JPH05242644A - Mold device for molding tape cassette half - Google Patents

Abstract

PURPOSE:To save the resin to be used for molding a tape cassette halves and to lessen the generation of shrinks by molding of ribs as far as possible. CONSTITUTION:Plural kinds of the tape cassette halves varying in the forms of head position discriminating holes can be selectively molded by exchanging nestings 48, 50. The nestings 48, 50 for forming the discriminating holes form the head position discriminating holes and both front and rear surfaces of the ribs enclosing these holes. The nesting for non-forming of the discriminating hole which forms the flank part of the tape cassette half in place of the head position discriminating hole is formed flat in the position corresponding to the above-mentioned rib. The rib enclosing the head position discriminating hole is thus not formed when the head position discriminating hole is not formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for molding audio tape cassette halves, and more particularly to a metal mold capable of selectively molding a plurality of types of tape cassette halves having different head position discrimination holes. Regarding mold device.

[0002]

2. Description of the Related Art FIG. 15 shows an audio cassette tape.
17 to 17, a magnetic tape 2 wound around a pair of rotatable hubs 1 is housed in a cassette 3. This cassette 3 is a pair of cassette halves 4a, 4b.
It is composed by combining. These cassette halves 4a,
As shown in FIGS. 9 and 10, 4b has a thin case shape in which side plate portions 6, 7, and 8 are vertically bent from each end edge of the rectangular flat plate-shaped base surface portion 5. A transparent window 9 for seeing through the tape winding diameter is provided at the center of the substrate portion 5. Further, at both ends of the side surface portion 8 on the rear side of the cassette 3, claws 11 are formed on each of the cassette halves 4a, 4b to break off when it is desired to prevent erroneous erasure of recording on the magnetic tape 2. By the way, there are several types of audio cassette tapes with different head positions, but in order to automatically determine the head position of the cassette tape mounted on the cassette tape player side,
The form of the head position determining holes 12 and 13 formed in the rear side surface portion 8 of the cassette 3 is changed according to the difference in the head position. That is, with the cassette tape in the metal position, as shown in FIGS. 15 and 9, the head position determination holes 12 are formed at both ends of the side surface portion 8 of the cassette 3.
And a pair of head position discriminating holes 13 are also formed in the central portion of the side surface portion 8. Also,
In the chrome position cassette tape, as shown in FIG. 16, head position determining holes 12 are formed only at both ends of the side surface 8 of the cassette 3. further,
As shown in FIGS. 17 and 10, the normal position cassette tape does not have a head position determination hole. The head position determination holes 12 and 13 are provided in the cassette 3
Head position identification hole 1
Ribs 14 and 15 that surround the heads 2 and 13 and that block the head position determination holes 12 and 13 from the inside of the cassette 3 are provided for each cassette half 4
It is formed on the inner surface of a and 4b. The ribs 14 surrounding the head position determination holes 12 at both ends of the side surface portion 8 are formed by the claws 11 described above.
It is connected to the rib 16 that surrounds.

By the way, the tape cassette half 4a,
Although 4b is an integrally molded plastic product, there is a mold device capable of selectively molding a plurality of types of tape cassette halves 4a, 4b having different head position determination holes 12, 13 as described above. That is, in this mold apparatus, the head position determination holes 12 and 13 are formed by replacing the nest,
The non-formation can be selected. Here, a configuration that has been conventionally adopted to enable the formation or non-formation of the head position determination holes 12 and 13 will be described by taking one head position determination hole 13 portion as an example. In FIGS. 11 to 14, 21 is a cavity main body member, 22 is a core main body member, and these cavity main body member 21 and core main body member 22 move vertically with respect to each other in the drawing to open and close. A cavity 23 in the shape of 4b is formed inside. The cavity body member 21
And the opening / closing direction of the core body member 22 is the cassette half 4
It is a direction orthogonal to the base surface portion 5 of a and 4b. The cavity body member 21 forms the outer surface of the cassette halves 4a and 4b, and the core body member 22 forms the inner surface of the cassette halves 4a and 4b. A concave nesting attachment portion 24 is formed in the core body member 22 at a position corresponding to the head position determination hole 13. The nest attachment portion 24 includes a nest 25 for forming a discrimination hole and a nest for non-discrimination hole formation.
26 and 26 are detachably and selectively attached. It should be noted that the cavity body member 21 is a recess into which the portions of the nests 25 and 26 located outside the cavity 23 are fitted.
27 are formed. And the nest for forming the discrimination hole
As shown in FIGS. 11 and 13, the reference numeral 25 has a shape penetrating the side surface portion 8 of the cassette halves 4a and 4b, and is located on the front surface side of the head position determination hole 13 and the rib 15 surrounding the head position determination hole 13. Is formed. The recess 28 that forms the back side of the rib 15 is formed in the core body member 22. On the other hand, the discrimination hole non-forming nest 26 is shown in FIG.
As shown in FIG. 14 and FIG.
Although there is a groove 29 that forms the side surface portion 8 that closes the inner surface of the rib 15, the surface side of the rib 15 is also formed. That is, as shown in FIG. 10, the conventional mold apparatus forms the corresponding ribs 14 and 15 even when the head position determining holes 12 and 13 are not formed.

