JPH09320212A - Magnetic disk drive - Google Patents

Abstract

(57) [PROBLEMS] To reduce the weight of a carriage, prevent the generation of dust and the like, and firmly couple a load beam. SOLUTION: A carriage 6 in which the other end of a load beam supporting one end of a magnetic head and an arm portion are coupled to each other, and a voice coil motor drives the magnetic head to rotate on a magnetic disk is molded from a foaming resin. Then, the surface of the foamable resin is covered with a non-foamed skin layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk device for recording / reproducing data by supporting a magnetic head on a carriage, and more particularly to reducing the weight of a carriage to increase the speed of recording / reproducing data. Disc device

[0002]

2. Description of the Related Art In general, a magnetic disk device is one in which a magnetic head slider is aerodynamically levitated above a magnetic disk on which data is recorded, and data is recorded / reproduced while rocking the magnetic head slider on the magnetic disk. is there. The mechanism for supporting and moving the magnetic head slider includes a magnetic head slider having a magnetic head element mounted thereon, and a load beam for elastically supporting the magnetic head slider so as to follow the magnetic disk surface in the roll and pitch directions. An arm portion that rigidly supports the load beam, and is rotatably provided around a rotation axis, is coupled to the arm portion at one end, and generates a rotational driving force about the rotation axis at the other end. And a carriage to which a voice coil motor is coupled, which are called actuators.

In order to reduce the moment of inertia of the carriage, the carriage for swinging the magnetic head slider is made lightweight in addition to supporting the magnetic head slider with rigidity in response to the recent demand for high-speed reading and writing of data. Speeding up is desired. In order to reduce the weight, a technique of integrally molding a carriage with a synthetic resin has been proposed in the prior art.
As described in Japanese Patent Publication No. JP-A-2003-96, by integrally molding a synthetic resin from an arm portion that holds a load beam to a coil holder that holds a coil that is a part of a voice coil motor through a bearing of the rotary shaft. In addition to reducing the moment of inertia by reducing the weight, the number of parts / the number of assembling steps are reduced and the synthetic resin is made transparent so that the connection state of the coil can be easily confirmed from the outside. It has also been proposed to make the carriage even lighter by hollowing the inside.

As a document describing a technique for molding this carriage with a synthetic resin, for example, Japanese Patent Laid-Open No. 5-3427 is disclosed.
76, JP-A-5-198140, JP-A-5
No. 6632, Japanese Patent Application Laid-Open No. 5-20806, Japanese Patent Application Laid-Open No. 4-195872, and Japanese Patent Application Laid-Open No. 3-280271.

The following are the effects of the carriages described in these publications made of synthetic resin. (1) Since the specific gravity is smaller than that of the conventional metal material, the weight of the carriage can be reduced, and thus the moment of inertia of the carriage can be reduced and the magnetic head slider can be moved at high speed. (2) The material cost is lower than that of conventional metal materials, and it is possible to integrally mold those that conventionally required the assembly of multiple parts, reducing the number of assembly steps and further reducing the cost. You can (3) Compared to conventional metal die casting, synthetic resin can be molded at a lower temperature, so it is possible to incorporate the parts that were attached by conventional screwing or adhesion at the time of molding and reduce cost. .

[0006]

In the magnetic disk device having the carriage made of synthetic resin according to the prior art described above, since the carriage is simply molded by the synthetic resin, minute recesses on the surface of the synthetic resin are produced at the time of manufacture. Dust, oil and other harmful substances enter the device and cannot be removed even by cleaning.Therefore, when driving a magnetic disk device, these dust particles may scatter inside the device and adhere to the magnetic head, adversely affecting the flying characteristics, or However, there is a problem in that it may cause damage to the disk surface by adhering to the disk, or that such adhesion may adversely affect the recording / reproducing characteristics of data or cause a head crash. In addition, a part of the resin is peeled off from the surface of the synthetic resin and adheres to the magnetic head and the magnetic disk, which causes the same adverse effect as described above. Further, the synthetic resin carriage described in the above-mentioned document merely describes that the carriage is made of synthetic resin, and does not disclose a structure for firmly coupling with a load beam having a magnetic head slider. There is a problem that the slider cannot be sufficiently supported.

