JPH0650871Y2 - Magnetic disk unit - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk device (hereinafter, simply referred to as "disk device"), and more particularly to a disk device suitable for an external storage device of a computer.

2. Description of the Related Art A conventional disk device is disclosed in, for example, Japanese Utility Model Laid-Open No. 60-89657. This device is rotated by a disk drive shaft, and a magnetic head is moved in a radial direction of the disk by a cam provided coaxially with the drive shaft to form a spiral track on the disk and record information on the disk. It has the advantage of short read and write times.

Problems to be Solved by the Invention Although the drive shaft and the first to third shafts are unitized by being supported by a common support, it is difficult to miniaturize the unit itself due to the large number of shafts. Since the flywheel is located below the support and is exposed, there is a problem in that the bottom cover needs to be spaced apart from the flywheel and is structurally limited. .

An object of the present invention is to provide a disk device that solves the above problems.

Means for Solving the Problems The present invention relates to a magnetic disk device in which a magnetic head is moved in the radial direction of a disk by a cam plate to form an information recording track on the disk in a spiral shape. A drive shaft having a lower end supported by the support member and a turntable on which the disc is placed is fixed at the upper end, a pulley integrated with a flywheel fixed near the lower end of the drive shaft, and a drive shaft of the drive shaft. A cam plate that is rotatably supported in the middle portion, and a single reduction gear that is rotatably supported by the support member and that decelerates and transmits the rotation extracted from the drive shaft to the cam plate. And a motor attached to the chassis of the disk device, the rotation of the motor is provided via a belt to the pulley. It is configured to be transmitted to.

Embodiment Next, one embodiment of the disk device according to the present invention will be described.

First, the disk device will be briefly described. FIGS. 1A to 1F are a plan view, a front view, a right side view, a left side view, a partially cut bottom view and a rear view of the disk device 1, respectively. FIG. 2 is a plan view of a disc cartridge mounted state in which a cartridge housing is partially cut away, and FIG. 3 is a right side view of the disc cartridge mounted state.

The disk device 1 generally includes a chassis 2, a front panel 3, a single motor 4, and a cartridge housing 5.
Have and. A disc cartridge 6 shown in FIG. 4 (A) is mounted on the disc device 1. The disk cartridge 6 has a 2.8-inch flexible magnetic disk 9 rotatably housed in a cartridge body 8 formed by combining a pair of cartridge halves 7.

The disk cartridge 6 has the head window 10 facing forward,
It is inserted into the cartridge housing 5 through the opening 11 of the front panel 3 in the arrow X ₁ direction. When the cartridge 6 is inserted all the way into the housing 5, the eject member
The lock 12 is released and the spring 13 slides in the direction of arrow X ₂ by the spring 13, the housing 5 is lowered together with the cartridge 6 in the direction of arrow Z _{1 as} shown in FIG. 3, and the cartridge 6 is mounted at a predetermined position. The center hole 14 of the magnetic disk 9 is the drive shaft 15
, The hub 16 is placed on the turntable 17, the motor 4 starts rotating in the direction of arrow A, and the hub 16 rotates at 423 RPM. The lower surface of the magnetic disk 9 contacts the magnetic head 18, and the pad 19 contacts the upper surface of the magnetic disk 9. The cartridge 6 has a cut-and-raised piece 120a formed by being cut and raised above the chassis 2 as shown in FIG.
By ~ 120d, the lower surface near the four corners is locked and the height position is restricted. The cut-and-raised pieces 27a to 27d serve as a substitute for the conventional pin, and the number of parts and the number of assembling steps are reduced.

Further, the cam plate 20 rotates clockwise by about 330 ° in FIGS. 2 and 6, pushes the guide roller 21, and causes the magnetic head carriage 22 to move.
There guide rods 23a, 23b, to move the guide of Sorcererゝarrow X ₂ direction by 24. The magnetic head 18 moves from the position P _{1 in} FIG. 6 to the position P _{2 in} the radial direction of the magnetic disk 9 in about 8 seconds, and a spiral track 25 shown by a chain line is formed on the magnetic disk 9.
It is formed with a pitch of about 0.4 mm, and an information signal is written therein. When reading, information is read from the track. Information signal writing and reading time is about 8
Seconds and short.

