JPH10233077A - Molding die of magnetic tape cartridge lid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To commonly use the metallic mold, which is used to mold the other ends of a lid, for the lids having various lengths by constituting the molding part of the metallic mold, that is used to form one end of the longitudinal direction of the lid, with the slide core, with which the length of the mold is made ajustable, positioning the core at a desired position in the longitudinal direction and conducting an injection molding. SOLUTION: The length of the inner lid of a home use digital video cassette(DVC) in its longitudinal direction is set to be a+b. By loading a nesting metallic mold 5a, a cavity having a length a+b is formed. The inner lid of a commercial DVC has a different length with respect to the home use DVC inner lid only in the longitudinal direction. The movable metallic mold and the fixed metallic mold are same to the metallic mold of the home use DVC and the length of the inner lid of the commercial DVC in the longitudinal direction is a+c. By mounting a nesting metallic mold 5b, which is provided with the molding section having a length c, the cavity having a length a+c is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding die for a magnetic tape cartridge having a lid structure.

[0002]

2. Description of the Related Art Along with recent technical innovations such as a high density magnetic recording medium, a magnetic tape cartridge, a video tape recorder (hereinafter, referred to as a VTR) and the like have become compact. As a result, VTRs are very often used outdoors, such as when shooting landscapes or people.

For this reason, in consideration of use outdoors, etc., a magnetic tape cartridge has been put into practical use as a two- or three-sheet lid that covers the entire surface and the back surface of the magnetic tape, respectively, as a measure against dust.

Hereinafter, the above-described conventional magnetic tape cartridge will be described with reference to the accompanying drawings.

As shown in an assembly perspective view of FIG. 4, a magnetic tape 14 is stretched on the front surface of a magnetic tape cartridge 13. When the magnetic tape 14 is not used, the outer lid 15, the top lid 16 and the inner lid 17 are not used. Covered by

FIG. 5 is a perspective view of the lid part, and FIG. 6 is a sectional view of the lid part.

[0007] The outer lid 15 covers the front surface of the magnetic tape 14 stretched over the opening 20.
5a and a side plate 15b covering the front of the upper and lower halves 18, 19
Consists of The side plate 15b has a pair of fulcrum pins 15c, and the fulcrum pins 15c are inserted into a pair of cutouts provided on both front side surfaces of the upper half 18. The outer lid 15 is rotatable about a fulcrum pin 15c. In addition, a pair of pin holes 15d is provided in the upper part of the front surface of the side plate of the outer lid 15.

The top lid 16 is provided with a top lid 16 a covering the upper edge of the magnetic tape 14 stretched over the opening 20.
And a side plate 16b that covers the side surface of the upper half 18. A pair of support pins 16c are provided on the side plate 16b of the top lid 16.
The support pin 16c is inserted into a pin hole 15d of the outer lid 15 and is rotatable.

A side plate 16b is provided in front of the side surface of the upper half 18.
Are provided with a pair of thin portions having a thickness substantially equal to the thickness of the thin portion. A groove for guiding the pair of top lids is formed in the thin portion, and a pair of guide pins 16d formed on the rear inner side of the side plate 16b are slidably mounted in the groove.

[0010] A pair of bracket portions 16e are provided inside the top lid 16, and the bracket portions 1e are further provided.
A pin hole 16f is formed in each of 6e.

Next, a perspective view of the inner lid 17 is shown in FIG.
Shown in

The inner lid 17 covers the back surface of the magnetic tape 14 stretched over the opening 20.
7a and a side plate 17b. A pair of support pins 17c are provided on the side plate 17b of the inner lid 17, and the pair of support pins 17c are rotatably attached to the pin holes 16f of the bracket 16e of the top lid 16. The lower side surface of the inner lid 17 has a pair of protrusions 17d, and the protrusions 17d are formed with guide pins 17e.

Behind the pair of tape guides formed in the lower half 19, and on both sides of the opening 20, there are provided a pair of inner lid guide grooves whose upper parts are opened. This inner lid guide groove has an inner lid 1
7 is formed on a pair of guide pins 17e formed on the projection 17d.
Are slidably inserted.

Next, a method of forming the inner lid 17 having the above configuration will be described. As shown in FIG. 8, the cavity 21 for molding the inner lid 17 is
It is provided by a movable mold 22 and a fixed mold 23.