An object of the present invention is to eliminate the above-mentioned problems caused by the prior art, and to provide a magnetic disk device capable of preventing the generation of dust and the like while reducing the weight of the carriage and firmly coupling the load beam. Is to provide.

[0008]

In order to achieve the above object, the present invention provides a magnetic disk rotatably driven by a spindle motor, a magnetic head for recording and reproducing information on the magnetic disk, and the magnetic head at one end. In a magnetic disk device including a supporting load beam and a carriage which is connected to the other end of the load beam at a connecting portion of an arm portion and rotationally drives the magnetic head on a magnetic disk by a voice coil motor, the carriage is foamed. The first feature is that the resin is integrally molded with a resin and the surface is covered with a non-foamed skin layer.

Further, according to the present invention, in the magnetic disk device of the first feature, the coupling portion between the load beam and the carriage penetrates a through hole provided at the end of the carriage and a hollow protrusion provided at the other end of the rotor beam. The second feature is that the other end of the load beam and the arm portion are joined at the joint portion by further pushing the hollow protrusion.

Further, according to the present invention, in the magnetic disk device of the first feature, the through hole at the end of the carriage is knurled with a high resistance on the surface in the connecting portion of the load beam and the carriage, and While fitting a fastening collar having a hollow hole that opens through the hollow projection of the funnel beam to the hollow light of the fastening collar, and further expanding the hollow projection to the hollow projection, the other end of the load beam and the arm portion A third feature is that the structure is configured to perform the connection at the connection portion.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A magnetic disk device according to an embodiment of the present invention will be described in detail below with reference to the drawings. 1 is an overall external view showing a state in which a cover of the magnetic disk device according to the present embodiment is opened, FIGS. 2 and 3 are external views of a carriage and an actuator according to the present embodiment, and FIG. 4 is an arm portion according to the present embodiment. Figure showing the tip, Figure 5 is Figure 4
6 is a cross-sectional view of the foamable resin having no skin layer, FIG. 8 is a cross-sectional view of the foamable resin having a skin layer and having a substantially spherical cell shape, and FIG. FIG. 10 is a diagram showing an actuator that does not use a fastening collar and a reinforcing collar according to an embodiment of the present invention, FIG. 10 is a diagram showing only the carriage part of FIG. 9, and FIG. 11 is a diagram showing a load beam and an arm part according to the present embodiment. 12 is a view showing the coupling structure of the load beam and the arm portion, FIGS. 14 and 13 are enlarged views of the tip of the arm portion, FIG. 15 is a sectional view taken along the line CC of FIG. 14, FIG. 16 is a view showing the fastening collar, and FIG. 17 is a view showing a coupling structure using a fastening collar, FIG. 18 is a view showing an arm portion using a reinforcing collar, FIG. 19 is an enlarged front view of the arm portion of FIG. 18, and FIG.
0 is a sectional view taken along line DD of FIG. 18, FIG. 21 is a view showing another embodiment of the fastening collar, FIG. 22 is a view showing a coupling structure using the fastening collar of FIG. 21, and FIG. 23 is the vicinity of the rotary bearing of the carriage. FIG. 24 is a sectional view taken along line EE of FIG.
FIG. 4 is a diagram showing an embodiment of a reinforcing collar on a rotating shaft.

The magnetic disk device shown in FIG. 1 has a magnetic disk 2 for recording information, a spindle motor 1 for rotationally driving the magnetic disk 2 while fixing the magnetic disk 2 to a shaft by a clamp 3, and a swinging motion on the magnetic disk 2. A magnetic head slider 4 having a magnetic conversion element for recording and reproducing the information, a load beam 5 (also called a gimbal) elastically supporting the magnetic head slider 4 at one end, and the load beam 5 being firmly A carriage 6 that includes an arm portion 7 that is coupled via a coupling portion so as to hold it, and is rotatably supported about a rotation shaft 8 by an electromagnetic interaction of a voice coil motor, and the other end of the carriage 6. A voice coil motor 10 configured to rotate the carriage 6 about a rotation shaft 8 and including the attached electromagnetic coil and magnet; A flexible circuit board (FPC) 12 for electrically transmitting information from the magnetic conversion element of the head slider to the outside, a filter 13 for supplementing dust and the like contained in an air flow circulating in the apparatus, and these circuit mechanisms. And a circuit board 11 on which a control circuit and other circuits are mounted. These are configured so that a cover (not shown) seals parts other than a breathing filter (not shown).

