JPH0734638B2 - Oscillating actuator - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oscillating actuator such as an actuator for a magnetic disk, and in particular, a functional member such as a magnetic head oscillates so as to draw an arc locus. The present invention relates to a swinging type (swinging type) actuator that moves.

[Conventional technology]

Conventionally, an oscillating or rotary actuator as shown in FIGS. 9 and 10 has been used to position the magnetic head on a recording track of a magnetic disk or the like. In both figures, a permanent magnet 2 is fixed to a yoke 1, and the magnets are arranged opposite to each other with different polarities, assembled by columns 3, and a magnetic circuit is formed via a gap 4. Reference numeral 5 denotes an arm. A flat type movable coil 6 is fixed to one end and a magnetic head (not shown) is fixed to the other end, and a shaft 7 is provided so that the movable coil 6 is located in the space 4. It is arranged so that it can rotate and swing freely. When a signal current is applied to the movable coil 6, a driving force around the shaft 7 acts on the movable coil 6 according to Fleming's left-hand rule, causing the arm 5 to rotate and swing,
The magnetic head fixed to the arm 5 is positioned on a predetermined recording track on the magnetic disk. The rotation direction is switched by reversing the direction of the current flowing through the coil.

[Problems to be Solved by the Invention]

In the conventional magnetic disk actuator described above, when the movable coil 6 is fixed to the arm 5, an adhesive is generally used. However, the fixing work using an adhesive is not only complicated and low in workability, but also has insufficient positioning accuracy of the movable coil, which results in low reliability. Further, the processing of the terminal of the movable coil 6 also requires a complicated work, and there is a problem that the workability of the whole assembling work is deteriorated. Further, in the recent field of magnetic disk devices, demands for smaller size, thinner thickness, higher functionality, etc. of the device have become more severe, and the positioning accuracy of the movable coil 6 and the workability and reliability in the bonding work have been improved. However, the conventional structure cannot meet the above requirements.

Therefore, the movable coil 6 is molded with resin to form the arm 5
Has been proposed (for example, Japanese Patent Laid-Open No. 63-
99756, JP-A-1-89946, etc.). With such a configuration, the structure for holding the movable coil 6 can be simplified and can be made considerably thin, which is advantageous for downsizing the entire actuator.

However, the conventional resin mold structure has a problem that mechanical strength is insufficient or that the arm 5 and the movable coil 6 are not firmly fixed to each other. In addition, there is a problem in that, during molding, the starting end and the terminating end of the movable coil 6 are likely to come into contact with each other or with the arm 5 to cause insulation failure.

The present invention solves the above-mentioned problems existing in the prior art, and is a small-sized and thin oscillating actuator having a high-strength coil-arm molded body, or a coil-arm with improved electrical insulation. An object is to provide an oscillating actuator having a molded body.

[Means for Solving the Problems]

In order to achieve the above object, in the first invention, a yoke is fixed to one side of permanent magnets having different polarities, and the two yokes are formed to face each other with a magnetic gap between the permanent magnets. And a movable coil at one end and a functional member fixed at the other end, respectively, and an arm swingably formed, and the movable coil is movably disposed in the magnetic gap. In the actuator, the arm and the moving coil are integrally fixed by a holding member made of a liquid crystal polymer having an elastic modulus of 10 × 10 ⁴ kg / cm ² or more, and the thickness of the holding member that holds the peripheral edge of the moving coil is fixed. We adopted the technical means of forming the moving coil substantially the same as its thickness.

Next, in the second invention, a yoke is fixed to one side of permanent magnets having different polarities, and a housing formed by facing the two yokes with a magnetic gap between the two yokes and a housing formed at one end. In an oscillating actuator composed of an arm formed by oscillating a movable coil with a functional member fixed to the other end, the oscillating actuator constituted by movably disposing the movable coil in the magnetic gap is movable with the arm. The coil and the coil are integrally fixed by a holding member made of thermoplastic resin, and the thickness of the holding member that holds the peripheral edge of the moving coil is formed to be substantially the same as the thickness of the moving coil. A technical means was adopted in which a locking claw was integrally projected and the claw was embedded in the holding member.