The movable mold 22 and the fixed mold 23 are opposed to each other so that the mold can be opened and clamped by a mold clamping device of the molding machine, and when the mold is clamped, the cavity is defined. When the molten resin is filled into the cavity 21 by the injection device and pressurized and cooled and solidified in the mold clamping state, the inner lid 17 can be formed.

[0016]

There are two types of magnetic tape cartridges, one for consumer use and one for business use. The inner lid for consumer use has a shorter longitudinal length than the inner lid for business use. Others have the same configuration. However, when making these two types of inner lids, a dedicated mold is prepared for each type, and according to the type to be produced, an inner lid molding method is used in which a dedicated mold is set in the molding machine. I was Such a molding method must be repeated in order for each change of the type that produces a troublesome work such as removing the mold from the molding machine, disassembling and assembling the mold, attaching the mold to the molding machine, etc. In addition, the operating rate is significantly reduced. In addition, there is a problem in that equipment costs increase due to an increase in the types of dies to be prepared, which leads to an increase in production costs.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks, and aims to improve the production operation rate by using a common die for molding a lid, and to reduce the cost of manufacturing the die. And

[0018]

SUMMARY OF THE INVENTION The object of the present invention is to provide a mold for molding a lid of a magnetic tape cartridge having an outer lid, a top lid and an inner lid, which covers a magnetic tape. The part for molding one end in the longitudinal direction of the lid is constituted by a nested mold, and a nested mold corresponding to the molding length in the longitudinal direction of the lid is selected, loaded, and injection-molded. The problem is solved by providing a molding die for the lid of the magnetic tape cartridge. Alternatively, the object is to cover a magnetic tape, a molding die for a lid of a magnetic tape cartridge including an outer lid, a top lid and an inner lid, wherein one end in the longitudinal direction of the lid of the die for molding the lid is formed. A lid for a magnetic tape cartridge, wherein a molding portion is constituted by a slide core capable of adjusting a molding length in the longitudinal direction of the lid, and the slide core is positioned at a desired position in the longitudinal direction and injection molded. Is solved by providing a molding die.

[0019]

According to the present invention, in the case of a nesting mold, the length of the cavity can be changed by loading a desired nesting mold, and a lid having a desired length can be formed. In the case of a mold having a slide core, by positioning the slide core at a desired position, the length of the cavity can be changed, and a lid having a desired length can be formed.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the accompanying drawings. Note that the configuration of the inner lid is the same as that of the conventional example, and a description thereof will be omitted.

First, a mold having a nesting mold according to a first embodiment of the present invention will be described. As shown in FIG. 1, a cavity 1 for forming an inner lid constituting a tape cartridge is provided by a movable mold 2 and a fixed mold 3. The movable mold 2 is mounted on a movable platen of a molding machine (not shown) via a mold mounting plate (movable side mounting plate). The fixed mold 3 forms a pair with a movable mold, and is mounted on a fixed platen of a molding machine (not shown) via a mold mounting plate (fixed side mounting plate). Nesting molds 5a and 5b, which will be described later, are loaded in the nesting mold loading section 4. The molding length (length of the cavity) a of the fixed mold 3 is constant, and the nesting dies 5a and 5b having different molding lengths are loaded into the nesting mold loading section 4 so as to have different lengths. A cavity is defined.

The movable mold 2 and the fixed mold 3 are opposed to each other so that the mold can be opened and clamped by a mold clamping device of the molding machine, and when the mold is clamped, the cavity is defined. Then, when the cavity 1 is filled with the molten resin and pressurized and cooled and solidified by cooling with the injection device in the mold clamping state, the inner lid is formed.

FIG. 2A shows a molding die for an inner lid of a consumer DVC (digital video cassette). The length of the consumer inner lid in the longitudinal direction is a10b. By loading a nesting mold 5a provided with a molding part with a length b into the nesting mold loading unit 4, a cavity with a length a and 10b is defined. The nesting mold 5a forms one side plate provided with a support pin, a protrusion, and a guide pin of the inner lid.

FIG. 2B shows a mold for forming the inner lid of the commercial DVC. The inner lid of the commercial DVC differs from the inner lid of the consumer DVC only in the length in the longitudinal direction. The movable mold 2 and the fixed mold 3 are the same as consumer molds. The length of the commercial inner lid in the longitudinal direction is a10c. By loading the nesting mold loading section 4 with the nesting mold 5b provided with the molding section having the length c, a cavity having a length a and 10c is defined, and the nesting mold 5b is provided with the inner lid. Of the side plate. As described above, the length of the cavity in the longitudinal direction can be changed only by changing the nesting mold, and the inner lid having different lengths can be formed. Therefore, the other movable mold 2 and the fixed mold 3 can be formed. Can be used in common.

