JPS59207471A - Magnetic disk cartridge - Google Patents

Abstract

PURPOSE:To improve remarkably the reliability for preservation of a magnetic disk by providing a spoiler concentrically at the outer fringe of the disk and at the same time drilling an air discharge hole to a case that stores the disk rotatably. CONSTITUTION:A spoiler 7 is fixed to both case upper and lower plates concentrically to the outer fringe of a magnetic disk. An air discharge hole 4a is drilled to the case side plate, and a dustproof filter 4b is set to the hole 4a in order to eliminate the disturbance of the air current within a cartridge. Thus the magnetic disk is revolved at high stability and high accuracy. Furthermore the dust is prevented from entering the cartridge. As a result, the reliability is remarakably improved for preservation of the magnetic disk.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention provides a magnetic disk recording/reproducing apparatus I? Concerning a long magnetic disk cartridge.

To give an example of a conventional magnetic disk cartridge, in FIGS. 1 and 2, 1 is a magnetic disk, 2 is a disk hub that drives and rotates the disk, 3, 4 and 5 are cases for storing and maintaining the magnetic disk. A case top plate, a case side plate and a case top plate 8 are each fastened with fixing screws 6, and a disk hub hole 3b is bored in each of the case top plate and bottom plate ζ, into which the disk hub is rotatably mounted. And is it possible to read and write on magnetic disk 1? A roaring head insertion port 6a is provided.

Therefore, in the conventional magnetic disk cartridge described above, when the magnetic disk 1 is rotated at high speed in the direction of arrow V, the air near the disk is moved by centrifugal force as shown by arrow a.
, or as shown by the arrow A. At this time, the flow at a position where the magnetic disk 1 and the case side plate 4 are relatively close together, that is, the flow shown by the arrow a, is reflected by the side plate and a vortex is generated. Since the flow then merges with the flow near the magnetic disk 1, the pressure near the disk changes, causing vibrations, especially at the outer circumference.

Furthermore, since the sides of the case 8 are formed in a sealed state, the air flow in the radial direction between the case upper and lower plates 3 and 5 and the magnetic disk 1 is as shown in FIG. ,
Only the secondary flow circulates, and as a result, the reflected flow is
The vibration source joins this secondary flow and causes the vibration source to spread toward the inner circumference of the magnetic disk 1-. The above-mentioned vibration of the magnetic disk 1 has an unavoidable disadvantage in that it affects the state of contact with the writing and reading heads, thereby adversely affecting the recording and reproducing characteristics of the disk.

This invention has been made in view of the current situation, and includes providing a spoiler on the outer periphery of a magnetic disk and providing a dust-proof air outlet on the side surface of a case that rotatably stores the disk. The present invention aims to provide a magnetic disk cartridge that eliminates the drawbacks of the prior art.

Next, referring to the embodiments of this invention, Section 3.4
．． In Figures 8 and 9, the upper case plate 6 and the lower case plate 5
The upper and lower plates of the case 9 are assembled by fastening the case side plates 4 with fixing screws 6, and the disk hub 2 is inserted into the hub hole. is rotatably fitted, and the corresponding
A magnetic disk cartridge 10 is obtained by attaching the magnetic disk 1 to the disk. In this invention, a spoiler 7 is fixed to the upper and lower plates of the f-space in a concentric manner, covering the outer peripheral edge of the disk. Furthermore, an air outlet 4af9 is provided on the side plate of the case, and a dust filter 4b is placed over the outlet, and the spoiler has a spoiler groove 11 having a width described below between each adjacent slot and in. At the same time, the outer peripheral edge of the disk maintains an inclination angle, which will be described later. Now, to explain in detail the setting of the width and inclination angle of the spoiler groove, the air flow between the case upper plate 6 and lower plate 5 and the rotating magnetic disk 1 is approximated by the Navier-Stokes equation expressed in polar coordinates. The following equation can be used to obtain C.

j6, ρ: air density, μ: viscosity coefficient of air, P: pressure, u: flow velocity in the radial direction of the air disk, V: flow velocity in the tangential direction, Z: coordinate in the height direction, ": Let the coordinates be in the radial direction.

In order to solve the above +11 and tel, calculate the flow t between the -C magnetic disk and the lower case plate, and find the relationship with the case upper plate from the symmetry regarding the magnetic disk. Letting the Z coordinate of the I-space lower plate be 0 and the Z coordinate of the magnetic disk be h, the following boundary strip t-1 is obtained.

Here, ω is the angular velocity of the magnetic disk.

