JP2008210463A - Hard disk carriage, its manufacturing method, and hard disk drive - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method which can manufacture a high quality disk carriage even if eliminating an anneal step indispensable before after injection molding. <P>SOLUTION: This manufacturing method puts the coil in the metal mold cavity to regulate its outside, fills a crystalline resin inside the coil to mold, and obtains a primary mold consisting of the coil and the crystalline resin filled in it. Then, it puts this primary mold in the cavity of a metal mold for molding a carriage, fills a crystalline resin to mold a secondary mold at a temperature higher than the crystallizing temperature of this resin, and obtains a hard disk drive carriage. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a hard disk carriage in which components are integrally formed by an insert injection molding method, a manufacturing method thereof, and a hard disk device using the same.

  The hard disk carriage is an arm portion that rotates on the hard disk in the hard disk device. This carriage has an arm that is pivotally supported and a driving coil fixed at a predetermined position of the rear end portion thereof, and a magnetic field formed by a permanent magnet is formed in the vicinity of the coil. The arm is rotated by appropriately energizing the coil through a terminal. A magnetic head for reading and writing magnetic recording information to and from the hard disk is attached to the tip of the arm in the vicinity of the hard disk surface.

  Conventionally, in a hard disk carriage, an insert part such as a coil is placed in a cavity of a molding die and insert injection molding is performed using a crystalline resin such as polyphenylene sulfide (PPS). It is manufactured as an integrally molded resin molded product.

As a prior art considered to be related to the present invention, for example, there are techniques disclosed in Patent Documents 1 to 3.
In Patent Document 1, protrusions that protrude from one surface of the swing arm are formed along the base end side fitting holes of a plurality of swing arms, and the protrusion ends of these protrusions are drawn narrower than the base end side. The plurality of swing arms are stacked by a predetermined interval by fitting the protrusions to each other, and the plurality of swing arms are squeezed to spread the protrusions fitted to each other from the inner peripheral side. Forming a plurality of swing arm units and a drive coil portion for pivotally driving the units, and a mold portion that is positioned on an inner periphery of the projecting portion of the mold portion. A method of manufacturing a hard disk arm is disclosed in which molding is performed so that a bearing hole into which a bearing for a pivot center axis of the arm can be mounted is formed. .
In Patent Document 2, a predetermined length is shaped from the cut end of an insulated wire, and a resin is injection-molded over a predetermined length on an insulating coating excluding the cut end of the shaped portion to obtain a primary injection molded body. At the same time, an annular protrusion is simultaneously formed on the outer peripheral surface of the primary injection molded body, and a resin is injection molded on the outer periphery including the annular protrusion of the primary injection molded body to form a secondary injection molded body. The lead of the temperature sensor is directly connected to the two core wires exposed at the cut end of the insulated wire, and then the entire periphery of the temperature sensor including the end of the molded portion and the insulation coating of the insulated wire is coated with resin. A method of manufacturing an electric wire insert injection-molded product characterized by sealing and sealing is disclosed.
Patent Document 3 discloses a two-stage molded product comprising a primary molded portion and a secondary molded portion made of polyamide resin, and the polyamide resin of the primary molded portion and / or the secondary molded portion is a polyamide 12 resin. A polyamide resin two-stage molded product comprising 100 parts by mass and 10 to 235 parts by mass of a polyamide 12/6 copolymer is disclosed.
Japanese Patent Laid-Open No. 2001-14822 Japanese Patent Laid-Open No. 6-304962 Japanese Patent Publication No. 6-10265

  In the prior art, a coil is placed in a cavity of a mold, and a crystalline resin such as polyphenylene sulfide (hereinafter abbreviated as PPS resin) is used to abbreviate it as insert injection molding (hereinafter referred to as injection molding or molding). ), After the injection molding was carried out by setting the mold temperature lower than about 140 ° C., which is the crystallization temperature of this resin (At this point, the PPS resin is rapidly cooled, so that it is completely crystallized. However, the PPS resin was crystallized by removing the molded product from the mold and annealing at a temperature equal to or higher than the crystallization temperature. For this reason, there was a problem that the manufacturing process was complicated and the manufacturing cost increased.

