JPH11935A - Injection molding die - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve an operation property by making exchange of an insert die easy by a method wherein a support bar urged with the loaded insert die on abutting surfaces at different two positions is, in a freely slidable manner, inserted in a groove communicated to an insert die charging hole side surface open to a fixed mold side surface having a molding space opposed to a surface on which the insert die charging hole is formed. SOLUTION: For exchange of an insert die 133, after transferring a movable side template 139 downward by functioning a clamping unit 140, a support bar 134 is extracted out from in a groove 136 to outside a fixed side template main body 132 to make up-down reversal, and inserted again into the groove 13b. An inclined surface 134a of the support bar 134 abuts against an inclined surface 138 of the insert die 133. When the support bar 134 is further pushed into, the pushing force is changed to a right angled direction with the inclined surface 138 to push out the insert die 133 downward. The insert die 133 is taken out from the fixed side template main body 132, another discrimination mark engraved insert die 133 is inserted into an insert die charging hold 135, the support bar 134 is again inserted into the groove 136, and held at a specific position. The insert groove 136, and held at a specific position. The insert die can be exchanged without detaching the mold.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection mold, and more particularly to a nest support structure for an injection mold having a nest.

[0002]

2. Description of the Related Art Various types of magnetic tape cassettes are provided for various purposes and functions, as well as for consumer and business use. Some of these magnetic tape cassettes have the same case shape for compatibility, and display an identification mark at the center of the lower half of the case to identify them.

[0003] Since the case of such a magnetic tape cassette differs only in the identification mark, a mold for injection-molding the case is provided with a nest having an identification mark engraved on the front end face, which is removably mounted on the mold body. By exchanging the nest, the molds are mainly shared.

FIG. 7 conceptually shows such a mold. The mold 1 includes a fixed mold plate 2 and a movable mold plate 3. The fixed mold plate 2 is attached to a mold clamping device via a fixed attachment plate 4, and the movable mold plate 3 receives It is attached to a mold clamping device via a plate 5. The movable mold plate 3 is pressed against the fixed mold plate 2 by the mold clamping device, and a molding space 6 is defined between the movable mold plate 3 and the fixed mold plate 2.

[0005] In the mold 1, a nesting hole 7 is formed through the stationary mold plate 2. Then, a nest 8 is loaded into the nest loading hole 7. An identification mark is engraved on the front surface 8a of the insert 8.

[0006] Then, a resin is injected into the molding space 6 of the mold 1 to perform mold molding. Thereafter, the movable mold plate 3 is lowered, and the molded product is taken out from the molding space 6 expanded by the movable mold plate 3.

When molding the case of another magnetic tape cassette having a different identification mark, the nest 8 is removed from the nest loading hole 7 of the fixed side template 2 and the nest having another identification mark engraved on the front surface. 8 is attached to the nesting hole 7 of the fixed mold plate 2 and molded in the same manner as described above.

[0008]

By the way, in the above-described conventional mold 1, the nest 8 loaded in the nest loading hole 7 is held on the upper surface of the fixed mold plate 2.

Therefore, when the nest 8 is to be replaced, the fixed mold plate 2 and the fixed mounting plate 4 are removed from the mold clamping device, and the fixed mold plate 2 is further removed from the fixed mounting plate 4 to replace the nest 8. I have to exchange,
The work was extremely complicated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks, and has as its object to facilitate exchange of nests and improve workability.

[0011]

SUMMARY OF THE INVENTION The object of the present invention is to provide an injection molding die comprising a fixed die and a movable die, and a nest inserted into the fixed die. A nest loading hole for loading the nest is formed on a surface of the stationary mold facing the molding space, and a groove communicating with a side surface of the nest loading hole is formed on a side surface of the stationary mold. In the groove, a support bar that abuts and engages with the nest loaded in the nest loading hole is slidably inserted, and the nest and the support bar have two different contact surfaces. One of the abutting surfaces constitutes an engagement holding means for engaging and holding the nest at a predetermined position of the fixed mold, and the other abutting surface has a side surface of the nest which is supported by the support bar. The nest is ejected from the fixed mold when pressed from , At least one of the abutment surface of the insert block and said support bars is achieved by an injection mold, characterized in that it is formed on the inclined surface.