[0004]

As described above, according to the molding die device for the conventional tape cassette halves 4a, 4b, the corresponding ribs 14, 15 are formed even if the head position determining holes 12, 13 are not formed. Are formed, but these ribs 1
4 and 15 are the ones without the head position discrimination holes 12 and 13,
It is functionally unnecessary. That is, when the head position determination holes 12 and 13 are not formed, the ribs 14 and 15
The formation of the resin wastefully uses the resin. When the ribs 14 and 15 are formed, the cassette half 4
There is also a problem that sink marks are likely to occur at the positions corresponding to the ribs 14 and 15 on the surfaces of a and 4b.

The present invention is intended to solve such a problem, and saves resin to be used in a mold device capable of selectively molding a plurality of tape cassette halves having different head position determining holes. In addition, it is intended to reduce the occurrence of sink marks due to the formation of ribs as much as possible.

[0006]

In order to achieve the above object, the present invention is a tape cassette half comprising a base surface portion and a side surface portion bent from an edge of the base surface portion, the tape cassette half being formed on the side surface portion. In a mold apparatus for molding a tape cassette half capable of selectively molding a plurality of types of tape cassette halves having different head position determination holes, the mold is clamped by opening and closing in a direction orthogonal to the base surface of the tape cassette half. A pair of mold members that sometimes form a tape cassette half-shaped cavity therein, and a plurality of types of nests that are detachably and selectively attached to a nest attachment portion provided in the mold members As a head position discrimination hole of the tape cassette half and a head position discrimination hole which is cut off from the inside of the tape cassette half. And nested for discrimination hole formed for forming the,
In place of the head position discrimination hole, the side surface portion is formed and a discrimination hole non-forming nest for flatly forming a position corresponding to the rib is provided.

[0007]

In the tape cassette half molding die apparatus of the present invention, a pair of die members are clamped to form a tape cassette half-shaped cavity between these die members, and the cavity is filled with resin. Then, the tape cassette half is molded. At this time, when the head position discrimination hole is formed on the side surface of the tape cassette half, the discrimination hole forming insert is attached to the insert attachment portion of the mold member. The nest for forming the discrimination hole forms a head position discrimination hole and a rib for blocking the head position discrimination hole from the inside of the tape cassette half. On the other hand, when the head position discrimination hole is not formed, the discrimination hole non-forming insert is attached to the insert attachment portion of the mold member. By this nesting for not forming the discrimination hole, the tape cassette half is formed with a side surface portion instead of the head position discrimination hole, and a position corresponding to the rib is formed flat.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a tape cassette half molding die apparatus of the present invention will be described below with reference to FIGS. Reference numeral 31 is a fixed die, 32 is a movable die, and the fixed die 31 has a cavity body member 33 which is a die member forming an outer surface of the tape cassette half 4b.
Has a core body member 34 which is a mold member forming the inner surface of the cassette half 4b. The fixed die 31 and the movable die 32 move in the vertical direction shown in FIGS. 2 to 7 to open and close, and when the mold is clamped, the cavity 35 having the shape of the cassette half 4b is inserted into the cavity body member 33 and the core body member 34.
It is formed between and. Fixed type 31 and movable type
The opening / closing direction with respect to 32 is a direction orthogonal to the base surface portion 5 of the cassette half 4b. The cavity main body member 33 is formed with a first primary runner 36 on the parting line surface with the core main body member 34, and is opened to a position serving as a side surface portion 6 on the front side of the cassette half 4b in the cavity 35. The first primary gate 37 is formed at the tip of the first primary runner 36 as a submarine gate. A second primary runner 38 is formed on the parting line surface of the core body member 34 and the cavity body member 33. On the other hand, in the cavity body member 33, a second primary gate 39, which communicates with the second primary runner 38 and opens to a position at the center of the rear side portion 8 of the cassette half 4b in the cavity 35, serves as a submarine gate. Has been formed. Further, a movable core member 40 forming the inner surface of the transparent window 9 of the cassette half 4b is slidably incorporated in the core body member 34. Meanwhile, the cavity body member
A secondary gate 41, which is a direct gate facing the movable core member 40, is formed on the 33.