The magnetic head 18 reaches the above positions P ₁ and P ₂ in the second
As shown in FIG. 7 and FIG. 7, a part of the magnetic head carriage 22 is detected by pushing the skeleton switches 121 and 122 to operate them. Skeleton switch 121,
122 is directly soldered and mounted on the printed circuit board 65. In FIG. 1 (E), 123 and 124 are solders for attaching the skeleton switches 121 and 122, respectively. When the reed switch is used as the detection switch, the magnet piece for operating the reed switch needs to be fixed to the head carriage, but when the skeleton switches 121 and 122 are used, the magnet piece is unnecessary.

When the eject button 26 is pressed, the eject member 12 slides in the arrow X ₁ direction and pushes up the housing 5 in the arrow Z ₂ direction. The cartridge 6 rises together with the housing 5, disengages from the drive shaft 15, is pushed in the direction of the arrow X _2, and partially ejects from the opening 11 to be ejected.

The magnetic head carriage 22 has a
SPC material is used. The cam plate 20 is made of stainless steel to prevent rust, and among them, SUS430, whose coefficient of thermal expansion is as close as possible to SPC, is used. Is prevented from occurring.

Next, the configuration of each part of the disk device 1 will be described.

First, the housing 5 will be described. Housing 5
As shown in FIGS. 1 (A) to (C), FIG. 2 and FIG. 3, holes 30 and 31 formed at both ends of one diagonal line 1 in FIG. , The guide poles 32, 33 that are planted at the corresponding locations on the chassis 2
It is guided by 33 and is movable in the directions of arrows Z ₁ and Z ₂ . One hole 31 is an elongated hole so that the dimensional error can be absorbed and the housing 5 can be smoothly moved up and down. The hole 31 is formed so that the direction of the diagonal line 1 of the housing 5 passing through the guide poles 32 and 33 is the longitudinal direction. As a result, the housing 5 is less likely to be rotated in the rotation plane about the guide pole 32.
The housing 5 can move up and down more smoothly than when the elongated hole is formed in the arrow X ₁ , for example. Two protrusions 5a to 5d are provided on the left and right sides of the housing 5, respectively.
As shown in FIG. 1 (D), a and 5b are in contact with the slanted surface portions 12a and 12b of the eject member 12, and other protrusions 5c and 5d are provided as shown in FIG. 1 (C). Slopes 12c, 12d
Is in contact with.

In the initial state in which the eject member 12 is moving in the direction of the arrow X ₁ , the housing 5 is in the raised position. When the eject member 12 moves in the direction of arrow X _2, the projections 5a~5d
Slides down the corresponding slopes 12a-12d, and the housing 5
Is pulled by the springs 34, 35 and 36 and descends along the guide poles 32 and 33 in the arrow Z ₁ direction. The eject member 12 is an arrow
When moving in the X ₁ direction, the slopes 12a to 12d push up the corresponding projections 5a to 5d, so that the housing 5 moves to the guide poles 32, 33.
Along the direction of arrow Z ₂ .

As described above, the guide poles 32 and 33 serve as the means for guiding the ascending / descending movement of the housing 5, and the number of parts is smaller than that of the conventional guide means in which the roller attached to the housing is fitted in the guide groove of the side plate. It is an inexpensive structure.

Further, as shown in FIG. 8 by taking out, the sloped portion 12a is
It is composed of an elongated plate portion bent outward. Therefore, the sloped portion 12a is wider and flat compared to the case where the side wall of the opening punched by the press is used. As a result, the surface pressure per unit area of the guided member that is guided and moved by the inclined surface portion 12a is reduced, and in addition to the fact that a large amount of lubricant can be applied, the frictional force is reduced, and wear is less likely to occur. . Therefore, instead of the roller, the protrusion 5a is used as the guided member without any support. Other slopes 12b, 12c, 12
The d also has the same configuration as the slope 12a.

In FIG. 2, 125 is a poly washer. Since the poly washer 125 has lubricity itself, the eject member 12 can move more smoothly than when a metal washer is used. Further, the poly washer 125 has better assemblability than a metal washer.

Next, a mechanism for rotating the drive shaft 15 and the cam plate 20 will be described with reference to FIGS. 9 to 12.

