JPH01149272A - Magnetic head assembly - Google Patents

Abstract

PURPOSE:To decrease a fitting error by fitting a head unit, for which a head slider, a spring plate and a shield plate are unitedly formed, with laser beam welding. CONSTITUTION:A carriage 4 and an arm 7 are formed by a metallic plate. Then, head units 2 and 5, which are unitedly formed from a magnetic head 25, a spring plate 26 to elastically support the magnetic head 25 and a shield plate 27 to remove the influence of a noise to the magnetic head 25, are fit through either of the spring plate 26 or the shield plate 27, at least, respectively to the carriage 4 and a head fitting part 14 of the arm 7 by the laser beam welding. At such a time, when the position of the gap of the magnetic head is adjusted to a distance between tracks, which is set in advance, in the both head units 2 and 5, the welding can be executed with non-contact. Thus, the fitting error can be decreased between the both magnetic heads.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic head assembly used in a drive device for a disk-shaped magnetic recording medium.

[Conventional technology]

A magnetic head assembly used for recording and reproducing a disk-shaped magnetic recording medium (hereinafter referred to as a disk) usually has a side in which the disk is inserted that can be opened via a hinge, and a stop and an arm in which the disk is inserted. is closed and recording/playback begins. When the arm is closed, the magnetic head and the disk come into sliding contact with each other using a predetermined sliding contact force to perform recording and reproducing.In both single-sided and double-sided recording, the pressing force (load) of the arm toward the carriage is The sliding contact force is adjusted by adjusting the pressure.

As such a magnetic head assembly, for example, the first
There are those shown in FIGS. 7 and 18. This magnetic head assembly consists of a carriage 52 equipped with a lower magnetic head 51 at its tip, and an arm 54 equipped with an upper magnetic head 53 at a position corresponding to the lower magnetic head 51. The arm 54 can be opened upward via a leaf hinge spring 55, and the arm 54 is attached to the carriage 52 by a screw 63 via a presser member 62 on the antimagnetic head side, that is, the proximal end 61 of the carriage 52. ing.

One end of a tension spring 57 is engaged with the arm 54 in order to obtain an appropriate sliding force of the magnetic head 53 against the disk 56 as described above, and the other end of this tension spring 57 is engaged with the bottom surface of the carriage 52. It engages with one end of an adjustment member 58 disposed on the side. The adjusting member 58 has a side surface abutting the tip of a support protrusion 59 protruding toward the bottom of the carriage 52 so as to be able to swing, and a male thread 60 is screwed onto the other end of the member 58 to be held on the bottom of the carriage 52. ing. A male screw 60 screwed into the adjustment member 58 adjustably supports the adjustment member 58 from the upper surface side of the carriage 52, and the tension of the tension spring 57 can be adjusted using the tip of the support protrusion 59 as a fulcrum. It has become.

The arm 54 is connected to the carriage 52 at the proximal end 61 as described above.
The arm 5 is attached to the disk 56.
Position 4 is the lower magnetic head 51 of the upper magnetic head 53.
The contact height is determined by the height of the support projection 69 formed on the base end side 61 of the carriage 52 with respect to the surface of the arm 54 facing the carriage 52. and,
When the arm 54 opens, as shown in FIG. 17, the contact portion 80 on the base end side of the arm 54 contacts the support protrusion 69 of the carriage 51, and the arm 54 opens at a predetermined angle using this contact portion as a fulcrum. ing.

[Problem that the invention seeks to solve]

By the way, the magnetic head assembly described above includes two magnetic heads 51 and 53, the lower magnetic head 51 on the carriage 52 side and the upper magnetic head 53 on the arm 54 side, and is capable of recording or reproducing data on both sides of the disk 560. It has become. Then, the lower and upper magnetic heads 51
．． The gap position of the disc 53 is adjusted with high precision so that, for example, it is shifted by 4 tracks for 487 PI and by 8 tracks for 96 TPI, thereby ensuring compatibility of the disc 56.

When attaching the arm 54 to the carriage 52, there is currently a method of tightening the screw 63 via the mounting bracket 62 while checking the deviation of the gap position (substituted by the core position) of the magnetic heads 51, 53 using a microscope; There are two methods: playback using a disc for gear position M and im adjustment, and tighten the screw 63 via the mounting bracket 62 while adjusting the position of the arm 54 so that the playback output reaches a predetermined level. are widely adopted.