[0012]

In the injection mold according to the present invention, the insert is inserted into the insert hole, the support bar is inserted into the groove from the side of the mold, and the support bar is formed at the tip of the support bar and the side of the insert. The nest is held by the mold main body by the joint holding means.
When replacing the nest, pull out the support bar from the groove of the mold main body, change the direction, and insert the support bar or another support bar into the groove of the mold main body from the side surface of the mold main body into the groove. Then, the pushing force of the support bar is changed to a force in a direction in which the nest escapes from the mold main body by the inclined surface of the support bar or the nest, and the nest is pushed out from the nest loading hole.
Therefore, the nest can be replaced without removing the mold main body from the fixed-side mounting plate or the receiving plate.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG.
FIG. 2 is an exploded perspective view showing main components of the apparatus. A pair of flanged tape reels 12 wound with a magnetic tape 11
Are accommodated in a cassette case composed of an upper cassette half 13 and a lower cassette half 14,
The tape drawer opening in front of 0 is covered by a guard panel 15.

The upper cassette half 13 is a box body comprising a front side wall 17 and a rear side wall 18 and right and left side walls 19, 19 standing upright on a peripheral edge of a rectangular upper wall 16 having a window opening. And a transparent window member is welded to the upper wall surface 16. Further, two sets of holes 16 a and 16 b into which the center cap 35 is inserted are provided on the upper wall surface 16.

The lower cassette half 14 is a box body composed of front and rear side walls 21 and 22 and right and left side walls 23 and 23 erected on the periphery of a rectangular bottom wall 20. Tape reel with flange 12
An opening 25 for insertion into the reel hub 24 is formed.

Inside the upper and lower cassette halves 13 and 14, partition walls 26 extending from the upper wall surface 16 and the bottom wall surface 20 toward the inside of the cassette and facing each other stand up in a substantially circular shape so as to surround the tape reel 12 with the flange. Has been established.

The flanged tape reel 12 has a disk-shaped upper flange 28 provided with an upper flange through hole 27.
And a disc-shaped lower flange 29 integrally formed with a cylindrical reel hub 24. An annular rib 29a (see FIG. 2) is formed on the lower surface of the lower flange 29. The tape reel 12 is configured such that the annular rib 29 a is
5 so as to be rotatably disposed on the lower half 14. In order to fix the end of the magnetic tape 11, a notch-shaped engaging portion 31 is provided on the reel hub 24 so that the clamp pin 30 can be fitted from the outside in the radial direction of the reel hub 24.

Above the tape reel 12, a reel holder 33, a reel spring 34, and a center cap 35 are sequentially provided. The lower end of the reel spring 34 is locked by a reel holder 33, and the upper end of the reel spring 34 is locked by a center cap 35. Therefore,
The reel holder 33 and the center cap 35 are fitted via a reel spring 34, and the tape reel 12 is urged toward the lower half 14 by the reel spring 34.

The upper half 13, the lower half 14, and the guard panel 15 configured as described above are assembled as shown in FIG. FIG. 2 is a perspective view showing the back side of the magnetic tape cassette 10, and an identification mark A is provided substantially at the center of the surface of the lower half 14.

FIG. 3 conceptually shows a main part of a fixed mold plate 131 of a mold 130 for injection molding the lower half 14. This fixed-side template 131 is composed of the fixed-side template main body 13.
2, a nest 133 and a support bar 134.

A nesting hole 135 is formed in the fixed side template main body 132 in the up-down direction, and an upper surface 132a of the fixed side template main body 132 is nested from a side surface 132b of the fixed side template main body 132. Groove 1 reaching the top of 135
36 are formed.

The support bar 134 is provided on the fixed-side template main body 1.
32 are slidably inserted into the grooves 136. An inclined surface 134a is formed at the tip of the support bar 134.

On the other hand, the insert 133 loaded in the insert hole 135 has an identification mark engraved on the front surface 133a and has a groove 137 on the rear side surface 133b. The shape of the groove 137 corresponds to the shape of the tip of the support bar 134, and the upper inner surface of the groove 137 has an inclined surface 137a having the same inclination angle as the inclined surface 134a of the support bar 134. . Further, an inclined surface 138 having the same inclination angle as the inclined surface 134a of the support bar 134 is also formed on the rear end surface 133c of the insert 133.