In each figure, 40 is a die-cast support (support member)
And has a substantially triangular flat plate portion 40a and the pillar portions 40b, 40c, 40d at the tops thereof integrally. This support 40
As shown in FIGS. 9 and 10, the tips of the columns 40b to 40d are recessed portions 41a to 41c formed in the substrate portion 2a of the chassis 2.
Are fastened with screws 42a to 42c in a state of being fitted to.

In particular, as shown in FIG. 10 (A), 43 is a resin pulley
It is a gear body and integrally has a pulley 43a and a small-diameter gear 43b. Reference numeral 44 denotes a flywheel, which is fixed to the pulley portion 43a in an overlapping manner. Pulley with flywheel 44 fixed
The gear body 43 is press-fitted and fixed to the drive shaft 15. Drive shaft
Reference numeral 15 denotes a bearing whose lower end is supported by a bearing 45 press-fitted into the flat plate portion 40a, and whose upper end is fixed to the base plate portion 2a.
It is supported by 46. As shown in FIG. 12, the bearings 45 and 46 are configured such that the bearing portions 45a and 46a are axially displaced from the fixed portions 45a and 46b. Therefore, the bearing 45 is fixed by crimping the fixed portion 45a, and the bearing 46 is fixed by press-fitting the fixed portion 46b.
The drive shaft 15 is satisfactorily supported without being affected by press fitting. The bearings 45 and 46 are the same part.

The cam plate 20 and the resin gear 47 are integrally configured, and the gear 43
It is rotatably supported by the drive shaft 15 at a position between b and the substrate portion 2a.

The gear body 48 integrally has a large diameter gear 48a and a small diameter gear 48b,
It is supported by a shaft 49 that is press-fitted and fixed to the boss 40e of the flat plate portion 40a, the large diameter gear 48a meshes with the gear 43, and the small diameter gear 48b meshes with the gear 47. No oil-impregnated bearing is provided on the boss portion of the gear body 48, and the gear body 48 is directly supported by the shaft 49. Further, the gear body 48 is prevented from coming off by a flange 49a on the top of the shaft 49.

A flat belt 51 is stretched between the pulley 50 and the pulley 43a of the motor 4.

The drive shaft 15 is rotated by the motor 4 via the flat belt 51. The cam plate 20 is rotated by decelerating the rotation extracted from the drive shaft 15 via the gear body 48 and the gear 47.

In the above configuration, the shaft is only the shaft 49 in addition to the drive shaft 15, the number of shafts is small, and accordingly the number of gears is also small,
The adverse effect of the dimensional change of the gear due to the temperature change is small. Further, since the number of gears is small, the structure is simple and the cost is low.

The flywheel 44 is disposed between the bearings 45 and 46 and is supported in an ideal state, so that the drive shaft 15 can rotate stably.

The pulley / gear body 43 and the flywheel 44 are fixed, the drive shaft 15 on which the cam plate 20 is supported, and the shaft 49 to which the gear body 48 is fixed are attached to the support 40 to form a subunit, The cam plate drive portion of the disk device 1 is easily assembled. The support 40 supports two shafts, the drive shaft 15 and the shaft 49, and the subunit is small. Further, the pulley / gear body 43 and the flywheel 44 are arranged above the support 40, and the support 40
Since there is no rotating body on the lower surface side of the above, it is possible to dispose the bottom cover 54 close to the lower surface of the support 40 as described later.

Further, as shown in FIG. 1 (E) and FIG. 10 (A), the pulley
A small opening 52 used for rotation detection is formed in 43a. The opening 52 draws a locus indicated by 53 in FIG. 1 (E) and temporarily passes through a portion which does not face the flat plate portion 40a.
The bottom cover 54 attached so as to cover the bottom surface of the box-shaped chassis 2 is provided with holes 55 at portions not facing the flat plate portion 40a and facing the locus 53. The flywheel 44 is black, and the inner part of the opening 52 has a black surface on which light is difficult to reflect. The pulley 43a is white.

When the light scope or the like is applied to the hole 55 while the drive shaft 15 is rotating, the light scope receives the reflected light from the lower surface on the pool 43a. When the opening 52 passes, the reflected light is temporarily reduced and the amount of received light is reduced, and the light scope detects this time. The rotation state of the drive shaft 15 is checked by the output signal from the light scope. That is, the check of the rotation state of the drive shaft 15 using the light scope,
This is possible with the bottom cover 54 attached.

