JPH0836847A - Magnetic disk device and assembling method thereof - Google Patents

Abstract

PURPOSE:To obtain a magnetic disk device in which the hight for mounting a head assembly is accurately maintained and also the assemblability is improved, and the assembling method thereof. CONSTITUTION:A cylindrical part 10a with the inner surface formed in a non- circular state, and erected on a mounting member 10, is spread by being pushed in the circumferential direction to calk and fix the head assembly 7 to a swing arm 4. Thus, no load is applied to the swing arm 4 in the direction of the hight (thickness) at the time of calking, therefore, the dimension of the hight for mounting the head assembly 7 is accurately maintained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for fixing a magnetic disk device and a head assembly, and more particularly to a magnetic disk device for fixing the head assembly while maintaining the mounting height of the head assembly with high accuracy, and an assembling method thereof. Regarding

[0002]

2. Description of the Related Art FIG. 4 is a diagram showing a schematic structure of a magnetic disk device. As shown in FIG. 4, a magnetic disk 1 is held by a rotating portion of a spindle motor, fixed by a disk holder 2 and rotated in an arrow A direction. Driven. A pair of head assemblies 7 each having a slider 3 attached to one end (tip) and a suspension 6 fixed to one end of a swing arm 4 with a screw 5 are arranged so as to face both sides of the magnetic disk 1. , Magnetic recording / reading is performed on the magnetic disk 1. The other end of the swing arm 4 is rotatably supported by a shaft 7, and is driven by a voice coil motor 9 about the shaft 8 as a fulcrum to rotatably drive the head assembly 7 in the direction of arrow B.

By the way, as a method of fixing the head assembly 7 to the swing arm 4, there are a method of screwing and a method of caulking with a ball.

In the fixing method by screwing shown in FIG. 4, one end of the swing arm 4 is machined through a mounting hole provided in a plate member called a mount fixed to the other end of the head assembly 7. This is a method of fixing the head assembly 7 to the swing arm 4 by screwing the machine screws 5 to the female threads.

On the other hand, in the fixing method by caulking using a ball (not shown), a hole provided in a plate member called a mount fixed to the other end of the head assembly 7 extends in a cylindrical shape, and this cylindrical portion Is inserted into the hole formed in the swing arm 4, and a hard ball having a diameter slightly larger than that of the cylinder is pushed through the cylinder with a jig to pass the hard ball to spread the cylinder. In this state, the head assembly 7 is caulked and fixed to the swing arm by plastically deforming.

[0006]

However, the above-mentioned fixing method by screwing has a drawback in that the swing arm 4 needs to be threaded. Further, in order to obtain sufficient strength of the screw tightening portion against the tightening torque of the screw 5, the screw tightening portion of the swing arm 4 needs to have a certain length, and therefore, the swing arm 4 needs to have a certain thickness. However, with the recent miniaturization and thinning of magnetic disk devices, the swing arm 4 tends to be thin, and there is a problem that a sufficient thickness cannot be secured for screwing.

The fixing method using caulking using balls has been widely used in recent miniaturized magnetic disk devices because the above-mentioned problem of screwing does not exist. However, in this fixing method, when the ball is pushed through the cylindrical portion, a load is applied in the height (thickness) direction of the swing arm 4, so that the swing arm 4 is deformed and an error occurs in the dimension in the height direction. It has the drawback of being afraid. If there is an error in the mounting height for mounting the head assembly 7 of the swing arm 4, it will affect the flying height of the slider 3 mounted at the tip of the head assembly 7, which may cause fluctuations in head output, Alternatively, there is a possibility that a problem such as a decrease in floating reliability may occur. However, as described above, in recent magnetic disk devices, the swing arm 4 tends to be thin and its rigidity tends to be low, and the above-mentioned problem tends to be magnified.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a magnetic disk device and a method for assembling the same, which maintain the mounting height of the head assembly with high accuracy and improve the assembling property. And

[0009]

In order to achieve the above object, a magnetic disk device of the present invention comprises a slider and a suspension having the slider fixed to one end and having a first through hole formed at the other end. A head assembly, a swing arm having a second through hole formed at one end, and a cylindrical portion having a non-circular inner surface and being inserted into the first through hole and the second through hole. And a mount member for fixing the other end of the suspension and expanding the cylindrical portion in the circumferential direction to caulk and fix the head assembly to the swing arm.

