JPH04236157A - Coil member and oscillating actuator - Google Patents

Abstract

PURPOSE:To obtain a small, thin and highly strong coil member and oscillating actuator excellent in electric insulation by integrally securing an arm and a moving coil through a holding member composed of thermoplastic resin having specific modulus of elasticity or higher. CONSTITUTION:An arm 5 and a moving coil 6 are secured integrally through a holding member 9 composed of thermoplastic resin having modulus of elasticity equal to or higher than 10X10<4>kg/cm<2>. A stop click 5a is projected integrally with the arm 5 and the click 5a is buried in the holding member 9. Furthermore, the arm 5, the moving coil 6, and a terminal block 11 made of heat-resistant insulating resin and planted with terminal pins 10a, 10b connected electrically with the start-of-winding and the end-of-winding of the moving coil 6 are secured integrally through the holding member 9 composed of thermoplastic resin.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to an oscillating actuator such as an actuator for a magnetic disk, and a coil member constituting this oscillating actuator. It relates to a swing type device that oscillates as if drawing a .

0002

2. Description of the Related Art Conventionally, a swinging or rotating actuator as shown in FIGS. 11 and 12 has been used to position a magnetic head on a recording track of a magnetic disk or the like. In both figures, 1 is a yoke, which is arranged facing each other and assembled by a support 3, with one yoke 1 (lower side)
A permanent magnet 2 is fixedly attached to the gap 4 to form a magnetic circuit. 5 is an arm, and a flat moving coil 6 is attached to one end.
and a magnetic head (not shown) is fixed to the other end thereof, and are rotatably disposed via a shaft 7 so that the movable coil 6 is located within the gap 4.

When a signal current is applied to the moving coil 6, a driving force around the axis 7 acts on the moving 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 at a predetermined recording track on the magnetic disk. Note that the rotation direction is switched by reversing the direction of the current flowing to the movable coil 6.

0004

[Problems to be Solved by the Invention] In the above-mentioned conventional magnetic disk actuator, the arm 5 has a movable coil 6.
Adhesives are generally used to secure them. However, the fixing work using adhesive is not only complicated and has low workability, but also has the problem of insufficient positioning accuracy of the moving coil and low reliability. Furthermore, the processing of the terminals of the moving coil 6 also requires complicated work, and there is also the problem that the workability of the entire assembly work is reduced.

[0005]Furthermore, in recent years in the field of magnetic disk drives, demands have become even more severe for devices to be smaller, thinner, more highly functional, etc., and the positioning accuracy of the moving coil 6 and the workability and reliability of the bonding work have become more demanding. There is a need to improve the above requirements, and there is a problem in that conventional structures cannot satisfy the above requirements.

Therefore, it has been proposed to integrate the movable coil 6 with the arm 5 by resin molding (for example, Japanese Patent Laid-Open No. 63-99756, Japanese Patent Laid-Open No. 1-89946).
(Refer to the publication number, etc.) With such a configuration, the structure for holding the movable coil 6 can be simplified and made considerably thinner, which is advantageous for making the entire actuator more compact.

However, the conventional resin molding structure described above has insufficient mechanical strength;
Alternatively, there is a problem that the arm 5 and the movable coil 6 are not sufficiently fixed. Another problem is that during molding, the starting and ending ends of the movable coils 6 come into contact with each other or with the arm 5, resulting in poor insulation.

The present invention solves the problems existing in the above-mentioned prior art, and is small and thin, has high strength,
Another object of the present invention is to provide a coil member with excellent electrical insulation and an oscillating actuator equipped with the coil member.

[0009]

[Means for Solving the Problems] In order to achieve the above object, in the first invention, an arm is formed by fixing a moving coil to one end and a functional member to the other end, and is arranged in a magnetic gap. For the coil member to be installed, a technical measure was adopted in which the arm and the moving coil are fixed together by a holding member made of thermoplastic resin with an elastic modulus of 10 x 104 kg/cm2 or more.

Further, in the second invention, the arm is formed by fixing a moving coil to one end and a functional member to the other end, and in the coil member disposed in the magnetic gap, the arm and the moving coil are fixed to each other. A technical measure was adopted in which the arms were fixed together by a holding member made of thermoplastic resin, and a claw was integrally provided on the arm to prevent it from coming off, and this claw was embedded in the holding member.

