixation of portions 7a and 27b. The collar 29 is made of an insulating material such as resin and is formed into a substantially half-ring shape with a square cross section, as shown in 5a and 5b.

In addition, in FIG. 3, the other end of the intermediate lead wire 27, which is the outer side of the spiral shape, is bent in parallel at the side, and the tip of this bent portion is fixed to the fixed case 28 and external. Leader line 30 (first
Connection terminal (outer terminal) 27 for connecting with
c, 27d.

The lead wire fixing case 28 is molded from an insulating material such as resin as shown in FIG.
This case 28 includes a hollow cylindrical portion 28a and a guide portion 2.
8b, and an insertion hole 28c is provided that penetrates a portion of the cylindrical portion 28a that corresponds to the guide portion 28b. Connection terminals 27c, 27 at the other end of the intermediate lead wire 27 (FIG. 3) are inserted into this insertion hole 28c.
d are simultaneously inserted from the inside, pulled out to the guide portion 28b, and fixed onto the guide portion 28b.
Further, external lead wires 30 (see FIGS. 1b and 1c) are connected to these connection terminals 27c and 27d. Also,
As described above, the intermediate lead wire 27 (FIG. 3) has its inner connecting terminals 27a and 27b connected to the terminal fixing plate 2.
6, the outer connecting terminals 27c and 27d are fixed to the lead wire fixing case, and the middle part is arranged to be freely operable, and is mounted with an appropriate offset (restoring force). .

In this example, the drawing structure of the coil lead wires 25A-1, 25B-1 of the moving coils 25A, 25B is configured as described above.
By passing current in the forward and reverse directions through 25B, the bobbin 24, cord boiler 31, and capstan 21
-1 and the rotating shaft 22 are integral and both rotate forward and backward (swing motion) within a predetermined rotation angle range. A steel belt (not shown) or the like is wound around the outer periphery of the capstan 21-1, and control operations such as positioning of a driven object (for example, positioning of a magnetic head in a magnetic disk device) are performed via this steel belt. It is done. At this time, coil lead wire 25
Since A-1 and 25B-1 move integrally with the coils 25A and 25B and the rotating shaft 22, the rotating shaft 22
It is completely unaffected by forward and reverse rotations, that is, no repeated stress acts on it at all. In the case of this example, the repeated stress acts on the spiral-shaped intermediate lead wire 27, but the intermediate lead wire 27 has springiness (elasticity) as described above, and can be repeatedly applied within its elastic limit range. Since the stress acts and is distributed throughout the intermediate lead wire 27, the fatigue strength against repeated stress can be greatly improved, and sufficient durability can be obtained even for, for example, one billion oscillations. can significantly improve reliability. In addition, coil lead wires 25A-1, 25
By having a structure in which B-1 is drawn out through the inside of the rotating shaft 22, this coil lead wire 25A-
1, 25B-1 has no effect on the rotational movement of the rotating shaft 22, the offset force around the rotating shaft 22 can be stabilized, and the motor can be made smaller.

Note that the encoder section in this example mainly includes the code wheel 31 and the code wheel 31 described above.
A light source (for example, an LED) 32 disposed opposite to one plate surface of the cold wheel 31, and a phase plate disposed opposite to the other plate surface of the cold wheel 31 with a gap in between (opposed to the light source 32). 33, a light receiving section (photodiode matrix) 34 disposed opposite to the phase plate 33, an encoder demodulating section printed board 35 on which the phase plate 33, the light emitting section 34, etc. are mounted. Note that reference numeral 36 indicates a mounting space for the encoder demodulator. In this encoder section, as the code wheel 11 rotates, the slit patterns provided on the code wheel 31 and the phase plate 33 interfere with each other, and the amount of transmitted light from the light source 32 changes. The transmitted light is received by the light receiving section 34 and photoelectrically converted, and as the code wheel 31 rotates, it finally demodulates and outputs a two-phase sine wave output with a 90° phase difference (1/4 pitch phase difference). It is formed like this. Then, this two-phase sine wave output signal is fed back to the coils 25A and 25B via a control section (not shown), etc., and a control operation is performed.