Solving equations (1) and (2) from equation (3) results in the following. (・
t) The first term on the right side of the equation is the Hagen-Boiseuille flow (Fh) caused by the pressure difference t between the inner periphery and the outer periphery of the disk, and the second term is the fluid ζ caused by the centrifugal force. - is the secondary flow that occurs, (F4) is shown. Also, (5j
The equation shows the Crafts flow (Fq) of the fluid. These are shown in Figures 5 and 6. Figure 5 shows the velocity distribution of the radial component U of the airflow, h/2
The maximum flow velocity is on the disk side rather than the position, and FIG. 6 shows the velocity distribution of the tangential component V of the air flow, and the maximum flow velocity is on the disk surface.

Now, if the radius of the magnetic disk is b, the velocity component near the outermost circumference of the magnetic disk is given by the formula [41, +51, r =
b is obtained by substituting
u (b, Z) , V (b, Z) ) = W(
Z) −・−−−−−−−16+. This velocity vector W (Z) changes both its magnitude and direction depending on Z, and if this is displayed in Fig. 7, W
o is the z=0 position, W6 is the velocity vector of the z=h device, and Wa is the velocity vector where the radial direction velocity component is maximum.
A velocity vector at the h i'naK position.

11 (b% llmax)”Llmax ((4
From formula 1 h/2〈llmaK＜h)・・・・・・・・・
・・・・・・・・・・・・・・・・・・・・・・・・
...(1), Vra-=W((u (b, hmax bar r (b% l
lmax) )・・・・・・・・・・・・・・・・・・
・・・・・・・・・・・・・・・・・・(8).

In the embodiment described above, the spoiler 7 having the spoiler groove 11 aligned with the streamline of the stroke having the largest velocity component in the radial direction is arranged concentrically outside the outer periphery of the magnetic disk 1. The inclination angle θ of the spoiler groove (FIG. 8) is made to coincide with the direction of the velocity vector w4, and its value is given by, and the groove width W of the spoiler groove 11 is cut out at a constant value.

Since this embodiment is configured as described above, its operation and effects are as follows.

In other words, the airflow generated as the magnetic disk 1 rotates has a velocity vector shown in FIG. This is the flow of Wa whose velocity component is the maximum in the radial direction, and this is caused by the spoiler 7 whose direction is coincident as shown in Fig. 4.
It passes smoothly through the spoiler groove 11 and forms a flow as indicated by the arrow C1 or arrow C1. The flow indicated by arrow C is discharged from the air outlet 4a to the outside of the case 9 via the dust filter 4b, and the flow indicated by the arrow collides with the case side plate 4 to form a vortex, which is reflected by the spoiler. Because the streamlines of the flow are different, the flow does not enter the magnetic disk 1 side and stagnates at point E inside the case 9, or it merges with the flow of arrow C and is discharged outside the case 9.

Also, regarding the flow other than w4 shown in Figure 7,
Crazy. Since the velocity vector of the flow Wa is zero, it does not affect the disk, and the flow Wa has a velocity component in the radial direction of zero value, so it does not pass through the spoiler groove 11 and rotates together with the magnetic disk 1. Therefore, a reflected flow is not formed (and a stable laminar flow is formed. Velocity vectors other than the above have velocity components in the radial direction, and their streamlines are given by equation (9) above. Inclination angle θ (although the slope does not match, the groove width W of the spoiler groove 11 in Figure 8 2)
If is set relatively large, many velocity vectors will pass through and be disturbed, and the velocity vectors that do not pass through the spoiler collide with the spoiler 7 and form a reflected flow, but this velocity vector has a radial component. Since it is generally small, the effect on the magnetic disk is small. Please note that when storing magnetic disks, it is required to shield them from dust.
Since a dustproof film 4b is attached to the air outlet 4a provided on the case side plate 4, there is no risk of dust entering the magnetic disk cartridge according to the present invention.

Furthermore, in the above embodiment, the inclination angle of the spoiler groove 11 of the spoiler 7 was given by equation (9), but if the complexity of the shape is not an issue, the spoiler whose inclination angle θ changes in the Z direction can be expressed as It may be formed in a groove, and the groove width W of the groove was set constant in the above embodiment, but as shown in FIG. The groove @W2 may be formed to be wider than the groove width W1 in the inner peripheral portion, and the planar shape of the groove in this case is approximately a regular ladder shape as shown in FIG. 10a, or an inclined ladder shape as shown in FIG. 10b. Various shapes are conceivable, such as a ladder shape with a curved base as shown in FIG. 10c.

Furthermore, in the above-mentioned embodiment, the spoiler 7 was disposed concentrically outside the outer periphery of the magnetic disk 1, but as shown in FIG. An upper spoiler 7a with a height h5 lower than the height h may be vertically provided, and a lower spoiler 7b may be similarly provided upright from the case lower plate 5, and the spoiler height h3 in this case is: h/2<lls<h...
・・・・・・・・・・・・・・・・・・・・・・・・
・・・・・・・・・・・・ Old) must be satisfied.