Furthermore, in the third invention, a permanent magnet is fixed to one side of a pair of opposing yokes, and a housing is formed by forming a magnetic gap on the surface of the permanent magnet, and a moving coil is attached to one end of the housing, and a moving coil is attached to one end of the housing. In the swing-type actuator, which is composed of a coil member formed by fixing functional members, and in which a movable coil is movably disposed within the magnetic gap, the coil member is formed by the coil member according to the first invention or the first invention. The technical means of configuring the invention as in invention No. 2 was adopted.

Furthermore, in the fourth invention, a permanent magnet is fixed to one side of a pair of opposing yokes, and a housing is formed by forming a magnetic gap on the surface of the permanent magnet, and a moving coil is attached to one end of the housing, and a moving coil is attached to one end of the housing. and a coil member formed by fixing functional members to each other, and a movable coil movably disposed within the magnetic gap. A coil and a terminal pin made of heat-resistant insulating resin and electrically connected to the starting and ending ends of the strands of the moving coil are implanted, and a partition piece is provided protruding to isolate a pair of strands near the terminal pin. A technical measure was adopted in which the terminal block and the terminal block were fixed together using a holding member made of thermoplastic resin.

[0013] In the above invention, the heat-resistant insulating resin forming the terminal block includes polyphenyline sulfide (PPS), polyamide (PA), and polyimide (P
I), polyether ether ketone (PEEK), etc. can be used, and can be appropriately selected in consideration of the characteristics of the thermoplastic resin forming the holding member.

[0014]

[Operation] With the configurations of the first to third aspects of the invention, it is possible to improve the positioning accuracy and reliability of the arm and the moving coil, and to greatly improve workability. Furthermore, the configuration of the fourth aspect of the invention prevents contact between the pair of strands constituting the starting and ending ends of the moving coil and/or contact between the strands and the arm, thereby ensuring desired electrical insulation. be able to.

[0015]

[Embodiment] FIGS. 1 and 2 are a plan view and a vertical sectional view of a main part showing a first embodiment of the present invention, respectively, and the same parts are designated by the same reference numerals as in FIGS. 11 and 12. . In both figures, the arm 5 is made of die-cast aluminum alloy, for example, and has a mounting hole 8a in the middle, a hole 8b for mounting a functional member such as a magnetic head (not shown) at one end, and a hole 8b at the other end for mounting a functional member (not shown) such as a magnetic head. A claw 5a is provided to prevent it from coming off. Next, a holding member 9 is made of thermoplastic resin and is formed so as to fix the arm 5 and the movable coil 6 together. That is, the claw 5a protruding from the arm 5 and the periphery of the movable coil 6 are formed so as to hold it, thereby forming a coil member.

Next, 6a is a terminal pin, 6b is a wire,
The terminal of the moving coil 6 is formed. The movable coil 6 is, for example, a multilayer air-core coil made by winding a self-fusing wire (an electric wire with a fusing film formed on the outermost layer of the core wire) in a predetermined shape a predetermined number of times, and then energizing this air-core coil to complete the whole process. It can be manufactured by integrating with a fusion film.

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, after inserting and positioning the arm 5, which has been die-cast in advance, and the moving coil 6, in which the terminal pin 6a is connected to the wire 6b by, for example, soldering, into an injection mold, for example, a glass-filled polyphenyline sulfide is inserted. Injecting a heated melt of thermoplastic resin such as resin,
After cooling and solidifying, it can be taken out from the mold. The arm 5 and the movable coil 6 are fixed together by the injection molding described above. In this case, the claw 5a provided on the arm 5 is embedded in the holding member 9, and therefore effectively acts as a retainer in the F direction. Furthermore, since the thickness of the holding member 9 that holds the peripheral edge of the moving coil 6 is formed to be substantially the same as the thickness of the moving coil 6, the magnetic gap can be reduced. Thrust and responsiveness can be improved.

FIG. 3 is a vertical sectional view of a main part of a moving coil 6 in a 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, and is formed in advance when the movable coil 6 is wound. By providing the groove 6c in this way, the holding member 9 (FIGS. 1 and 2)
(see) can increase the fixation effect.