In addition, the hole 20a of the cam plate 20 allows the turntable 17 to connect to the cam plate 2
Used to position and fix with respect to 0. That is, the hole 2 corresponding to the hole 20a is formed in the board portion 2a of the chassis 2.
26 (see FIG. 2) is drilled. First, the pin locks the cam plate 20 in the position shown in FIG. 2 with respect to the two holes 126 and 20a. In this state, the motor 4 is energized to shift the backlash of each gear in the rotating direction, and in this state, the turntable 17 is moved in the direction of the arrow X ₁ through which the spindle pin 127 passes through the drive shaft 15 as shown in FIG. The turntable 17 is fixed by aligning the turning position on the line m and tightening the set screw 128.

Effect of the Invention As described above, according to the magnetic disk device of the present invention, the turntable and the mechanism for driving the cam constitute one assembly, and therefore, the assembling property of the device can be improved. Of course, the assembly does not include the motor, and the belt is used to transmit the rotation of the motor attached to the chassis to the pulley. Therefore, the assembly does not have the influence of the vibration of the motor. The structure can be made as hard as possible to receive,
As a result, the magnetic head can be moved accurately. In addition, since the assembly has a structure in which only the single reduction gear is supported by the support member in addition to the drive shaft, the assembly itself can be downsized, and thereby the device can be downsized. Also, since the number of shafts supported by the support member is small,
The adverse effects of expansion and contraction due to temperature changes can be minimized. Furthermore, since all the rotating bodies are located on the upper side of the supporting member and the rotating body is not present on the lower surface side of the supporting member, other parts such as the bottom cover etc. It has the feature that it can be easily assembled.

[Brief description of drawings]

1 (A) to 1 (F) are a plan view, a front view, a left side view and a right side view of an embodiment of a disk device according to the present invention, respectively.
FIG. 2 is a plan view showing a cartridge housing partially cut away, FIG. 2 is a plan view showing a cartridge housing partially cut away.
3 is a right side view of the disc device with the disc cartridge mounted, FIG. 4 (A) is a perspective view of the disc cartridge mounted in the disc device, and FIG. 4 (B) is the same diagram (A). A cross-sectional view taken along the line IVB-IVB in FIG. 5, and FIG. 5 shows a mounted state of the disk cartridge, which is V- in FIG.
6 is a view showing a cam plate and a track formed on the disk by the rotation of the cam plate, and FIG. 7 shows a mechanism for detecting the moving position of the magnetic head carriage. FIG. 8 is a perspective view showing the shape of one slope portion of the eject member, FIG. 9 is a plan view of a unit in which a drive shaft and a cam plate are assembled, and FIGS. 10 (A) and 10 (B). Are cross-sectional arrow views taken along the lines XA-XA and XB-XB in FIG. 9, respectively.
FIG. 11 is an exploded perspective view of the unit shown in FIG. 9, and FIG. 12 is an enlarged sectional view showing the bearing of the drive shaft. 1 ... Disk device, 4 ... Motor, 6 ... Disk cartridge, 9 ... Magnetic disk, 15 ... Drive shaft, 16 ...
… Hub, 17… Turntable, 18… Magnetic head, 20
...... Cam plate, 25 …… Swirl track, 40 …… Support, 40a …… Plate part, 40e …… Bearing part, 43 …… Pulley / gear body, 43a …… Pulley, 43b …… Gear, 44… … Flywheel, 47 …… Gear, 48 …… Gear body, 48a …… Large diameter gear, 4
8b …… Small diameter gear, 49 …… Axis, 50 …… Pulley, 51 …… Flat belt.

Claims (1)

[Scope of utility model registration request] 1. A magnetic disk device in which a magnetic head is moved in a radial direction of a disk by a cam plate to form an information recording track on the disk in a spiral shape. One supporting member and a lower end of the supporting member are supported by the supporting member. And a drive shaft to which the turntable on which the disc is placed is fixed, a pulley integrated with a flywheel fixed to the lower end of the drive shaft, and a bearing rotatably supported in the middle of the drive shaft. And a single reduction gear that is rotatably supported by the support member and that decelerates and transmits the rotation extracted from the drive shaft to the cam plate. A structure in which the assembly is attached to the chassis of the disk device, a motor is attached to the chassis, and the rotation of the motor is transmitted to the pulley via a belt. Magnetic disk apparatus according to claim.