In any case, the arm 54 is fixed to the carriage 52 via the screw 63, but even if the relative position between the arm 54 and the carriage 52 is adjusted accurately, when tightening the screw 63, the leaf hinge spring 55 and the screw Torque is applied between the leaf hinge springs 55 and the arm 54.
There was a problem in that the position was slightly deviated from the adjusted position. Also, after tightening the carriage 52
There is also the problem that the stress accumulated in the leaf hinge spring 55 is released, causing displacement.

These problems have resulted in a high rate of defective products, pushing up product costs.

The present invention has been made in view of the problems of the prior art, and its object is to provide a magnetic head assembly with less mounting error between both magnetic heads.

[Means for solving problems]

In order to achieve the above object, the present invention is equipped on a magnetic disk drive device for double-sided recording, and includes a carriage on which a lower magnetic head is mounted, an arm on which an upper magnetic head is mounted, and an arm that is swingable relative to the carriage. In the magnetic head assembly, the carriage and the arm are formed of a metal plate, and
a magnetic head and a spring plate that elastically supports the magnetic head;
A head unit integrally formed with a shield plate for eliminating the influence of noise on the magnetic head is laser beam welded to the head mounting portion of the carriage and arm, respectively, through at least one of the spring plate and the shield plate. It is configured to be installed by

[Effect]

According to the above means, the arm is swingably supported by the carriage in advance and the two are integrally formed, and then the integrated head unit is attached to the carriage and the head attachment part of the arm by laser beam welding. . At this time, if the position of the gap between the magnetic heads of both head units is adjusted to the preset distance between the tracks, welding can be performed without contact, making it possible to easily install the two head units without shifting their positions. Become.

〔Example〕

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

1 to 16 are for explaining the magnetic head assembly according to the embodiment. FIG. 1 is a side view of the magnetic head assembly, FIG. 2 is a rear view of the magnetic head assembly, and FIG. 3 is a view of the carriage. Plan view, Fig. 4 is the same side tooth, Fig. 5 is a plan view of the arm, Fig. 6 is the same back view, Fig. 7 is the same side view, Fig. 8 is the same side view.
Figure 9 is a plan view of the magnetic head unit, Figure 9 is an explanatory diagram showing the mounting state of the shield plate and magnetic head, Figure 10 is an explanatory diagram showing the engagement state of the follower and screw shaft, and Figure 11 is an explanatory diagram showing the attachment state of the follower and screw shaft. 12 is a main part M arrow view in FIG. 11 showing the presser spring part of the follower, FIG. 13 is a bottom view of the follower, and FIG. 14 is a front view showing the disassembled state of the support shaft. FIG. 15 is a bottom view of the main part showing the state in which the magnetic head unit is attached to the carriage, and FIG. 16 is a sectional view of the main part.

In FIGS. 1 and 2, a magnetic head assembly 1 includes a carriage 4, which is equipped with a lower magnetic head unit 2, and which is linearly transported along a guide shaft 3 in the radial direction □ of the magnetic disk, and an upper magnetic head unit 2. an arm 7, also called a hold case, mounted with a head unit 5 and swingably supported with respect to the carriage 4 via a support shaft 6;
It mainly consists of a coil spring 8, which is disposed between the rear end of the arm 7 and the carriage 4, and elastically biases the remagnetic head units 2.5 in a direction toward each other.

As shown in FIGS. 3 and 4, the carriage 4 includes a base plate 9 and a pair of arm mounting plates 1 erected on both edges of the base plate 9.
0a, 10b, a follower mounting plate 12 to which a follower 29 (described later) is attached, and a guide shaft insertion portion 13 inserted into the guide shaft 3 are integrally formed by bending two aluminum alloy thin plates. It is.

Further, on the left end side in the drawing of the board 9, there is a pair of parallel mounting portions 14 for the lower magnetic head unit 2 divided into two.
is formed. The arm mounting plates 10a and 10b have elasticity, are formed in a slightly tapered shape, and are approximately parallel to each other, and are provided with a mounting hole 15 into which the support shaft 6 can be inserted in a direction perpendicular to the longitudinal direction of the board 9. . This mounting hole 15 is chamfered in the shape of a dish, and the inclined surfaces 31b and 32b of the contact portions 31c and 32c, which will be described later, of the support shaft 6 having a similar inclination come into contact with each other, and both arm mounting plates 10a , 10b in the direction of approaching each other, and the inclined surfaces 31b, 3
2b and the mounting hole 15 are set to swing.