FIG. 4 is an explanatory view of the main parts of a thermoplastic resin injection means in a third embodiment of the present invention, and the same parts are designated by the same reference numerals as in FIGS. 1 to 3. Figure 4
10 is a pin gate, which is provided in a molding die (not shown) in the thickness direction of the holding member 9 in order to inject the thermoplastic resin constituting the holding member 9.

[0020] With this 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 regard, in the case where the injection gate 13 is provided on the end edge 6d of the holding member 9 as shown in FIG.
Since the flow direction of the thermoplastic resin forming the holding member 9 is along the longitudinal direction of the holding member 9 as shown by the arrow, the longitudinal elastic modulus in the thickness direction cannot be increased.

[0021] The type of thermoplastic resin constituting the above-mentioned holding member 9 can be appropriately selected in consideration of the rigidity, heat resistance, etc. required of the holding member 9. In addition to the above, for example, polybutylene terephthalate resin, polyamide Known resins (preferably heat-resistant resins) such as resin, polyimide resin, polyamideimide resin, and polyester resin can be used. Among these resins, longitudinal elastic modulus (measurement method: AST
MD-638) is 10×104 kg/cm2
or more (preferably 13×104 kg/cm2 or more)
Preferably. In particular, liquid crystalline polyester resin (polyester having rigid and straight chains in the main chain) is a type of liquid crystal polymer (exhibiting liquid crystallinity in a molten state) as a thermoplastic resin.
It is preferable to use

The liquid crystalline polyester resin includes (a) a copolymer of parahydroxybenzoic acid and polyethylene terephthalate, (b) a copolymer of poly-p-hydroxybenzoate, aromatic dicarboxylic acid, and aromatic diol, (
c) There are polymers with various basic compositions such as copolymers of poly-p-hydroxybenzoate and naphthoic acid, but in terms of strength and elastic modulus, wholly aromatic ones ((b),
(c)) is preferred, and (c) is more preferred. In particular, fully aromatic polyester resin (c) has rigid molecular chains oriented in the flow direction during molding, so in addition to having a large longitudinal elastic modulus in that direction, it also has good vibration absorption properties and a low coefficient of linear expansion. It has the advantage of being small (close to metal).

When molding a liquid crystal polymer at a liquid crystal state temperature lower than the complete melting temperature, the polymer has high fluidity and is easy to mold. In particular, the longitudinal elastic modulus (tensile elastic modulus) is 16 x 104 k
It is preferable to use a liquid crystal polymer of g/cm2 or more. A specific example of such a liquid crystal polymer is Vectra A1, which is a fully aromatic thermotropic liquid crystal polyester.
30 (18 x 104) (unit: kg/cm2, same below), C130 (16 x 104), A230 (
30×104), B230(38×104),
A410 (21 x 104), A422 (18 x 10
4), C400 (17 x 104), A540 (
16×104) (Clanese Inc.), XYDAR
RC-210 (16.2×104), G-43
Examples include C(16.1×104) (all manufactured by Dartco).

Incidentally, the longitudinal elastic modulus is steel: 220×104
, Aluminum: 68×104 , Methacrylic resin:
4.2 × 104, polystyrene resin: 3.2 ~ 3
．． 6 × 104, polyphenyline sulfide resin:
Since it is 10×10 4 (all units are kg/cm 2 ), greater rigidity can be obtained than when using a general thermoplastic resin. Further, as this liquid crystal polymer, one to which filler such as glass fiber or carbon fiber is added can be used in order to improve mechanical strength, heat resistance, etc. The amount added is preferably 10 to 50% by weight, more preferably 20 to 40% by weight.

In the present invention, the thermoplastic resin has a flexural modulus (measurement method: ASTM D792) of 13×
Those with a weight of 104 kg/cm2 or more can also be used effectively. As such a resin, for example, the above-mentioned Vectra A1
30 (15 x 104) (unit: kg/cm2, same below), C130 (14 x 104), A230 (
29×1014), B230(36×104), A
410 (18 x 104), A422 (17 x 104
) , A540 (14×1014) , XYDAR
RC-210 (13.6×104), G-43C
(14.9×104), Ryton R-4 (14
×104) (Philips Oil), DIC/PPS
FZ・1140 (14×104), ASAHI・
PPS RG-40JA (14.4 x 104) (
Asahi Glass), Fortron 1140A1 (13 x 104
) (Polyplastics), GS-40 (15 x 10
4), G-10 (20 x 104), G-6 (18
×104), G-4F (14×104), FC
Examples include polyphenyline sulfide such as -5 (16×104) (all manufactured by Tosoh Sussteel).