FIG. 2 shows the structure of an actuator including a carriage according to this embodiment. In this actuator, one end of a load beam 5 that elastically supports the magnetic head slider 4 is coupled to an arm portion 7 at a coupling portion via a fastening member 23, which will be described later, and a coil 14 attached to the right end around a rotary shaft 8 is used. The magnetic head slider 4 swings about the shaft 8 by electromagnetic interaction of a magnet (not shown). Further, the actuator guides a flexible circuit board (FPC) 12 that electrically transmits information (data) read and written to and from the magnetic disk by the magnetic conversion element of the magnetic head slider 4 along the back surface of the arm portion 7 and to the outside. Wiring.

FIG. 3 shows the carriage 6 according to the present embodiment extracted from the carriage 6. The carriage 6 is formed of a foaming resin, and has a metal fastening collar 15 (described later) at the joint with the load beam 5 at the left end. The metal reinforcing collar 16 for fitting the rotating shaft 8, the electromagnetic coil 14 and other parts are integrally formed. This integral molding is
As described above, since the foamable resin that can be molded at a relatively low temperature is used for the carriage according to the present embodiment, it can be easily carried out by embedding in the foamable resin during molding.

As shown in FIG. 4, the connecting portion 41 at the tip of the arm portion 7 is provided with a through hole 40 for fitting a protrusion of the load beam 5 which will be described later, and the hole 40 is hollow and has a collar. A fastening collar 15 made of metal is provided. The thickness of the arm portion 7 is 1 to 1 in the arm portion main body on the right side in the drawing.
It is about 1.5 mm and about 0.6 to 1 mm at the connecting portion 41 at the tip. As shown in FIG. 5 showing the AA cross section of FIG. 4, the arm portion 7 is a foamable resin 18 containing a large number of bubbles 18a as shown in the lower right corner of the inside, as shown in FIG. Further, a skin layer 17 made of non-foamed resin is provided.

The material of the foamable resin having the skin layer and the molding method thereof are as described in, for example, JP-A-06-100722, "Foam molding method and molded article thereof". As a product, polypropylene resin and ABS resin, etc., in the range of 0.05 to 2.0% by weight of an endothermic foaming agent having a thermal decomposition temperature of 160 ° C. or higher based on citric acid and sodium carbonate as a foaming agent. It is known that a resin mixture containing a foaming agent is directly compounded with a tumbler and then foamed by an injection molding machine using a square plate mold having a thickness of 3 mm and length and width of 150 mm. There is. This thermoplastic resin and the composition thereof are foam-molded by injection molding using an endothermic foaming agent having a specific decomposition temperature to obtain a foam-molded article having a thin-walled molded article (skin layer) which has excellent appearance and maintains rigidity. Obtainable. According to this method, it is possible to obtain an expandable molded product having an average wall thickness of 0.5 to 6.0 mm and an unfoamed surface skin layer in the cross section of the molded product having 15% or more of the average wall thickness.

As another foaming resin material and a molding method, for example, an elastomer containing a foaming agent as described in JP-A-07-80885, "Foam Injection Molding Method".
After injecting into the mold, it is foamed by opening the mold to obtain a foam-molded article having a skin layer on the mold surface side and a foam layer inside the mold. This method is known. Is the mold opening speed V when the mold is opened is 0.5 to 10 mm / sec.
By making the expansion ratio of the foam layer 1.2 times or more, the foam layer can be made to have a specific expansion ratio or more, an appropriate expansion ratio can be secured, and a foam molded article excellent in grain transfer property can be obtained. You can The mold opening speed V is 0.5 mm / s.
If it is less than ec, the required expansion ratio of 1.2 cannot be obtained, and if the mold opening speed V exceeds 10 mm / sec, the skin layer a becomes extremely thin and the cell structure becomes non-uniform, and at the same time, the texture transfer property is poor. It is also known to become.