Further, in the third invention, a yoke is fixed to one side of the permanent magnets having different polarities, and a housing formed by facing the two yokes with a magnetic gap between the permanent magnets and a movable end. In the swing-type actuator, which is composed of an arm formed by swinging a coil with a functional member fixed to the other end, a movable coil is movably arranged in the magnetic gap, A terminal pin, which is made of a coil and a heat-resistant insulating resin and is electrically connected to the starting and ending ends of the wire of the movable coil, is planted, and a partition for separating a pair of wires near the terminal pin is projected. We adopted the technical means of integrally fixing the terminal block and the terminal block with a holding member made of thermoplastic resin.

In the above invention, polyphenylene sulfide (PP) is used as the heat-resistant insulating resin forming the terminal block.
Although S), polyamide (PA), polyimide (PI), polyetheretherketone (PEEK), etc. can be used, they can be appropriately selected in consideration of the characteristics of the thermoplastic resin forming the holding member.

[Work]

With the configurations of the first and second aspects of the invention, the positioning accuracy and reliability of the arm and the movable coil can be improved, and the workability can be greatly improved.

Further, according to the third aspect of the invention, contact between a pair of wires and / or contact between the wires and the arm that form the start and end of the moving coil is prevented, and desired electrical insulation is secured. be able to.

〔Example〕

FIG. 1 and FIG. 2 are a plan view and a longitudinal sectional view of an essential part showing a first embodiment of the present invention, respectively, and the same parts are designated by the same reference numerals as those in FIG. 9 and FIG. . In both figures, the arm 5 is formed by, for example, aluminum alloy die casting, a mounting hole 8a is formed in the middle portion, and a hole 8b for mounting a functional member (not shown) such as a magnetic head is formed at one end.
And a retaining claw 5a at the other end. Next, a holding member 9 is made of a thermoplastic resin, and is formed so that the arm 5 and the movable coil 6 are integrally fixed. That is, the claw 5a protruding from the arm 5 and the periphery of the movable coil 6 are formed so as to be held. Further, the thickness dimension of the holding member 9 that holds the peripheral portion of the movable coil 6 and the thickness dimension of the movable coil 6 are formed to be substantially the same. 6a is a terminal pin and 6b is a wire, which forms the end of the moving coil 6. The movable coil 6 is, for example, a self-bonding electric wire (an electric wire having a fusion coating formed on the outermost layer of the core wire) is wound into a predetermined shape by a predetermined number to form a multilayer air-core coil, and the air-core coil is energized to It can be manufactured by integrating with a fusion coating.

As a means for integrally fixing the arm 5 and the movable coil 6 as described above, for example, injection molding means is effective. That is, the arm 5 pre-die-casted and the terminal pin on the wire 6b.
The movable coil 6 which has been wire-bonded to 6a by, for example, soldering is inserted into an injection molding die and positioned, and then a heated melt of a thermoplastic resin such as glass-filled polyphenylene sulfide resin is injected, It can be taken out from the mold after solidification by cooling. The arm 5 and the movable coil 6 are integrally fixed by the injection molding. In this case, since the claw 5a provided on the arm 5 is embedded in the holding member 9, it effectively acts as a retaining member in the F direction.

FIG. 3 is a longitudinal sectional view of a main part of the movable coil 6 according to the second embodiment of the present invention. In FIG. 3, 6c is a groove for preventing the movable coil 6 from coming off in the thickness direction, which is formed in advance when the movable coil 6 is wound. By providing the groove 6c in this way, the fixing action by the holding member 9 (see FIGS. 1 and 2) can be increased.

FIG. 4 is an explanatory view of a main part of a thermoplastic resin injecting means in a third embodiment of the present invention, and the same portions are denoted by the same reference numerals as those in FIGS. 1 to 3. In FIG. 4, 10 is a pin gate, which is provided in the thickness direction of the holding member 9 in a molding die (not shown) for injecting the thermoplastic resin forming the holding member 9.

With such a configuration, the molecular chains are oriented in the flow direction of the thermoplastic resin (thickness direction of the holding member 9), so that the longitudinal elastic modulus in this direction becomes large and the rigidity can be improved.
In this respect, as shown in FIG. 5, in the case where the holding gate 9 is provided with the injection gate 13 at the end edge portion 6d, the flow direction of the thermoplastic resin for forming the holding member 9 is as shown by an arrow. Since the holding member 9 extends along the longitudinal direction, the longitudinal elastic modulus in the thickness direction cannot be increased.