Next, FIGS. 6 and 7 are a plan view and a vertical sectional view of a main part showing a coil member, which is the premise of the fourth embodiment of the present invention, respectively, and the same parts are shown in FIGS. 1 to 5. Indicated by the same reference numerals. In FIGS. 6 and 7, 61,
62 is a wire, 61 is a winding start end, and 62 is a winding end end. 10a and 10b are terminal pins.

For example, injection molding is effective for forming the coil member having the above structure. That is, the arm 5 is die-cast in advance, and the terminal pin 10 is attached to the wires 61 and 62.
After inserting and positioning the movable coil 6 with wires a and 10b connected by soldering into an injection mold, a heated melt of thermoplastic resin such as glass-filled polyphenyline sulfide resin is injected. After cooling and solidifying, it can be removed from the mold. The arm 5 and the movable coil 6 are fixed together by the injection molding described above. In this case arm 5
Since the claws 5a provided in are embedded in the holding member 9, they effectively act as a retainer in the F direction.

However, in the above injection molding, the pair of wires 61 and 62 and the pair of terminal pins 10a and 10b are connected and inserted into the injection mold, and the holding member 9 is inserted into the injection mold.
When a heated melt of a thermoplastic resin to be formed is injected, the flow of the heated melt may cause the strands 61 and 62 to flow and come into contact with each other, or cause the strands 61 and 62 to fall into the arm 5 and/or Otherwise, it may come into contact with the claw 5a, resulting in poor insulation. In order to prevent the wires 61, 62 from flowing or swinging as described above, it is conceivable to tension the wires 61, 62 between the moving coil 6 and the terminal pins 10a, 10b. The vicinity of the terminal pins 10a and 10b is extremely narrow, and the injection mold usually has a diameter of 200 mm.
It is difficult to perform the above operations because the temperature is heated to ~250°C.

FIGS. 8 and 9 are a partial cross-sectional enlarged plan view and an enlarged main part front view showing a fourth embodiment of the present invention, respectively, and the same parts are designated by the same reference numerals as in FIGS. 6 and 7. Indicated by In FIGS. 8 and 9, 11 is a terminal block, in which terminal pins 10a and 10b electrically connected to wires 61 and 62 of the moving coil 6 by, for example, solder are implanted. The terminal block 11 can be formed by injection molding using polyphenyline sulfide resin, for example.

FIG. 10 is a perspective view showing the terminal block 11 in FIGS. 8 and 9, and the same parts are designated by the same reference numerals as in FIGS. 8 and 9. In FIG. 10, the terminal block 11 is made of the above-mentioned material, and has an L-shaped longitudinal section, for example, and has a partition piece 11b integrally provided between the top plate 11a and the terminal pin 10b. Therefore, terminal pin 10
In the vicinity of a and 10b, the pair of wires 61 and 62 are separated by the partition piece 11b, thereby ensuring an electrically insulated state.

With the above structure, injection molding means similar to those shown in FIGS. 6 and 7 is effective as a means for fixing the arm 5, movable coil 6, and terminal block 11 together. In this case, as a means for positioning the terminal block 11 within the injection mold, positioning pins 12 that are in contact with three sides of the terminal block 11 can be used as shown in FIG. That is, the positioning pins 12 may be implanted in the injection mold in advance, and the terminal block 11 may be inserted.

In this case, the outline of the positioning pin 12 is formed as a slight recess on the surface of the holding member 9, and the protrusion dimension of the positioning pin 12 into the cavity of the mold is, for example, 0.8 to 1. Since it is 0 mm, the strength and other functions of the holding member 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 isolated by the partition piece 11b provided on the terminal block 11, and the wires 61 and 62 are separated from each other by the terminal block 11. 5 and/or the claw 5a.

