JPH0617222Y2 - Magnetic head device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a magnetic head device mounted in a magnetic disk drive or the like.

[Outline of device]

The present invention relates to a magnetic head device in which a magnetic head portion including a magnetic circuit portion and a slider portion is mounted on a supporting member via a mounting plate, wherein the mounting plate and the supporting member are integrally formed of a polymer material. , It aims to improve temperature characteristics, dimensional accuracy, and assembly accuracy.

[Conventional technology]

A disk-shaped magnetic disk such as a floppy disk is relatively easy to handle and is capable of recording a large-capacity signal, so that its range of use is expanding as an external storage device such as various computers and word processors.

By the way, when recording and reproducing an information signal to and from this floppy disk, it is important to keep the contact pressure (also called head pressure) between the disk surface and the magnetic head constant. In other words, a floppy disk is different from a magnetic tape in that a magnetic disk is rotated at a high speed for recording and reproduction, so that "swelling" occurs on the disk during this rotation.
Is likely to occur, and it is difficult to keep the sliding contact state constant. If the head pressure fluctuates or becomes in a non-sliding contact state, recording / reproduction cannot be effectively performed due to deterioration of reproduction output.

Under such circumstances, various measures have been taken in magnetic disk drive devices, particularly magnetic head devices, in order to keep the head pressure constant.

For example, in a magnetic head device mounted on a double-sided disk drive that records / reproduces information signals on both sides of the disk, the magnetic heads arranged on both sides of the magnetic disk are called gimbal plates, and It is attached to a support member (carriage or rotating arm) via a mounting plate that is movable in the radial direction or the thickness direction. Therefore, these magnetic heads have a structure in which the head pressure is kept constant while exhibiting a good followability with respect to the waviness.

In a single-sided disk drive that records and reproduces information signals on one side of the disk, a magnetic head is fixed to a supporting member (carriage) via a mounting plate called a base, and the disk is sandwiched between A pressing member called a pad is arranged at a position facing the magnetic head portion, and the pressing member is pressed against the magnetic head with a constant pressure, whereby the head pressure between the disk and the head is kept constant. ing.

[Problems to be solved by the invention]

By the way, in recent years, the magnetic disk drive device tends to be smaller and thinner, and with the advent of a micro-floppy disk having a large recording medium, the magnetic head device is required to have higher dimensional accuracy and assembly accuracy. There is.

However, in the conventional magnetic head device, the sixth
As shown in the figure, after fixing the magnetic head part (101) to the mounting plate (102), the mounting plate (102) is supported by a supporting member (rotating arm).
Since it is mounted on (103), there is a problem in terms of reliability because the mounting accuracy tends to vary due to deformation of the mounting plate (102).

Further, when the micro floppy disk is taken into consideration, deterioration of dimensional accuracy due to the temperature characteristics of the mounting plate (102) and the supporting member (103) is also a serious problem.

That is, conventionally, the supporting member is mainly composed of a polymer material such as polycarbonate (PC) or polyphenylene sulfide (PPS) having excellent mechanical strength and heat resistance.
Using a mixture of glass fiber, glass flakes, and filler such as mica to add chassis, lead screw,
This has been dealt with by matching the coefficient of thermal expansion with the peripheral components such as the mounting plate or the disc.

However, the thermal expansion coefficient of the above PC (unit: cm / cm / ° C)
The flow direction is 1.8 × 10 ^{−5 to} 5 × 10 ⁻⁵ , the direction perpendicular to this is 2 × 10 ^{−5 to} 7 × 10 ⁻⁵ , and that of the above PPS is
A magnetic head device for micro-floppy disks requiring a high dimensional accuracy, with a large flow direction of 1.2 × 10 ^{-5 to} 2.2 × 10 ^-5 and a perpendicular direction of 2.5 × 10 ^{-5 to} 4.1 × 10 ^-5. There is a problem in dimensional accuracy due to temperature characteristics when used.