The follower mounting plate 12 extends outward from the arm mounting plate 10a, which is the lower side in FIG. 3, parallel to the board 9, and has three protrusions 16 on the follower mounting portion 12a at the tip thereof as shown in FIG. It protrudes downward as shown.

The guide shaft insertion part 13 is made of a plate piece cut downward along the center line in the longitudinal direction of the board 9, and has a shaft insertion hole 13a in the center, and the guide shaft insertion part 13 is formed in the center thereof. 3 is inserted through the carriage 4 to regulate the direction of movement of the carriage 4. Further, on the upper surface of the substrate 9, a protrusion 17 for regulating the position of the lower end of the coil spring 8 is provided.
is drilled.

As shown in FIGS. 5 to 7, the arm 7 includes a substrate 18 having an inclined surface 18a formed in the center, and an inclined surface 18a.
A pair of energized plates 19a and 19b are provided upright on both sides of the carriage 4, a mounting portion 20 for attaching the magnetic herad unit 5, and a protruding piece 2 for opening and closing the arm 7.
1, and is integrally formed by bending a thin plate made of the same aluminum alloy as the carriage 4.

The mounting plates 19a and 19b are formed in a slightly parallel shape and have mounting holes 22 smaller in diameter than the mounting holes 15 formed in the arm mounting plates 10a and 10b. A cross-shaped cut groove 23 is formed in this mounting hole 22, and the inner surface of the mounting hole 22 is chamfered into a dish shape. The distance between the mounting plates 19a and 19b, that is, the substrate 1
The width of the inclined surface 18a of the carriage 4 is narrower than the inner diameter of the arm mounting plates 10a, 10b of the carriage 4.
The outer surfaces of b can face each other.

The mounting portion 20 of the upper magnetic head unit 5 formed on the left end of the substrate 18 in FIGS. 5 and 7 is formed in the same shape as the lower magnetic head unit 2 formed on the carriage 4, and both have the mounting portion It is possible to install the unit by inserting it from the open end of 20. Further, on the lower surface of the substrate 18 on the side opposite to the upper side where the magnetic head unit is attached, that is, on the right end side in FIGS. It is installed vertically.

As shown in FIGS. 8 and 9, the upper magnetic head unit 5 has a read/write gap formed therein and a single read/write gap.
Magnetic head 2 consisting of a head slider including a light core
5 is glued to the center spring plate part of the gimbal spring 26 having a substantially circular outer shape, and the ninth part of the flange part 27 of the shield plate 27 is provided with a bowl-shaped storage part 27a and a flange part 27b.
In the figure, the outer ring portion of the gimbal spring 26 is bonded to the lower surface by laser beam welding, and the magnetic head 25, the gimbal spring 26, and the shield plate 27 are integrally formed.

The shield plate 27 is integrally molded with an elastic body, and a hole 27c for positioning the shield plate 27 with respect to the mounting part 20 is bored in the upper surface of the storage part 27a in FIG. 8, and a gimbal spring is provided in the flange part 27b. A positioning hole 27d for positioning with 26 is bored. Correspondingly, a positioning hole 26a having the same diameter is also formed in the ring portion 26b of the gimbal spring 26. The shield plate 27 is further provided with a bent piece 28a formed by folding a point-symmetrical portion of the flange portion 27b 180 degrees, and between the opposing surfaces of the bent piece 28a and the flange portion 27b, A mounting groove 28 to be inserted into the mounting portion 20 is formed. The lower magnetic head unit 2 is also formed in the same manner.

The follower 29 attached to the follower attachment part 12a of the follower attachment temporary work 2 engages with the spiral feed groove 30a formed on the outer periphery of the screw shaft 30, as shown in FIGS. shaft 30
This is for converting the rotational motion of the carriage 4 into the linear motion of the carriage 4. The stainless steel fence for the spring is integrally folded from the protrusion 29a that engages with the feed groove 30a and the pressing spring portion 29b that elastically clamps the screw shaft 30 together with the protrusion 29a and prevents the protrusion 29a from coming off the feed groove 30a. It is curved and shaped.

