JPH09213046A - Disk cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve slidability of a shutter and to prevent failure of recording and reproducing due to worn particles stuck to a recording body by providing an annular recessed part around the vestige of a gate formed by injection molding into a shutter slide recessed part and making the shutter traverse above the vestige of the gate. SOLUTION: An upper case and a lower case, constituting a cartridge case 1 are molded out of a hard synthetic resin such as ABS resin, etc. When the upper case 1a (the lower case 1b) is molded, a plate thickness t2 of a triangular part 22 surrounded by a circumferential wall 12c(12b) and an arcuate rib 13b is thinner than a disk plate thickness t1 on the inner side from the arcuate rib 13b, and both plate surfaces are in almost the same plane. A plane thickness t3 of the arcuate rib 13b is also thinner than the plate thickness t1 on the disk housing side. A plate thickness t4 of the circumferential wall 12c at least in the vicinity of the middle part is also thinner than the plate thickness t1 . Consequently, a resin flow into the housing side from its surrounding part is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk cartridge such as a magnetic disk cartridge, an optical disk cartridge and an optical-magnetic disk cartridge, and more particularly to a disk cartridge using a cartridge case made of a synthetic resin molded body. .

[0002]

2. Description of the Related Art FIG. 13 is a partially exploded perspective view showing a lower case of a magnetic disk cartridge conventionally used, with the lower case facing upward, FIG. 14 is a plan view of an upper case used for the magnetic disk cartridge, and FIG. FIG. 4 is a bottom view of a lower case used for the magnetic disk cartridge.

A magnetic disk cartridge is, for example, AB
A cartridge case 1 including an upper case 1a and a lower case 1b formed of a hard synthetic resin such as S resin;
It mainly comprises a magnetic disk body 2 rotatably housed therein and a metal or synthetic resin shutter 3 slidably supported by the cartridge case 1.

At a predetermined position of the upper case 1a and the lower case 1b, a rectangular, elliptical or oblong head insertion opening 4 is provided, which can be opened and closed by the shutter 3. Also, almost in the center of the lower case 1b,
A circular opening 5 is formed.

The magnetic disk unit 2 comprises a donut-shaped flexible magnetic disk 2a and a hub 2b made of, for example, a magnetic stainless steel plate and fixedly supported on the inner peripheral portion of the magnetic disk 2a. . The hub 2b is disposed in the opening 5 of the lower case 1b as shown in FIG.

The upper case 1a and the lower case 1b
In the vicinity of the front surface, a shutter slide recess 6 which is slightly lowered to restrict the sliding range of the shutter 3 is formed.
Has been established. The shutter 3 is always elastically urged by a spring member (not shown) in a direction to close the head insertion port 4. On the other hand, a guide groove 7 extending in the sliding direction of the shutter 3 is formed near the front surface of the lower case 1b.

[0007] In FIG. 14 and FIG.
Is a label sticking part, and upper case 1a and lower case 1b
Slightly lower than the surface. 9 is the case 1a, 1b
Is a gate trace that is generated when is injection-molded.

[0008]

As described above, the upper case 1a and the lower case 1b are formed by injection-molding a synthetic resin.
As shown in FIG. 5, the gate at the time of injection molding is the case 1a (1
The synthetic resin in the molten state is placed in the molding die from a total of four positions, two at a predetermined interval in the recess 6 of FIG. b) and two at a predetermined interval in the label sticking portion 8. It was molded by injection, filling, and then holding and cooling.

By the way, the conventional disk cartridge is
Gate marks 9 formed by injection molding protrude from the surfaces of the shutter slide recess 6 and the label sticking portion 8. When the gate mark 9 protrudes from the surface of the concave portion 6,
The slidability of the shutter 3 is poor, so that the opening and closing of the head insertion opening 4 is not smooth, and the gate mark 9 is shaved by the edge of the shutter 3 to generate abrasion powder, which passes through the head insertion opening 4 to the magnetic disk body 2. Adheres and hinders data recording and reproduction. In particular, in the case of the metal shutter 3, the gate mark 9 is remarkably scraped.

Further, if the gate mark 9 is projected from the surface of the label sticking portion 8, there is a defect that the label wrinkles when the label is stuck and the appearance is impaired.