  In order to simplify the manufacturing process, in order to reduce the annealing process, if the mold temperature is raised above the crystallization temperature of the PPS resin and injection molding is performed, the resin that bundles the coils softens due to the high temperature. However, there is a problem that it deforms due to the resin pressure.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a manufacturing method capable of manufacturing a high-quality hard disk carriage even if the annealing process after injection molding, which is essential in the conventional method, is omitted.

  In order to achieve the above object, the present invention performs molding by filling a coil with a crystalline resin in a state where the coil is placed in the cavity of the mold and the outside of the coil is regulated by the mold. A primary molded product composed of a primary molded part made of a crystalline resin filled inside is produced, and then the primary molded product is placed in a cavity of a carriage molding die and filled with a crystalline resin. A hard disk carriage manufacturing method is provided, wherein the hard disk carriage is manufactured by secondary molding at a mold temperature equal to or higher than the crystallization temperature of the crystalline resin.

  In the method of manufacturing the carriage for hard disk, when forming the primary molded product by filling the coil inner portion with the crystalline resin and performing molding, the molding is performed at a mold temperature equal to or higher than the crystallization temperature of the crystalline resin. In addition, it is preferable to perform secondary molding at a mold temperature equal to or higher than the crystallization temperature for portions other than the primary formed product.

  The present invention also provides a hard disk in which a core is placed inside a coil, placed in a cavity of a carriage molding die, filled with a crystalline resin, and molded at a temperature equal to or higher than the crystallization temperature of the crystalline resin. A method of manufacturing a carriage for a hard disk is provided.

  In the method for manufacturing a carriage for a hard disk of the present invention, the coil may be formed by bundling conductive wires with a thermoplastic resin, and the thermoplastic resin may have a softening temperature lower than the crystallization temperature of the crystalline resin.

  The present invention also provides a hard disk carriage manufactured by the above-described method for manufacturing a hard disk carriage according to the present invention.

  The present invention also provides a hard disk carriage in which a coil is integrally formed at a predetermined position of an arm, and a primary molding portion made of a crystalline resin is provided inside the coil. .

  The present invention also provides a hard disk drive having the hard disk carriage according to the present invention described above.

  According to the present invention, a high-quality hard disk carriage can be manufactured and the manufacturing process can be simplified even if the annealing process after injection molding, which is essential in the conventional method, is omitted, thereby reducing the manufacturing cost of the hard disk carriage. it can.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a plan view for explaining an embodiment of a method of manufacturing a hard disk carriage according to the present invention. A primary molded product 3 shown in FIG. The portion 2 is provided. Reference numeral 4 in the figure denotes terminals of the coil 1 corresponding to the winding start end and the winding end end.

  The hard disk carriage manufacturing method of the present embodiment performs molding by filling the inside portion of the coil 1 with a crystalline resin in a state where the coil 1 is placed in the cavity of the mold and the outside of the coil 1 is regulated by the mold. A primary molded product 3 comprising a coil 1 and a primary molded part 2 made of a crystalline resin filled inside is produced, and then the primary molded product 3 is placed in a cavity of a carriage molding die. The hard disk carriage is manufactured by filling the crystalline resin and performing secondary molding at a temperature equal to or higher than the crystallization temperature of the crystalline resin.

  The coil 1 can be appropriately selected and used as a coil for a hard disk carriage from a conventionally known structure and size, and in particular, a self-bonding wire in which a conductive wire is bundled using a thermoplastic resin is used. preferable. This is prepared by winding and bundling while the coating resin is uncured and then heating and integrating. As this thermoplastic resin, polyamide resin, polyvinyl butyral resin, polyester resin, or the like can be used.

  The crystalline resin used in the primary molding part 2 and the secondary molding part includes PPS resin, polybutylene terephthalate (PBT) resin, liquid crystal polymer, polyethylene terephthalate (PET) resin, polyacetal (POM) resin, crystalline polyamide Resin, polyetheretherketone (PEEK) and the like. The resin used in the primary molded part 2 and the secondary molded part may be the same or different.

  FIG. 3 is a cross-sectional view showing an example of a process for producing the primary molded product 3. In this example, the mold 8 having a cavity in which the outer periphery of the coil 1 is just fitted is used, the coil 1 is fitted in the cavity of the mold 8, and the crystalline resin melted in the inner portion of the coil 2. Is molded by injection, and then the primary molded product 3 is taken out to produce the primary molded product 3 shown in FIG.