At the positions corresponding to the head position discriminating holes 12 and 13 in the core body member 22, a pair of first nesting attachment portions 46 and a pair of second nesting attachment portions are provided.
47 is formed in a concave shape across the position facing the cavity 35 and the position outside thereof. The first nesting attachment part
Reference numeral 46 designates a first discriminating hole forming insert 48 and a first discriminating hole non-forming insert 49 which are detachably and selectively attached, and the second insert attaching portion 47 is formed by The identification hole forming insert 50 and the first identification hole non-forming insert 51 are detachably and selectively attached. That is, the nests 48, 49, 50, 51 are partially fitted in the nest mounting portions 46, 47 and fixed to the core body member 34 by the bolts 52 at the position outside the cavity 35. is there. The cavity body member
The recess 33 has recesses 53, 54 into which the parts of the inserts 48, 49, 50, 51 located outside the cavity 35 are fitted. Further, both the second nesting attachment portions 47 and the pair of concave portions 54 corresponding to these second attachment portions 47 are provided in the second primary runner 38.
And the second primary gate 39 is sandwiched therebetween.

The first discriminating hole forming insert 48 has a shape penetrating the side surface portion 8 of the cassette half 4b.
The head position determining hole 12 and the front and back surfaces of the rib 14 surrounding the head position determining hole 12 are formed, and the claw 11 and the front surface side of the rib 16 surrounding the same are formed. Therefore, as shown in FIG. 2, the first discrimination hole forming nest 48 is provided with a groove 56 to be the rib 14 and a hole 57 to be the claw 11.
In contrast, the first discrimination hole non-forming nest 49,
Again, the claw 11 and the surface side of the rib 16 surrounding the claw 11 are formed, while the side surface portion 8 is formed instead of the head position determination hole 12, and the position corresponding to the rib 14 is formed flat. Further, a rib 17 having a shape in which the rib 16 is extended to the side surface portion 8 is formed. Therefore, as shown in FIG. 3, the first discrimination hole non-forming nest 49 is formed with a hole 57 to be the claw 11, and
A groove 58, which serves as the side surface portion 8 in place of the head position determination hole 12, and a groove 59, which communicates with the groove 58 and serves as the rib 17, are formed. Since the pair of claws 11 in the entire cassette 3 is formed separately in both cassette halves 4a and 4b, the first nests 48 and 49 on one end side of the cassette half 4b have holes 57 to be the claws 11. However, in the first nests 48, 49 on the other end side,
There is no hole 57. Further, the second discriminating hole forming nest 50.
As shown in FIGS. 4 and 6, it has a shape penetrating the side surface portion 8 of the cassette half 4b, and forms the head position determination hole 13 and both front and back surfaces of the rib 15 surrounding the head position determination hole 13. For this reason, the second discrimination hole forming insert 50 is provided with a groove 61 to be the rib 15. On the other hand, as shown in FIGS. 5 and 7, the second discrimination hole non-forming nest 51 has a side surface portion 8 instead of the head position discrimination hole 13 and a position corresponding to the rib 15 is flat. To form. Therefore, the second discriminator hole non-forming insert 51 is provided with a groove 62 which serves as the side surface portion 8 in place of the head position discriminating hole 13.