As for the foaming of the foamable resin having no skin layer, the foaming shape may be unspecified as shown in FIG. 6 or the foaming shape may be substantially spherical as shown in FIG. However, in the state without this skin layer, a large number of recesses 19 due to foaming are exposed on the surface as shown in the figure, and as described above, dust, oil and other harmful substances enter the minute recesses 19 and cannot be removed even by washing, so When the disk device is driven, these dust particles may scatter inside the device and adhere to the magnetic head to adversely affect the flying characteristics, or may adhere to the magnetic disk surface and cause damage to the disk surface. May adversely affect the recording / reproducing characteristics of and cause a head crash. Further, there is a possibility that the end portion of the recess 19 of the resin may be peeled off and adhered to the magnetic head and the magnetic disk to exert the same adverse effect as above.

Therefore, in the present embodiment, the above and FIG.
As shown in FIG. 5, the skin layer 17 is provided on the surface of the foamable resin 18 having the spherical foam 20 to prevent the recesses from being exposed. The expandable resin according to the present embodiment is formed by forming the spherical foam 20 so that the foaming ratio is suppressed to less than 1.2 so that the space between cells is sufficiently widened to maintain rigidity. The reason why the foaming is made spherical is that stress and strain in the resin are likely to be concentrated in the case of irregularly shaped bubbles, and the spherical bubbles can prevent concentration of this stress and the like.

As described above, the carriage according to the above-described embodiment is formed integrally with the other parts by the foaming resin, and the non-foaming skin layer is provided on the surface thereof. Occurrence can be prevented, and adverse effects on the magnetic disk / magnetic head can be prevented.

Next, a carriage according to another embodiment will be described. FIG. 9 shows the structure of the actuator including the carriage according to the present embodiment. This actuator has an arm portion 7 coupled to a load beam 5 that elastically supports the magnetic head slider 4, a rotary shaft 8, and a coil attachment portion, as in the above embodiment, and a flexible circuit board (FPC) 12 is provided on the side surface. Mounted carriage 6
Is provided. As shown in FIG. 10, the carriage 6 has a fastening hole 21 for fitting a fastening member 23 (FIG. 11), which will be described later, at the tip of the arm portion 7, and a fixing hole 22 for fitting a bearing. I have it.

As shown in FIGS. 11 (a) and 11 (b), the fastening member 32 is a hollow projection 23a (or a hollow projection 23a (or a hole) at the end of the load beam 5 (or 5 ') and the hole 21 of the arm 7. 23
a '), for example, by sandwiching the load beam 5 of the upper magnetic head slider from the upper side, the projection 23a is formed into the hole 21.
The load beam 5 and the arm portion 7 are coupled by inserting and fitting into.

In this connection, as shown in FIG. 12 showing the BB cross section of FIG. 11 (a), the protrusion 23a of the fastening member 23 having the upper load beam 5 inserted thereinto is inserted into the hole 21, and then the lower side. The protrusion 23a 'of the fastening member 23 with the load beam 5'of is inserted into the hollow inside of the protrusion 23a inserted earlier in the hole 21, and the rigid ball 2 is placed inside the hollow of the protrusion 23a'.
5 through the projections 23a and 23a '
The load beam and the arm portion are joined by pushing the inside out. That is, the connecting portion 4 of the arm portion 7
Fastening members (23, 23a ') having hollow protrusions (23a, 23a') so as to sandwich the load beam 5 from above and below in the hole 21 of No. 2
23 ') are sequentially inserted, and the inside of this hollow protrusion is a hard ball 2
Bonding is done by spreading out by 5. still,
The protrusion and the diameter have a relationship of the inner diameter of the hole 21> the outer diameter of the protrusion 23a> the inner diameter of the protrusion 23a> the outer diameter of the protrusion 23a ′> the diameter of the hard sphere 25> the inner diameter of the protrusion 23a ′.

The force that the hard sphere 25 spreads acts as a force that compresses the foamed resin 18 of the joint portion 42 as Fs in FIG. 12, and the force Fc when penetrating the hard sphere 25 is the fastening member 23. It acts as a force to hold it so that it does not float up. As described above, according to the connecting structure of the present embodiment, the arm portion can be firmly connected to the foamable resin carriage.

Now, the connection according to the above-mentioned embodiment may cause the deformation of the foamable resin due to the compression as described above.
This deformation affects the attitude of the magnetic head slider, and it is desirable to minimize it. Therefore, it is preferable to fit a fastening collar made of metal such as aluminum / stainless steel / brass into the hole 21. This embodiment is shown in FIG.
The following description will be given with reference to the drawings from 3 onward.