In this embodiment, an example was described in which a pair of terminal pins were formed to the same depth into the holding member, but for example, if the terminal pin on the side closer to the moving coil was inserted into the holding member The immersion depth may be reduced. In this way, the contact between the pair of wires can be made more reliable.

In the above embodiments, an actuator for a magnetic head has been described, but the function is the same even if the functional member to be provided at one end of the arm is not only a magnetic head but also an optical head or something else. It should be noted that the coil member is not limited to the structure shown in FIG. 12, but it is also possible to use it by interposing it in the magnetic gap formed by fixing the permanent magnets 2 to the inner surfaces of the opposing yokes 1. be.

[0035]

[Effects of the Invention] Since the present invention has the structure and operation as described above, the following effects can be expected. (1) Positioning accuracy and fixing reliability between the moving coil and the arm are greatly improved. (2) Since terminal processing of the moving coil can be performed at the same time,
Manufacturing and assembly costs can be reduced. (3) In relation to (1) and (2) above, each component can be made smaller, thinner, and lighter, and the responsiveness of the actuator can be improved. (4) It is possible to completely prevent contact between the strands of the moving coil at the starting end of the strands and/or in the vicinity thereof, as well as contact between the strands and the arm, thereby significantly improving electrical insulation.

[Brief explanation of the drawing]

FIG. 1 is a plan view of essential parts showing a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of a main part showing a first embodiment of the present invention.

FIG. 3 is a vertical sectional view of a main part of a moving coil in a second embodiment of the present invention.

FIG. 4 is an explanatory diagram of a main part of a thermoplastic resin injection means in a third embodiment of the present invention.

FIG. 5 is an explanatory diagram of a main part of a thermoplastic resin injection means in a third embodiment of the present invention.

FIG. 6 is a plan view of a main part showing a coil member, which is the premise of a fourth embodiment of the present invention.

FIG. 7 is a longitudinal cross-sectional view of a main part showing a coil member, which is the premise of a fourth embodiment of the present invention.

FIG. 8 is a partially cross-sectional enlarged plan view of essential parts showing a fourth embodiment of the present invention.

FIG. 9 is an enlarged front view of main parts showing a fourth embodiment of the present invention.

10 is a perspective view showing the terminal block in FIGS. 8 and 9. FIG.

FIG. 11 is a partially exploded, partially sectional plan view showing an example of a conventional swing-type actuator.

12 is a view taken along arrow A in FIG. 11. FIG.

[Explanation of symbols]

1 York 2. Permanent magnet 5 Arm 5a Claw 6. Moving coil 61,62 Element wire 9 Holding member 10a, 10b Terminal pin 11 Terminal block 11b Partition piece

Claims (4)

[Claims] Claim 1: An arm formed by fixing a movable coil at one end and a functional member at the other end, and in a coil member disposed in a magnetic gap, the arm and the movable coil have an elastic modulus of 10×104. A coil member characterized in that it is fixed together with a holding member made of a thermoplastic resin of kg/cm2 or more. Claim 2: An arm formed by fixing a moving coil to one end and a functional member fixed to the other end, and in a coil member disposed within a magnetic gap, the arm and the moving coil are made of thermoplastic resin. 1. A coil member which is fixed together by a holding member, and has a claw integrally protruding from the arm to prevent the arm from coming off, and the claw is embedded in the holding member. [Claim 3] A permanent magnet is fixed to one side of a pair of opposing yokes, and a housing is formed by forming a magnetic gap on the surface of the permanent magnet, a moving coil is fixed to one end, and a functional member is fixed to the other end. A swing-type actuator comprising a coil member formed of A swing type actuator characterized by: 4. A permanent magnet is fixed to one side of a pair of opposing yokes, and a housing is formed by forming a magnetic gap on the surface of the permanent magnet, a moving coil is fixed to one end, and a functional member is fixed to the other end. In the swing type actuator, the arm forming the coil member, the moving coil, and a heat-resistant insulating A terminal block made of resin, in which terminal pins electrically connected to the starting and ending ends of the wires of the moving coil are implanted, and a partition piece protruding to isolate a pair of wires near the terminal pins is heated. A swing type actuator characterized in that it is fixed integrally with a holding member made of plastic resin.