Next, the operation of the above configuration will be described. At the time of molding the tape cassette half 4b, the fixed mold 31 and the movable mold 32 are clamped, and the movable core member 40 is
Is pressed against the cavity body member 33 to form a cassette half-shaped primary cavity 35 excluding the transparent window 9 between the cavity body member 33 and the core body member 34, and the primary runner 36 is formed in the primary cavity 35. , 38 through the primary gates 37, 39 with opaque resin. Then, after the opaque resin is solidified, the movable core member 40 is separated from the cavity body member 33 to form a secondary cavity therein, and the secondary cavity is filled with a transparent resin from the secondary gate 41. Furthermore, after this transparent resin solidifies,
The fixed mold 31 and the movable mold 32 are opened to take out the molded cassette half 4b.

By the way, the molding is performed by the head position determination hole.
When switching to the tape cassette halves 4b having different shapes of 12 and 13, the nests 48, 49, 50 and 51 are appropriately replaced.
That is, when the head position discriminating hole 12 is formed in the side surface portion 8 of the cassette half 4b, the first discriminating hole forming nest 48 is attached to the first nest attaching portion 46 of the core body member 34, and the head position discriminating hole 12 is formed. When not forming, the first discrimination hole non-forming nest 49 is attached. Also,
When the head position determination hole 13 is formed, the second determination hole forming insert 50 is attached to the second insert attachment portion 47 of the core body member 34, and when the head position determination hole 13 is not formed, the first determination hole 13 is formed. Attach the non-forming nest 51. That is, when molding the cassette half 4b in the same metal position as shown in FIG. 9, the first discrimination hole forming nest 48 and the second discrimination hole forming nest 50 are attached. Further, when molding the tape cassette half 4b in the chrome position, the first discrimination hole forming nest 48 and the second discrimination hole non-forming nest 51 are attached.
Further, when molding the tape cassette half 4b in the normal position similar to that shown in FIG. 8, the first discrimination hole non-forming nest 49 and the second discrimination hole non-forming nest 49 are formed.
Install 51. When the first discrimination hole forming nest 48 is attached, the first discrimination hole forming nest 48 forms the head position discrimination hole 12 and the front and back surfaces of the rib 14 surrounding the head position discrimination hole 12, and 11 and a rib 16 surrounding the rib 11 are formed. The back side of the rib 16 is formed by the core body member 34. On the other hand, when the first discrimination hole non-forming nest 49 is attached, the side position 8 is formed by the first discrimination hole non-forming nest 49 instead of forming the head position discrimination hole 12. Also rib
14 is not formed, and the position corresponding to this rib 14 is formed flat. Along with this, the claw 11 and the ribs 16 and 17 surrounding it
And are formed. Further, when the second discriminating hole forming nest 50 is attached, the first discriminating hole forming nest 50 forms the head position discriminating hole 13 and both front and back surfaces of the rib 15 surrounding the head position discriminating hole 13. On the other hand, when the second discrimination hole non-forming nest 51 is attached, the head position discrimination hole
Instead of not forming 13, the side surface portion 8 is formed by the second discrimination hole non-forming nest 51. At the same time, the rib 15 is not formed, and the position corresponding to this rib 15 is formed flat.

As described above, according to the structure of the above-described embodiment, the nests 48, 49, 50, 51 for selecting the formation or non-formation of the head position discriminating holes 12, 13 are provided at the entire positions of the ribs 14, 15. When the head position determination holes 12 and 13 are not formed, the ribs 14 and
Since 15 is not formed, the amount of resin used for molding the tape cassette half 4a can be saved. Further, when the head position determination holes 12 and 13 are not formed, the outer surface of the tape cassette half 4a does not have a sink mark at the positions corresponding to the ribs 14 and 15. Thus, the occurrence of sink marks due to the formation of the ribs 14 and 15 can be reduced as much as possible.

The construction and operation of the molding die device for one of the tape cassette halves 4a and 4b constituting the cassette 3 has been described above.
The configuration and operation of the molding die device for the other cassette half 4a are similar. FIG. 8 shows the other tape cassette half 4a molded by the mold device of this embodiment.

The present invention is not limited to the above embodiment, but various modifications can be made. For example,
In the above-described embodiment, the discrimination hole forming nests 48 and 50 are formed on both front and back surfaces of the ribs 14 and 15 that surround the head position discrimination holes 12 and 13. However, the discrimination hole forming nests are formed on the front surface side of the ribs. Even when only the ribs are formed, the nest for non-discrimination hole formation can be formed so that the ribs are not formed by abutting the core body member at a position corresponding to the rib.