FIG. 4A shows the fixed-side mold plate main body 132.
As shown in FIG.
It is fixed to 41. Then, the nest 133 is inserted into the nest loading hole 135 of the fixed-side template main body 132, and the support bar 134 is inserted into the groove 136 of the fixed-side template main body 132. At this time, the tip of the support bar 134 is fitted into the groove 137 of the insert 133, and the inclined surface 134 a of the support bar 134 contacts the inclined surface 137 a of the insert 133, and
3 is pulled into the nest loading hole 135 of the fixed-side template main body 132, and the nest 133 is moved to the fixed-side template main body 13.
2 at a predetermined position.

On the other hand, the movable mold plate 139 is
40 is fixed to the receiving plate 142. Then, the mold clamping device 140 is operated to move the movable-side mold plate 139 upward, and the movable-side mold plate 139 is brought into contact with the fixed-side mold plate main body 132, so that the movable-side mold plate 139 and the fixed-side mold plate 131 Molding space B between
Is defined.

Into the molding space B, a synthetic resin is injected through a spool (not shown) formed in the main body 132 of the fixed-side mold plate, and thereby the lower half 14 of the magnetic tape cassette 10 is molded. You. Next, the mold clamping device 140 is operated to move the movable mold plate 139 downward, and the lower half 14 is taken out from the expanded molding space B. An identification mark A is formed on the lower half 14 thus formed as shown in FIG.

In order to replace the insert 133, the mold clamping device 140 is operated to move the movable mold plate 139 downward, and then the support bar 134 is moved out of the groove 136 to the outside of the fixed mold plate main body 132. Pull out, turn upside down, and insert the support bar 134 into the groove 136 again. Then, as shown in FIG. 4B, the inclined surface 134a of the support bar 134 contacts the inclined surface 138 of the nest 133, and the support bar 13
4, the pushing force of the support bar 134 is changed in a right angle direction by the inclined surface 138, and the nest 133 is pushed downward by the force.

The nest 133 is fixed to the fixed-side template main body 132.
Nest 133 with another identification mark
Is inserted into the nesting hole 135 of the fixed-side template main body 132, and the support bar 134 is again inserted into the groove 1 of the fixed-side template main body 132.
36. At this time, the tip of the support bar 134 is fitted into the groove 137 of the nest 133, the inclined surface 134 a of the support bar 134 is brought into contact with the inclined surface 137 a of the nest 133, and the nest 133 is inserted into the nest loading hole of the main body 132 of the fixed mold plate 132. The nest 133 is held at a predetermined position of the main body 132 of the fixed side template while being pulled into the 135.

In the above embodiment, the nest 133
As an escape means, an inclined surface 138 is formed at the upper end surface 133c of the nest 133, and an inclined surface 134a is also formed at the tip of the support bar 134. However, as shown in FIGS. The inclined surface may be formed only on one of the end face and the tip of the support bar.

In the embodiment shown in FIG.
An inclined surface 51 is formed on the upper end surface 50a, a groove 52 is formed on the side surface 50b, and a projection 54 having a distal end surface in an arc shape is formed on the distal end portion of the support bar 53.

In this embodiment, as shown in FIG. 5 (a), the projection 54 of the support bar 53 inserted into the groove 56 of the fixed die plate main body 55 fits into the groove 52 of the nest 50, 50 is held in the nest loading hole 57. As shown in FIG. 5B, when the support bar 53 is inserted upside down into the groove 56 of the main body 55 of the fixed side template, the projection 54 of the support bar 53 comes into contact with the inclined surface 51 of the insert 50. When the support bar 53 is further pushed in, the pushing force is changed to a downward force at the inclined surface 51, whereby the nest 5
0 is pushed out in a direction to escape from the fixed-side template main body 55.

In the embodiment shown in FIG.
In addition to forming an inclined surface 61 at the tip of
A notch 63 is formed in the upper end surface 62a of the, and a groove 64 is formed in the side surface 62b.

In this embodiment, as shown in FIG. 6 (a), the tip of the support bar 60 inserted into the groove 66 of the fixed-side die plate main body 65 fits into the groove 64 of the insert 62, and the insert 62 Is held in the nest loading hole 67. FIG.
As shown in (b), when the support bar 60 is turned upside down and inserted into the groove 66 of the fixed-side template main body 65, the support bar 6
When the leading end of the abutment 0 contacts the arc-shaped corner of the notch 63 of the insert 62 and further pushes the support bar 60, the pushing force is changed to a downward force on the inclined surface 61, whereby the insert 62 is fixed to the fixed side. It is extruded in a direction to escape from the template main body 65.