Therefore, the present invention has been proposed in view of the above circumstances, and an object thereof is to provide a magnetic head device having excellent temperature characteristics, dimensional accuracy, and assembly accuracy.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention provides a magnetic head device in which a magnetic head part including a magnetic circuit part and a slider part is mounted on a support member via a mounting plate. It is characterized by being integrally molded with a liquid crystal polymer.

The properties required for the materials that make up the mounting plate and supporting member are high mechanical strength and elastic modulus, low thermal expansion coefficient, low melt viscosity and excellent workability, and heat resistance during soldering. And excellent chemical resistance,
A liquid crystal polymer is mentioned as a material satisfying these characteristics.

[Action]

As described above, in the present invention, since the mounting plate and the supporting member are integrally formed of the polymer material, the step of mounting the mounting plate on the supporting member is not necessary, and the mounting accuracy of the magnetic head portion is significantly improved. .

Further, since the above-mentioned liquid crystal polymer has a coefficient of thermal expansion which is extremely small as 1/2 to 1/3 as compared with PC or PPS, the dimensional accuracy can be secured even when the magnetic head device is in a high temperature state.

〔Example〕

Next, an embodiment of a magnetic head device to which the present invention is applied will be described with reference to the drawings.

First, record / playback on both sides of the floppy disk,
A magnetic head device mounted on a so-called double-sided floppy disk drive will be described.

As shown in FIG. 3, the magnetic head device of this embodiment is fixed to a guide bar or the like of a floppy disk drive main body (not shown) and is moved in the radial direction of the disk (5) along the guide bar by a stepping motor. Carriage part
(1) and a magnetic head part (4) facing the magnetic head part (3) mounted on the tip side of the carriage part (1) with a disk (5) in between, the carriage part (1) 3 is composed of a rotating arm portion (2) fixed so as to be rotatable in the direction of arrow A in FIG. Then, the magnetic head portions (3) and (4) mounted on the carriage portion (1) and the movable arm portion (2) respectively record and reproduce on both sides of the floppy disk (5). There is.

That is, during the chucking operation of the floppy disk, the movable arm portion (2) is attracted toward the carriage portion (1) by the tension spring (8), and the magnetic head portion (3),
The configuration is such that the information signal is recorded / reproduced with the disk (5) sandwiched between (4).

Here, as shown in FIG. 1, the carriage portion (1) is provided with slide guide shafts on the side surface of the base end portion and the side surface of the middle portion.
(13), (14) through holes (13a), (14a) is supported by the guide bar, the support member (11) is moved in the radial direction of the disk
And a mounting plate (12) for making the magnetic head portion (3) fixed to the tip end side movable, which are integrally molded of a polymer material.

Further, the mounting plate (12) has notches (15a), (1
5b) and (16a), (16b) are provided so as to face each other. And notches (15a), (15b) provided in the inner circumference
So that it can move in the circumferential direction of the disc.
A) and (15B) remain, and the connecting portions (16A) and (16A) so that they can be moved in the radial direction of the disc by the notches (16a) and (16b) on the outer circumference.
(16B) remains formed. Also, the notch (15a),
Inside the (15b), a magnetic head portion (3) for writing / reading to / from the magnetic disk (5) is fixed by an adhesive such as epoxy.

On the other hand, the rotating arm portion (2) is, as shown in FIG.
A support member (21) attached to the carriage portion (1) via a leaf spring (23) provided on the base end side and a magnetic head portion (4) fixed on the tip end side are made movable. A mounting plate (22) for holding is integrally formed of a polymer material.

Here, notches (25a), (25b) and
(26a), (26b) are provided, the magnetic head part (4) fixed to the mounting plate (22) by leaving the connecting parts (25A), (25B) and (26A), (26B), respectively. The disk is movable in the circumferential direction, the radial direction, and the thickness direction.