  In the primary molding process using the mold 8, when the crystalline resin is filled in the inner portion of the coil 1, the outer shape of the coil 1 is in contact with the mold 8 and the shape is maintained. Even if the bundled thermoplastic resin is softened, the coil 1 will not be deformed by the pressure of the crystalline resin filled in the inner part of the coil 1, and the inner part will remain crystalline while maintaining the original coil shape. A primary molded product 3 filled with a primary molded portion 2 made of resin can be produced.

  Next, the primary molded product 3 including the above-described coil 1 is set in a cavity of a hard disk carriage molding mold (not shown), and another accessory is set as necessary. Is closed and a crystalline resin is press-fitted into the cavity for secondary molding, and then the molded product is taken out of the mold to produce a hard disk carriage.

  In this secondary molding, since the coil 1 has the primary molding portion 2 on the inner side, the coil 1 is deformed by the resin pressure when the crystalline resin is pressed into the outer side of the coil 1. The secondary molded portion is formed outside the coil 1 while the original coil shape is maintained, and a hard disk carriage can be obtained.

  In the method for manufacturing a hard disk carriage of this embodiment, a primary molded product 3 in which a primary molded part 2 made of a crystalline resin is previously filled in an inner part of a coil 1 is placed in a mold for manufacturing a hard disk carriage. Since the hard disk carriage is manufactured by performing the secondary molding in which the crystalline resin is injection-molded, the coil 1 is not deformed even if the mold temperature is higher than the crystallization temperature of the crystalline resin during the secondary molding. Subsequent molding can be performed to produce a hard disk carriage. Therefore, according to the present embodiment, the annealing process after injection molding of the hard disk carriage, which is essential in the conventional manufacturing method, can be reduced, the manufacturing process of the hard disk carriage can be simplified, and the manufacturing cost can be reduced. be able to.

In addition, embodiment mentioned above is an example of this invention, and this invention is not limited only to the said embodiment, A various change and correction are possible.
For example, instead of the configuration in which the inner portion of the coil 1 is filled with the primary molding portion 2 made of a crystalline resin, the core is placed in the coil and placed in the cavity of the carriage molding die. A hard disk carriage can be manufactured by filling a crystalline resin and molding at a temperature higher than the crystallization temperature of the crystalline resin.

[Comparative example]
FIG. 4 is a schematic view showing a conventional coil setting method for a mold.
In the prior art, the wound coil 11 is set in accordance with the positioning pin 12 of the mold, so that it is weak against the resin pressure from the lateral direction (indicated by an arrow in FIG. 4) and is heated in a high-temperature mold. As a result, the thermoplastic resin bundled with the coil was softened, and the coil 11 was deformed. Therefore, molding cannot be performed with a mold having a crystallization temperature (about 140 ° C.) or higher of the PPS resin, and the annealing process for heating the molded product to a temperature higher than the crystallization temperature after molding at a low temperature cannot be reduced. It was.

[Example]
In the manufacturing method of the present invention, as shown in FIG. 1, primary molding is performed by previously filling a crystalline resin along the shape inside the coil 1 and performing primary molding, and the primary molding portion and the coil 1 are combined. By producing the product, even if it was set in a 140 ° C. mold in the subsequent main molding, no deformation of the coil due to the resin pressure was observed.
Next, the detail of the experiment conducted as an Example which concerns on this invention is described.

(Outline of molded product)
FIG. 2 shows an outline of the manufactured molded product. This molded product 5 is produced by primary molding as shown in FIG. 3, and is formed by secondary molding of a primary molded product 3 in which a primary molded portion 2 made of PPS resin is molded inside the coil 1. The secondary molded part 6 and the spacer 7 made of PPS resin are provided outside the primary molded product 3.

(Used resin)
A glass fiber-containing PPS resin (for example, “Ryton R-4 230BL” manufactured by Chevron Philips Chemical Co., Ltd.) was used.

(Molding condition)
The molding conditions were as shown in Table 1.

(Primary molding)
The primary molded portion indicated by reference numeral 2 in FIG. 3 was molded at a mold temperature of 140 ° C. At this time, since the outer periphery of the coil is regulated by the mold, the coil does not swell even if the coil is filled with PPS resin at a mold temperature of 140 ° C. at which the thermoplastic resin bundled with the coil is softened. There was no.
In the primary molded product thus produced, the primary molded portion (coil bobbin portion) made of PPS resin in the coil had an average (N = 5) crystallinity of the resin of 25.2%.

