JPH0963836A - Production of actuator for hard disk - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent short-circuiting between lead wires or between a lead wire and other parts by temporarily retaining the lead wires through opposing columnar parts while spacing apart from other die parts by a distance equal to or shorter than the diameter of the lead wire. SOLUTION: A drive coil 2 is formed previously or an arm part is set, as required, for a lower die and lead wires 4, 5 are inserted into the gap between respective columnar parts. An upper die is then fitted to the lower die and clamped thus stopping the lead wires 4, 5 temporarily by means of upper and lower dies. Under that state, resin is injected into the die and the upper and lower dies are eventually separated after the resin has cured thus forming an actuator where the lead wires 4, 5 are embedded in the resin part 3 while being insulated. Since no insulation coating is required on the arm part side where the possibility of touching the lead wire is highest, the actuator can be produced at low cost.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an actuator for a hard disk by injection molding.

[0002]

2. Description of the Related Art When a drive coil is integrated by injection molding to manufacture a hard disk actuator, it is necessary to dispose the drive coil on a mold and to provide a terminal for supplying power to the drive coil. is there. Therefore, conventionally, as a first method, a coil wire of a drive coil is unwound to form a lead wire, a terminal pin is connected to the end portion by soldering, and the drive coil is mounted on a mold. A method of installing the terminal pin at a predetermined position according to a guide and inserting the terminal pin into a terminal pin guide hole on the mold is adopted.

Alternatively, as a second method, a lead wire is further inserted between the lead wire guide pins on the mold to guide the lead wire.

[0004]

However, according to the first method, the lead wire position is not fixed due to the resin flow pressure at the time of resin injection, and the lead wire may come into contact with the arm side of the actuator. In that case, since the material on the arm side is an electrical conductor, a short circuit will occur. Further, the risk of short-circuiting the lead wires is the most important issue to consider.

According to the second method, when the resin is injected, the lead wire may come off the lead wire guide pin due to the resin flow pressure. That is, the second method merely reduces the occurrence rate of the above-mentioned short-circuit state.

Further, in order to prevent a short circuit to the arm side member, there is known a method of forming an insulating coating film on a portion on the arm side which has the highest probability of contact with a lead wire, but there is a problem that the price increases. is there. Insulation by an insulating coating film is a method that is difficult to adopt because the coating film is likely to be detached due to the heat of the molten resin.

An object of the present invention is to provide a method for manufacturing an actuator which is free from the risk of short-circuiting the lead wire from the driving coil and is inexpensive in view of the problems of the prior art.

[0008]

In order to achieve this object, according to the present invention, a driving coil and its lead wire terminal portions are fixed on a molding die, and the die is clamped to form a die. In a method for manufacturing a hard disk actuator by injecting a resin into a coil to manufacture a hard disk actuator, a die projects in a direction substantially orthogonal to a lead wire arrangement path and guides the lead wire to each other. It is provided with three columnar parts which are arranged so as to have a gap and whose ends, after mold clamping, are opposed to each other via a parting line with a distance equal to or smaller than the diameter of the lead wire from the other mold part. When the terminal portion is arranged, the lead wire is guided by the columnar portion.

The mold is characterized by being separated into an upper mold and a lower mold.

Further, the column interval in the upper die or the lower die is at least larger than the diameter of the coil lead wire.

[0011]

According to this, the lead wire has its terminal portion fixed on the mold through the space between the pillars before the mold is clamped. Then, when the die is clamped, the distance between the tip of each columnar portion and the facing portion thereof is equal to or less than the diameter of the lead wire or comes into contact with it. Therefore, even if the resin is injected into the mold,
The lead wire is held between the pillars without deviating from the gap between the pillars due to the flow pressure of the resin. Therefore, the lead wire does not come into contact with the arm portion side of the actuator, or the lead wires do not come into contact with each other to cause a short circuit.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a structure of a coil portion of an actuator according to an embodiment of the present invention. This actuator includes an arm portion for mounting a head such as a magnetic sensor, and a coil portion adjacent to the arm portion.
The arm portion has a bearing support hole 1 for rotatably mounting the arm portion on a rotary pivot of the disk device, and is made of a conductive material. The head side of the arm portion is not shown. The coil portion has a drive coil 2 for swinging the arm portion, and a resin portion 3 for fixing the drive coil 2 in a bearing support hole 1 portion of the arm portion. Lead wires 4 and 5 are drawn out from the drive coil 2, pass through the inside of the resin portion 3, and are respectively connected to the terminal pins 6 and 7.
It is connected to the.