In the above embodiment, one support bar 134, 53, 60 is used.
Nesting 133, 50, 62 grooves 13
The nests 133, 50, 62 are held by engaging with the engaging bars 7, 52, 64 (engaging holding means), and the supporting bars 134, 53, 60 are held.
0 and / or the nest 1 through the inclined surfaces 138, 134a, 51, 61 formed in the nests 133, 50, 62.
The nests 135, 50, 62 are brought into contact with the nesting holes 135,
Although they are extruded from 57 and 67, their functions may be made independent by using two bars for holding and escaping their work.

In the above embodiment, the nest 13
Although the example in which 3, 50, 62 are disposed on the fixed-side template main bodies 132, 55, 65 has been described, the inserts 133, 50, 62 can also be disposed on the movable-side template.

In the above-described embodiment, the injection mold for the magnetic tape cassette is shown. However, the present invention is a nest support structure that facilitates the exchange of the nest. Therefore, the present invention is limited to the magnetic tape cassette mold. Instead, the present invention can be applied to injection molding dies of other products.

[0037]

As described above, in the injection molding die of the present invention, the nest is inserted into the nest loading hole, and the nest is held by the support bar inserted into the groove from the side surface of the die main body. Let it. When changing the nest, the nest is pushed out of the nest loading hole by the support bar. Therefore,
When exchanging the nest, the nest can be exchanged without removing the mold from the fixed side mounting plate, the receiving plate, etc. of the mold clamping device, so that the work becomes extremely easy and the work efficiency is improved.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a magnetic tape cassette to which an injection mold according to the present invention is applied.

FIG. 2 is a perspective view showing a back surface side of the magnetic tape cassette shown in FIG. 1;

FIG. 3 is a perspective view conceptually showing a main part of an injection mold according to the present invention.

FIG. 4 is a conceptual cross-sectional view showing the operation of the injection molding die according to the present invention, in which (a) is a state in which a nest is held at a predetermined position of the die main body, (b) is a conceptual cross-sectional view showing a state where the nest is taken out of the mold main body.

FIG. 5 shows another embodiment of the injection mold according to the present invention, and FIG. 5 (a) is a conceptual cross-sectional view showing a state where a nest is held at a predetermined position of a mold main body. And
(B) is a conceptual sectional view showing a state in which the nest is taken out of the mold main body.

FIG. 6 shows still another embodiment of the injection mold according to the present invention, in which (a) is a conceptual cross-section showing a state where a nest is held at a predetermined position of a mold main body. It is a figure and (b) is a conceptual sectional view showing the state where a nest is taken out from a metallic mold main part.

FIG. 7 is a cross-sectional view conceptually showing a conventional nest-type injection mold.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Magnetic tape cassette 12 Reel 13 Upper half 14 Lower half 15 Guard panel 25 Hole 50 Nesting 51 Inclined surface 52 Groove 53 Support bar 54 Projection 55 Fixed side template main body 60 Support bar 61 Inclined surface 62 Insertion 63 Notch 64 Groove 65 Fixed Side mold plate main body 130 Mold 131 Fixed side mold plate 132 Fixed side mold plate main body 133 Nesting 133a Front surface 133b Rear side surface 133c Rear end surface 134 Support bar 134a Inclined surface 135 Nested loading hole 136 Groove 137 Groove 137a Inclined surface 138 Inclined surface 139 Side mold plate 140 Mold clamping device 141 Fixed side mounting plate 142 Receiving plate A Identification mark B Molding space

──────────────────────────────────────────────────続 き Continued on front page (51) Int.Cl. ⁶ Identification code FI // B29L 31:34

Claims (1)

[Claims] 1. An injection molding mold comprising a mold main body consisting of a fixed mold and a movable mold, and a nest loaded in the fixed mold, a surface of the fixed mold facing a molding space. A nesting loading hole for loading the nesting is formed;
A groove communicating with a side surface of the nest loading hole is formed in a side surface of the fixed mold, and a support bar that slides and engages with the nest loaded in the nest loading hole is formed in the groove. The insert is movably inserted, and the insert and the support bar press against each other at two different contact surfaces, and one of the contact surfaces engages the insert with a predetermined position of the fixed mold. The holding bar constitutes an engagement holding means, and the other contact surface is configured such that the support bar and the support bar are ejected from the fixed mold when the support bar presses the nest from the side. An injection molding die, wherein at least one contact surface of the nest is formed as an inclined surface.