As shown in FIGS. 11 to 13, the pressing spring portion 29b of the follower 29 is bent into a figure 7 shape from a base portion 29c on which a protrusion 29a protrudes so as to face the protrusion 29a. A raised cut 29d is formed along the edge to ensure rigidity, and the irises have a narrow shape. The base portion 29c also has a mounting/positioning hole 29 inserted into the protrusion 16 formed in the follower mounting portion 12a.
e is bored at a position corresponding to the protrusion 16.

The follower 29 is attached to the carriage 4 by inserting the hole 29a into the projection 16 and caulking the portion of the projection 16 protruding from the base portion 29c. In addition to this, laser beam welding, spot welding, etc. may be used for this attachment, but since the carriage 4 is made of aluminum alloy and the follower 29 is made of stainless steel, caulking is simple and effective.

As shown in FIG. 14, the support shaft 6 has a pair of irregularly shaped bolts 3.
1 and a nut 32.

The bolt 31 and the nut 32 are formed with large diameter abutting portions 31c and 32c having two stages of inclined surfaces 31a, 31b, 32a and 32b, respectively, and the inner small diameter inclined surfaces 31a and 32a are formed on the bolt 31 and the nut 32. , the large diameter inclined surfaces 31b and 32b on the outside contact the chamfered portions of the mounting holes 22 of the mounting plates 19a and 19b on the arm 7 side, respectively, and the mounting holes 1 of the arm mounting plates 10a and 10b on the carriage 4 side
It comes into contact with the chamfered portions of No. 5, respectively.

Next, the assembly of the magnetic head assembly I having each layer as described above will be explained.

When assembling the magnetic head assembly 1 according to the embodiment, first, both arm mounting plates 10a, 1 of the carriage 4 are assembled.
0b, and the mounting plates 19a and 19b of the arm 7 are opposed to each other to hold both mounting holes 15 and 22 concentrically. Thereafter, the bolts 31 constituting the support shaft 6 are inserted into both the mounting holes 15.22, and the nuts 32 are screwed together from the other side. Insert it between the corrugated mounting plates 19a and 19b and tighten with a predetermined torque. As a result, the arm mounting plates 10a, 10b and the mounting holes 19a, 19b are elastically deformed in the direction of approaching each other, and the arm mounting plates 10a, 10b,
10b and between the attached plates 19a and 19b, respectively, and the shafts are coupled without any play.

In this embodiment, this axial connection is the attached plate 19a.

A strong fit is established between the mounting hole 22 of the arm mounting plate 19b and the inclined surfaces 31a, 32a by the tightening described above, and the arm 7 and the support shaft 6 move together, and the mounting holes 15 of the arm mounting plates 10a, 10b are connected to each other. Between the inclined surfaces 31b and 32b, the dimensions and tightening torque of the king are set so that pressurization that allows sliding is applied, and thereby the arm 7 is supported in a swingable manner with respect to the carriage 4. be done. In this case, it goes without saying that, for example, grease or the like may be used to ensure sliding properties between the mounting hole 15 and the inclined surfaces 31b and 32b. However, it is also possible to provide a similar cut groove in the mounting hole 15 and use this cut groove as a grease reservoir. In this way, for bolts 31 and nuts 32 that have been tightened to a predetermined torque, an adhesive is applied to the threaded portions of the bolts 31 and nuts 32 so that the tightening conditions of both do not change.

Subsequently, the follower mounting portion 12a of the carriage 4, which is axially coupled as described above, is attached to the follower 29 as described above.
It is attached by caulking, and is equipped with a motion direction changing device for the magnetic head assembly 1. Incidentally, this follower 29 may be attached before the above-mentioned shaft coupling step.

Next, the magnetic head unit is attached. Attachment of the magnetic head unit is performed by first attaching the lower magnetic head unit 2 to the carriage 4. That is, the magnetic head 25 of the lower magnetic head unit 2 is directed toward the arm 7 side, the mounting groove 28 is inserted into the mounting portion 14 from the left side in FIGS. 3 and 4, and the positioning with respect to the carriage 4 is performed using optical means. After doing so, the 15th
As shown in the figure, laser beam welding is performed at two points each indicated by P from the front side of the bent piece 28a.

Also, laser beam welding is performed at two points each from the side opposite to the bent piece 28a of the flange portion 27b to securely secure the mounting portion 1.
4, attach the lower magnetic head unit 2. This attached state is shown in FIG.