Further, as shown in FIGS. 14 and 15, the upper case 1a and the lower case 1b formed as described above have the molten resin merged and merged at a substantially intermediate position of the case 1a (1b). Scars formed at the time,
The so-called weld lines 10 and 10 'often occur.

[0012] In the ABS resin molded product, the mechanical properties are as follows as compared with the portion where the weld line is formed and the portion where the weld line is not formed.

.. The tensile strength drops by about 2-10%. . The creep rupture time is reduced to about 1/10 to 1/100. . The tensile impact strength is reduced by about 70-80%. . The fatigue strength when a constant high load is applied is about 1 /
Decrease by 3 to 1/2. When the weld lines 10 and 10 'are formed substantially at the center of the case 1a (1b), the mechanical strength of the weld lines 10 and 10' is extremely reduced, which causes the case 1a (1b) to crack or deform. .

If the weld lines 10 and 10 'are formed, the appearance is also unfavorable, and the molding is subject to poor molding.
Furthermore, it is difficult to provide a gas vent structure for facilitating the flow of the resin at these resin confluence points (central portion), and there is a drawback that quality defects related to appearance and strength due to air pockets and gas burning frequently occur. .

An object of the present invention is to eliminate the disadvantages of the prior art, to provide good shutter slidability, to prevent recording and reproduction from being hindered by the attachment of abrasion powder to a disk recording medium, or to provide a label. An object of the present invention is to provide a disk cartridge free from wrinkles and the like.

[0016]

According to a first aspect of the present invention, a shutter slide recess is provided at a predetermined position, and a head is inserted into the shutter slide recess. A cartridge case having an opening, a recording disk body rotatably housed in the cartridge case, and a shutter slidably mounted in the shutter slide recess to open and close the head insertion opening. It is intended for disk cartridges.

A gate mark is formed by injection molding in the shutter slide recess, and an annular recess is provided around the gate mark to prevent the gate mark from protruding from the surface of the shutter slide recess. , So that the shutter crosses the top.

According to a second aspect of the present invention, there is provided a cartridge case made of a synthetic resin molded article having a head insertion opening and a label sticking portion at predetermined positions, and a cartridge case having the same. And a recording disk body rotatably accommodated in the disk cartridge.

A gate mark is formed by injection molding in the label sticking portion, and an annular concave portion is provided around the gate mark to prevent the gate mark from protruding from the surface of the label sticking portion. It is a feature.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As described above, in the first aspect of the present invention, by providing an annular recess around a gate mark formed by injection molding of a cartridge case, the gate mark projects from the surface of the shutter slide recess. Therefore, even if the shutter crosses over the gate mark, the shutter does not contact the gate mark. Therefore, the sliding of the shutter is smooth, and there is no generation of wear powder due to the scraping of the gate mark, so that the recording and reproduction obstacles due to the attachment of the wear powder to the disk recording body are eliminated, and the reliability can be improved.

According to the second aspect of the present invention, as described above, by providing an annular concave portion around the gate mark formed by injection molding of the cartridge case, the gate mark is prevented from protruding from the surface of the label sticking portion. Therefore, when the label is applied from above the label affixing portion, the label can be applied neatly without generating wrinkles, and the appearance defect is eliminated. It should be noted that even if an annular concave portion is provided around the gate mark, it can be covered and hidden with a label, so that the appearance is not impaired.

Next, an embodiment of the present invention will be described with reference to the drawings. 1 is a plan view of the upper case, FIG. 2 is a bottom view of the upper case, FIG. 3 is a plan view of the lower case, FIG. 4 is a bottom view of the lower case, and FIGS. FIG. 7 is an enlarged cross-sectional view near a gate mark, and FIG. 8 is an enlarged cross-sectional view taken along the line AA of FIG.

The upper case 1a and the lower case 1b constituting the cartridge case 1 are formed of a hard synthetic resin such as an ABS resin or a styrene resin. And FIG.
As shown in FIG. 5, a rectangular, elliptical or oval head insertion port 4 is provided substantially at the center near the front end face of the upper case 1a, and the shutter 3 (not shown) is provided so as to include the head insertion port 4. A shutter slide recess 6 for regulating the sliding range is formed, and this portion is thinner than its surroundings. A wide label sticking portion 8 slightly lower than the surface is provided from the middle portion to the rear end surface of the upper case 1a so as to be adjacent to the concave portion 6, and this portion is formed thinner than its surroundings. .