Therefore, each of the magnetic head portions (3) and (4) exhibits a good followability to the undulation generated by the rotation of the disk (5) and keeps the head pressure constant.

Although not shown, the magnetic head portions (3) and (4) are
It goes without saying that the back surfaces of the mounting plates (12) and (22) are electrically connected to the flexible printed wiring board or the like and electrically connected to the external drive circuit. As the magnetic head portions (3) and (4), any magnetic heads usually used as a magnetic head mounted in a floppy disk drive can be used. Specifically, a so-called tunnel erase head (bulk type or laminate type), a so-called straddle erase head, or the like is applied.

As described above, according to the present invention, the mounting plates (11) and (21) and the supporting members (12) and (2) that form the carriage part (1) and the rotating arm part (2) are
2) and are integrally molded with a polymer material, the properties required for this polymer material are that they have high mechanical strength and elastic modulus, a low coefficient of thermal expansion, and excellent injection moldability. , Excellent heat resistance and chemical resistance during soldering, and the like. Examples of the polymer material satisfying these characteristics include liquid crystal polymers, and specifically, wholly aromatic polyesters [for example, Celianse (Ceian
ese), trade name "Vectra"], DARTCO, trade name "XYDAR" and the like.

The liquid crystal polymer is made of a rigid polymer, and even if it is in a molten state, its molecular chain is hard to bend and maintains a rod shape.
There is little entanglement of molecules during melting, and it is oriented in one direction only by receiving a slight shear stress. Therefore, although it is liquid, it exhibits crystalline properties. Due to such properties, a self-reinforcing effect is exerted, and large mechanical strength and elastic modulus can be obtained without adding a reinforcing agent such as glass fiber or carbon fiber.

The coefficient of thermal expansion is an order of magnitude smaller than ordinary plastics and is comparable to that of metals.

The melt viscosity is low and the injection moldability is excellent, and ordinary molding equipment can be used.

Since it already has crystallinity in the molten state, the molding shrinkage is small.

It has excellent heat resistance and chemical resistance, and there is no problem in soldering during the assembly process.

Good adhesion.

And so on.

Here, since the liquid crystal polymer has a self-reinforcing effect, the flexibility required for the mounting plates (12) and (22) can be sufficiently ensured by setting the plate thickness appropriately.

As described above, since the above-mentioned liquid crystal polymer has a small thermal expansion coefficient (for example, Vectra is 1 × 10 ⁻⁵ cm / cm / ° C.), the temperature characteristic of the obtained magnetic head device is remarkably improved. Therefore, the present invention is suitable for a magnetic head device such as a magnetic head device for a micro floppy disk that requires strict dimensional accuracy.

Further, since the above-mentioned liquid crystal polymer has an extremely low viscosity when melted, the carriage part (1) and the rotating arm part (2) can be easily manufactured by injection molding. At the same time, since the molding shrinkage rate is very small, processing accuracy and dimensional accuracy are greatly improved. Moreover, since the solidification speed is high, the work can be performed in a very fast molding cycle, and the productivity and mass productivity are excellent. Further, it has an advantage that a conventional injection molding machine can be used because the viscosity at the time of melting is low.

Furthermore, since the mounting plates (12) and (22) are integrally formed with the support members (11) and (21), the work of mounting the conventional mounting plate on the support members and the notches (15a) and (15b) , (16a), (16b) and (25a), (25
The work of forming b), (26a), and (26b) is unnecessary, and the manufacturing process can be simplified. Also, as the mounting plates (12) and (22), B
Since a polymer material which is less expensive than the e-Cu alloy is used, the material cost can be reduced.

Further, since the liquid crystal polymer has excellent heat resistance and chemical resistance, it does not hinder the soldering work between the magnetic head portions (3) and (4) and the flexible printed wiring board.

Next, record and play on one side of the floppy disk,
A magnetic head device mounted on a so-called mold surface type floppy disk drive will be described.