The kind of the thermoplastic resin forming the holding member 9 can be appropriately selected in consideration of the rigidity, heat resistance and the like required for the holding member 9. A known resin (preferably a heat-resistant resin) such as a resin, a polyamide-imide resin or a polyester resin can be used. Among these resins, the longitudinal elastic modulus (measurement method: ASTM D-638) is 10
Those having a density of 10 ⁴ kg / cm ² or more (preferably 13 10 ⁴ kg / cm ² or more) are preferable. In particular, it is preferable to use, as the thermoplastic resin, a liquid crystalline polyester resin (polyester having a rigid straight chain in the main chain) which is a kind of liquid crystal polymer (which exhibits liquid crystallinity in a molten state).

The liquid crystalline polyester resin includes (a) a copolymer of parahydroxybenzoic acid and polyethylene terephthalate,
(B) a copolymer of poly-p-hydroxybenzoate, an aromatic dicarboxylic acid and an aromatic diol, (c) poly-p
There are various basic compositions such as copolymers of hydroxybenzoate and naphthoic acid, but wholly aromatic ones ((b), (c)) are preferable in view of strength and elastic modulus, and (c Those of () are more preferable. Particularly in (c), the wholly aromatic polyester resin has a large longitudinal elastic modulus in that direction because the rigid molecular chains are oriented in the flow direction during molding, and also has good vibration absorption characteristics and a linear expansion coefficient. It has the advantage of being small (close to metal). If the liquid crystal polymer is molded at a liquid crystal state temperature lower than the complete melting temperature, it has high fluidity and is easy to mold. Especially the longitudinal elastic modulus (tensile elastic modulus) is 16 × 10
^{It is} recommended to use a liquid crystal polymer of ⁴ kg / cm ² or more. Specific examples of such a liquid crystal polymer include Vectra A130 (18) which is a wholly aromatic thermotropic liquid crystalline polyester.
× 10 ⁴ ) (Unit is kg / cm ² , the same applies below), C130 (16 × 10 ⁴ ), A
230 (30 × 10 ⁴ ), B230 (38 × 10 ⁴ ), A410 (21 × 10 ⁴ ), A42
2 (18 × 10 ⁴ ), C400 (17 × 10 ⁴ ), A540 (16 × 10 ⁴ ) (above Celanese), XYDAR RC-210 (16.2 × 10 ⁴ ), G-43C
(16.1 × 10 ⁴ ) (above Dartco) and the like.
By the way, the longitudinal elastic modulus is steel: 220 × 10 ⁴ , aluminum: 68 × 10 ⁴ ,
Methacrylic resin: 4.2 × 10 ⁴ , polystyrene resin: 3.2 to 3.
6 × 10 ⁴ and polyphenylene sulfide resin: 10 × 10 ⁴ (both units are kg / cm ² ), so greater rigidity can be obtained than when using a general thermoplastic resin. Further, as the liquid crystal polymer, in order to improve mechanical strength, heat resistance and the like, a material to which a filler such as glass fiber or carbon fiber is added can be used. Addition amount is 10 to 50
Weight% is desirable, and more preferably 20 to 40 weight%.

In the present invention, the thermoplastic resin having a flexural modulus (measurement method: ASTM D-792) of 13 × 10 ⁴ kg / cm ² or more can be effectively used. Examples of such resins include the aforementioned Vectra A130 (15 × 10 ⁴ ) (unit is kg / cm ² , the same applies below), C130 (14 × 10 ⁴ ), A230 (29 × 10 ¹⁴ ), B230 (36 × Ten
⁴ ), A410 (18 × 10 ⁴ ), A422 (17 × 10 ⁴ ), A540 (14 × 1
0 ¹⁴ ), XYDAR RC-210 (13.6 × 10 ⁴ ), G-43C (14.9 × 10
⁴ ) Others, Ryton R-4 (14 × 10 ⁴ ) (Phillips Oil), DIC / PPS FZ.1140 (14 × 10 ⁴ ), ASAHI / PPS RG−
40JA (14.4 x 10 ⁴ ) (Asahi Glass), Fortron 1140A1 (1
3 x 10 ⁴ ) (Polyplastics), GS-40 (15 x 10 ⁴ ), G
-10 (20 × 10 ⁴ ), G-6 (18 × 10 ⁴ ), G-4F (14 × 10 ⁴ ),
Examples include polyphenylene sulfide such as FC-5 (16 × 10 ⁴ ) (above Tosoh Sustil).