The connection according to this embodiment is shown in FIGS.
As shown in FIG. 4, the joining is performed with the fastening collar 15 fitted in the fastening hole 21 of the joining portion 26 of the arm portion 7. As shown in FIG. 16, it is preferable that the fastening collar 15 is knurled with a large number of projections having an uneven surface on the outer circumference, and the length thereof is slightly longer than the thickness of the coupling portion 26. The reason for performing this knurling is to generate resistance against both the rotational force and the pulling force that act on the fastening collar. As shown in FIG. 15 showing the CC cross section of FIG. 14, the joint portion 26 in which the fastening collar 15 is fitted has a hole 21 of the joint portion 26 made of the expandable resin 18 and provided with the skin layer 17 on the surface. The fastening collar 15 is inserted into and the upper and lower sides of the collar 15 are fitted so as to project from the surface of the coupling portion 26 by the length h. The fastening portion 23 (23 ') and the load beam 5 are previously joined by welding.

As described above, the fastening portion 23 is attached to the joint portion 26.
FIG. 17 shows a cross section in a state where the bonding is performed using (23 ′). The force by which the hard sphere 25 spreads in this state is Fs and the force Fc that suppresses the lifting, acting as a force for directly compressing the foamable resin 18 of the joint portion 26 by acting on the inner side surface and both end surfaces of the fastening collar 15. Does not work, it is possible to prevent deformation and prevent the influence on the attitude of the magnetic head slider. Further, since the force Fs uniformly acts on the inner peripheral surface of the fastening collar, the force that acts on the foamable resin 18 to deform it is also uniform, and the inclination of the load beam can be prevented. In particular, since the fastening collar 15 projects from the surface of the joint portion 26, the mounting height of the load beam 5 can be secured in the same manner as when the entire joint portion is made of metal.

As described above, the carriage according to the present embodiment can prevent the deformation of the coupling portion by providing the fastening collar at the coupling portion, and can prevent the influence on the attitude of the magnetic head slider.

The diameter of the fastening collar 15 is as small as 3 to 4 mm in terms of the size of the end face of the cylinder, so that a slight tilt is likely to occur when the fastening collar 15 is attached (when inserted), and the attitude of the magnetic head slider is tilted. there is a possibility. This problem can be solved by increasing the area of contact between the joint portion and the collar portion of the fastening collar. However, simply increasing the contact area of the collar portion of the fastening collar increases the weight of the fastening collar and hinders the weight reduction of the carriage, which is not preferable.

Therefore, in the present invention, the embodiments of the fastening collar shown in FIG. 18 and subsequent figures are invented. As shown in FIGS. 18 and 19, this fastening collar is formed by inserting a fastening collar 28 having a wide flange portion into the fastening hole of the coupling portion 26 of the arm portion 7 when the carriage is molded. As shown in FIG. 21, the fastening collar 28 has a collar portion projecting with a diameter d so that the upper and lower end surfaces have a large contact area, and a gear-like processed collar portion on the surface. It is composed a little longer.

As shown in FIG. 20 showing a DD cross section of FIG. 19, the joint portion 26 with the fastening collar 28 fitted therein is made of a foaming resin 18 and has a skin layer 17 on the surface thereof. The fastening collar 28 is inserted into a hole having a relatively large diameter, and the upper and lower sides of the collar 28 are fitted so as to project from the surface of the coupling portion 26 by the length h. Further, the fastening portion and the load beam are previously joined by welding.

As described above, the fastening portion 23 is connected to the connecting portion 28.
FIG. 22 shows a cross section in a state where the bonding is performed using (23 ′). The force by which the hard sphere 25 spreads in this state is Fs and the force Fc that suppresses the lifting, respectively, acting on the inner side surface and both end surfaces of the fastening collar 28, and the collar portion of the collar 28 together with the load beam 5 moves up and down the coupling portion 26. Since it widely contacts the surface, it does not directly act as a force for compressing the foaming resin 18 of the coupling portion 26, and the fastening portion 23 can be fitted vertically, preventing deformation and preventing the posture of the magnetic head slider. Can be prevented.