As shown in FIG. 5, this single-sided magnetic head device is fixed to a guide bar or the like of the main body of a floppy disk drive (not shown) and moved in the radial direction of the disk (33) along the guide bar by a stepping motor. It has a carriage portion (31) and a pad member (34) facing the magnetic head portion (32) attached to the tip end side of the carriage portion (31) and is rotatable in the direction of arrow B in FIG. It is composed of a fixed pad arm portion (35). Then, recording / reproducing is performed on one side of the floppy disk (33) by the magnetic head (32) mounted on the carriage (31).

That is, during the chucking operation of the floppy disk, the pad arm portion (35) is attracted toward the carriage portion (31) by the tension spring (36), and the magnetic head portion (35) is pulled.
With the disc (33) sandwiched between the pad (32) and the pad portion (34), information signals are recorded / reproduced on one side of the disc (the lower face of the disc (33) in this example).

Here, as shown in FIG. 4, the carriage portion (31) is provided with slide guide shafts (46) on the side surface on the proximal end side and the side surface in the middle part.
A support member (41) that supports the guide bar in the through hole (46a) of the disk and is operated to move in the radial direction of the disk, and a mounting plate (42) provided on the tip side for mounting the magnetic head section (32) It is integrally molded from polymer.

Further, the magnetic head portion (32) is fixed to the upper surface of the mounting plate (42) with an adhesive such as epoxy, and the magnetic head portion (32) has a hole (not shown) provided in the mounting plate (42). ) And is electrically connected to the flexible printed wiring board.

Also in this embodiment, the support member (41) and the mounting plate (42) are integrally formed of the liquid crystal polymer. Therefore, it is possible to provide a single-sided magnetic head device which has excellent temperature characteristics, dimensional accuracy, and assembly accuracy, and is advantageous in terms of productivity, material cost, and the like.

The present invention is not limited to these embodiments. For example, since the liquid crystal polymer is excellent in injection moldability, the mounting plate integrally formed with the supporting member has a positioning protrusion for securing the fixing accuracy of the magnetic head portion, a magnetic head portion from a disk jacket, or the like. A three-dimensional design is possible, such as molding a protective member for protection at the same time.

[Effect of device]

As is clear from the above description, in the present invention, the support member and the mounting plate are integrally molded with the liquid crystal polymer, so that the temperature characteristics, the dimensional accuracy, the processing accuracy, and the productivity are excellent, and the electromagnetic conversion characteristics are excellent. A high performance magnetic head device can be provided. Therefore, it is possible to easily cope with a large capacity (high density) of the floppy disk or a miniaturization of the magnetic head device.

Further, since the mounting plate and the support member are integrally molded, it is possible to reduce the number of parts, the number of assembly steps, or the assembling accuracy, and it is not necessary to change the design of other components. Therefore, it can be said that the present invention has extremely high practical value.

[Brief description of drawings]

1 to 3 show an embodiment in which the present invention is applied to a magnetic head device mounted in a double-sided floppy disk drive, FIG. 1 is an external perspective view of a carriage part, and FIG. 3 is a schematic side view of the magnetic head device. FIG. 4 and 5 show an embodiment in which the present invention is applied to a magnetic head device mounted in a single-sided floppy disk drive, and FIG. 4 is an external perspective view of a carriage part.
FIG. 5 is a schematic side view of the magnetic head device. FIG. 6 shows an example of a conventional magnetic head device (rotating arm portion).
It is an exploded perspective view showing. 1,31 …… Carriage part 2 …… Rotating arm part 3,4,32 …… Magnetic head part 11,21,41 …… Supporting member 12,22,42 …… Mounting plate

Claims (1)

[Scope of utility model registration request] 1. A magnetic head device in which a magnetic head portion comprising a magnetic circuit portion and a slider portion is mounted on a supporting member via a mounting plate, wherein the mounting plate and the supporting member are integrally molded with a liquid crystal polymer. Characteristic magnetic head device.