[0016]

According to the present invention, by replacing the nest,
In a mold device capable of selectively molding a plurality of types of tape cassette halves having different head position discrimination holes on the side surface, as a nest, the head position discrimination hole and this head position discrimination hole are formed from inside the tape cassette half. Provided are a discrimination hole forming nest for forming a rib for blocking and a discrimination hole non-forming nest for forming a side surface portion of the tape cassette half in place of the head position discrimination hole and flattening a position corresponding to the rib. When the head position determination hole is not formed, the rib surrounding the head position determination hole is not formed, so that the amount of resin used for molding the tape cassette half can be saved and the occurrence of sink marks due to the formation of the rib can be reduced as much as possible. ..

[Brief description of drawings]

1A and 1B show an embodiment of a molding apparatus for a tape cassette half according to the present invention, wherein FIG. 1A is a plan view of a core body member, and FIG. 1B is a plan view of a cavity body member.

FIG. 2 is a perspective view of the vicinity of a first discrimination hole forming insert attached to the core body member of the same.

FIG. 3 is a perspective view of the vicinity of a first discrimination hole non-forming insert attached to the core body member.

FIG. 4 is a perspective view of the vicinity of a second discriminating hole forming insert attached to the core body member.

FIG. 5 is a perspective view of the vicinity of a second discrimination hole non-forming insert attached to the core body member of the same.

6 is a sectional view of the portion shown in FIG. 4 above.

7 is a sectional view of the portion shown in FIG. 5 above.

FIG. 8 is a perspective view of a tape cassette half in a metal position, which is molded by the mold device of the embodiment.

FIG. 9 is a perspective view of a tape cassette half in a normal position.

FIG. 10 is a perspective view of a tape cassette half in a metal position formed by a conventional mold device.

FIG. 11 shows an example of a conventional die unit for molding a tape cassette half, and is a perspective view of a discrimination hole forming nest attached to a core body member.

FIG. 12 is a perspective view of the vicinity of a discriminant hole non-forming insert attached to the core body member.

13 is a sectional view of the portion shown in FIG. 11 above.

14 is a sectional view of the portion shown in FIG. 12 above.

FIG. 15 is a perspective view of the cassette tape in the metal position.

FIG. 16 is a perspective view of the cassette tape in the chrome position.

FIG. 17 is a perspective view of a cassette tape in a normal position.

[Explanation of symbols]

4a, 4b Tape cassette half 5 Base surface 6 Side surface 7 Side surface 8 Side surface 12 Head position determination hole 13 Head position determination hole 14 Rib 15 Rib 33 Cavity body member (mold member) 34 Core body member (mold member) 35 Cavity 46 First Nesting Attachment Part (Nesting Attachment Part) 47 Second Nesting Attachment Part (Nesting Attachment Part) 48 First Discrimination Hole Forming Nest (Discrimination Hole Forming Nest) 49 First Discrimination Hole Not Formed Insert (Nesting Hole Non-Forming Nest) 50 Second Identification Hole Forming Nest (Identification Hole Forming Nest) 51 Second Identification Hole Non-Forming Nest (Identification Hole Non-Forming Nest)

Claims (1)

[Claims] 1. A tape cassette half comprising a base surface portion and a side surface portion bent from an edge of the base surface portion, wherein a plurality of types of tape cassette halves have different head position determination holes formed on the side surface portion. In a mold device for molding a tape cassette half capable of selectively molding, a pair of molds that opens and closes in a direction orthogonal to the base surface portion of the tape cassette half and forms a tape cassette half-shaped cavity inside during mold clamping. A member and a plurality of types of inserts that are detachably and selectively attached to an insert attachment portion provided on the mold member. As these inserts, the head position determination hole of the tape cassette half and the head position determination A discrimination hole forming nest that forms a rib for blocking the hole from the inside of the tape cassette half,
A mold apparatus for molding a tape cassette half, comprising: a discrimination hole non-forming nest for forming the side surface portion in place of the head position discrimination hole and forming a flat portion corresponding to the rib.