The magnetic disk device of the present invention is characterized in that a step is provided on the surface of one end of the swing arm to which the head assembly is fixed.

Further, the magnetic disk device of the present invention is characterized in that the outer peripheral surface of the cylindrical portion is formed in an uneven shape.

Further, according to the method of assembling the magnetic disk device of the present invention, the first through hole formed at the other end of the suspension for fixing the slider to one end and the second through hole formed at the one end of the swing arm are formed. A step of fixing the other end of the suspension by inserting the cylindrical part into the first through hole in a mount member on which a cylindrical part having an inner surface to be inserted and having a non-circular shape is erected. A step of inserting the cylindrical portion of the mount member whose end is fixed into the second through hole; and a caulking jig formed with an outer shape having a convex portion corresponding to a non-circular shape of the inner surface of the cylindrical portion. The head assembly is inserted into the cylindrical portion, and the caulking jig is rotated around the axis of the cylindrical portion to rotate the convex portion to push the cylindrical portion in the circumferential direction to spread the head assembly to the swing arm. Characterized by comprising a step of tightening fixing.

[0013]

The magnetic disk device and the assembling method thereof according to the present invention are
Since it is configured as described above, the inner surface is formed into a non-circular shape, and the cylindrical portion erected on the mount member is circumferentially pushed out to swage and fix the head assembly to the swing arm. Since no load is applied to the swing arm in the height (thickness) direction, the mounting height dimension of the head assembly is accurately maintained.

Further, in the magnetic disk device of the present invention, since the step is provided on the surface of the one end of the swing arm to which the head assembly is fixed, the mounting member is prevented from rotating during caulking.

Further, in the magnetic disk device of the present invention, since the outer peripheral surface of the cylindrical portion is formed in an uneven shape, loosening after caulking is prevented.

[0016]

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

FIG. 1 is a diagram showing a main part of a magnetic disk device according to an embodiment of the present invention. FIG. 1 (a) is a perspective view showing one end of a swing arm, and FIG. 1 (b) is the other end of a suspension. 2 is a perspective view showing the mount member, FIG. 2 (a) is a plan view, and FIG. 2 (b) is a sectional view taken along line AA.
And FIG. 3 is a perspective view of the caulking jig.

Generally, in the magnetic disk device, as shown in FIG. 4, the magnetic disk 1 is held by a rotating portion of a spindle motor, fixed by a disk holder 2 and rotationally driven in the direction of arrow A. A pair of head assemblies 7 each of which has a slider 3 attached to one end (tip) and a suspension 6 fixed to one end of a swing arm 4 is disposed so as to face both sides of the magnetic disk 1. Perform magnetic recording / reading on 1. The other end of swing arm 4 is pivotally supported on shaft 7,
It is driven by a voice coil motor 9 with 8 as a fulcrum, and the head assembly 7 is rotatably driven in the direction of arrow B.

The mechanism for fixing the head assembly 7 including the slider 3 and the suspension 6 to the swing arm 4 in one embodiment of the present invention is as follows.

That is, a through hole 4a is formed at one end of the swing arm 4, and a step 4b is provided on one surface thereof as a rotation stop during caulking as described later. A through hole 6b is also formed at the other end of the suspension 6 at a position facing the through hole 4a formed in the swing arm 4 when the edge 6a is brought into contact with the step 4b of the swing arm 4. There is. Also, 10 is a swing arm
4 is a mount member having the same width as the fixed portion at one end of the suspension 4 and the other end of the suspension 6, and the mount member 10 has a through hole 4a for the swing arm 4 and a through hole for the suspension 6
A cylindrical portion 10a inserted into 6b is erected. And
As shown in FIG. 1B, one end edge 10b of the mount member 10 and the other end edge 6a of the suspension 6 are aligned with the mount member 10, and the suspension portion 6 penetrates the cylindrical portion 10a. Suspension with hole 6b inserted
6 is glued and fixed.

