JPH06238671A - Mold for thin-walled deep groove synthetic resin part - Google Patents

Abstract

PURPOSE:To mold a deep groove part in uniform wall thickness by providing an adjusting core reaching a center core and forming a part of a cavity to one of the left and right slide cores sliding toward the center core provided to a movable mold and replacing the same to finely adjust the deviation of the center core. CONSTITUTION:For example, when the shutter fitted and inserted in the case of a 3.5 in microfloppy disk is molded, a center core 5 having a tip part 5b having width same to the groove width of the shutter and having length larger than the groove depth thereof and slide cores 3, 4 sliding toward the tip part 5b and having the side wall forming parts 3c, 4c of the shutter are provided. A recessed part 6 is provided to one slide core 3 to incorporate an adjusting core 7. The adjusting core 7 is constituted by providing protrusions 7b, 7c reaching the tip part 7b of the center core to one side part of a plate-shaped substrate 7b and selected from several kinds of ones different in protruding width S to finely adjust the deviation of the center core 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding die capable of uniformly forming a thin deep groove synthetic resin part.

[0002]

2. Description of the Related Art As is well known, in deep groove synthetic resin parts having a wall thickness of 2 mm or more, even if the wall thickness changes by about 0.01 mm to 0.05 mm, the accuracy of the parts is not affected. However, for thin-walled deep groove synthetic resin parts (hereinafter abbreviated as thin-walled deep groove parts) that are molded to a wall thickness of 2 mm or less, the thinner the wall thickness, the greater the effect of a change in wall thickness of about 0.01 mm. Met.

For example, in a shutter fitted on the upper part of a hard synthetic resin case of a 3.5-inch micro-floppy disk, one of a front wall 1b and a rear wall 1c hanging from a ceiling wall 1a as shown in FIGS. Perforation windows 11 and 12 are formed on the side, and the rear wall
Projecting ridges 13 and 14 project inward from the left and right upper portions of 1c, and a hook 17 is hung below the top wall 1a to project ridges on the rear wall 1c.
13 and the claw legs 17 and the mold holes 15 and 16 necessary for forming the ridges 14 are formed to form the shutter 1 having a wall thickness of about 0.3 mm. (For example, Japanese Patent Laid-Open Nos. 2-110067 and 2-22
9019, JP-A-3-69077)

[0004]

The problem has been how to accurately hold the center core as a means for uniformly forming the wall thickness of the thin deep groove part. In other words, if the tip of the center core is slightly offset to one side, there will be a difference in the thickness of the front and rear walls,
As a result, there are problems that the flow of the resin is different and the pressure is different. In addition, if the wall thickness of the side wall of the component is different, there is a problem that a burr is generated on the component and the front and rear walls are warped, and there is also a problem that the assembly of a precision product is hindered.

Further, the cavity formed in the movable mold or the fixed mold has a problem that the cavity becomes more difficult to process as the precision molding requirement of the product increases or the number of fine shapes is increased. The present invention has been made in view of such problems of the prior art, and an object of the present invention is to provide a molding die suitable for forming a thin deep groove part having a wall thickness of 2 mm or less. Has an aim.

[0006]

In order to achieve the above object, a molding die for a thin-walled deep groove component according to the present invention comprises a center core at a front portion of a movable die which reciprocates toward a fixed die, and A slide core that slides from the left and right toward the center core is incorporated, and a recess is provided in one of the slide cores.
An adjustment core that reaches the tip of the center core is incorporated in the recess, and the deviation of the center core is finely adjusted by exchanging adjustment cores with different protrusion widths, and a part of the cavity can be formed by the adjustment core. Is.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A molding die for a thin-walled deep groove component according to the present invention will be described below with reference to the drawings of the embodiments. The drawing shows a shutter molding die of a 3.5-inch floppy disk. The center core 5 is incorporated in the front part of the movable mold 2 that reciprocates, the slide cores 3 and 4 that slide from the left and right toward the center core 5 are incorporated, and the recess 6 is provided in one slide core 3. An adjusting core 7 that reaches the center core tip portion 5b is incorporated in the recess 6.

The center core 5 is formed by a base portion 5a fixed to the front portion of the movable mold 2 and a core tip portion 5b protruding from the base portion 5a toward the fixed die 8, and the core tip portion 5b is a groove of the shutter 1. The protrusion width corresponds to the width e and is longer than the groove depth H. The slide cores 3 and 4 have side wall forming portions 3c and 4c of the shutter 1 formed therein, and inclined side surfaces 3a and 4a that are tapered toward the fixed mold 8 are provided on the outer side surfaces 3b and 4b. It is assembled to the left and right of the center core tip portion 5b so as to be slidable toward.

The adjusting core 7 is provided on one of the plate-like substrates 7a,
The protrusion 13 protruding inward from the rear wall 1c of the shutter 1 and the protrusion 7b used for forming the hook 17 vertically extending from the ceiling wall 1a are protruded on the other side and the protrusion 7c used for forming only the protrusion 14 is protruded. To set up,
Both protrusions 7b and 7c are assembled so as to contact the center core tip portion 5b. The adjustment core 7 is formed in several types so that the protrusion width S of the protrusions 7b and 7c is as large as 1/100 to 1/1000 mm, and the adjustment core 7 having the protrusion width S is appropriately selected from among them. Is incorporated into the slide core 3.