As described above, according to this embodiment, since the contact area of the fastening collar with the joint portion is widened, the joint portion can be provided vertically, and the deformation of the foaming resin of the joint portion can be prevented. Thus, the attitude of the magnetic head slider can be maintained in a suitable state.

Although the load beam supporting the magnetic head slider and the arm portion have been described in each of the above-described embodiments, the present invention can be applied to the coupling structure of the rotary shaft portion of the carriage. This embodiment will be described with reference to FIGS. 23 to 25.

The carriage 6 according to this embodiment is shown in FIG.
And 24, a rotary shaft hole 50 for fitting the above-mentioned rotary shaft is provided, and the reinforcing collar 1 is provided in the rotary shaft hole 50.
6 is inserted at the time of molding. This reinforcement collar 16
24 is knurled on the surface as shown in FIG.
Like the foamable resin 1 inside the rotary shaft hole 50 of the carriage 6
8 is directly inserted. The reason why the outer periphery of the reinforcing collar 16 is knurled is that the surface of the reinforcing collar 16 is made uneven to resist the rotational force and the pulling force acting on the reinforcing collar 16, and the reinforcing collar 16 is firmly coupled. .

Further, by providing the reinforcing collar 16, the present embodiment prevents deformation of the foamable resin due to the screw tightening force even when a screw is used when attaching another component to the collar 16, and Even if the bonding is performed, the deformation due to the difference in thermal expansion between the carriage and the rotating shaft can be prevented.

The present invention may also be embodied as the following modes. First Embodiment A spindle motor rotatably supported, a magnetic disk fixed to the spindle motor,
A magnetic head arranged to face the magnetic disk for writing and reading arbitrary information, a load beam supporting the magnetic head at one end thereof, a carriage supporting the other end of the load beam, and a swinging motion of the carriage. In a magnetic disk device including a rotary shaft that is movably supported, and a base that supports and fixes one end of each of the spindle motor and the rotary shaft, the carriage is integrally formed of foaming resin. Disk device.

<Embodiment 2> The magnetic disk device according to Embodiment 1, wherein the surface of the carriage is covered with a non-foamed skin layer, and the core layer therein is made of a foaming resin.

<Third Embodiment> The magnetic disk drive according to the second embodiment is characterized in that the bubbles generated by foaming are substantially spherical.

<Fourth Embodiment> A magnetic disk drive according to a third embodiment is characterized in that a cylindrical metal member is inserted into a load beam mounting portion of the carriage.

<Fifth Embodiment> A magnetic disk device according to a fourth embodiment is characterized in that both end surfaces of a cylindrical metal member are at the same height as the carriage surface or project from the carriage surface.

<Embodiment 6> A magnetic disk drive according to Embodiment 5, wherein the cylindrical metal member has a flange portion larger than the diameter of the cylindrical portion at both ends thereof.

<Embodiment 7> The magnetic disk device according to Embodiment 6 is characterized in that both end surfaces of the flange portion of the cylindrical metal member are at the same height as or protrude from the carriage surface.

<Embodiment 8> A magnetic disk drive according to Embodiment 3, wherein a cylindrical metal member is inserted in the mounting portion of the rotary shaft of the carriage.

[0045]

As described above, according to the present invention, the other end of the load beam which supports the magnetic head at one end is coupled to the arm portion at the coupling portion, and the voice coil motor drives the magnetic head to rotate on the magnetic disk. By integrally molding the carriage with a foaming resin and covering the surface with a non-foaming skin layer, it is possible to reduce the weight of the carriage and prevent generation of dust and the like.

Further, according to the present invention, the connecting portion of the load beam and the carriage penetrates a hollow protrusion provided at the other end of the funnel beam into a through hole provided at the end of the carriage, and further spreads the hollow protrusion. By coupling the other end of the load beam and the arm portion at the coupling portion, the load beam and the cure can be firmly coupled.

Further, in the present invention, in the connecting portion of the load beam and the carriage, a through hole at the end of the carriage is provided,
The surface is subjected to knurling with high resistance, and a fastening collar having a hollow hole that opens through the inside is fitted, and the hollow light of the fastening collar penetrates the hollow protrusion of the funnel beam,
Further, the carriage is prevented from being deformed by the fastening collar by connecting the other end of the load beam and the arm portion at the joint portion by pushing out the hollow protrusion.

