JPS6341646Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a rotation mechanism of a magnetic disk device for recording or reproducing signals using a magnetic disk cartridge generally called a microfloppy disk. .

2. Description of the Related Art A magnetic disk cartridge 1, which is called a microfloppy disk, shown in FIGS. 3
It is constructed by accommodating the Magnetic head insertion openings 6 and 7 are provided on the front surface 4 and back surface 5 of the case 3 of this cartridge 1, respectively.
When not in use, the openings 6, 7 are closed by a sliding shutter 8. The shutter 8 is biased to the right in FIG. 1 by a spring (not shown), and in use, the shutter 8 is moved to the left against this biasing force. The disk 2 housed in the case 3 consists of a magnetic sheet 2a and a hub 2b made of magnetic metal such as stainless steel attached to the center of the magnetic sheet 2a. A spindle insertion hole 10 and a drive protrusion (drive pin) insertion hole 11 are provided in the hub 2b exposed through the opening 9 of the back surface 5 of the case 3. A conventional rotation mechanism for rotating the disk 2 in order to record or reproduce data using a magnetic head (not shown) using the disk cartridge 1 formed as described above is as shown in FIG. A spindle 13 is arranged in the center of a metal disk support 12 made of stainless steel, etc., and a drive protrusion 14 with a roller, generally called a drive pin, is provided adjacent to the spindle 13, and a metal hub 2b in the center of the disk 2 is provided. It is constructed by fixedly disposing a substantially arc-shaped (horse-shaped) permanent magnet 15 for attracting. Note that if the metal hub 2b is directly suction-supported by the metal disk support base 12, the hub 2b cannot be attached or detached smoothly, so as shown in FIG. A resin sheet 17 with good slipperiness may be attached to the support base 12.

When rotating the disk 2 using this rotation mechanism, place the hub 2b of the disk 2 on the support stand 12, and as shown in FIG. It is inserted into the holes 10 and 11, and the metal hub 2b is attracted by the magnet 15, and the support base 12 and the disk 2 are driven by the motor 18. At this time, hub 2
If the protrusion 14 does not align with the hole 11 from the beginning, the drive protrusion 14 enters the hole 11 after the hub 2b rotates while sliding on the resin sheet 17 on the support base 12, and then the drive protrusion 14 is hole 11
Move to the specified position inside.

Problems to be solved by the invention By the way, in the conventional rotating mechanism shown in Fig. 6,
Since the structure is such that the resin sheet 17 is attached, there is a drawback that the accuracy and flatness of the height of the surface that attracts the hub 2b is poor. If the disk support is made of only metal, the height and flatness of the disk abutting surface are improved by cutting, and the disk abutting surface is protected by plating. This results in better mechanical precision. However, this method has disadvantages of high cost, and because the metal support base comes into contact with the metal hub 2b, there is a possibility that the hub 2b will be attracted to the support base more strongly than necessary.

Therefore, the purpose of the present invention is to
It is an object of the present invention to provide a disk rotation mechanism that can easily move the hub 2b toward and away from the disk and can suppress an increase in cost.

Means for Solving the Problems The present invention for achieving the above object will be described with reference to the reference numerals in the drawings shown in the embodiments for ease of understanding. The disc cartridge 1 rotatably drives the disc 2 in a disc cartridge 1 in which a recording medium disc 2 consisting of a metal hub 2b having a metal hub 2b and a recording medium sheet 2a attached to the hub 2b is rotatably housed in a case 3. A metal support stand 12, a spindle 13 provided to protrude from the support stand 12 and inserted into the spindle insertion hole 10, and the support stand 1.
a drive protrusion 14 protruding from the hub 2b and inserted into the drive protrusion insertion hole 11; and a magnet 15 for attracting the hub 2b.
In a disk rotation mechanism having
The present invention relates to a rotation mechanism of a magnetic disk device characterized in that a contact surface 21 for the hub 2b is provided.

Effects According to the above invention, since the resin part 20 is insert-molded on the support base 12, the precision of the abutting surface against the hub 2b can be increased by cutting or the like. Further, since the metal hub 2b is not supported by a metal surface but is supported by the resin part 20, the hub 2b
The contact and separation can be performed smoothly.

Embodiment Next, a rotation mechanism of a magnetic disk device according to an embodiment of the present invention will be described with reference to FIGS. 1 to 5. However, in FIGS. 1, 2, and 5, the symbols 2, 2a, 2b, and 10 to 15 are substantially the same as those indicated by the same symbols in FIG. 6, so the explanation thereof will be omitted. Omitted.

The rotation mechanism shown in FIGS. 1 and 2 rotates the disk 2 of the disk cartridge 1 shown in FIGS. 3 and 4. In the disk support base 12 of this embodiment, the top surface of the central portion 12a is the hub 2b.
Instead, the groove 19
A resin part 20 that is insert-molded to include an annular protrusion 12b having a shape is configured to come into contact with the hub 2b. Since the groove 19 is formed to correspond to half of the dovetail groove, the resin part 2
0 is firmly integrated into the support base 12. The resin part 20 is made of a fluorine-containing polyacetal resin that has low frictional resistance against the hub 2b, has sufficient hardness, and has good workability, and has a surface that stably supports the hub 2b at a predetermined height. It has a hub abutting surface 21 which is machined. Since the hub contact surface 21 of the annularly projecting resin part 20 projects beyond the top surface of the central part 12a of the metal support base 12, the hub 2b is supported by the resin part 20 at the outer peripheral end of the disk 2. .