As shown in FIG. 2, the inner surface of the cylindrical portion 10a is not formed in a uniform circular shape, but is formed in a non-circular shape having a large inner diameter portion 10c and a small inner diameter portion 10d.
On the outer peripheral surface of the cylindrical portion 10a, a so-called knurled groove 10e is formed in which minute concave portions and convex portions are formed over the entire surface.

Numeral 11 pushes out the cylindrical portion 10a to swage the mount member 10 into the through hole 4a of the swing arm 4 to fix it.
In other words, this is a rod-shaped caulking jig for caulking and fixing the head assembly 7 to the swing arm 4.
Has an outer diameter corresponding to the inner diameter of the inner surface of the cylindrical portion 10a in a part of the outer circumference. For example, as shown in FIG. 3, there are three convex portions 11a in the circumferential direction of the outer circumference of the caulking jig 11. The parts with a large outer diameter (projections 11a) and the part with a small outer diameter
11b is set. The convex portion 11a of the caulking jig 11 is set to be slightly smaller than the large-diameter portion 10c of the cylindrical portion 10a and slightly larger than the small-diameter portion 10d. 11b is set to be slightly smaller than the small-diameter portion 10d of the cylindrical portion 10a, and the caulking jig 11 can be inserted into the cylindrical portion 10a. Since the outer shape of the caulking jig 11 is set in this way, the caulking jig 11 does not easily rotate, so that the head assembly 7 can be firmly caulked and fixed to the swing arm 4.

Next, a method of assembling the magnetic disk device, more specifically, a method of fixing the head assembly 7 will be described.

First, the cylindrical portion 10a of the mount member 10 to which the suspension 6 of the head assembly 7 is fixed is inserted into the through hole 4a formed in the swing arm 4, and one of the mount members 10 that is integrated is inserted. The end edge 10b and the other end edge 6a of the suspension 6 are aligned with the step 4b formed at one end of the swing arm 4 and set on a positioning jig (not shown) for positioning. Then, the caulking jig 11 is inserted according to the inner shape of the cylindrical portion 10a, the convex portion 11a having a large outer diameter of the caulking jig 11 is made to correspond to the large inner diameter portion 10c of the cylindrical portion 10a, and Forcibly rotate the caulking jig 11. As the caulking jig 11 rotates, the cylindrical portion 10a moves to the convex portion 11a of the caulking jig 11.
Then, the mounting member 10 is swaged in the circumferential direction by caulking, and the mount member 10 is caulked and fixed to the swing arm 4, that is, the head assembly 7 is caulked and fixed to the swing arm 4. After the caulking is completed, the caulking jig 11 is pulled out from the cylindrical portion 10a, the swing arm 4 and the head assembly 7 are removed from the positioning jig, and the caulking fixing of the head assembly 7 to the swing arm 4 is completed.

As described above, according to this embodiment, when caulking and fixing, only a load is applied to the swing arm 4 in the circumferential direction of the through hole 4a, and a load is applied in the height (thickness) direction. Since no pressure is applied, the mounting height dimension of the head assembly 7 can be accurately maintained.

By the way, when the caulking jig 11 is rotated, the rotation of the caulking jig 11 is transmitted to the mount member 10 by the rotational force of the caulking jig 11, and the mount member 10 tries to rotate. One edge 10b and suspension
Since the edge 6a at the other end of 6 coincides with the step 4b formed at one end of the swing arm 4, the step 4b functions as a detent and the mount member 10 does not rotate. Therefore, the step 4b can prevent the mount member 10 from rotating, and the head assembly 7 can be firmly caulked and fixed to the swing arm 4.