[Brief description of drawings]

FIG. 1 is an overall external view showing a state in which a cover of a magnetic disk device according to an embodiment of the present invention is opened.

FIG. 2 is a diagram showing an appearance of an actuator according to an embodiment of the present invention.

FIG. 3 is a diagram showing a carriage according to an embodiment of the present invention.

FIG. 4 is a diagram showing a tip of an arm portion according to an embodiment of the present invention.

5 is a view showing a cross section taken along line AA of the carriage arm part shown in FIG.

FIG. 6 is a view showing an example of a cross section of a foamable resin having no skin layer.

FIG. 7 is a view showing an example of a cross section of a foamable resin having no skin layer.

FIG. 8 is a view showing a cross section of a foamable resin having a skin layer according to the present embodiment and having a substantially spherical cell shape.

FIG. 9 is a diagram showing an actuator that does not use a fastening collar and a reinforcing collar according to an embodiment of the present invention.

FIG. 10 is a diagram showing only the carriage section of FIG. 9;

FIG. 11 is a diagram showing a load beam and an arm portion according to the present embodiment.

12 is a cross-sectional view showing a combined structure of the load beam and the arm portion of FIG.

FIG. 13 is a view showing a tip of an arm portion according to another embodiment of the present invention.

14 is an enlarged view of the tip of the arm portion shown in FIG.

15 is a cross-sectional view taken along the line CC of FIG.

FIG. 16 is a view showing an example of a fastening collar according to this embodiment.

FIG. 17 is a view for explaining a coupling structure using the fastening collar shown in FIG.

FIG. 18 is a view showing a tip of an arm portion according to another embodiment of the present invention.

FIG. 19 is an enlarged view of the tip of the arm unit shown in FIG. 18.

20 is a view showing a DD cross section of FIG. 19;

FIG. 21 is a view showing still another embodiment of the fastening collar.

22 is a view for explaining a coupling structure using the fastening collar shown in FIG.

FIG. 23 is a view showing a carriage rotating shaft portion according to another embodiment of the present invention.

FIG. 24 is a diagram showing a cross section taken along line EE of FIG. 23;

FIG. 25 is a view showing an embodiment of a reinforcing collar on a rotating shaft.

[Explanation of symbols]

1: Spindle motor, 2: Magnetic disk, 3: Disk clamp, 4: Magnetic head slider, 5: Load beam, 6: Carriage, 7: Arm part, 8: Rotation axis, 9:
Base, 10: Voice coil motor, 11: Circuit board,
12: Flexible circuit board (FPC), 13: Filer, 14: Coil, 15: Fastening collar, 16: Reinforcing collar ,: 17: Skin layer, 18: Foaming resin, 19: Recess, 20: Bubble, 21: Fastening hole, 22: fixing hole, 23:
Fastening member, 24: boss portion, 25: ball, 26: coupling portion, 27: knurling portion, 28: fastening collar, 2
9: knurled portion, 40: through hole.

Claims (3)

[Claims] 1. A magnetic disk rotatably driven by a spindle motor, a magnetic head for recording and reproducing information on the magnetic disk, a load beam for supporting the magnetic head at one end, and the other end of the load beam and an arm. In a magnetic disk device including a carriage that is connected at a connecting portion of the above-mentioned parts and that rotationally drives the magnetic head on a magnetic disk by a voice coil motor, the carriage is integrally formed of foaming resin and has a non-foamed surface. A magnetic disk device characterized by being covered with layers. 2. The load beam and the carriage are joined together by a hollow projection provided at the other end of the funnel beam through a through hole provided at the end of the carriage, and by further expanding the hollow projection. 2. The magnetic disk drive according to claim 1, wherein the other end of the magnetic disk is connected to the arm at a connecting portion. 3. A coupling collar between the load beam and the carriage, wherein a knurled surface having a high resistance is applied to a through hole at the end of the carriage and a fastening collar having a hollow hole for opening the inside is fitted. , The hollow collar of the fastening collar is penetrated through the hollow projection of the funnel beam and further expanded to the hollow projection so that the other end of the load beam and the arm portion are coupled to each other. The magnetic disk drive according to claim 2, wherein