〔Effect of the invention〕

As explained above, according to the present invention, the coil lead wires 25 of the moving coils 25A, 25B
A-1 and 25B-1 are pulled out through the inside of the rotating shaft 22 of the motor, fixed to the end 22d of the rotating shaft 22 via the terminal fixing plate 26, and wound around the outer circumference of the fixing plate 26 in a spiral shape. By arranging and configuring the intermediate lead wire 27 having a spring property, the intermediate lead wire 27 absorbs repeated stress and the coil lead wires 25A-1, 25B-1
It is possible to completely eliminate repeated stress on the
Since the intermediate lead wire 27 and the repeated stress are dispersed and absorbed throughout the lead wire 27 within the elastic limit range, the fatigue strength due to oscillating rotation can be greatly improved, for example, for a billion oscillations. Sufficient durability can be obtained, and practically sufficient reliability can be obtained even when the swing angle is large. In addition, the space occupied by the coil lead wires 25A-1 and 25B-1 can be reduced, and the coil lead wires
Since 5A-1 and 25B-1 can have no influence on the rotational movement of the rotating shaft 22, it is possible to downsize the motor and stabilize the offset force around the rotating shaft 22, improving controllability. can do. Furthermore, by applying an offset force (restoring force) to the intermediate lead wire 27 in advance, the restoring force can be used to automatically move the object to be controlled to a predetermined reference position when the motor power is turned off. can be restored to.

[Brief explanation of drawings]

Figures 1a, b, and c are diagrams showing embodiments of the present invention;
Figures 2a, b, and c are views showing the terminal fixing plate 26 in Figure 1, and Figures 3a and b are views showing the intermediate lead wire 27 in Figure 1.
FIGS. 4a, b, and c are views showing the lead wire fixing case 28 of FIG. 1, and FIGS. 5a and b are views showing the collar 29 of FIG. 1. FIG. 6 is a diagram showing a conventional example. In Figures 1 to 5, 21 is a motor case;
1-1, 21-2 are magnets (permanent magnets), 2
2 is a rotating shaft (output shaft), 22b is a through hole, 22c
22d is an insertion hole, 22d is one end surface, 22-1 is a capstan, 23A, 23B are bearings, 23-2 is an outer ring support sleeve, 24 is a bobbin, 24a is a cylindrical wall, 24b is a bottom wall, 25A, 25B are moving coils, 25A-1 and 25B-1 are coil lead wires, 26 is a terminal fixing plate, 26d is an insertion hole, 27 is an intermediate lead wire, 27-1 and 27-2 are ribbon-shaped conductors, and 27a and 27b are connection terminals (inner terminals). ), 2
7c and 27d are connection terminals (outer terminals), 28 is a lead wire fixing case, 29 is a collar, 30 is an external leader wire, 31 is a code wheel of the encoder section, α
indicate the center axis of rotation, respectively.

Claims (1)

[Claims] 1. In an oscillating moving coil type motor, the rotating shaft 22 of the motor has its rotation center axis α.
A radial insertion hole 22c is provided in the hole 22b along the hole 22b and a radial insertion hole 22c is provided in the middle part of the hole 22b to communicate with the hole 22b. A predetermined space is provided in the motor case portion corresponding to the end surface 22d of the shaft 22, and the terminal fixing plate 26 fixed to the end surface 22d is positioned in this predetermined space, and the coil lead wires 25A-1, 25B of the moving coils 25A, 25B are -1 to the insertion hole 2
2c and hole 22b from the end surface 22d side of the rotating shaft 22, and penetrates through the terminal fixing plate 26 fixedly provided on the end surface 22d.
A ribbon-shaped intermediate lead wire 27 having spring properties and conductivity is wound like a clockwork around the outer periphery corresponding to the radial direction of the terminal fixing plate 26, and the intermediate lead wire 27 is fixed to the terminal fixing plate 26. The inner terminals 27a and 27b are connected and fixed to the lead wires 25A-1 and 25B-1, respectively, and the outer terminals 27c and 27d are fixed to the motor case 21 side so that they can be connected to the external lead wire 30. An oscillating moving coil motor.