The fixed mold 8 is the center core 5 of the movable mold 2.
A top wall forming portion 8c of the shutter 1 is formed at a position corresponding to, and push portions 9 and 9'protruding toward the outside of the separating slide cores 3 and 4 are provided on the left and right sides of the top wall forming portion 8c. Inner sloped surfaces 9 that match the slanted side surfaces 3a, 4a of the slide cores 3, 4
A and 9b are formed, and a spacer 19 is attached to the inclined surfaces 9a and 9b as necessary, and the slide cores 3 and 4 slide toward the center core 5 when the mold is closed.

Specifically, when the movable mold 2 and the fixed mold 8 are in a separated state, the slide cores 3 incorporated in the movable mold 2 are
4 is also separated from the center core 5. When the movable mold 2 is moved toward the fixed mold 8 from the above state and the mold is closed, first, the inclined side surfaces 3a and 4a of the slide cores 3 and 4 which are in the separated state are pushed to the fixed part 8 of the fixed mold 8. , 9b are in contact with each other, and the slide cores 3, 4 are slid toward the core tip portion 5b of the center core 5 by the pressing portions 9, 9 ′. Upon completion of mold closing, the slide cores 3 and 4 are joined to the left and right of the core tip portion 5b, and the fixed die 8 is joined to the slide cores 3 and 4 and the center core tip portion 5b to form the cavity C of the shutter 1. .

To mold the thin-walled deep-groove shutter 1 using the molding die according to the present invention, first, the shutters 1 are test-molded in an appropriate quantity, and the precision of the test-molded shutters 1, especially the wall thickness of the side walls 1b and 1c. The t is measured, and the test molding is repeated while the adjustment core 7 is exchanged until the shutter 1 with constant accuracy is obtained with high frequency. When the shutter 1 with constant accuracy is obtained with high frequency, mass production is started. .

As a result of measuring the accuracy of the shutter 1 that has been test-molded, if the rear wall 1c of the adjusting core 7 on the incorporated side becomes thick, the adjusting core 7 having a smaller protruding width S than that is replaced, and the protruding width S is changed. Center core tip 5b
Is biased toward the formation side of the rear wall 1c. On the contrary, when the rear wall 1c of the adjusting core 7 on the built-in side becomes thin, the adjusting core 7 which has been built up to now is replaced with the adjusting core 7 having a larger protruding width S, and the protruding width S becomes larger. The center core tip portion 5b is biased toward the formation side of the front wall 1b by an amount.
That is, when there is a difference between the wall thickness t1 of the front wall 1b and the wall thickness t2 of the rear wall 1c, the adjustment core 7 having a large protrusion width S by a half of (t1−t2) or the adjustment core 7 having a small protrusion width S Exchange.

[0014]

EFFECTS OF THE INVENTION Since the molding die for thin-walled deep groove parts according to the present invention is configured as described above, it has the following effects. Since one slide core incorporates an adjustment core that comes into contact with the tip of the center core, when there is an unacceptable difference in the side wall thickness of the thin deep groove part molded by this mold, the difference in wall thickness By simply exchanging with an adjustment core with a small protrusion width by 1/2 or an adjustment core with a large protrusion width, it is possible to easily fine-tune the deviation of the tip of the center core and form a thin deep groove component with a uniform thickness. . As a result, the molding die according to the present invention is suitable for highly accurate molding of thin deep groove parts.

If several kinds of adjusting cores having different projecting widths are provided, it is possible to form a thin-wall deep groove component having a constant wall thickness by replacing only the adjusting core without replacing the slide core. The mold can be provided significantly cheaper. Moreover, the adjustment core can be easily and easily replaced, and the deviation of the center core tip can be finely adjusted by the replacement, so not only does it require a high degree of skill in molding thin wall deep groove parts, but also the fine machining of the cavity can be adjusted. Since it can be formed by the core, the processing of the precision mold becomes extremely easy and easy.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part in a separated state of a molding die according to the present invention.

FIG. 2 is a longitudinal sectional view of an essential part showing an example of a mold closing process of (A), (B) and (C) molding dies.

FIG. 3 is a lateral cross-sectional view of a main part showing an example of a mold closing process of the molding dies (A) and (B).

4A and 4B are a front view and a cross-sectional view of (A) and (B) adjusting cores.

5 (A), (B), and (C) are main part side views showing an example of the shape of the thin deep groove part.

FIG. 6 is a vertical cross-sectional view showing a structural example of the shutters (A) and (B).

FIG. 7 is a longitudinal sectional view of an essential part showing a structural example of a fixed mold.

[Explanation of symbols]

1 Shutter, 1a Top wall, 1b, 1c Side wall 2 Movable mold 3,4 Slide core 5 Center core, 5b Center core tip 6 Recess 7 Adjustment core 8 Fixed mold 9,9 'Pushing part 11,12 Viewing window, 13,14 Convex strips, 15,16 Mold hole, 17 Claw legs, 19 Spacer C Cavity S Projection width H Shutter groove depth e Shutter groove width t, t1, t2 Shutter side wall thickness

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Claims (1)

[Claims] 1. A center core (5) at the front of a movable mold (2) that reciprocates toward a fixed mold (8), and a slide core (3, 3 that slides toward the center core in the left-right direction).
4) is installed, and a recess (6) is provided in one of the slide cores, and an adjustment core (7) that reaches the center core tip (5b) is installed in the recess, and an adjustment core with a different protrusion width (S) is exchanged. A molding die for a thin deep groove synthetic resin part, characterized in that the center core is finely adjusted and a part of the cavity (C) is formed by the adjustment core.