(Secondary molding)
Using the primary molded product produced by the primary molding, PPS resin was injection molded at a mold temperature of 50 ° C. and 140 ° C. to perform secondary molding.
The degree of crystallinity of the secondary molded portion of the sample produced under each mold temperature condition was measured before and after annealing at 140 ° C. × 2 hours, and is summarized in Table 2.

  From the results shown in Table 2, it can be said that by forming with a 140 ° C. mold, the same degree of crystallinity as that obtained after annealing with a 50 ° C. mold can be realized without annealing.

The dimensional change before and after annealing of the sample produced at each mold temperature was measured. As a result, when it was molded at a mold temperature of 50 ° C., it was deformed by a maximum of 3.8%. This is presumably because the crystallization shrinkage of the resin progressed due to annealing.
On the other hand, when molding was performed at a mold temperature of 140 ° C., the deformation was as small as 0.3% at the maximum. This is probably because crystallization has occurred sufficiently at the time of molding at 140 ° C., and crystallization shrinkage hardly occurred even after annealing.

(Influence of primary mold temperature)
In the primary molding, the primary molding was performed at a mold temperature of 140 ° C., which is higher than the crystallization temperature of the PPS resin, but the case where the primary molding was performed at a mold temperature of 50 ° C. was also verified. Table 3 shows the crystallinity measurement results of the resin when the primary mold temperature is 50 ° C. and 140 ° C., the secondary mold temperature is both 140 ° C., and annealing is not performed.

  From the results in Table 3, even when the primary molding is performed at a mold temperature lower than the crystallization temperature of the PPS resin, by inserting into the mold at 140 ° C. higher than the crystallization temperature in the secondary molding, It is thought that crystallization has occurred. That is, when the secondary molding is performed at a mold temperature higher than the crystallization temperature, it can be said that there is no problem in the degree of crystallization even if the primary molding is performed at a low temperature.

It is a top view explaining one Embodiment of the manufacturing method of the carriage for hard disks of this invention. It is a top view which shows the molded article manufactured in the Example which concerns on this invention. It is sectional drawing of the metal mold | die which shows the state of the primary shaping | molding performed in the Example. It is a principal part top view which shows the state of the injection molding performed in the comparative example.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Coil, 2 ... Primary molded part, 3 ... Primary molded product, 4 ... Terminal, 5 ... Molded product, 6 ... Secondary molded part, 7 ... Spacer, 8 ... Mold, 11 ... Coil, 12 ... Positioning pin.

Claims (7)

The coil is placed in the cavity of the mold, and the outside of the coil is regulated by the mold, and the inner part of the coil is filled with a crystalline resin for molding, and the coil and the crystalline resin filled in the inside are formed 1 A primary molded product consisting of a next molded part is produced,
Next, the primary molded product is placed in a cavity of a carriage molding die, filled with a crystalline resin, and then secondary molded at a mold temperature equal to or higher than the crystallization temperature of the crystalline resin to produce a hard disk carriage. A method for manufacturing a carriage for a hard disk.   In the production of the primary molded product, when the inner portion of the coil is filled with a crystalline resin and molded, the molding is performed at a mold temperature equal to or higher than the crystallization temperature of the crystalline resin, and other than the primary molded product. The method for manufacturing a carriage for a hard disk according to claim 1, wherein the part is also subjected to secondary molding at a mold temperature equal to or higher than the crystallization temperature.   With the core inside the coil, it is placed in a cavity of a carriage molding die, filled with a crystalline resin, and molded at a temperature equal to or higher than the crystallization temperature of the crystalline resin to produce a hard disk carriage. A method of manufacturing a carriage for a hard disk.   4. The coil according to claim 1, wherein the coil is formed by bundling a conductive wire with a thermoplastic resin, and the thermoplastic resin has a softening temperature lower than a crystallization temperature of the crystalline resin. Of manufacturing a hard disk carriage.   A hard disk carriage manufactured by the method for manufacturing a hard disk carriage according to claim 1.   A hard disk carriage in which a coil is integrally formed at a predetermined position of an arm, wherein the coil has a primary molded portion made of a crystalline resin inside the coil.   A hard disk device comprising the hard disk carriage according to claim 5.

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