Next, FIGS. 6 (a) and 6 (b) are a plan view and a longitudinal sectional view of an essential part showing an oscillating actuator which is the premise of the fourth embodiment of the present invention, and the same parts are the same as those in FIG. Through fifth
The same reference numerals as in the figure are used. In FIGS. 6 (a) and 6 (b), 61 and 62 are strands, 61 is a winding start end, and 62 is a winding end end. 10a and 10b are terminal pins.

Injection molding means, for example, is effective for forming the oscillating actuator having the above structure. That is, the arm 5 die-cast in advance and the movable coil 6 in which the terminal pins 10a and 10b are connected to the wires 61 and 62 by soldering are inserted into the injection molding die and positioned. It suffices to inject a heated melt of a thermoplastic resin such as phenylene sulfide resin, cool and solidify it, and then remove it from the mold. The arm 5 and the movable coil 6 are integrally fixed by the injection molding. In this case, since the claw 5a provided on the arm 5 is embedded in the holding member 9, it effectively acts as a retaining member in the F direction.

However, in the above injection molding, a pair of wires 61, 62
And a pair of terminal pins 10a and 10b are connected to each other and inserted into a mold for injection molding, and when a heating melt of a thermoplastic resin that constitutes the holding member 9 is injected, this heating melt The wires 61 and 62 may flow and contact each other, or the wires 61 and 62 may contact the arm 5 and / or the claw 5a to cause insulation failure. In addition, the above-mentioned strand 6
In order to prevent the flow or swing of 1,62, the wires 61,62
It may be possible to tension the movable coil 6 and the terminal pins 10a and 10b by tension, but the vicinity of the terminal pins 10a and 10b is extremely narrow, and the injection molding die is usually 200-250.
It is difficult to perform the above work because it is heated to ℃.

FIGS. 7 (a) and 7 (b) are an enlarged plan view and an enlarged front view of an essential part of a partial cross section showing a fourth embodiment of the present invention, and the same parts are shown in FIGS. 6 (a) and 6 (b). And one reference numeral. In FIGS. 7 (a) and 7 (b), 11 is a terminal block in which terminal pins 10a, 10b electrically connected to the wires 61, 62 of the movable coil 6 by, for example, soldering are implanted. The terminal block 11 can be formed by injection molding using, for example, polyphenylene sulfide resin.

FIG. 8 is a perspective view showing the terminal block 11 in FIGS. 7 (a) and 7 (b), and the same portions are designated by the same reference numerals as those in FIGS. 7 (a) and 7 (b). In FIG. 8, the terminal block 11 is made of the above-mentioned material and has, for example, an L-shaped longitudinal section, and a partition 11b is integrally projected between the top plate 11a and the terminal pin 10b. Therefore, near the terminal pins 10a and 10b,
The pair of wires 61, 62 are isolated by the partition 11b, and an electrical insulation state can be secured.

With the above structure, as the means for integrally fixing the arm 5, the movable coil 6 and the terminal block 11, the injection molding means similar to those shown in FIGS. 6 (a) and 6 (b) is effective. In this case, as a means for positioning the terminal block 11 in the injection molding die, a positioning pin 12 which is in contact with the three sides of the terminal block 11 can be used as shown in FIG. 7 (a). That is, the positioning pin 12 may be previously implanted in the injection molding die and the terminal block 11 may be inserted. In this case, the contour of the positioning pin 12 is formed as a slight recess on the surface of the holding member 9. However, since the protruding dimension of the positioning pin 12 into the cavity of the mold is, for example, 0.8 to 1.0 mm, the holding member is The strength and other functions of 9 are not affected at all. By using the terminal block 11, the wires 61 and 62 near the terminal pins 10a and 10b are completely separated by the partition 11b provided on the terminal block 11, and the wires 61 and 62 are armed by the terminal block 11. 5
And / or contact with the claw 5a can be prevented.

In the present embodiment, an example is described in which the depth of immersion of the pair of terminal pins into the holding member is formed to have the same size. For example, the immersion of the terminal pin on the side closer to the moving coil into the holding member is described. The depth may be small. In this way, the contact action between the pair of strands can be made more reliable.