As described above, the present invention is characterized in that spoilers are disposed concentrically around the magnetic disks within the magnetic disk cartridge disk storage/protection case, and a dust-proof air outlet is provided by drilling in the side plate of the case. A simple method that effectively removes airflow turbulence inside the cartridge to obtain a magnetic disk that rotates stably and with good precision, and at the same time prevents dust from entering the cartridge and improves disk storage. It can be said that this invention has high industrial utility value, such as greatly improving reliability.

[Brief explanation of the drawing]

Fig. 1 is a cutaway diagram showing the main parts of a conventional magnetic disk cartridge, Fig. 2 is a cross-sectional view taken along line A-A from the previous time, and Fig. 6 shows main parts showing an embodiment of the present invention. Fig. 4 is a cutaway perspective view, Fig. 4 is a plan view with the main parts cut out, Fig. 5 is a flow velocity distribution diagram of the air flow in the magnetic disk cartridge in the disk radial direction, and Fig. 6 is the same in the disk tangential direction. FIG. 7 is a velocity vector distribution diagram of the air flow near the outermost edge of the magnetic disk; FIG. 8 is a plan view showing the spoiler, spoiler groove, groove width, and inclination angle according to an embodiment of the present invention; FIG. 9 is a sectional view taken along B-B from the previous time showing the mutual relationship between the spoiler and the disc.
Figure 1 [1a, b and 0] show the main parts of spoiler groove shapes according to other embodiments, respectively. The plan view and FIG. 11 are longitudinal sectional side views of essential parts showing the mutual relationship between a spoiler and a disk according to another embodiment. 1...Magnetic disk, 2...Disk hub, 6...
・Case top plate, 4...-r-side plate, 5...Case bottom plate, 6...Fixing screw, 7...Spoiler, 3a...
・Head insertion port, 6b... Disc hole, 4a.
... Air outlet, 4b... Dust filter, 8... Conventional magnetic disk case, 9... Magnetic disk storage protective case according to the present invention, 10... Magnetic disk cartridge, 11... - Spoiler groove, 7a...An upper plate side spoiler according to another embodiment of the present invention, 7b...Similarly, a lower plate side spoiler 1. Note that the same reference numerals in the figures indicate the same or corresponding parts. Agent Masuo Oiwa Figure 1 Figure 2 Figure 3 ν ( 4II Figure 4 Figure 5 Cause Figure 6 Figure 7 Figure 8 B Section 9/b Figure 10 [a) (b) (+:) No. 11 Figure 7b 5 Procedural amendment (voluntary) 59 5 F7 Showa Year Month Date Commissioner of the Japan Patent Office 1. Indication of case Japanese Patent Application No. 1982-82009 2. Name of invention magnetic disk cartridge 3. Person making the amendment (1 ) Column 6 of "Detailed Description of the Invention" in the specification, contents of amendment (1) rVIJ in box 7, line 6 of the specification, lines 4, 5, and 14 of the same page Correct it with "a". (2) The text "rVIoJ" on page 7, line 7 of the specification is corrected to "V″o". (3) The text rVI6J on page 7, line 8 of the specification is corrected to "f6". (4) The text "■4" on page 7, line 8 of the specification box, line 14 of the same page, and line 17 of the box on the same page is corrected to "Y4". (5) r on the 3rd line of page 8 of the middle part of the specification and the 15th line of the box on the same page
Correct W4J to ra4J. (6) “■4” on page 9, line 7 of the specification,
Correct as [4]. (7) Correct the text "rVl, J" on page 9, line 8 of the specification to read "Ryo0". (8) "■6" on page 9, line 9 of the specification,
16”. (9) Correct boxes 6 and 7 in the drawing as per the attached sheet.

Claims (1)

[Scope of Claims] A magnetic disk cartridge characterized in that a spoiler is disposed concentrically around the outer peripheral edge of an Ell magnetic disk, and an air outlet is provided in a case for rotatably housing the disk. 2. The magnetic disk cartridge according to claim 1, wherein a +21 spoiler is engaged with and disposed outside the outer periphery of the magnetic disk. 2. The magnetic disk cartridge according to claim 1, wherein the +31 grooves 2 are disposed in engagement with each other above and below the outer peripheral edge of the magnetic disk. (Magnetic disk cartridge according to claim 1, in which the angle of inclination of the groove of the spoiler is adjusted to the air flow line at the outer periphery of the magnetic disk. (5) The width of the groove of the spoiler is set to a constant width inside and outside the groove. A magnetic disk cartridge according to claim 1, wherein the groove width of the 61 spoiler is formed such that the inside width is larger than the outside width inside and outside the groove. (7) The magnetic disk cartridge according to claim 1, wherein the air outlet has a dust-proof structure.