Gate traces 9a and 9b are formed at substantially equal intervals near the front end face of the upper case 1a with the head insertion opening 4 interposed therebetween. Gate mark 9 near the rear end of 1a
Is not formed. Therefore, when molding the upper case 1a, molten resin is injected into the mold from two pin gates, and the rear end 11 becomes the resin filling end position of the upper case 1a.

As shown in FIG. 2, discontinuous rib-shaped peripheral walls 12a, 12b and 12c are formed at the peripheral end of the upper case 1a. Inside the peripheral wall 12, arc-shaped ribs 13a, 13b, 13c connected to them are provided.
The inside of the rib 13 is a storage space for a disk (not shown).

At a position corresponding to one of the gate traces 9a,
A frusto-conical gate recess 14 protruding toward the inside of the upper case 1a is formed. In addition, at the position corresponding to the other gate mark 9b, the gate recessed portion 14 is not formed because the thick portion is formed at that portion. However, if the portion is not thick, it must be formed.

Gate mark 9a and gate recess 14
As shown in FIG. 7, an annular recess 15 is formed around the gate trace 9a, and the gate trace 9a is
A escapes from the surface a, that is, the surface of the shutter slide recess 6 and the surface of the label sticking portion 8.

The gate recess 14 is provided at a position facing the gate mark 9a, and the inclination angle θ of the gate recess 14 is 30 to 30 to smooth the flow of resin during molding.
It is about 60 degrees and the gate recess 14
The thickness L2 of the thinnest portion is designed to be substantially equal to the thickness L1 of the upper case 1a.

As shown in FIG. 3, a rectangular, elliptical or elliptical head insertion port 4 and a guide groove 7 are provided substantially at the center near the front end face of the lower case 1b. Shutter 3 including groove 7
A shutter slide recess 6 for regulating a sliding range (not shown) is formed. An opening 5 into which the drive shaft is inserted is provided substantially at the center of the lower case 1b, and a label sticking portion 8 slightly lower than the surface is formed near the rear surface.

In the vicinity of the front end surface of the lower case 1b, the gate marks 9 are located at substantially equal intervals with the head insertion port 4 therebetween.
a and 9b are formed, and the molten resin is injected from two places in the same manner as in the upper case 1a, and the rear end 11 becomes the final resin filling position of the lower case 1b.

As shown in FIG. 4, discontinuous rib-shaped peripheral walls 12a, 12b and 12c are formed at the peripheral end of the lower case 1b. Inside the peripheral wall 12, three arc-shaped ribs 13a, 13b, and 13c are provided so as to be continuous with them, and the inside of the rib 13 serves as a disk storage space.

As in the upper case 1a, one of the gate traces 9
A frustum-shaped gate drop portion 14 protruding toward the inside of the lower case 1b is formed at a position facing the position a. In addition, the position corresponding to the other gate mark 9b has a thick portion formed in that portion, so that the gate drop portion 14
Is not formed.

As schematically shown in FIGS. 5 and 6, the molten resin is injected from the positions of the gate marks 9a and 9b (pin gate positions). As shown by the arrow, it flows in one direction toward the other side end, the rear end 11 becomes the final filling position, and a weld line is not formed in the center of the case 1 unlike the conventional case.

As shown in FIGS. 2 and 4, near the rear end 11 of the upper case 1a (lower case 1b), a single rib-shaped peripheral wall 12 extending along the rear end 11 is provided.
and two arc-shaped ribs 13b connected over the peripheral wall 12b and the peripheral wall 12c.

In addition, the upper case 1a (the lower case 1) corresponding to between one arc-shaped rib 13b and the other arc-shaped rib 13b.
Since the label sticking portion 8 is provided on the surface of b), the plate thickness is designed to be considerably thin. Further, the face plate portion of the case at the portion surrounded by the arc-shaped ribs 13a and 13b forming the disk storage space is formed to be thinner than the triangular portion 22 at the outer peripheral corner.

From the above, when molding the upper case 1a (lower case 1b), the synthetic resin in the molten state can be quickly removed toward the portion where the arc-shaped rib 13b, the triangular portion 22, and the peripheral wall 12c are formed. The thin portion between the arc-shaped ribs 13b, which is the end position of the resin filling of the face plate portion of the case forming the disk storage space, tends to have a poor flow of the resin. For this reason, there is a concern that the thickness of the thin-walled portion becomes insufficient, or a hole is formed in an extreme case.