Next, a mold having a slide core according to a second embodiment of the present invention will be described. FIG. 3 (a)
Fig. 2 shows a molding die for a consumer inner lid. The length of the consumer inner lid in the longitudinal direction is d (= a10b), and the length of the cavity is set to d by adjusting the position of the slide core 6 provided between the movable mold and the fixed mold. I do.
The slide core 6 forms one side plate of the inner lid.

FIG. 3B shows a molding die for a commercial inner lid which differs only in the length in the longitudinal direction. The movable mold and the fixed mold are the same as consumer molds. The length of the commercial inner lid in the longitudinal direction is e (= a10c),
The side plate of the inner lid can be formed by changing only the slide amount of the slide core 6 provided between the movable mold and the fixed mold from the consumer slide amount. Thus, by changing only the sliding amount of the slide core 5, it is possible to mold inner lids having different lengths in the longitudinal direction, so that other molds can be shared.

Although the embodiment of the present invention has been described above, the molding die of the present invention is not limited to the molding of two types of inner lids for consumer use and business use. A variety of different lids can be formed.

[0028]

As described above, according to the present invention, the portion for molding one end of the lid in the longitudinal direction of the lid is formed of a nested mold, and the molding length of the lid in the longitudinal direction is provided. Injection molding by selecting and loading a nesting mold according to the above, or a part of the mold for molding the lid, which forms one end in the longitudinal direction of the lid, has a molding length in the longitudinal direction of the lid. The slide core is adjustable in length, and the slide core is positioned at a desired position in the longitudinal direction and injection-molded.Therefore, a mold for molding the other end of the lid has various lengths. Can be shared for lid molding. Therefore, it is possible to use a common die for molding the lid, thereby improving the production operation rate and reducing the cost of manufacturing the die.

[Brief description of the drawings]

FIG. 1 is a sectional view of the present invention.

FIG. 2 (a) is a sectional view of a molding die for a consumer inner lid using a nesting die according to the present invention,
(B) is a sectional view of a molding die for a commercial inner lid.

FIG. 3A is a cross-sectional view of a molding die for a consumer inner lid using a slide core according to the present invention;
(B) is a sectional view of a molding die for an inner lid for business use.

FIG. 4 is an assembled perspective view of a magnetic tape cartridge according to the related art.

FIG. 5 is a perspective view of a lid part according to the related art.

FIG. 6 is a cross-sectional view of a lid part according to the related art.

FIG. 7 is a perspective view of the inner lid.

FIG. 8 is a sectional view of a mold for a conventional inner lid.

[Explanation of symbols]

 Reference Signs List 1 cavity 2 movable mold 3 fixed mold 4 nested mold loading section 5a, 5b nested mold 6 slide core 13 magnetic tape cartridge 14 magnetic tape 15 outer lid 15a outer lid section 15b side plate 15c support pin 15d pin hole 16 Top lid 16a Top lid portion 16b Side plate 16c Support pin 16d Guide pin 16e Bracket portion 16f Pin hole 17 Inner lid 17a Inner lid portion 17b Side plate 17c Support pin 17d Projection 17e Guide pin 18 Upper half 19 Lower half 20 Opening 21 Cavity 22 Movable mold 23 Fixed mold

Claims (2)

[Claims] 1. A mold for molding a lid of a magnetic tape cartridge provided with an outer lid, a top lid, and an inner lid, which covers a magnetic tape, wherein one end of the mold for molding the lid in a longitudinal direction is formed. Part to be composed of a nesting mold,
A mold for molding a lid of a magnetic tape cartridge, wherein a nesting mold according to a molding length in a longitudinal direction of the lid is selected, loaded, and injection molded. 2. A mold for molding a lid of a magnetic tape cartridge having an outer lid, a top lid, and an inner lid, which covers a magnetic tape, wherein one end of the mold for molding the lid in a longitudinal direction is formed. A part of the lid of the magnetic tape cartridge, wherein the slide core is formed of a slide core capable of adjusting a molding length in the longitudinal direction of the lid, and the slide core is positioned at a desired position in the longitudinal direction and injection-molded. Molding mold.