On the other hand, the upper magnetic head unit 5 is attached to the attachment portion 20 of the arm 7 in the same manner after the lower magnetic head unit 2 is attached. In this case, the gap between the upper magnetic head 25 and the gap between the lower magnetic head 25 must be accurately shifted by 4 or 8 tracks according to the standard. The gap between the upper magnetic head unit 5 and the upper magnetic head 25 is optically observed, and the upper magnetic head unit 5 is inserted into the hole 27.
Adjustment is made via the rod inserted in c, and laser beam welding is performed when this adjustment is completed.

In addition to the optical method, this adjustment may also be performed by rotating a position adjustment disk and picking up the output from the upper magnetic head 25.

These adjustment methods are arbitrarily selected depending on the working conditions.

After the follower 29 and the lower and upper magnetic head units 2.5 are attached as described above, the coil spring 8 for applying load pressure is attached between the carriage 4 and the protrusion 17.24 of the arm 7. In this way, the magnetic head assembly 1 made of sheet metal is manufactured, which is swingably supported by the support shaft 6 and which adjusts the gap when the magnetic head unit 2.5 is attached to the carriage 4 and the arm 7.

In addition, in the above embodiment, the contact portion 31c of the support shaft 6,
32c is a mounting plate 19a on the arm 7 side.

19b, and the mounting plates 10a and l on the carriage 4 side.
Although it is set so that it slides with Qb, it goes without saying that it may be set so that it is the other way around.Also, in the above embodiment, both the carriage 4 and the arm 7 are formed by bending plate materials. However, the arm mounting plate 10a is made of synthetic resin material,
10b and the mounting plates 19B and 19b may be erected by outsert molding, and the carriage 4 and arm 7
The main body of can be selected as appropriate depending on the specifications.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, in which a head unit that is integrally formed with a head slider, a spring plate, and a shield plate is attached by laser beam welding, the attachment can be easily performed because no external force is applied. Since no error occurs and no residual stress is generated, it is possible to provide a magnetic head assembly that does not cause positional deviation after installation.

[Brief explanation of the drawing]

1 to 16 are for explaining an embodiment of this invention. FIG. 1 is a side view of the magnetic head assembly, FIG. 2 is a rear view thereof, and FIG. 3 is a plan view of the carriage. Fig. 4 is a side view of the same, Fig. 5 is a plan view of the arm, Fig. 6 is a rear view of the same, Fig. 7 is a side view of the same, Fig. 8 is a plan view of the magnetic head unit, and Fig. 9 is a plan view of the shield plate. FIG. 10 is an explanatory diagram showing the state of attachment of the magnetic head, FIG. 10 is an explanatory diagram showing the engaged state of the follower and the screw shaft, FIG. 11 is a front view of the follower, and FIG. 12 is a diagram showing the pressing spring part of the follower. 13 is a bottom view of the follower, FIG. 14 is a front view showing the spindle disassembled, and FIG. 15 is a bottom view of the main part showing the magnetic head unit attached to the carriage. , Fig. 16 is a sectional view of the same essential parts, Fig. 17 and Fig. 1
8 is for explaining a conventional example, FIG. 17 is a sectional view of the magnetic head assembly in a non-loaded state, and FIG. 18 is a sectional view of the same in a loaded state. 1...Magnetic head assembly, 2...
...Lower magnetic head unit, 4...
...Carriage, 5... Upper magnetic head unit, 6... Support shaft, 7...
...Arm, 10a, 10b...
Arm mounting plate, 14...Mounting part, 19a
, 19b... Attached part, 20...
...Mounting part, 25...Magnetic head,
26...Gimbal spring, 27...
...shield plate. Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 2418σ Fig. 7 Fig. 8 Fig. 9 Fig. 10 Fig. 12 Fig. 15 Fig. 16 Fig. i(ζV Fig. 17 tlEle Fig.

Claims (1)

[Claims] In a magnetic head assembly consisting of a carriage on which a lower magnetic head is mounted, an arm on which an upper magnetic head is mounted, and support means for swingably supporting the arm relative to the carriage, the carriage and the arm are formed of a metal plate. At the same time, a head unit that is integrally formed of a magnetic head, a spring plate that elastically supports the magnetic head, and a shield plate that eliminates the influence of noise on the magnetic head is attached to A magnetic head assembly characterized in that it is attached to a head attaching portion of a carriage and an arm through at least one of them by laser beam welding.