The disk 2 is attached to and detached from the rotating mechanism shown in FIG. 1 in the same manner as in the case shown in FIG. 6. When installing the disk 2, if the hole 11 and the drive protrusion 14 do not match, the hub 2b presses the protrusion 14,
The protrusion 14 is displaced together with the leaf spring 14a supporting it, the hub 2b rotates while sliding on the resin part 20, and then the protrusion 14 enters the hole 11.
At this time, the hub 2b rotates smoothly on the resin part 20 because the hub abutting surface 21 of the resin part 20 has high slipperiness.

When the hub 2b is attracted and held by the magnet 15,
In FIG. 1, the magnetic closed circuit consisting of the magnet 15 magnetized in the vertical direction (vertical direction), the hub 2b, and the center part 12a of the support base 12 greatly contributes to the attraction of the hub 2b, and the magnet 15 and the hub 2b The path consisting of the outer peripheral end protrusion 12b hardly contributes to adsorption. That is,
A central portion 12a of the disk support base 12 of this embodiment is arranged close to the hub 2b, and a protruding portion 12b at the outer peripheral end.
is separated from the hub 2b by the resin portion 20.
Therefore, most of the magnetic flux passes through the magnetic circuit including the central portion 12a with low magnetic resistance, and there is almost no magnetic flux leaking between the hub 2b and the outer peripheral end protrusion 12b. Therefore, the influence of leakage magnetic flux on the magnetic sheet 2a of the disk 2 is extremely reduced.

The resin part 20 of this embodiment is formed by insert molding, is firmly integrated with the protruding part 12b, and the accuracy of the height and flatness of the hub contact surface 21 is improved by cutting. As a result, disk 2
can be stably supported.

Furthermore, since the outer peripheral end of the hub 2b is supported, even if an external force is applied to the magnetic sheet 2a by a head or the like, the distance from the support point to the point of application of the external force is shorter than that shown in FIG. The moment becomes small, and the stability of the rotation of the disk 2 becomes high.

In addition, in the rotation mechanism shown in FIG. 1, the stainless steel hub 2b is not directly supported by the stainless steel support base 12, but is supported by the resin part 20 with a small coefficient of friction, so that the two are firmly connected. It is not. Therefore, the disk 2 can be removed smoothly.

FIG. 5 shows a disk rotation mechanism according to another embodiment of the present invention. In this example, a groove 19 corresponding to half of the groove is provided in the central portion 12a of the stainless steel disk support 12, and a resin portion 20 is provided therein by insert molding. Then, the top surface of the central resin portion 20 is cut, and the hub 2b
are formed so that they are in contact with each other.

Effects of the Invention In the present invention, since the contact portion with the hub is composed of a resin portion formed by insert molding, a highly accurate contact surface can be easily obtained. Further, since the metal hub is not supported by metal but by a resin portion, the disk can be smoothly attached and detached.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a rotating mechanism and a disk according to an embodiment of the present invention, FIG. 2 is a plan view of the rotating mechanism shown in FIG. 1, FIG. 3 is a plan view of a magnetic disk cartridge, and FIG. FIG. 3 is a bottom view of the cartridge, FIG. 5 is a sectional view showing a rotation mechanism according to another embodiment of the present invention, and FIG. 6 is a sectional view showing a conventional rotation mechanism. 1... Cartridge, 2... Disk, 2b...
... hub, 10 ... spindle insertion hole, 11 ... drive projection insertion hole, 12 ... support stand, 12b ... annular projection, 13 ... spindle, 14 ... drive projection, 15 ... magnet, 19 ... Groove, 20...resin part, 21...contact surface.

Claims (1)

[Scope of claims for utility model registration] (1) Spindle insertion hole 10 and drive projection insertion hole 1
1 and a recording medium sheet 2a mounted on the hub 2b, the disk cartridge 1 rotatably accommodates a recording medium disk 2 in a case 3. , a metal support 12; a spindle 13 provided to protrude from the support 12 and inserted into the spindle insertion hole 10; and a spindle 13 provided to protrude from the support 12. In addition, in the disk rotation mechanism having a drive protrusion 14 disposed to be inserted into the drive protrusion insertion hole 11 and a magnet 15 for attracting the hub 2b, the metal support base 12 is A rotating mechanism for a magnetic disk device, characterized in that a resin part 20 is provided in an integrated state by insert molding, and this resin part 20 is provided with an abutting surface 21 for the hub 2b. (2) The rotation mechanism according to claim 1, wherein the resin portion 20 is a portion formed of a hard resin that has low frictional resistance with respect to the hub 2b. (3) The rotation mechanism according to claim 1 or 2, wherein the resin portion 20 is provided on the outer periphery of the support base 12.