Further, since the concave and convex knurled grooves 10e are formed on the outer peripheral surface of the cylindrical portion 10a, it is possible to prevent the swing arm 4 and the head assembly 7 from being loosened after the caulking.

In the above embodiment, the knurled groove 10e having an uneven shape is formed on the outer peripheral surface of the cylindrical portion 10a, but the uneven shape of the outer peripheral surface is not limited to the knurled groove 10e. The shape may be a cross groove. Further, if the manufacturing accuracy of the inner diameter shape of the cylindrical portion 10a and the outer diameter shape of the caulking jig 11 is good, the outer circumference of the cylindrical portion 10a may be a smooth surface.

Further, the present invention is not limited to the above-mentioned embodiments, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

[0030]

As described above in detail, in the magnetic disk device and the assembling method thereof according to the present invention, the cylindrical portion having the inner surface formed in a non-circular shape and standing on the mount member is expanded in the circumferential direction. By caulking and fixing the head assembly to the swing arm, a load is not applied to the swing arm in the height (thickness) direction during caulking, so that the mounting height dimension of the head assembly can be accurately maintained.

Further, in the magnetic disk device of the present invention, since the step is provided on the surface of the one end of the swing arm to which the head assembly is fixed, it is possible to prevent the mount member from rotating during crimping.

Further, in the magnetic disk device of the present invention, since the outer peripheral surface of the cylindrical portion is formed in an uneven shape, it is possible to prevent loosening after caulking.

[Brief description of drawings]

FIG. 1 is a diagram showing a main part of a magnetic disk device according to an embodiment of the present invention, FIG. 1 (a) is a perspective view showing one end of a swing arm, and FIG. 1 (b) is the other end of a suspension. It is a perspective view.

2A and 2B are views showing a mount member, FIG. 2A is a plan view, and FIG. 2B is a sectional view taken along line AA.

FIG. 3 is a perspective view of a caulking jig.

FIG. 4 is a diagram showing a schematic configuration of a magnetic disk device.

[Explanation of symbols]

 3 ... slider 4 ... swing arm 4a ... through hole (second through hole) 4b ... step 6 ... suspension 6b ... through hole (first through hole) 7 ... head assembly 10 ... mount member 10a ... cylindrical portion 10e ... knurl Groove (uneven shape) 11… Caulking jig 11a… Protrusion

Claims (4)

[Claims] 1. A head assembly comprising a slider, a suspension having the slider fixed to one end and a first through hole formed at the other end, and a swing arm having a second through hole formed at one end. , An inner surface is formed into a non-circular shape, and a cylindrical portion that is inserted into the first through hole and the second through hole is erected, fixes the other end of the suspension, and pushes the cylindrical portion in the circumferential direction. A magnetic disk device, comprising: a mount member that is unfolded to fix the head assembly to the swing arm by caulking. 2. A magnetic disk device according to claim 1, wherein a step is provided on a surface of one end of a swing arm to which the head assembly is fixed. 3. The magnetic disk drive according to claim 1, wherein the outer peripheral surface of the cylindrical portion is formed in an uneven shape. 4. An inner surface to be inserted into a first through hole formed at the other end of a suspension for fixing a slider at one end and a second through hole formed at one end of a swing arm is formed in a non-circular shape. A step of inserting the cylindrical portion into the first through hole in a mount member having a cylindrical portion provided upright to fix the other end of the suspension; and the cylinder of the mount member having the other end of the suspension fixed. Part above the second
And the step of inserting into the through-hole, and the caulking jig formed with an outer shape having a convex portion corresponding to the non-circular shape of the inner surface of the cylindrical portion is inserted into the cylindrical portion, Magnetic disk device, comprising the step of rotating the convex portion by rotating about the axis of the portion to spread the cylindrical portion in the circumferential direction and caulking and fixing the head assembly to the swing arm. Assembly method.