Therefore, in the present embodiment, the following measures are taken. That is, as shown in FIG. 8, (a) than the thickness t ₁ of the inner disk housing side than the arcuate rib 13b, the peripheral wall 12b and the peripheral wall 12c and the arcuate rib 13b
The plate thickness t ₂ of the triangular portion 22 surrounded by is reduced, and the surfaces of both are made substantially flush. (B) The plate thickness t ₃ of the arcuate rib 13b is also made thinner than the plate thickness t ₁ on the disk storage side. (C) thinner than the thickness t ₄ also the thickness t ₁ of the disc storage side of at least near the central portion of the peripheral wall 12c (during the connection of the connecting portion and the other of the arcuate rib 13b between one arcuate rib 13b) did.

By reducing the thickness of the peripheral wall 12c, the triangular portion 22, and the arc-shaped rib 13b, these thin portions serve as resistance portions against the flow of the resin in the mold.
Also, by making the surface of the triangular portion 22 flush with the surface of the inner portion (disk storage portion side) of the arc-shaped rib 13b, the flow of resin from the periphery to the disk storage portion side is improved, and the molding as described above is performed. The occurrence of defects is prevented.

FIGS. 9 and 10 are bottom views of the upper case 1a for explaining another embodiment of the present invention.
In the case of this example, as shown in FIG. 9, the arc-shaped ribs 13b are intermittently divided and formed. By doing so, the resin flow resistance effect near the arc-shaped rib 13b during molding becomes remarkable.

In the case of this embodiment, as shown in FIG. 10, the triangular portion 22, the arc-shaped rib 13b and the peripheral wall 12 are provided.
The thicknesses t ₂ ′, t ₃ ′, and t ₄ ′ of c have the following relationship with the thickness t ₁ ′ near the disk storage space.

T ₂ ′ = 1.4 t ₁ ′ t ₃ ′ = 1.4 t ₁ ′ t ₄ ′ = 1.4 t ₁ ′ FIG. 11 shows an upper case for explaining still another embodiment of the present invention. It is a top view of 1a. In the case of this example, one or more (two in the present embodiment) gate traces 9 are formed on the rear surface edge 11 (label sticking portion 8) side. In the case of the present embodiment, the concave portion 6 is a thin portion. Therefore, the peripheral wall 12a is made thin, and the peripheral wall 12a and the peripheral wall 1 are formed.
It is better to take measures to make the triangular portion 22 surrounded by the arc-shaped ribs 13a thinner and to make the triangular portion 22 substantially flush with the surface on the side of the disk housing portion inside the arc-shaped ribs 13a.

9 and 11, the upper case 1
Although only a is shown, the lower case 1b has the same shape as the upper case 1a.

FIG. 12 is a characteristic comparison diagram between the embodiment according to the present invention and a comparative example. In the figure, the mark “良好” indicates a result determined to be good, the mark “X” indicates a result determined to be bad, and the mark “△” indicates a result determined to be intermediate.

As is apparent from this figure, in the case of the embodiment of the present invention, the number of weld lines generated in the cartridge case is at least one, and the appearance quality due to the pinhole due to the gas reservoir at the center portion and the gas burnt. No defect,
Further, the mechanical strength is not lowered by the two complicated weld lines, a stable product size is obtained, and a high quality disc cartridge can be provided.

Although the above embodiment has been described with reference to a magnetic disk cartridge, the present invention is also applicable to disk cartridges such as an optical disk cartridge and an optical-magnetic disk cartridge.

[0046]

According to the first aspect of the present invention, as described above, an annular recess is provided around a gate mark formed by injection molding of a cartridge case, so that the gate mark is formed on the surface of the shutter slide recess. Since the protrusion is further prevented, the shutter does not come into contact with the gate trace even when the shutter crosses the gate trace. Therefore, the sliding of the shutter becomes smooth, and since there is no generation of abrasion powder due to the scraping of the gate trace, the obstruction of recording and reproduction due to the attachment of the abrasion powder to the disk recording body is eliminated.
Reliability can be improved.