FIG. 2 is a sectional view taken along the line AA of FIG. FIG. 3 is a perspective view showing a state in which the mold parts forming the parts 8 and 9 in FIG. In FIG. 3, 10 is an upper die portion corresponding to the portion 8, and 11 is a lower die portion corresponding to the portion 9. The lower mold part 11 is
It has three columnar portions 12 protruding in a direction substantially orthogonal to the wiring paths of the lead wires 4 and 5. These columnar portions 12
Are arranged so as to have a gap between each other for guiding the lead wires 4 and 5, and the ends of the parting line P. It is formed so as to be in contact with the upper die portion 10 via L or to face each other with a space equal to or smaller than the diameter of the lead wires 4 and 5.

The actuator of FIG. 1 is manufactured using this mold. That is, first, the drive coil 2 previously formed in the lower die and the arm portion (not shown) as needed are set, and the lead wires 4 and 5 are inserted into the gaps between the columnar portions 12. . Then, the upper mold is aligned with the lower mold, and the mold is clamped. As a result, the lead wires 4 and 5 are temporarily fixed by the lower mold portion 11 and the upper mold portion 10, and in this state, the resin is injected into the mold. Then, after the resin is solidified, the upper mold and the lower mold are separated. As a result, an actuator is formed in which the lead wires 4 and 5 are embedded and fixed in the resin portion 3 in a completely insulated state.

The gap between the columnar portions 2 is designed to be slightly larger than the diameter of the lead wires 4 and 5. Also, in the molded actuator, as shown in FIG. 2, the portions 8 and 9 remain as holes, but since they are small holes, they do not affect the strength of the actuator. Further, in the above description, the arm portion is formed in advance, but the present invention is not limited to this, and the arm portion and the resin portion 3 may be integrally molded in the same mold at the same time.

[0017]

As described above, according to the present invention, since the columnar portions facing each other with a distance equal to or smaller than the diameter of the lead wire from the other die portion are used to temporarily fix the lead wire, the lead wires and the leads are not fixed. It is possible to prevent a short circuit between the wire and another portion. Therefore, it is not necessary to form an insulating coating on the arm side that has the highest probability of contacting the lead wire.
The actuator can be manufactured at low cost.

[Brief description of drawings]

FIG. 1 is a diagram showing the vicinity of a coil portion of an actuator according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a perspective view showing a state in which a mold portion forming a part of FIG. 2 is matched.

[Explanation of symbols]

1: bearing support hole, 2: drive coil, 3: resin part,
4, 5: Lead wire, 6, 7: Terminal pin, 8, 9: Part,
10: upper mold, 11: lower mold, 12: columnar part.

Claims (3)

[Claims] 1. A drive coil and a terminal portion of its lead wire are fixed on a molding die, the die is clamped, and resin is injected into the die to integrate the coil. In the method for manufacturing an actuator for a hard disk according to the above, the mold is arranged so as to protrude in a direction substantially orthogonal to the arrangement path of the lead wire, and has a gap for guiding the lead wire between the mold and the mold clamping. After that, the end portion is provided with three columnar portions which are in contact with each other through a parting line and are opposed to the other mold portion, or which are opposed to each other with an interval equal to or smaller than the diameter of the lead wire. A method for manufacturing a hard disk actuator, wherein the lead wire is guided by the columnar portion when the terminal portion is arranged. 2. The method for forming a coil lead wire according to claim 1, wherein the mold is divided into an upper mold and a lower mold. 3. The method for molding a coil lead wire according to claim 3, wherein the column interval in the upper die or the lower die is at least larger than the diameter of the coil lead wire.