In the above embodiments, the actuator for the magnetic head has been described, but the functional member to be provided at one end of the arm is not limited to the magnetic head, but the optical head and other functional members have the same operation.

〔The invention's effect〕

Since the present invention has the configuration and operation as described above,
The following effects can be expected.

(1) The positioning accuracy and the fixing reliability of the movable coil and the arm are significantly improved.

(2) Since the terminal processing of the moving coil can be performed at the same time,
Manufacturing and assembly costs can be reduced.

(3) In connection with the above (1) and (2), each component can be made smaller, thinner and lighter, and the responsiveness as an actuator can be improved.

(4) It is possible to completely prevent the mutual contact between the strands of the movable coil and / or the vicinity thereof and the contact between the strand and the arm, and to significantly improve the electrical insulation.

(5) By forming the thickness dimension of the holding member at the peripheral portion of the moving coil to be substantially the same as the thickness dimension of the moving coil, it is possible to form a small magnetic gap and improve thrust and responsiveness. Can be done.

[Brief description of drawings]

1 and 2 are respectively a plan view and a longitudinal sectional view of a main part showing a first embodiment of the present invention, and FIG. 3 is a longitudinal sectional view of a main part of a movable coil in a second embodiment of the present invention. FIG. 4 and FIG. 5 are explanatory views of the principal part of the thermoplastic resin injecting means in the third embodiment of the present invention, and FIGS. 6 (a) and 6 (b).
Is a plan view and a longitudinal sectional view of an essential part showing an oscillating type actuator which is the premise of the fourth embodiment of the present invention. FIGS. 7 (a) and 7 (b) are respectively the fourth embodiment of the present invention. FIG. 8 is a perspective view showing the terminal block in FIGS. 7A and 7B, and FIG.
FIG. 10 is a plan view of a partially crushed and partially cross-sectional view showing an example of a conventional rocking type actuator, and FIG. 10 is a view as seen from an arrow A in FIG. 1: Yoke, 2: Permanent magnet, 5: Arm, 5a: Claw, 6: Moving coil, 6
1,62: strands, 9: holding member, 10a, 10b: terminal pin, 11: terminal block, 11b: partition.

Claims (3)

[Claims] 1. A housing formed by fixing a yoke to one side of permanent magnets having different polarities, the two yokes being opposed to each other with a magnetic gap between them, and a movable coil at one end. In an oscillating actuator composed of an arm formed by oscillating and having functional members fixed to each end, and movably arranging the movable coil in the magnetic gap, the arm and the movable coil are elastic. The holding member made of liquid crystal polymer with a rate of 10 × 10 ⁴ kg / cm ² or more is integrally fixed, and the thickness of the holding member that holds the periphery of the moving coil is substantially the same as the thickness of the moving coil. An oscillating actuator characterized by being formed identically. 2. A housing in which a yoke is fixed to one side of permanent magnets having different polarities, and the two yokes are opposed to each other with a magnetic gap between them, and a movable coil is provided at one end. In an oscillating actuator composed of an arm formed by oscillating and having functional members fixed to each end, and movably arranging the movable coil in the magnetic gap, the arm and the movable coil are elastic. The holding member made of thermoplastic resin with a rate of 10 × 10 ⁴ kg / cm ² or more is integrally fixed, and the thickness of the holding member that holds the peripheral edge of the moving coil is substantially the same as the thickness of the moving coil. An oscillating actuator characterized in that the same shape is formed on the arm, a retaining hook is integrally provided on the arm, and the retaining hook is embedded in the retaining member. 3. A housing in which a yoke is fixed to one side of permanent magnets having different polarities, and the two yokes are opposed to each other with a magnetic gap between them, and a movable coil is provided at one end. An oscillating actuator comprising an arm formed by oscillating and having functional members fixed to each end thereof, the oscillating actuator being movably arranged in the magnetic gap, the arm, the oscillating coil, and A terminal made of a heat-resistant insulating resin, in which terminal pins electrically connected to the starting and ending ends of the wire of the movable coil are planted, and a partition for projecting a pair of wires near the terminal pin is projected. An oscillating actuator characterized in that the block and the block are integrally fixed by a holding member made of a thermoplastic resin.