According to the second aspect of the present invention, as described above, by providing an annular concave portion around the gate mark formed by injection molding of the cartridge case, the gate mark can be formed from the surface of the label attaching portion. Since it is prevented from protruding, when the label is applied from above the label affixing portion, the label can be neatly applied without causing wrinkles on the label, and the appearance defect is eliminated. It should be noted that even if an annular concave portion is provided around the gate mark, it can be covered and hidden with a label, so that the appearance is not impaired.

As described in claim 3, when the thick part is provided on the surface of the cartridge case opposite to the surface on which the gate mark is formed so as to face the gate mark, the annular recess is formed as described above. Even if provided, the flow of molten resin is smooth.

According to the fourth aspect, if the gate mark is formed only near the front end of the cartridge case and the rear end of the cartridge case is at the resin filling end position, the number of weld lines is reduced, and A stable product size can be obtained without lowering the mechanical strength, and a high-quality disk cartridge can be provided.

According to the fifth aspect, if the gate mark is formed only near the rear end of the cartridge case and the front end of the cartridge case is at the resin filling end position, the number of weld lines is reduced, and A stable product size can be obtained without lowering the mechanical strength, and a high-quality disk cartridge can be provided.

[Brief description of drawings]

FIG. 1 is a plan view of an upper case of a magnetic disk cartridge according to an embodiment of the present invention.

FIG. 2 is a bottom view of the upper case.

FIG. 3 is a plan view of a lower case of the magnetic disk cartridge.

FIG. 4 is a bottom view of the lower case.

FIG. 5 is an explanatory diagram showing a flow state of a resin at the time of molding the upper case.

FIG. 6 is an explanatory diagram showing a flow state of a resin at the time of molding a lower case.

FIG. 7 is an enlarged sectional view of the vicinity of a gate mark in the upper case and the lower case.

FIG. 8 is an enlarged sectional view taken on line AA of FIG. 2;

FIG. 9 is a bottom view of an upper case of a magnetic disk cartridge according to another embodiment of the present invention.

FIG. 10 is an enlarged sectional view taken on line 9B-B of FIG. 9;

FIG. 11 is a plan view of an upper case of a magnetic disk cartridge according to still another embodiment of the present invention.

FIG. 12 is a characteristic comparison diagram between the embodiment according to the present invention and a comparative example.

FIG. 13 is a partially exploded perspective view showing a conventional magnetic disk cartridge with its lower case up.

FIG. 14 is a plan view of an upper case used for the magnetic disk cartridge.

FIG. 15 is a bottom view of a lower case used in the magnetic disk cartridge.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cartridge case 1a Upper case 1b Lower case 2 Magnetic disk body 3 Shutter 4 Head insertion opening 6 Concave part 8 Label sticking part 9, 9a, 9b Gate mark 11 Rear end part 12a-12c Peripheral wall 13a, 13b Rib 14 Gate drop part 15 Annular recess

Claims (5)

[Claims] 1. A cartridge case comprising a synthetic resin molded body, a shutter slide recess at a predetermined position, a head insertion opening formed in the shutter slide recess, and a rotatable housing in the cartridge case. A recording disk body, and slidably mounted in the shutter slide recess,
A disk cartridge having a shutter for opening and closing a head insertion opening, wherein a gate mark is formed by injection molding in the shutter slide concave part, and an annular concave part is provided around the gate mark, whereby the gate mark is formed in the shutter slide concave part. A disc cartridge characterized in that the shutter is configured to avoid protruding from the surface and to cross over the gate mark. 2. A cartridge case made of a synthetic resin molded body and provided with a head insertion port and a label sticking portion at predetermined positions, and a recording disk body rotatably housed in the cartridge case. In the disk cartridge provided, a gate mark is formed by injection molding in the label sticking portion, and an annular concave portion is provided around the gate mark to prevent the gate mark from protruding from the surface of the label sticking portion. A disk cartridge characterized by the above-mentioned. 3. The disk according to claim 1, wherein a thick portion is provided on a surface of the cartridge case opposite to a surface on which the gate mark is formed so as to face the gate mark. cartridge. 4. The disk cartridge according to claim 1, wherein the gate mark is formed only near the front end of the cartridge case, and the rear end of the cartridge case is at a resin filling end position. 5. The disk cartridge according to claim 2, wherein the gate mark is formed only near the rear end of the cartridge case, and the front end of the cartridge case is at the resin filling end position.